Setting the AV Receiver Crossover, 80Hz?

hey folks I'm Jean de LaSalle with audio holics and we are doing a live event this Friday evening on May 3rd I apologize for the problem they had sent you guys the invite to do this live and I was trying to coordinate it with Google Hangouts and we had a glitch with YouTube so I had to recreate so hopefully the 30 or 40 people that were waiting found their way into this version that were broadcasting with and I wanted to delay this a little bit because I wanted to bring one of our new writers and our new youtubers Matthew posed on board with me because Matthew is really into this stuff he's really into base management room acoustics he's kind of one of our hard hitters on these topics so I wanted to have his perspective to add to this discussion so Matt how you doing my friend I'm glad that you here today thanks Jean yeah I'm really glad to be here this is exciting it's nice to be riding with you now and great to be on this livestream awesome so why don't you give us a little bit of your background so people know we are coming from sure well a lot of people look me up see what I do for a day job which is not related to audio at all and best way to put it as a researcher in child development but my interest and passions for audio have existed for a long time and I originally had gone to school for a while for electrical and computer engineering and when I decided to go onto graduate school I had the opportunity to also take courses in acoustics acoustical physics audio engineering so I've been into audio since I was a kid I actually had a home theater in my bedroom when I was like 12 13 years old just put together extra speakers my dad had or things I found at rummage sales got myself an inexpensive Dolby Pro Logic receiver one of the first things I bought that was like a big upgrade was actually a HiFi stereo VHS player just to be able to get they'll be surround at the time since then I've taken things more professionally as I said took courses in graduate school at a graduate level in acoustics and began offering acoustic consulting and advice for folks opened a small company doing that I've now been writing for about two three years doing audio reviews technical articles and I would say acoustic acoustic measurement is probably one of my biggest passions it's something I love doing studying the the physics behind it is really interesting and from the writing pieces that I really like to help explain the stuff in ways that are easier to understand for the average person I mean it's physics you're never gonna get around the fact that it is a science but you know a lot of this stuff can be really overwhelming and I love the idea of being able to take that stuff and try to explain it and down-to-earth way so people can apply it to help make their systems sound better yeah guys for those of you who've been paying attention to our channel on a weekly basis we just published a review a video maybe four or five days ago of you teaching people how to use rtw acoustic measurement software so definitely check that out because really when when we give this advice to you when we tell you how to set up your base management or we tell you where to place your speakers or how to set up your EQ a lot of it still depends on you doing some real room measurements because you can only go so far with rules of thumb but in reality proof is in the pudding and proof is what matters is what measures in your listening area using a calibrated microphone properly using an acoustic program like re W and that's why we're putting more emphasis on educating in that realm and and Matt's going to be helping us with that as well thanks yeah so I wanted to share my screen because what here's what I've been noticed and this is why I've done probably three or four at least three videos on base management over the last few years on on our YouTube channel we've got tons of articles on it we even have articles on and videos on multi sub but I think I need to do a more core video about the 80 Hertz crossover and why that actually is a pretty damn good number and thx actually did their homework in this realm because I've seen I've seen over the last few months I've seen threads pop up on various forums where people are buying new tower speakers and even on YouTube I see videos on YouTube the way they buy this tower speaker with a couple of six-inch drivers and it and the frequency response on it's rated down the forty Hertz so they set that crossover at forty Hertz or they said that at sixty Hertz and they're just limiting their total system base response by doing that so what I wanted to do is I wanted to show you why I want to give you some example here I'm gonna share my screen on the here hopefully this comes out okay I want to go over kind of a history of base management and how its evolved in receivers and how it's gotten a little bit confusing for some ever especially since we have the triple crossovers where you could set the crossover is at different frequencies for each channel group so back in the day just to show my age I'm talking about the first at most not sorry the first Dolby Digital DTS receivers Matt do you see that screen shot that I'm showing you right now yeah I can see that okay so this is like I think this is an old Denon or an old Yamaha receiver and you could see that there was no multiple crossover settings it was just one crossover 80 Hertz is where I have it set for low-pass and high-pass and what that was the low-pass was set for 24 DB per octave the high-pass was set for 12 DB per octave and this was a THX certified receiver and the logic behind why they chose these slopes was thx was trying to make the most compatible system possible in a regular room that way when someone would bring in thx speakers and the thx receiver it would be you know they would have known they would have known variables to setting up a room for home theater and this would ensure good integration without having to do a lot of legwork and they made assumptions that their satellite speakers were sealed designs sealed designs naturally have a 12 DB per octave roll-off so when you take a 12 DB per octave acoustical roll-off mix it with a 12 DB per octave electrical roll-off of the high pass filter you get to 24 DB per octave on the low pass filter for the sub and theoretically you'll have the best integration at the crossover frequency between the satellite speakers and your subwoofer so that's where the whole crux of the 80 Hertz came from and why thx chose that the other reason why they chose 80 Hertz was that was based on research about the limit of where you wanted to set the crossover to not have localization of base waves in actuality it's a little bit higher than 80 Hertz I think you could go almost up to about 120 to 150 Hertz before you start localizing it and that you might want to in Jax um some of your knowledge here I think a lot of it depends on the slope of the cross over and how far away you are from the subwoofer yeah actually there's an interesting story there 80 Hertz was set because that was two standard deviations below the point at which localization wasn't noticeable so when you said it's actually a little bit higher that's that's exactly right it was a little bit higher but they wanted to set a point where there was no chance anybody could hear it and so the 80 Hertz was chosen the the idea of using the natural high-pass of a sealed box with an actual second-order high-pass filter as well was chosen to try to create two fourth order crossovers with the idea that the summation would be really good in practice that's actually not true it works fine we've been talking about this before you and I that a lot of these ends up being just rules or rules of thumb that you can apply because it helps to work and and in practice it does work fine but the notion that you need to have a symmetric crossovers at forth order to get good summation in a room it kind of doesn't hold a lot of water when you realize all the things that are going on acoustically in the room in the first place so while there's nothing wrong with that there's other ways you can actually achieve the same results yeah reality let me just interject for a section I for a section in reality you're talking maybe anechoic Lee that this would work perfectly yeah anechoic Lee and they