Jesco Lohan (Acoustics Insider) explains WHY the room is critical to good sound

[Music] we've got our coffee so my name is yes colo Han and I'm a mixing engineer and studio acoustician from Berlin and I run an online platform called acoustics insider where I teach audio professionals acoustic treatment techniques that they can that they I that actually work without all that voodoo so they can get professional results in getting a great sounding room in their home studio and in the project studio I am in terms of acoustics I apply my knowledge to professional rooms yeah professional audio rooms so mixing rooms recording rooms that sort of thing yeah so that's really my expertise obviously the underlying principles are all the same what really changes is the kind of the use case right it's like how do you approach what you want to get out of the room and often cases the priorities change right but we see the underlying principles are the same yeah well the room in its entirety obviously has a huge impact I mean we all know that if you're watching this you definitely know that and the the kind of the best way to split it up or the easiest way to kind of think about it in and separate it out is on one side the low end and then on the other side kind of the mids and highs right so in the low end what you get in these typical kind of living room sized rooms are room resonances or standing waves which basically effects the the balance in the low end and they they will they will increase the volume at certain parts in the room and they will cancel out the volume in certain other parts of the room so depending on where you sit in the room where you're actually located you might get a lot of bass at a certain frequency or none at some other frequency and the the the the the span is quite large so you can easily get 20 30 DB x' between the peaks and the kind of troughs of these of this imbalance and so that's that's kind of the thing when you move around a room as you're listening to music and you kind of hear the bass come in in some place and in a year it disappear in another place that's this thing of room resonances that I'm talking about so that kind of happens in the low end and then in in terms of the mids and highs we're talking about reflections so this is like like a game of pool really where you're kind of thinking okay I'm here my lads because over there so I've got the direct sound coming at me but then there's one for example one particular beam of sound hitting the wall on my left and bouncing back to me and that mixes with the direct sound and those two sounds interact they will interfere and they will cause a comb filter which basically affects the though tonality the richness the color of the sound and obviously you don't have just one reflection coming off of one wall but you have them coming from everywhere and they create this big mush of comb filters that can really destroy the sound and on top of that you've got that timing aspect so not just that it it messes with the tone of the the the color of the sound but it actually messes with the timing of the sound so you've got the direct sound that your ear picks up on but then you've got that delayed sound coming from the rest of the room and to a certain extent your brain will start to try to integrate those and will try to do the best to figure out what's actually going on but in the process it gets really confused and so you're left with this this big mush of sound really and I mean it's it's it's realistic it's to say or it's it's not was how do you say it him it's yeah it's kind of realistic to say you could argue that in a typical untreated living room if you are just listening to your speakers you're you're basically listening to upward 50 to 70% room what you're hearing is more room than actual speaker so this is this is one of the the things that really is underestimated you know like it depends how far you weigh what so you sit from the speaker but in a let's say in a typical kind of - listening scenario where you're three meters away from your speakers you could you could definitely say okay I'm actually listening to more room than speaker and so that's that's how strong this impact is and that's one of the reasons why I as a professional all your profession obviously put so much focus on or so much emphasis on trying to remove the room as much as possible from that equation [Music] okay so this is the kind of main corridor I guess outside of my studio so my Studios in an old factory building and this is quite a nice space to demonstrate just how strong this effect that the distance to the sound source makes in an untreated room so I have my microphone here and I'm gonna obviously I can't see it right now I'm gonna try and take it off all right so obviously I'm now talking into the microphone but now if if in here and they'll pay attention to what happens how the sound changes as I move the microphone away from my mouth so John if I'm just going to give this to you put it back attach it back to my shirt you can tell just that the proximity of it kind of clearing cleans up the signals of some extent right and this is the same that happens with the speakers while you listen to it so in an untreated room the further you go away from the speaker the stronger the impact of the room will be I'm gonna we're gonna go back to my studio I'm gonna do the same thing in there just to give you a quick comparison of what that sounds like now let's do the same kind of little experiment in this this space my treated studio so again I'm talking to you with the microphone fairly close to my mouth now and as I move this away and I give it to John you'll start to hear that you can tell that there's more distance and recording but that impact of the room is nearly as large you should be able to understand me quite a