How Does An Infinite Baffle Work?

the infinite baffle subwoofer is about as popular amongst the audio Community as Flat Earth is to science uh not that uh not that's a good comparison but it is a point of contention between different groups of people in the audio Community as to whether it's better or not than more conventional uh sealed or ported enclosures the infinite baffle subwoofer has some advantages inherent in the design uh of the application that the subwoofer is used in uh one of those advantages is that it can play lower uh consistently and more smoothly so if you're looking for transients and lows infinite baffle is definitely going to give you advantages there uh in uh transients meaning ability to start and stop a note quickly uh like Fast kick drums and things of that nature so yeah if you're a death metal guy this is this is going to give you the subbase you're looking for one of the other advantages to infinite baffle subwoofers is they require a lot less power to get into their operating range and uh in today's age uh Power is cheap so that's not really a huge thing but it is something to consider because they can also handle less power you're not going to be um this is where the the debate starts okay uh your IB guys will say yes the infinite baffle can get just as loud as a sealed enclosure or a ported enclosure which and and then the other side of the fence they'll say well no your sub will lose control and blah blah blah and there's points to be made made from both sides both sides are inherently correct uh an infinite baffle subwoofer does have to be controlled at the lower end because it will just keep trying to play that low note and lower and lower and lower until it literally tears itself out of the basket uh so you have to use a subsonic filter to stop it from trying to reproduce 10 Hertz at you know 130 DB because it's going to try to do that uh infinite baffle subwoofers tend to fail mechanically rather than electrically because there's not a lot of power going in them but there's a whole lot of movement happening um now having covered that that's the nuts and bolts of the whole operation an infinite baffle situation is whenever you have a subwoofer essentially in a cabinet that's far too large for the subwoofer so all you're doing is blocking the front front wave from getting to the back wave because if you don't block those waves they cancel each other out so as that front wave moves forward is that sub is doing this right as that front wave moves forward that wave of air is going to go around behind the sub and fill in that vacuum as it's moving forward so here's your sub moving forward here's the wave going to the back here's it moving back and here's the wave going to the front it's just going to to keep this the the air is going to keep going to where the vacuum is and that's why a sub without any box doesn't make a whole lot of base now if you add a barrier around that sub those sound waves have a lot further to go to to where they can get to that vacuum and that's what a baffle does the front of the subwoofer box now making a baffle that's infinite means you just go out you just go out in an infinite distance and the sound waves can never get to the back and it sounds awesome well we know building an infinite box is going to cost a lot because Birch is expensive these days so we can't do that now what you can do is wrap the listening area in the baffle so essentially putting yourself inside of the subbox and you can make the whole world be your subbox does that make sense inside and then everything outside and then you're where it's awesome yeah I like that idea too give me a subbox to live in any day I'm good with that so in a car situation that could mean multiple things there's what they call a true infinite baffle then there's what they call a simulated infinite baffle and these are words that people have just kind of made up for this because they both mean more or less the same thing a true infinite baffle is whenever you're playing your sub into the outside world so say you cut a hole in the roof of your car and you mounted a sub in that now the outside world is your subbox your sub is playing in that is an infinite baffle it would be horrible idea but it is an infite baffle a more common approach to that situation is cutting a hole in the bottom of the trunk and building some sort of apparatus back there to allow the subs to play out into the open world but still be inside the car uh they use something U called a manifold sometimes where they build like a like a triangular shaped thing like this and mount the sub here and a sub here and in the bottom down where my Palms are this is open to the world so you create this little pyramid a little uh well more like a a tent shape in your trunk and you mount a sub on both sides and cut the hole out in the middle which allows the air to get out but also kind of helps to keep the subs from getting in the weather this is a true infinite baffle that's where a manifold sometimes they just mount it straight to a plate and let it fire magnet up and then let it fire down at the ground and there's just a hole and if you got into the car and looked up you'd see the con of a subwoofer there's lots of different options but ultimately it has to play to the outside and the outside has to be sealed off from the inside well here's one of the Cav caveats come in remember I said the outside has to be sealed off