would have to be essentially in the same that the superposition idea they'd have to be in the same point in time and space as well so given that we typically don't necessarily put our subwoofers in fact with the new way of doing things with subwoofer is using multiple subwoofers throughout the room they're often nowhere near your main speakers a lot of that doesn't apply so well anymore yeah and you raise a good point because now that we we've been preaching multi sub for years so now that we have multi sub and we can put the subs in ideal locations in the room to manipulate the modes in the room so we can have consistent bass from C to C I would argue that the crossover at 80 Hertz could actually be tuned a little higher because I don't think you're going to localize when you have bass coming from multiple sources and you're pressurized in that room equally and you've got a flat response without big bumps or resonances you might even be able to extend that past 80 Hertz maybe to 100 Hertz it really depends on your situation but I don't want to go too far to that topic yet I just wanted to bring that up I wanted to kind of show you guys some more of the base management stuff that gets people flapped up especially with some of the YouTube videos I've been seeing lately as well so here's a Yamaha this is the yamaha CX a 5100 processor it's the same thing with their oven Taj line you could see here this is my setup I have in my theater room I have my speaker groups I have the front speaker is the center channel the Atmos channel all that stuff it this processor along with a lot of processors on the market now allow you to change crossover frequencies per channel groups and it sounds good on paper but sometimes it's a mixed bag years ago when this first came out Cirrus Logic was the first to do it it was I remember Matt you probably remember those old outlaw processors that in there that had the cirrus logic chipset absolutely those things were were kind of a nightmare because when they were doing the summation back into the subwoofer you were getting very uneven responses I measured this and it was funny that you and I talked about this because you did the same thing but initially when these triple crossovers came out they were not doing the summation properly into the subwoofer channel it was a mess so that's when I came up with the guideline don't vary your channel groups more than 20 Hertz so if you're setting your speakers at 80 Hertz don't set any other speaker in your channel groups lower than 60 Hertz or higher than a hundred Hertz otherwise you might get this uneven response coming through the subwoofer output now there are companies that are doing it correctly luckily it's gotten a lot better I've taken Denon and Yamaha stuff apart and my audio precision and measured their inputs I have an HDMI analyzer so I could interject that a channel signal into the processor measure the outputs and see what's going on and they are doing the summations correctly for most part let's say and all the products are some of the esoteric stuff out there still might have this problem but my my recommendation still holds true in this case you really shouldn't be choosing speakers that don't have similar dynamic range with the exception maybe of the high channels for Atmos and we're not talking about the bouncy house crap we're talking about the discreet speakers that in the ceiling in most cases you really want to have all your speakers having symbol a band with similar dynamic range capability so really I mean mad if you based on your experience I'd like to hear that as well but your opinion is on this I don't think you should be changing your crossovers more than twenty thirty Hertz per channel groups yeah Gina I think you're probably right I mean there's other reasons too I think that if the high pass ends up being too dramatically different the speaker's tonal balance can be somewhat changed you also can start to have issues integrating those other surround speakers and with the subwoofers so you know often when I'm setting up systems for folks and I'm measuring all the different speakers and looking at how they one of the things I always check is how it integrates with the subwoofer when you start to see really dramatic differences in crossover one of the problems you have is trying to get for instance like a full-range speaker to integrate with the subs and another speaker that's crossed over at 120 Hertz they don't always integrate all that well and so if you do keep the crossovers constant it makes things significantly easier to get good integration yeah it's much easier when you start at a clean slate and you keep things simple they the KISS principle keep it simple stupid usually works in everything in life it definitely applies here you start out simple and then after you get the basics going then you could start tweaking if you know what you're doing and you've got rvw and you're making acoustical measurements so the thing about this Yamaha that kind of / tubes me a little bit is somewhere around when Yamaha switched from there are X Z or X the the RX Z line that was built in Japan over to the oven Taj they got rid of the LFE crossover setting and I didn't notice that probably until a couple like a year or two ago and I'm like what the heck I where's the setting for LFE crossover and people kind of get that confused that they think the LFE crossover is the subwoofer crossover when in fact it's not now I'm assuming in Yamahas case they must default it at 120 Hertz I want to show you some other examples and then we'll talk more about that so here's a here's an Integra receiver that I'm using for my bedroom it's the DRX 4.2 I believe and you see I have 80 Hertz set the l2 low-pass filter for the LFA channels 120 Hertz now what I wanted to show you guys I wrote a little cheat sheet here the elephants are setting is not the same thing as the Lopez filter setting for the summer for out I want people to really understand this when you're talking about a multi-channel signal remember in the days it was 5.1 now with Atmos it's five point one point four that point one is the subwoofers the LFA Channel it's the low frequency effects that are mixed from the movie into this into that channel which just happens to be the same output that you're using for your subwoofer where your bass management and sending all of your bass from speaker set small into it as well so there's a summation between your bass manage speakers and the LFE channel all going to that output so I just wanted to make sure you guys really understand that because I've seen people talking about oh I'm setting my L my LFE to 80 Hertz to match the crossovers from my main speakers well that's not really the case this is a separate discrete Channel and you typically want to keep it at 120 Hertz to take full advantage of the LFE content that's mixed in the DVDs and blu-rays so let's go back over here TV we saw the Integra one I just wanted to show you one more this is the marantz SR eighty 12 and again I'm doing an Atmos system here now they also have the LFE setting here as well it's on a separate page somewhere from mode so why don't you guys to understand that and then the next topic I wanted to talk about and then met you could elaborate whenever you you feel like you need to hear I'm seeing people a lot on the forums where they buy bookshelf style speakers like these SPS I'm using SPS I'm not picking on SPS it's just that SPS is one of those few companies that really give you a good detailed specs on their products and I just started doing some calculations in my head using their products to figure out you know how much output you're getting from the speaker versus their subwoofer in this case I see people on the forums that will go and use a speaker like this as an LCR and then the made it with like two or four giant 18 inch subwoofers so they're taking a speaker that has maybe 87 DB of efficiency which is the prime bookshelf 87 DB the minus 3 DB point of 48 Hertz right they're taking that they're mating with it a subwoofer that puts out over 120 DB of output so there's kind of a mismatch of dynamic range especially if they're stuck bandwidth limiting their subwoofer channel because they want to put more bass into their main speaker so like if you look in the example the prime tower which I was showing you