bit better it doesn't take as much effort to understand your brain doesn't need to decode that audio quite as as heavily as in the other space yeah so that's just a quick demonstration of how strong the impact of the sound of the room is on the sound with changing distance to the source [Music] [Music] so the geometry and the dimensions the overall dimensions the ratios of the different distances and yeah and the geometry has a huge impact mainly on or yeah both on the the reverb in the room and and and the frequency response so the the the the balance of the frequency is against each other right and and depending on how all those dimensions work together you might find that they accentuate certain frequencies or they actually cancel out certain frequencies because of this thing of room modes that I was talking about before and also reflections causing home filters because if they sit on top of each other basically the effect kind of aggravates and you get a stronger effect and so yeah you get you the the the shape has a huge impact now depending on what the materials of the the room or the what materials the room is built from what the walls are made out of they might let certain frequencies pass through while others are reflected right so so for example typical drywall gypsum boards that kind of stuff plaster board actually as it that definitely in if it's single air but even if it's double layer will let low frequencies pass through and I mean obviously the flip side of this is an isolation issue right obviously the more sound passes through the walls the less well isolated that room is again coming from the studio world but if if energy passes through then obviously it doesn't get reflected and doesn't start doesn't it doesn't play into this this all this craziness that happens in the room right so the material does make a big difference but in general you could say that in most rooms unless it's very thin room with thin walls the majority of the sound is reflected and and plays into the craziness that actually happens in terms of these resonance and reflection effects so in your professional opinion what is it the geometry of the room that has the the most pronounced effects or the materials of the the floor you can't you can't say it's it's definitely one or the other but again considering that most walls are built to be based mainly reflective or mainly not let sound through the the geometry definitely has in most cases a larger impact yeah for example and this is something that's that that I teach as part of my as part of ku6 insider and treating Studios is in if you are if your room dimensions aren't optimal from the start that the impact that has on the frequency response so just the tonal balance of what you're hearing it permeates right through to the end you can you can you can really do quite a lot of treatment and actually suck up a lot of that reverb time make the room really dry but the impact that the dimensions has on the overall tonal balance will still be there and it takes a lot to remove that impact on the frequency response right and so in in most typical kind of home home yes scenarios be it as a listening environment or as a professional environment if you're building a studio or just a like a high quality listening room in a living room or a basement or an attic or whatever spare bedroom that room is built to be lived in it's not built to sound good and so nobody will have thought about optimizing those dimensions and there's nothing you can do about it you have to live with it and so that impact that has on in this case the frequency response is just something you have to deal with either you live with it or you can you can think about using something like EQ to optimize certain parts of the room where you sit obviously you can really only apply EQ in a way that it optimizes for a certain area but those are kind of the tools that you then have at hand and you can think about they're all compromises if you never get a free lunch you know but if this is something you're fighting with if you're fighting a really bad frequency response you've done a decent amount of treatment and you're just like look I don't have space mode for more treatment I'm not gonna be ripping out any walls think about EQ for example you know it's the tool that is as there might as well use it so yeah our playback software has is it parametric EQ in the back end or it up from a plug-in so you can measure your room using Roo re w only room EQ wizard for example yeah could you talk a bit about how people can use EQ to solve these problems so it's it's actually pretty tricky to solve individual problems yeah it's just it's not as easy as the internet might make you think alright so there's there's the whole science of doing measurements properly which you obviously need to do properly to figure out for example if you have a very narrow reference narrow resonance where that actually sits to apply your Q property one of the one of the quickest or simplest mistakes to make is to think I did my measurements correctly therefore my peak is at thirty eight point two Hertz when it's actually at thirty seven point five because the measurement was slightly off we made some mistake it wasn't perfectly accurate then you can't actually apply the EQ perfectly at that particular frequency so you you're just like one tiny bit off and that's enough for it not to work there are also certain acoustic effects that you can't actually EQ so again talking about room modes because we're all interested in bass obviously if you think about room modes standing waves it's a resonance means that that if you have two parallel walls sound travels one way and then gets reflected and travels back the other way and if the wavelength fits between those two walls perfectly it gets reflected back exactly