from the inside keep that in mind now you look at a cabin of a vehicle what do you have you have a leaky box okay so when you've got your sound set up the way you want it and you roll the window down it's going to change it may change in ways that you like it or it may change in ways that you don't like it but it's going to change because you're now opening that enclosure and you're allowing those sound waves from back there under the trunk to work their way around the vehicle and come in the window is it far enough away from the uh back of the sub to stop to resist the the cancellation probably but it is it will show up on a meter if you've got a if you're taking a reading of the sound inside the vehicle whenever you roll the window down it's going to change uh and um because it has to you know it depends on how low the note is the lower the note is the the further it goes you know so and then the outside trying to pressurize the outside air enough to where it comes in you know think about what you're doing here you're putting enough air you're moving air from from underneath the vehicle and violently moving it away from that spot and it has to pressurize the air around the car enough to where the air around the car forces air to come into the car you may think that's ridiculous but it happens and it's measurable and it's consistent it definitely happens um so that's the way You' app plot a car that's that's the true infinite baffle then there's what they call a trunk baffle or a simulated baffle and that's where like for example uh your whoers are in the back uh dash of your car playing into the trunk the trunk is obviously way too large and and leaky for a box but it technically does provide some acoustic resistance not a lot but it does in this case you're separating the cab from the trunk the trunk being the non-listening area and the cab being the listening area and the wall where the seat and the dash meet that is your outside wall so your infinite baffle is what that is you're still pressurizing the cabin the same way you would in the original but in this case you're actually playing the sub into another area a chamber versus outside and that's where uh again more of the purists are like oh no that's that's not really an infinite baffle that's a trunk baffle or something you know they they they go down this horty torty hole and start you know quoting Shakespeare and so then you've got that scenario and of course in a home you would uh usually mount it on a large panel I've seen them on just large large panels with open baffles where you have essentially a big piece of plywood with a woler mounted in it and you the plywood provides enough of a baffle to stop most and then you got the ones where they mount it in the wall of the room and they let the backside play into another room or or they mount it in the ceiling or the floor let it play into the basement or the attic any way it goes infinite baffle is always a lot more trouble to do than a sealed or ported enclosure of any kind but let's say you want to embrace the infinite baffleless of a situation and you want to put that to work so how do you go about to that so the question first would be is can any sub play in an infinite battle the answer is yes any speaker at all can play in an infinite battle um should any sub play that's a whole another ball game you see okay first of all uh subwoofers in general pretty much all speakers are designed to have uh a QTC of 7 to be in their best spot a QTC is the subwoofer or speakers and the enclosure it's in whatever that enclosure is whatever baffle it's in the combination of all the elements once it's in a system meaning it's in a box or in a wall or in a baffle the QTC is the accumulated uh measurement of how willing that speaker is to move okay that's the best way to explain it I'm trying to keep this in as much of a basic understandable simple format how hard is it to move the speaker when it's mounted in the enclosure and everything that's a QTC the qts if you take away everything else in just the driver itself how willing is it to move by itself okay think about it as a as a shocks on a car the shocks and springs coilovers yeah we're going to call it that coilovers so drivers with a lower than around A7 qts okay drivers with lower than a 7 qts uh tend to ride like a Cadillac as long as you're going along a nice smooth Road everything's fine it's super cushy and super comfortable and perfect but you try to go take the Twisted with it and you'll find your suspension gets completely bottomed out twisted up and the thing goes all caddy Wampus all of a sudden anything lower than 7 is softt soft cushy and floppy and sloppy okay but if you take that a driver that's a qts of say 5.5 or five z uh 0.5 and you put it in an enclosure that that raises the the QTC 2.7 now you're back in the happy spot again the enclosure will always raise the QTC will always be higher than a qts whatever the qts is the enclosure has to make up for that to get it back up to around a 7 or higher uh a sports car would be like a 1.0 it rides like crap but it'll it'll handle like a dream that's a sports car point or 1.0 that's way up there again it's it's kind of the opposite problem see the S is your happy place you want to get your QTC in the end to 7 uh whenever you're playing infinite baffle you don't really have any control in a situation there's no enclosure to add to the qts to get that QTC to 7 so you're