before I've seen people that buy a tower like this which has a you know two or three six and a half inch drivers amid and a tweeter and they see oh look the 3 DB points 29 Hertz that means I should set my crossover lower I should set it maybe 10 Hertz higher than then the rating 3 DB point of the speaker because on paper this speaker will put out 29 Hertz solidly well what they're not realizing is the speakers might be doing 29 Hertz but that's rated at 1 meter at 1 watt or 2.8 3 volts assuming it's an 8 ohm speaker so we don't know how much output that this speaker is putting out when you're really cranking it up there's no way that a triple three triple six and a half inch woofers is gonna put out the same kind of output at 60 Hertz as a PV 4000 sub that has a 13 inch driver and a thousand watt amplifier mathieu there yeah I'm there I just go say gene and I've actually asked quite a few manufacturers if they'll let me take their speakers out to the field with James and measure for James Larson of course does a lot of the subwoofer testing for us and he and I do this together so I you know I asked them all the time can I take your speakers out to the field and test them with the CEA 2010 but nothing will let me stick a thousand watt amp to the speakers see what it does building no voice coils left you're talking about most of these most of these six and a half inch drivers maybe have a one inch one and a half inch voice coil and they have an X max of maybe what a couple like 0.3 or 0.5 millimeters or something like that I mean it's way smaller than you're getting in a dedicated base driver for a subwoofer oh absolutely yeah and there's a lot of reasons to set the crossover up a little bit higher so one of them is as you mentioned the speakers themselves are dynamically limited the amplifier power out of the receiver is we talked about earlier is at best a hundred watts and many some of them are putting up maybe 120 which is not even a full decibel louder and so you've got this at this receiver that really doesn't have the power to power it the speaker can't actually handle that much more power anyway and you're trying to put a lot a bass through it whereas the subwoofer itself has a lot of xmax the subwoofer has better ability to actually output up to you know one hundred hundred twenty Hertz fine and the other reason actually is what we were talking earlier about multiple subwoofers when you can place a subwoofer optimally whether it's one subwoofer two subwoofers or four the more subwoofers the more low frequency sources basically you have operating in that key crossover region that we're talking about the smooth of the bass tends to be so first and foremost is even if it's just one subwoofer if you can get that in the right location the subwoofer is the better speaker to be producing that hundred hundred and twenty Hertz but if you've got multiple subwoofers you also can smooth that out quite a bit yeah absolutely and here's here's the problem now is when you get people that are that are lower in the crossover let's say because they have this SBS prime tower that's rated down the twenty nine Hertz as soon as when you set the main crossovers and you're running those full range or even if you're running in base manage and you set that crossover to sixty Hertz you're not you're taking away the advantage of multi sub all the way out to the full bandwidth of base so if your subs are flat up to 82 or even 100 Hertz and you're now crippling it by saying these subs should not produce anything more than 60 Hertz or they're gonna they gonna roll off at 24 DB per octave you're taking away that advantage of the multi sub modal averaging by having those subs running a full range bandwidth like that so not only are you losing dynamic range in the in the critical mid bass frequencies but you're losing the seat to seat consistency that you can have by having the multi subs play higher up and in the base region and of course you're losing a firepower like you said because now you're asking that receiver to produce those base power robbing frequencies because that's really where all the power goes you suck a lot of power a lot of these towers if they have multiple drivers parallel connected you could have some good you know three or four ohm impedance dips at the low frequencies and that's where it just taxes the receiver and most receivers don't have the largest power supplies especially in the days of Atmos when we're stuffing more channels into the same size chassis you want to try to free up that receiver as best as you can and not try to make it overworked by producing bass in two speakers that really aren't designed to produce that kind of bass yeah and and I'll add to that a lot of these speakers even these big towers are ported and one of the problems with running these speakers too low because they're ported is the my view is this there's no such thing as a good port there's just less bad ports so all ports for the most part or are somewhat noisy at some point they start to chuff and when you're watching a movie there's nothing more distracting than some distortion or port chuffing and so when you're running these speakers full range and you get that action kicking in and you start to overload the speaker or the woofers are really moving and the port's really active you start to hear a lot of that noise if you high-pass it a little bit higher you know so that you're above that port tuning by a good amount then you're not really getting anything coming out of the port anymore and that kind of takes care of that issue so even though the speaker needs the port if it's running full range to get the full bass response that the speaker is capable of if you're using a subwoofer you don't need that anymore and you can get rid of basically what isn't a great port a lot of the speakers we review you know when I listen to them what I find is that when you really push them with something that's loud and highly dynamic those ports aren't as quiet as they should be right yeah that makes a lot of sense the other thing I wanted to add to this discussion is if you want to run your main speakers large if they do have decent output if they have within 10 DB of output as you're powered subs which is rare to be honest with you you know you're gonna have to have some towers that have good multiple 10 inch drivers or 12 inch drivers or something to really get that kind of output you can run them large and you can still run an 80 Hertz crossover by setting the crossover to 80 Hertz for the mean chance the thing you have to be careful about it the double bass you're gonna get now because now you're gonna have the four to channel audio I'm talking about you're gonna have the full range going to your main speakers and then you're gonna have the bass copied over to the subs that could work if you have the ability to EQ because what you're gonna find sometimes is by combining the towers with multi multiple subs in the room is you're gonna have overlapping frequencies that can add to a room bode problem that you have or just just too much energy at certain frequencies that's when you need to go in whether it's through the main channels or through the subwoofer Channel and do some peq function to to kind of squash that down and flatten it out yeah and I think people who follow me on the forums know that I often promote it proponent of using large mains but I think that the issue is it's not so simple so I talked about you do it I do it I think people hear that like oh I want to do it too well it actually takes quite a bit of work to be able to make large mains integrate well with subs like that so that they're overlapping so substantially so you'll often hear on the forums or on YouTube videos people will say never run the I think it's called like LFE plus or LFE plus mains or something like that where you're getting the double bass actually you can do that and yeah that's what you're talking about but the problem you run into is that your mains have to be as dynamically capable as your subwoofers in the range that they're overlapping or your end up having your mains distort the other problem is you need enough amplification well for the most part there's no such thing as a receiver that's that's powerful enough to really do that so you run separate amplifiers with I'm not sure how much power