inverted and when it's when these two the wave going one way in the way of coming back the other way when they start interfering that's when you get those those boosts and dips right now the problem is if you start applying EQ we've got a huge dip and we're going to boost the energy to get rid of that dip so now we're pushing 10 DB into this room mode so we're pushing much more energy into the wave going one way but obviously the reflection is going to get that same boost and the cancellation or the the dip that we're getting is caused by those two cancelling each other out now we've put more energy into both so we're putting energy to try and boost away this dip in the frequency response but is exactly the opposite is happening in in the room because we're putting more energy into that room mode so basically I think from what you're saying is you can correct yeah pretty much it's this is all very theoretical in practice like I said it's a big mush of a lot of effects on top of each other so you might find that in theory it shouldn't work and then in practice it does for some reason and then in other five cases you might find this should work and then it doesn't it's quite it's it's that's why I'm saying it's actually difficult to do in practice because the problem is pretty complex not so much in terms of how difficult the actual fists are understanding the physical principles are but because of the quantity just there's so many of these effects on top of each other and figure it like pulling it apart and figuring out that this particular thing is this thing that I think it is that's the tricky part so all that said when you're applying EQ it's a much better approach to try and fix broad problems so for example if you've got a general well for you it's obviously this side probably she's got a general dip in the low end you can try and boost that with a shelving EQ boost the overall area you're not trying to correct individual mistakes you're trying to correct the overall shape you have a wide q yeah same in the high end if you're in the midst if you've got some if you've got a big dip somewhere in the mids that makes though the whole sound a bit Hollow instead of trying to decipher all those little individual peaks and dips of the comb filters start with just fixing the big issues that's going to give you the big wins like one of the one of the things about how we hear is that we're not particularly sensitive to all these little fluctuations even in the low end when you've got these big differences between the peaks and the dips in the low end we're actually surprisingly insensitive to it and what we're much more sensitive to is the overall amount of energy in the entire low-end for right so focus on fixing those because because the effect the gratification you will get is much higher and because it just sounds better and and it's actually possible to do [Music] basically there are three big wins that you can focus on in terms of fixing up the sound in a Holmen project studio and the first big win is making sure that your listening position in the room is right right so we were talking about these room resonances before about how they change the low-end and how where you actually sit when you listen or where you are positioned in the room while you're listening to music you might get a big boost or you might get a big dip in the low end somewhere all right so I said you get this example you walk around and the bass changes as you walk around so we can actually make use of that to find the best spot in the room where it's the the the the kind of the least bad basically right you find the spot where it's as balanced as it can possibly be and and I kinda I like to make that analogy it's kind of like in a old-school battle on the battlefield you're trying to find the high ground and so finding that spot in the room where your low end sounds the most balanced is a big advantage if you're if you're trying to fight if you're trying to fight yeah if you're trying to fight your way out of a bad sounding room yeah yeah yeah this is why I'm saying you might in the hi-fi world you might like you have to really ask yourself if if you want to implement this and I mean it's the same with studio people if I tell them you know like look you got to move your desk and they're just like have you felt this thing speaker position is pivotal for many many speakers but what a lot of people don't think about is moving the couch yeah it's both it's both and the easiest way to think about it is that coming up with a good or finding a good low-end balance is about the couch in your case and coming up with or improving the optimizing the the both the balance in the mids and highs but also the stereo image that's about speaker placement so the the speaker placement does impact the low-end but not nearly as much as where you are sitting while you're actually listening to the music so you got a you got to optimize where you sit and then once you found that spot and then you can place your speaker's relative to that spot to optimize the mids and eyes and the stereo image the second one so now we've we've found our high ground in the battle right and so now it's time to actually start fighting the battle and this is about treatment right so now we're gonna we're gonna do as much treatment as we possibly can and or as we're willing to do as we as our budget allows whatever right so I think the main the main thing about this is to understand or to just to keep in mind I think the biggest misconception that I seat or the biggest mistake that I see people making is not realizing just how much treatment you actually need so if you're thinking about fixing the room and you're like fixing the low end in your room and you're thinking about buying a couple of panels maybe 10x that and you'll probably get the