looking for drivers that have a natural qts of around 78.9 7 these are all pretty good 7 is where you really want to be right in that area actually it's 77 to be honest or 707 is the magic spot but we're not going to we're not going to pick it apart if you find a driver that's got like a 65 qts it's going to play lows a little bit more it's also probably going to start getting into mechanical clipping at low frequencies because it just has no control over itself without a box to help it if you find a driver that's like a 7 uh n or A8 it's going to handle everything fine but it's not going to be able to give you the low low extension that you're looking for in the perfect world those super deep you know 10 htz 15 htz lows that are subsonic way down there um the the sweet spots 7 so you want to be 7 somewhere between 7 and 08 in that range is going to give you what you're looking for in a car in an IB setup so you have to find the driver with that a qts of you know between 7 and 08 somewhere in there um and there's not a lot of them they exist but there's not a whole lot of them um so of course you can go higher than that you're just going to the higher you go up above 7 however how that is the less you're going to be able to reproduce that 15 htz and 20 HZ and 25 Hertz that's going to slowly the higher that qts goes past seven the further up those very lowest notes are going to go and the scale of that I couldn't tell you it's it's uh it's going to vary from driver to driver and just know that you want to be around 7 to 08 uh the next thing you're going to want to look at if you find multiple drivers that are point 7 okay this is a 7 it's 15 in this is a 7 it's 15 in so which is the best you know you're starting to pick now uh what you're going to look for then is drivers that have drivers that have larger vas numbers what's important is bigger number vas is better so if you find a driver that you like bunch of drivers you like the prices are all good and you're trying to weed out the best of the best the higher vas number is going to be better for infinite baffle um and the VAS is a combination of comparing the driver's stiffness to the amount of airspace it's to amount of cone area cone area stiffness equation and again it's not important just know that bigger is better when it comes to infinite baffle or large enclosure so most of your drivers designed to go in cars I'm not talking about Subs here I'm talking about mid-base and mid-range door speakers Co axles components most of the drivers designed to go in cars have a qts which is the speaker alone's a qts of around 7 because almost all the locations that car audio drivers are going to go are infinite baffle you think about it the rear deck of a car the doors there's no box there it's just a a baffle that's big and with holes all in it so most car audio drivers are have a qts of7 most subwoofers do not because they are anticipated that they'll be going into a sealed or ported enclosure so ultimately if you're looking for an infinite baffle setup you're going to want a nice rigid mounting surface you're going to want a subwoofer with a Q factor of 7 or higher uh you know what the trade-offs are for going higher than that uh and you know what the trade-offs are for going lower than that and what you'd have to do to make that work um and you're going to want an environment where you can more or less keep the backside of that baffle away from the listening area uh because that's going to give you Optimum situation and beyond that adventurous attitude willingness to make a hole in something because it doesn't matter where you're going to put the infinite BFF you're going to make a hole in something that surrounds you that's just the nature of the Beast and I'm studying on whether I'm going to do something like this in my Tahoe I just Rebel in the fact that I know that lots of people have made big holes and very expensive cars over the years and they are beautiful so it's just a it's that first cut cut man it's like getting your first tattoo you're like oh man you know you got to jump off the bridge and just go for it so now you guys know a little more about subwoofers and couple of the pieces that you can look for to decide what applications you're good at because stuff that makes an infinite baffle sub good also make a sealed enclosure sound better a big one you just want to get that Q factor that QTC the total Q up to around 7 you know it's going to be in the Honey Spot if you want to play hard and fast you want to get it a little higher than that if you want to play low and sexy you might want to keep it around 7 or maybe just a little below that but hopefully I've given you guys some new knowledge and uh not overwhelmed your brain with too many specifications because I hate mathing and I'm not going to get into it I'm more of a concept guy not so much of an analytic guy hopefully this was helpful guys if it was please hit this button right here because I need subscribers and you guys are doing awesome by the way please throw some comments down in there because that helps my my YouTube Al algorithm gives me more viewers more people watch my stuff and I just started doing this full-time as my job because of some medical reasons and I need to action thanks guys peace

Channel: Car Audio Enthusiasts

Views: 9,407

Keywords: km_20231027_1080p_30f_20231027_085144

Id: s_5JdqVv0Cw

Length: 21min 26sec (1286 seconds)

Published: Fri Oct 27 2023