hundreds of watts I have 300 watts per tune and going to mine there's plenty of power I have highly efficient speakers same with you that's one of the ways we're able to get away with doing that the other part is that I do extensive measurements so just to give me an idea of how extensive and how heroic this can end up being trying to make this work I just gave a talk at Expo know about how to integrate mains and subs and one of the things I did was I tested both how to do it where I did a hard crossover so there was a high pass on the mains and a low pass on the sub that the speakers actually were the recently reviewed clips the reference to premiers ERP 8000s and the subwoofer was a Martin one of the newer 12 inch subs and I what I did was I ran them full range and then I also did the hard crossover so the hard crossover was easy basically I set everything up I set the filters where I wanted them got the levels right got the distance right to be able to get the time alignment phase alignment and a little bit of EQ good to go then I went and did the full range version of everything all of a sudden it's a mess so what did I have to do I ended up having to go in and actually plug the ports in order to get the because the port output was causing some interference I had to plug the ports with some acoustic insulation I had to play quite play around quite a bit with the phase and the time alignment to get that right EQ and levels had to be adjusted I actually had to put a shelf filter on the on the main speakers to get a better integration there to get the levels right to match the kind of room curve I was looking for and so it took a lot of work actually took twice as long to set that up and in the end it measured a little bit better I thought it sounded a little bit better but the work that took to get there was pretty extreme and I probably wouldn't recommend the average person doing that yeah it's it's a challenge I mean you know you always hear people say you never want to mix and match you know ported with sealed subs that that you hear that a lot the reason why that is is because a ported sub versus a sealed sub has a different high-pass so if you don't get those two a line at very low frequencies you're gonna get cancellations and in my system I'm running very large very powerful towers like you said have tripled 10 inch drivers they exceed our extreme bass a holic rating just each sub alone that are built into those speakers that's how much output they have those are ported but my main subs I have to valid I'm DD 15 plus as those are sealed and in order for me to get the best integration down to below tuning of those speakers which are tuned at 18 Hertz I had to put a high pass on my Valentines in order for them to integrate properly otherwise I was getting cancellations between the poor tuning of my big speakers and the sealed enclosure the natural response of the roll-off so by doing that again you have to use measurement software I've got you know extension down to 12 Hertz meaningful extension down to 12 Hertz in my room across all six seats but it's not for the faint of heart that's why there are some good guidelines to start with and in most cases I would say 90% of installs I really recommend people base management in base managing their speakers even if their towers unless they're unless you got a pair of rebel salons or you got something that's really high caliber output or one of the JT our speakers for example like you're a big fan of in most cases I would say base manage you know use 80 Hertz as your starting point for crossovers if you really want to get savvy and you really think you've got some special towers and you want to add that base into the mainstream of the rest of the subs to get you know to smooth out your response and you've got the tools for it you've got EQ and you've got the ability to measure then you can take it to the next level but I just want people you know I don't want people to get frustrated because it takes time if you're gonna do this right and sometimes keeping it simple is the best way yeah absolutely I think actually trying to keep that in mind a lot of the rules you hear are really good ways to help keep it simple so the things come together and work you know when I do installation and calibration for systems it's not uncommon for it to take 8 to 12 hours and and I'm not sitting around wasting time in that 8 to 12 hours it's just a lot of measurements a lot of setting changes you know in some cases you can only predict so much so you end up having to try something see how it works and then investigate what didn't work the way you expected it to adjust that try again when I've done some of the Oxbow no event setups I've had that take you know most of the day Jeff you mentioned jtr so Jeff was texting me this year a tax Boehner they were up to like I think three or four in the morning fine-tuning that the night before the event started and they actually didn't get it totally tuned until two days later basically the event was already well into having kicked off and they had been showing the room off but they didn't get everything finalized until around Saturday so the reality is properly setting up and calibrating a system is a lot of work and so these rules of that we've been talking about like you mentioned using proper base management really makes it easier to get everything integrated properly yeah no doubt and you know I've seen some questions on here just kind of while you were talking I was looking at some of the questions that are popping up one of them that kind of caught me was someone said if the room ik autocorrection system sets the subwoofer distance different than the physical different distance you know which one's correct and that's that really depends on a couple of factors because we're dealing with some group some processor delay now when you've got subs that have a lot of DSP power in them to make sure that they don't overload themselves or to even EQ them to a flat response you will be adding physical delay to that subwoofer so that's why some of the room EQ systems if you're so poor first twelve feet away but it's identifying it as 15 feet away then you've got three or four milliseconds of delay built into the process of the the auto EQ is probably correct but most auto EQ systems don't do the greatest job of Auto calibrating multi sub so you're still gonna have to go in and hopefully you have multiple subwoofer outputs with independent delay and independent Channel trims so you can really time align the subs because if you don't have symmetry placement of your subs relative to where you're sitting then you're gonna have to compensate for the time you know you got to compensate for it with time delay and I didn't want to really get off into this because it's kind of an advanced topic and we've covered this before but there are solutions for that if you're if your receiver only has a single sub out or it's got parallel sub outs which is basically the same thing they just use an op amp to buffer two outputs but they don't have independent time delay you could get a little dot a little box from mini DSP that'll take one or two sub or four inputs and bring it out to four independent outputs then you can do your parametric EQ you could do your time alignment you can do your level adjustments so guys the sky is the limit I mean we're in the era now where DSP is so powerful and there's really no excuse to have bad bass in your home theater anymore if you follow some guidelines and you do some elbow work and you're willing to do some measurements or hire someone that that knows acoustics that understands how to integrate subs with your speakers yeah I saw that question when it came up and it was really funny because you and I of course just had a conversation recently we were talking about how substantial some of the delay has gotten in some of the DSP that's being used in subwoofers and you're right it's an advanced topic but I think it's important for people to know that in many cases the physical distance measurement that you would take using a tape measure will not be correct and that the system itself is able to detect more correctly the acoustic delay but what I found is that certain systems and this came up again in that exponent awk when I did my case study and in my case I was using a