result that you want or you get close to it yeah so I'm serious like this is yeah this is this is one of the biggest mistakes that I've seen people making is that they under they really are hardly like they strongly underestimate how much treatment you need and and to be honest it's not surprising because you cannot find solid information for example on the internet and even in books even in like in the literature on how much treatment you need calculating that is actually pretty tricky in small rooms I would dare say close to impossible for various reason that I'm not going into right now it's very difficult and so and people aren't sharing this type of information freely so it's really difficult to come across kind of studies that say say you need X amount of treatment I mean people say good as much based traps as possible which is true but it's kind of it's like it's it's difficult to to judge what that really means but if you think about it this way low end fixing though and once again right we have really long wavelengths we have wavelengths at 100 Hertz three and a half meters right which is 10 feet roughly and that's a hundred Hertz 50 Hertz double that 25 Hertz double that we're talking about these huge waves sloshing around in our room and you're trying to get those in check and you think putting a little 60 by 60 panel somewhere in the wall is gonna do something to this wave this way it's just gonna say yeah you know and it's just gonna continue doing its thing you know so in order to really affect the low-end especially down at those lowest low frequencies you it's you need quantity and this is both in terms of the depth of the material if we're talking about like pours absorption like insulation material but it's all also about just surface area so so it's both and you that's something to just keep in mind yeah you need a lot of it so this is the second step treatment do as much as you can as you're willing to do as your budget allows and and then the third step that I talked about is EQ which we kind of talked about at the beginning right so you can do all this positioning finding the high ground in your battle doing as much treatment as you can possibly manage as you're wanting to sacrifice in terms of space but even then if your room dimensions select your frequency response is probably still going to suck you know so the the timing of the room is gonna be nice all that treatment sucked up all that that reverb hopefully you've ended up with a balanced reverb across the spectrum which was really key to to not having the room sounding dead and but the frequency balance still sucks and this is again something that you kind of learn with experience you kind of expect oh yeah I'm gonna put this treatment in and it's just gonna even out to some extent it gets better and better and better the more treatment you do but but unless you are willing to start from scratch build a room from scratch and do all the steps right from the very start it's very difficult to end up with a balanced frequency response a flat frequency response just with treatment and so that's why in my opinion EQ is a useful tool obviously kind somewhat to somewhat the to some extent depends on how far you want to go how how high-end you want your room to be you know up to a certain point people get really what's the word picky I guess you know they're just like I don't want to use your cue [Music] [Music] you've confirmed pretty much what I've been thinking for the last few years number one most audiophiles well most people listening at home do not listen in a dedicated treated room they're listening in their lounge room that lounge room is inherently compromised by its dimensions therefore it's almost like there's a glass ceiling that the room applies on any item so no matter how much money you throw your speaker in you're gonna get to a point where it's just dead money yeah that's right I would suggest that glass ceiling is pretty damn low yeah you wouldn't expect it to be so low yeah and I mean I think it's probably similar in the kind of high five world as it is in the pro audio world is that you grow with your ability to hear or your ability to hear grows and with it your your expectations of your speakers and your room grow right and it's just like you you gotta work on the entire aspect on all aspects to get great sound or to get the best out of what you've got let's let's say like that and it doesn't really make sense if your if your room is completely untreated and and you've got some bad dimensions going on from the start some tricky geometry and it's just a the glass ceiling as you said is really low and then you get just ridiculously expensive speakers and on top of that your hearing ability isn't particularly great I mean like I'm not I'm not judging like we all start somewhere and it kind of like I said it grows as you gain experience you know you develop your hearing ability and so just make sure that you kind of invest similar amounts on or invest not a mouse but invest similarly in all aspects right once so that that's there you don't have a bottleneck somewhere that's that you or your you're not you're kind of ignoring because you don't want to deal with it you know and yeah for 2,000 euros speaker you probably you might actually want to invest more than 2,000 euros in the room yeah at that point if I was an if I bought pair of speakers one thousand euros each I would probably justify investing up to ten thousand euros in the acoustics of the room if I build somewhere five to ten thousand euro room for some people people's jaws drop you know obviously it's because they haven't yet experienced that before they also see the transformation from the untreated room which they have already gathered some experience in to the treated room so they can really tell that difference and obviously the jump is a lot more obvious if you kind of leave an empty room in the morning and then I come in and I do my thing ten hours later you come back and and the room looks and sounds completely different and so that you get that that real that real comparison but one of my very general approaches or mentalities is and obviously I know because I've studied it and all this but there it's it's it is just science there's no there is no voodoo people talk way too much about this stuff about things that are totally irrelevant or just not as important as you might know like not nearly as important as you might think and just focus on the basics take it easy get started do something gained some experience yeah it's like I said before it's like you kind of you improve the quality of your room as your speakers improve as your listening ability improves you know you don't need to go out and spend a ton of money on acoustic treatment at the start just like yeah invest 500 euros you know that's that's a decent amount to get started and is it gonna fix your room no but it's gonna give you an impression of what five hundred euros of acoustic treatment can do and and it does improve what you're hearing it's not gonna fix it but it's gonna improve it it's gonna put you on that path you know don't don't be scared there's nothing to break I think this is one of the other things that there's inherent fear of doing something wrong oh god am I gonna am I missing something important here that I need to address and I just don't know about because it's all voodoo you know there's nothing to break yeah it's it's like it's like you're when you're showing your mum how to use the internet you know and she's like what do I do if I click this place my computer and Cystic look mum you can probably like reverse just about anything just give it a go you know and it's the same with acoustics like there's nothing to break there's you can't really it's it's difficult to mess up a room to the extent that it actually is worse than before yes it can be done but like again just focus on the basics get started don't be afraid there's no problem [Music] so let's talk about the placement first of all tell it and I'll tell you something about the design afterwards so in anything happening at ear height on the plane of the speakers and my ears as I'm sitting there is anything any panels placed across that distance across that plane on that plane is in some shape or form designed or place to remove reflections right so behind the speakers we've got mainly stuff happening in the low frequencies right so speakers obviously directional too in the or get gay get directional as you move up in frequency but in the low frequencies they're pretty much only directional so speakers will play low frequencies backwards and that's what these are for so they would table to some extent reduce if not eliminate energy hitting the front wall bouncing back right saying with these guys yeah these guys pick up some some more high frequency energy mid frequency energy from that speaker this one is obviously facing that way so there's picking up more low-frequency entity from that one but again it's about reflections energy reflecting back to the listening position these guys the ones that are at ear height also contributed to that that whole reflexion game 90-degree corners have an interesting property of reflecting sound back in that direction where it came from because no matter what angle it comes in at it will always bounce out of two walls and then just get pointed right back in the action where it came from no matter what angle of incidence it first got introduced into that corner like a pool table so 90-degree corners room corners will reflect sound back to wherever it came from so prime prime candidates for reflections so that's what these guys are fourth this one particular here obviously on top of that the entire height is covered along with all the other corners and that is basically base trapping or doing the same panels function as base trap in that position and because we were introducing a an air-gap behind the panel the the entire trap the affective trap gets deeper because of that and so the the the trap has better low frequency absorption on these slats this is a very primitive type of diffuser it's called an amplitude grating diffuser a binary amplitude grating diffuser because it's binary because it's either reflective or just absorptive and the particular pattern is a maximum length sequence a mathematical sequence that determines how energy is reflected off of the surface the entire surface of this panel and that reflected energy that reflected sound will again interfere with itself and that interference pattern actually causes a very simple type of diffusion it's it doesn't work as well or it's not as as the type of diffusion isn't as effective as a qrd a quadratic residue diffuser or Schroder diffuser which is one of those pyramid things that you might have seen but it's it does scatter and break up the energy fairly effectively and and and by choosing the slat size this size it actually only works upwards of about two and a half three killers so this whole panel is a broadband absorber up to about three kilohertz from where on on it's scatters energy it reflects and scatters energy and so it's a kind of a combined absorber diffuser and that works really well for these side points here but obviously you can see them in the back as well because they they don't suck up that's that high-frequency energy it gets returned to the room but it is broken up so it doesn't contribute to that whole reflection issue of causing home filters not as much at least but at the same time it it gives you a sense of space in the room and gives our ears as we are in here a sense of space the actual average reverb time