Yamaha with Y PA Oh inaccurately measured it so a physical mention measure was incorrect that would have been about eight feet the measurement that the YPA Y PA Oh came up with was incorrect that came up with I think it was twelve feet after fully accounting for the delay that the DSP was introducing it was actually 21 feet and so it's a it can be tricky and I would say your best bet if you don't know what you're doing is stick with what the auto setup comes up with because it's probably closer to what you'll do but one of the nice things about measurements is that you can in fact measure what the proper delay is and go back and set it up and in the old days the way people typically did that is they would look at the impulse response and they would try to compare it and that's really tricky it's hard to do that yeah yeah so I've actually come up with a much simpler technique and it was what I present about an exponent it relies on using wavelets which sounds really confusing but the nice thing is it's just a picture you're basically looking at a line on a picture and that gives you the time delay and so that's one of my tricks that you know I probably can share with everybody a little bit more how to do that but it makes it so you can use Romi cue wizard to built-in feature the measurement itself is the same straightforward measurement you would normally take you just take a full range measurement of your speakers and subs together and it'll actually show you on this graph how much extra time delay you have that you need to compensate for well you put that in your aw video last week didn't you I probably did yes I think there's some about that yes yeah yeah we probably probably will cover that topic again I wanted to do put out another question here that from Ted Ted Monza Manzana he's asking limit the room correction eq'd a room transition frequency or 2x you know there's two camps in that there's one camp that like the guys from Harmon for example they don't believe in doing room correction beyond the room transition frequency and for those that don't know what the room transition frequency is basically in small room acoustics like you're dealing with in your home theater or you know 20 by 30 room something like that I'm not talking about like a stadium but like a normal home theater in a house the frequency of the room transition is where the base is dominated by the room itself whereas above that frequencies the speaker kind of dictates what's going on and the theory is you don't want to EQ above that frequency because it's kind of hard to differentiate what's going on between the speaker versus the reflections in the room so there's two schools of thought on that I'm more leaning towards don't eq above the room transition frequency some people really just like to use room eq as a tone control i've i've tried both and i've got mixed results with both but overall in general like I used anthem Ark recently and I think that defaults to 5 kilohertz I got better results when I eq'd that to 500 Hertz and I limited it to 500 Hertz correction Odyssey is kind of a mixed bag it really depends on you know your room acoustics I mean your speaker positioning Odyssey used to be pretty harsh when I would do it like it sounded very synthetic but now that they have the editor app you can kind of limit the range of correction if you go full bandwidth you could say hey don't boost more than 3 DB because I don't like when you see somebody's room correction systems boosting 9 or 10 DB you can get into areas where you're you're causing more problems than yourself and especially if it's doing high q-- correction and it's starting to create its own resonances I've heard room correction systems actually introduced resonances that weren't there before you know you turned it on so Matt maybe you can shed some light on this as well based on your experience yeah I I might play a little bit of a devil's advocate on this one I definitely wouldn't advocate for these types of Corrections to go out to 5 kilohertz or beyond unless they're very very sophisticated in nature but you know most rooms the the actual Schroeder frequency is around 100 hundred and 50 maybe 200 Hertz and I actually think that you can go into the transition zone which is a period after the Schroder frequency but before things become truly stochastic it's called just it's the point at which you totally can't tell the difference in modes you can't separate them out there's this this kind of overlap zone and I would say 500 Hertz is probably the limit there where it's okay things get pretty messy in that range and a little bit of EQ not a lot but a little bit of EQ can sometimes help make it sound a little bit more natural and I also find sometimes if you only EQ below let's say a hundred Hertz you get this nice smooth bass response and then things get crazy and so you can also improve the transition a little bit if you do that you know oh go ahead sorry oh I'm sorry the other gentleman they bring up is here's another problem with room key cueing at high frequencies when you're rude when you're doing room EQ at low frequencies and you have multi sub so the multi sub is allowing you to have CTC consistency it's allowing that microphone to measure consistently from each seat when it does its correction it's gonna work across a wide listening area but when you're dealing with high frequency correction from a single source let's say it's your Left Front tower well the mic positions vary so much depending on where you're sitting the frequency response output it's going to be such a big difference that even with the best statistical analysis or if it tries to do a best fits curve it's not going to be perfect it's not going to make every seat better so it's really you're still when you're doing high frequency room correctional full bandwidth room correction it's over a very small listening window and if you notice back in the day when Odyssey first came out and I'm not trying to pick on them but I have a lot of experience with Odyssey because of Denon they would basically tell you you know put the put the microphone all over the room put it on all your seats we have 32 mic positions you can measure you know put it in your fish tank if you want that kind of crap the problem with that as I said is the positional differences are so great that EQ and becomes kind of a fruitless you know a nebulous goal so lately if you look at what Odyssey is doing now in their setup guides when it's in the marantz or Denon product they tell you do not place the microphone more than a distance of two to three foot radius from the primary seat and finally they have some sanity and their recommendations so you have a very very narrow listening window where the EQ can be moderately effective for full bandwidth yeah those are good points I find that whether you're doing this manually in your optimization or you're doing an auto correction system placing the microphone your boundaries can be especially bad you know if you sit in a boundary position like your chair is up against a wall you don't really have a choice and you do want to optimize for that but if your primary listening position is actually a more ideal place where you're out in the room and you happen to have some cheap seats or mother-in-law seats I think as you call it that are up near the wall and you take measurements there one of the problems you get it's at the boundary itself tends to there's a strong reflection there and so what happens is that you tend to get a lot more intense anomalies and those anomalies then get compensated for when it's trying to come up with as you put like a best fit curve so what it's trying to do is look at all the different measurements and come up with a correction curve that has the the minimum of variance basically across them you don't want to introduce more problems by by doing this and the algorithm is designed to do that even Odyssey really has its it's an F IR based correction system it uses actually a relatively sophisticated algorithm but the problem is what it's trying to fix is actually not really that fixable through that technique and so the closer the mic ends up getting to places like these boundaries the more bad information it gets to work with and the algorithm makes bad decisions ultimately making the sound worse where you spend most