in this room is 0.2 seconds that's so it's very short very dry room in terms of reverb time technically speaking but it doesn't feel that way it actually feels quite comfortable [Music] if you are if you're treating or if you want to improve the sound in your living room that your whole family uses that you potentially invite guests in for dinner have friends over whatever the the threshold for you saying screw it I'm gonna like put all this stuff up that threshold is obviously way higher and to be frank I don't see a solution to this problem like you this is a matter of getting your priorities right like you cannot if you cannot do something you cannot fix the problem you know so like it's just like I yeah I get I get what you're saying and I wished I could offer you better about a solution but in that case I just have to say look you're gonna have to decide what you want and then do what is appropriate and you cannot fix a problem if you're not willing to do anything about it you know and so this is this is just the reality of it you know and so you're sure there are certain ways to hide acoustic treatment but it comes at a price and that's why I'm saying beyond a certain functionality you're paying for looks and I'm not just saying make them the actual panel look pretty that you're putting the wall I'm talking about at some point actually changing the structure of the room to incorporate acoustic treatment that is invisible anymore you know so at that point this isn't about functionality this is purely about looks and and a lot of the cost in in more high-end rooms of whatever use case it goes into improving the looks fix fixing the looks if you will I mean let's that's also kind of is that is that a saying when you leave the church in the town is that how you say it there's a literal translation from from German as in let's not let's not blow things out of proportion yeah so if you are willing capable to invest ten thousand euros in treating your room the impact that we'll have is of course going to be noticeable with a 100 thousand euros speaker set yeah are you going to hear them completely unaltered no but with the things like this the the the curve of effectiveness it's like like with anything else this it's the Pareto principle 80/20 you know you were getting 80% of the the result for 20% of the investment so the beginning investment that you make by far has the largest impact and so you don't need to go nuts with the treatment of your studio or sorry you your listening room your whatever yeah you don't need to need to go completely crazy but but if like if you are if you're investing that much money in a set of speakers do the best you can justify with the room as well yeah you don't need to build the house around the speaker and getting kind of the fundamentals right is gonna give you the biggest improvement that or the yeah the biggest value for your money if you want the best to kinda like them if you want the best of the best then obviously it's gonna cost ya buddy I mean just thinking back to my three big wins the speaker set wasn't even part of those three yeah just to put that in perspective yeah so I mean you my approach is definitely when people come to me and say like look I'm thinking about treatment but I'm also thinking about upgrading my speakers and I'm just like hold on with upgrading your speakers because you've never heard your speakers reach their full potential you might find you don't need to invest in new speakers obviously once you've done all this other stuff now you can tell just how different a different speaker set will sound now you can tell whether you actually prefer this speaker set over that one so I yeah so I mean my mother where where I write about the stuff is acoustics insider.com right so again this is focus this is I'm aiming all this stuff at audio professionals yeah nonetheless the principles obviously apply to just about anyone so you're as like a hi-fi person with a listening room that you want to improve you will definitely find things in there that that will help you with the sound in your room then you can kind of cherry-pick the things yeah and there's a youtube channel as well acoustics insider has what I started that YouTube channel while ago at the moment I'm not producing any content so that's kind of it is what it is but I'm going to again it is it is planned and and so you can you can also check that out and you'll probably find some stuff there as well [Music]

Channel: Darko Audio

Views: 367,813

Keywords: Audio, streaming, High-End Audio, Audiophile, head-fi, porta-fi, sound quality, Darko, reviews, show reports, berlin, techno, room, acoustics, recording studio, mixing studio

Id: cTnituQu8ig

Length: 37min 49sec (2269 seconds)

Published: Mon Aug 19 2019

Reddit Comments

[u/dlrr_poe]

10k acoustics for 1k speakers. hokay.

​

that being said, rest of the video's real useful and informative. 500 is something that makes much more sense than that 10k to 1k ratio

[u/heywaj10]

It's amazing how much more easily a principle can be understood when you have someone explain it in relativistic and simple terms vs. reading it yourself. I love how he presented this information, and it has certainly piqued my interest in learning more about room acoustics/treatments.

I did an experiment in my (horrible - 11'x12') room the other day, where I moved my couch and speakers based on the Cardas method - just for shits and giggles. While that configuration is completely infeasible for permanent placement, the difference (with 0 room treatments) was, in short, dramatic. Everything about the sound cleaned up, the center image was precise, and while the soundstage didn't get larger, it certainly expanded rather far in terms of depth.

I'll be following this guy's website for sure. Thanks for sharing!

[u/Zurevu]

tl;dw?