of your time listening so it's it's important that if you're going to use those systems you do it right the other thing I just want to mention is that and it's one of the reasons why I kind of bagged on auto EQ quite a bit it's also why people like Floyd to lure so against them as much as is I can say this nicely there's a lot of bad speakers in the world especially not it and one of the things that I would say makes a speaker bad is when the response of that speaker off axis the polar response is you get off with the standard loosening axis starts to change dramatically from the on axis response what it means is that when did that speakers in a room the reflections don't have the same response as the direct sound now in and of itself that's not ideal but it becomes especially problematic for audio eq because they're relying on an omnidirectional microphone that's picking up all of that information equally and actually can't tell the difference that well between the direct sound from the speaker and its response shape and those reflections and so it tries to correct for that but your ear actually has the ability to filter out a lot of those reflections so the eq will actually compensate for something your ear isn't hearing thus introducing an error and so you might say oh I have great speakers they're they're really good they're a high-end model they're well reviewed they don't do this but the reality is we've measured a lot of speakers in audio holux a stereo file is another one that John Atkinson measures speakers all the time and if you go through those measurements what you'll find is there actually are quite a few speakers that have a fairly poor off excess response and what that means is a lot of Autoweek use end up having a bad basically a bad speaker to work with and you can't correct that EQ cannot fix that kind of problem yeah I mean that's a good point I've seen I've seen auto EQ systems you know the results of them vary a lot depending on not only room acoustics but on the quality of the speaker so another thing I wanted to bring up since you talked about boundary problems people when they run auto EQ and they look at the crossover settings that let's say Odyssey gives you or you know Arc or whatever Oh many times I see like a surround channel will be set as large or it'll set it at 40 Hertz crossover instead of 80 Hertz what these auto EQ systems are not compensating for is the fact that most people have their surround speakers I know I do and I saw in your room you do as well we have a mounted on a wall and when you place a speaker against a surface like that you get a lot of boundary gain in those in that crowd in those frequencies so that's causing Odyssey or whatever room correction your system you're using to think that that speaker is larger than it is or it has more base capability than it is these room correction systems are not accounting for dynamic abilities of speakers yeah it's a really good point and it's a common issue when you place the speaker against a wall you get a lot of boundary reinforcement and it increases bass output while that does technically mean that the speaker has more bass you know you can see in my room and I have a very high output theater but actually on the way back wall there there's some really tiny surround speakers and they've got little four inch woofers now what you can't see because I design these myself is that there's also four inch drivers on either side so there's three four inch drivers on each one and the ones on the sides are actually low-pass to work to help address the boundary issue because the other problem is when speakers are on walls the sound from the speaker hits the wall and then comes back and causes interference so minor setup to address that it increases output but the reality is they don't really have that much more output than they would have and so if you allow it to crossover at 40 Hertz besides the problems we mentioned earlier which it can cause integration problems you also risk overloading the speaker quite a bit yeah absolutely so there's another question here someone did in a super chat JT East I think it's a question it says clips thx ultra - with at most add ons or typical five point three point four I guess you're asking whether you should use the modules or use discreet speakers if you've got a nice system like that the thx ultra - system from clips is actually a really good speaker system why would you limit your entire system now it's a bouncing sound off of a ceiling in an unpredictable manner because you don't you know I don't know what your ceiling is I don't know if it's flat I don't know how taller your ceiling is the other problem with the bouncy house at most modules is when they do their bounce it works in a very narrow listening window so I've seen people do demos online where hey sit here and you'll hear the height effect yeah it sounds great in that row but go in another row and all the sudden it evaporates because you're dealing with trying to bounce sound and you know hitting the right angles by doing the BAM as opposed to getting the direct sound from the speaker pointed at you you're really limiting the amount of coverage you're getting and also you're limiting the bandwidth because now your sound is scattering it's not just it's not acting like a laser like you see the you see the diagrams that Dolby put on their website where the sound goes perfectly up to the ceiling and then 90 degrees down and hits you in the area it doesn't work like that there's always some sound that scatters all around you and Matt I don't know if you play with the Atlas modules I hate to keep bringing this up but people keep asking but my experience the reason why I'm so against the Atmos modules two reasons why his number one is I couldn't stand the claims that Dolby was making when they first came out saying oh my god this is the greatest breakthrough in twenty years it's better than discreet speakers notice how they're not making those claims anymore because we've been drilling them for like five years those claims are gone I can't even find it on their website that was that was all over their website all over all over a BS form with the sponsored posts all that stuff's gone now so it's kind of like quietly went away but the second reason why I'm not a big fan of these at most modules is the fact that when you put a speaker on top of another speaker if you're listening to music you're gonna really focus on hearing that sound kind of coming out all around you because unless you have a perfect way of controlling that dispersion and not having that sound escape around the actual host speaker it's gonna bleed over and I've heard this because I've done a lot of music listening I listen to a lot of DVD audio you know the Steven Wilson mixes and stuff like that and when I put those add most modules on it blurred the main speakers and I've had people come in and listen I'm like I had them sit down to do demos people that don't even know home-theater and as soon as when I put those at most modules on they're like something doesn't sound right like I don't hear the focus anymore out of the front soundstage or the front speakers so I don't know I didn't want to get off too much on this topic but since it was asked I figured why not man if you've got any insights to add to this based on your experience I'd like to hear it as well yeah sure Jean I'll say it looks like the gentleman who's been asking about this that's something within ceilings not modules but I'm not totally sure what he's asking so to say if you could react your question again it might help us to understand what your to ask but but in terms of the the bouncy out speakers I actually that's a funny term I had never heard that before and you'd said that to me in an email once and I actually had to ask a friend I said what's bouncy house speakers and they said you know when they pointed the ceiling and it bounces off and oh my god alright yeah so I it is too bad that those were presented as as good as or better than discreet in ceiling speakers because there's no denying that that's a compromise so my my view on that and I've used them before I've set them up for people I've used them in my own system I had them sent to me once and I tried them out is that it's it can be better than nothing for that at most effect only sometimes when they work right but it's definitely nowhere near as good as actual in ceiling at most speakers those are significantly better and in terms of the the bouncy house speaker working well it's as you mentioned there's very specific circumstances for it to work well work well being relative I still I'm going to say it's never as good as discreet speakers in the ceiling but you know it I've heard it where it provided a fairly believable Atmos experience now the time that it was most believable was actually mark Seaton had him set up at acts Bona and he didn't obviously we're not allowed to drill holes in the walls right an exponent so what he did was now these were like probably twenty five foot high ceilings and he was aiming a coaxial speaker he had just made up at the ceiling in an angle processing it with I think it was like either a dataset or a storm audio very high end processor lots of EQ and he was processing it with that and it was a pretty believable atmos presentation you know under those conditions but they were a really good speaker they were placed way overhead I mean they were actually put up on trusses you just hit the nail on the head my friend if you really want those Atmos modules to work you don't want to place them right on top of their parent speaker you want to place them above your level because otherwise they become more localized especially if you've got those at most modules too close to a listening area like for the back height channels man I as soon as when I turn those things on it was like I could tell there's a speaker right here I could tell it's coming from that speaker and that's because it's at if it's at ear level if you have your side channels at ear level and you put an atlas module on top of it you're not controlling that sound 100% it's gonna leak over and you're gonna be able to do it to localize it if you're a few feet away from that speaker yeah I think you're right now I'll just mention it looks like the questions been asked again and the question this time appears to be saying would you go with the thx clip setup or spend it's the setup or spend the same on a typical five point two point four seven point two point four so I'll say a couple things on this quick and then I'll let you weigh in Jean a I'm not a huge fan of the THX certification and that doesn't mean there's anything implicitly wrong with it I actually think it's a great idea I just think that there are lots of good speakers out there that aren't thx-rated I think that the thx rating system was a lot more of a black box and I would have liked which made it hard to tell what exactly you were getting with that rating and so I would just say I wouldn't spend extra money just to get a THX certification on a speaker I think you get but but you do want to get a good speaker now in terms of verses five point two point four or seven point two point four in my view is you should put as much money into the best speaker you can get better speakers make a bigger difference than more speakers oh yeah its quality over quantity and and that's that's the thing I always see people going nuts on some of the forums is they just there's a new processor that's nine point one point six I'm like well wait a minute the format right now as it is it's limited to seven point one point four blu-ray doesn't go beyond seven point one point four so unless you have a really large theater room and you need multiple speakers for it to cover a wider area you're just matrix in those extra channels anyway those are not going to be we have nothing that's decoding or nothing that's encoded and then decode it discreetly in the home beyond seven point one point four right now yeah yeah I think people go a little bit nuts putting too many speakers into a room and often they they they get lesser quality and and I think one of the things is you'll see these reviews you know we do it to we'll talk about a speaker will say for the money this is a really good speaker and I think what happens is this becomes this misperception that you know we said for the money it's a really good speaker they saw it's a really good speaker and so they settle on that and they just keep buying more because they can afford it the reality is if you spend more you get more and sure there's limits I saw in your last video there was some talk about a $80,000 speaker you know there's definitely a point where diminishing returns is we've gone way past that right like where the speaker is about as good as it gets but for most of the people that I work you know that I deal with around this the kinds of speakers that they're getting are still well in the range we're spending more it gets more and you know going for a seven or a nine channel speaker system I mean besides the fact that it's hard to get everything set up and aimed correctly so that it integrates well and the sound has a nice flow around the room the reality is that money was probably better spent on simply better speakers yeah agreed I guys we said this before you want to have you go on the channel years ago start out with your bassist and get the firt at least get good get a good 5.2 setup going you know five good speakers two subwoofers then build your system from there I like having back channels in my setup I would probably get back channels before I'd get a single pair of height channels because again I'm more biased towards music listening and I love listening to multi-channel and I love listening to to channel up mixed into 5.1 or 7.1 so I'm just looking over the questions here a lot of them are basically asking what crossover frequency they should set their speakers I think we can I can't go for over every scenario but I I think our our guidance here as a rule of thumb the 80 Hertz thing is really something you guys should be looking at to start with and if you want to experiment on your own you're more than welcome to do so just realize in your receiver in most receivers whatever you set the crossover for the main channels whether its large or small that dictates where the subwoofer croffer crossover is gonna be when you listen in to to channel music and if you have multi-channel multi subwoofers set up and then letting you set that subwoofer crossover to low you're losing a lot of the benefits that you're trying to get with multi sub in terms of getting c2c consistency in your bass frequencies so Matt do you have anything else you want to add cuz I think we're probably gonna wrap this up I know I think this has been a great talk this was a lot of fun thanks for having me one thing I want there's one question that just got me here is so you can't EQ dipoles why are you using dipoles don't use dipoles for surround speakers anymore I think that's been that should have died when we got discrete audio there shouldn't be dipoles in your in your set up anymore I'm sorry especially if you listen to music guys at least switch to a bi pole or if you're doing Atmos I really recommend Mono poles for your side and back channels and then do the discreet in-ceiling speakers and you'd be really happy with that yeah and I'll just add you can EQ dipoles there's no reason why you can't sure it's they can be a little trickier to measure in room but in the end especially at low frequencies it really doesn't matter a lot of people get hung up on this idea that somehow the the base can be direct directional outside yes you can make directional bass and that can affect measurement somewhere in a room no because what you're measuring if the microphone is actually the direct sound plus all the reflections so it doesn't matter if the speed the subwoofer itself had it's basically directivity modified in some way by the time it hit the microphone it was already mostly reflections yeah someone named sneaky pete just said i only have an SPL meter well sneaky I really recommend you get yourself the UM m6 microphone I'll put a link to our to the Amazon the Amazon page we have for that it's about a 90 or 100 dollar microphone it's a USB microphone it comes with a calibration file you entered into our DW and you should be good to go to start doing acoustical measurements I mean you can do stuff with an SPL meter you can at least get your levels right you could check the phase I mean it you could do you could run the pink noise test of your subs and you could see if they're in phase or out of phase by I flipping the phase of one of your subs and check in the SPL at the listening area and see if it increases or decreases there's some stuff you could do with an SPL meter but man we're in the day and age where it's so cheap and easy to do acoustical measurements and rtw is such an awesome program and it's free I mean it doesn't cost you anything to use it's relatively easy to setup and it can really make or break your system it could just spend the time and get your calibration right yeah I definitely hi anybody that's really into this hobby I think getting a microphone not only can help you with the especially the base set up getting it optimized but to be honest it's fun I mean that was one of the things that got me into this early on is I just really enjoyed being able to see essentially the fruits of my labor yeah my ears mattered and ultimately it doesn't sound good it isn't good but there's something fun about being able to do this you learn a lot in the process you learn about how making all these changes and adjustments affects the actual sound of the system as well as how it measures and it's it's really helpful in trying to see if something is better sometimes you'll hear something and you're like well it's different I don't know which is better but it's clearly different and the microphone can really allow you to take measurements to help you figure out which is actually better yeah I mean like I've always said this before I use a microphone just two more as a troubleshooting guide when I set up base centers in a room I want to make sure that my subs aren't cancelling each other out so that's really why I use the microphone once I get that smooth integration with all the subs of course you got a deer listening to guys we're not just about measurements I don't always follow the best measurement because sometimes you could tweak things here or there you can add a little bit more bass so you might have to take away a little bit more bass depending on your listening habits so it really does pay to get the measurements at least good first and then go back and do your listening do you have any good guides for re W and Mike choice I just put one out yeah we just did go sneaky prick I'm not gonna say your name actually I saw that yeah go on our last video we put it up four or five days ago I think it's called guide to use an already W or something like that and I put links for using the u f to get the UM m6 microphone all you need is a um m6 microphone and an HDMI cable and you plug the HDMI cable from your laptop into your receiver and then you're good to go and I mean it's that's it it's a hundred dollar investment maybe $20 for the HDMI cable so you're looking on 120 bucks that's all you need yeah the cost is modest it's really not that hard we said a lot of people I think we're complaint not a lot but there were a number of people who complained about that video not going into the settings very much that was actually quite intentional re W already comes with a lot of settings preset where you want them and so if you set it up the way I showed you in that video it should work the way it needs to be get get you started taking measurements what I did was showed you the simplest possible way to get started to do that and I also add you know audio holux has a forum so if you get started with all this go over to the forum you have questions it's not working right just post screenshots or MDF files or any of that and we'll help you you know I'm around all the time so I'm happy to help in fact I'll post the link now to our forums in case people don't I mean I would assume anyone that's watching this channel knows that we have an editorial site and a forum but you never know so there's our forum there's a lot of knowledgeable people on that forum that guys I just heat and live base all day long and if I can't go on there or Matt can't go on there you'll find people there's a community of people there and we're all preaching the same thing good base you got to get good base because all the research shows you know 35 to 40 percent of the experience of home theaters enjoyment factor is is getting good base if you don't have good pace you're you're really a handicap in your situation yeah I'll actually even add it's it's not just home theater music - I think people sometimes get hung up on this idea that people like you and I are too into base or base heads whatever that's not really true there is actually hard objective research that has been done on this that found that the quality of the bass played a huge role in how you perceive sound quality and I've actually participated in speaker shootouts as well as research studies trying to double-blind test which was the best sounding speaker and one of the things that often threw off both the shootouts in the studies was substantial differences in the quality of bass coming out of the different speakers and so one of the things we had to do to make the the studies work was actually add in many cases something like a subwoofer or multiple subwoofers and get that set up correctly so that integrated right with the speakers because otherwise people weren't judging the speaker by its qualities outside of the base they were actually judging it solely by the base and whatever speaker had the best bass was the one that always sounded the best oh yeah that's that's it that's a really good point especially if you're going if you're demoing speakers in a in a busy show floor like a the Best Buy or something it's when people a be speakers the louder speaker or the Bates ear speaker is always gonna win that comparison so unless you level match and get everything on equal playing field it's hard to do an objective comparison between two products so I think we're gonna wrap it up guys if you have any other questions you know feel free to put them down below and Matt or myself will go in and answer them I wanted to tell you guys we do have a patreon channel a Tron slash audio holics and if you become a member of that you get some extra perks I put content there before it goes on here or before it goes on the editorial site we also have will invite you to our Google Hangouts I'm just getting used to getting this stuff set up so just give me some time I had some operational hiccups today I apologize for that but I'm trying to get more savvy with this YouTube stuff and another thing we're gonna be doing because we keep getting asked what should I buy you know what's the best speaker at this price point what's the best amplifier at this price point I'm setting up an Amazon store an affiliate store where I'm gonna we're gonna be putting recommended products in there I'm gonna be putting my own recommendations maybe we'll get math to put his and whatever products that are that we're reviewing if we find that they reviewed well we're gonna throw them into the Amazon store so you guys could go directly there and get it we'll even try to put some systems in there as well so just try to make things easier for you because I know people are always kind of confused what's the best thing to buy we kind of like to take the scientific approach and we like to measure stuff we like to make sure the things sound good before we recommend it that's why I often don't give absolute recommendations when people ask so anyways guys with that said Matt it was great having you on here I'm gonna commit you to try to do this maybe a couple of times a month with me because I love having these tech discussions and I'm sure people appreciate that as well yeah thank you I really I'm glad I was able to do this and I'm happy to spend a Friday or Saturday for an hour doing this with you this was a lot of fun awesome well guys we are wrapping this up put your questions and comments down below could all on our patreon channel you know become a member you could start asking us what kind of videos you want covered we'll get mad we'll get other guests on here as well and my friends until next time keep listening

Channel: Audioholics

Views: 348,133

Keywords: audioholics, video review, home theater, audiophile, tech, headphones, speakers, amplifier, movies, music, audio, video, projection, bass, subwoofer, hdtv, blu-ray, dolby, atmos, #hangoutsonair, Hangouts On Air, #hoa

Id: u1ecOpvb89E

Length: 62min 45sec (3765 seconds)

Published: Sat May 04 2019