Hi all. I'm trying to finalize the design for my new mixing room and have decided to flush mount my speakers (NS1000's, Genelec 1029A's and a mono NS10), and have a question about the baffle. After some research, many people suggest making the baffle as rigid and massive as possible, but some (including a mastering engineer with 40+ years of experience) & this post (https://www.gearslutz.com/board/studio- ... ectly.html), have a completely soft baffle (just 703 with cloth on top) with a bit of diffusion. According to the mastering engineer, through his experience, near fields especially benefit from the 'soft-soffit' approach. Anyone else have any comments? I'm thinking about just lightly framing my soffit wall, stuffing it completely with regular old pink stuff (apparently really good for low end absorption if uncompressed), covering it with a nice fabric and putting some diffusive slats in front, then drinking a beer and listening to a vinyl. Does this seem like a bad idea? Here's a screenshot of my digital model. (Room dimens are 15' wide, 19' long, 10' tall).
Hard vs. Soft Soffit Design
Originally posted at johnlsayers.com, topic 19672.
As boggy mentioned in that thread on Gearslutz, that's two totally different things. One is a true soffit mount, the other is just a speaker stuck into a superchunk trap. And also as Boggy said, if that's the case then why bother? It would be much better to forget about trying to fit the speakers into the "soft" bass trap, and rather just mount them conventionally, free-standing out in the room. The issue is this: With a true soffit mount, the speaker is technically no longer in the room at all. Therefore, all (or most) of the artifacts caused by having a speaker in the room are totally eliminated. SBIR, edge diffraction, power imbalance, comb filtering and several other issues just aren't there any more, because they are due to the speaker being inside the room, located near to walls. Remove the speaker from the room by mounting it flush with the walls, and they go away. Soffit mounting is more correctly called "flush mounting" for this reason. But if you just put the speaker in the corner of the room and surround it with a bunch of porous absorption (insulation), then you have not removed the speaker from the room! It is still there, and still suffering from the same artifacts as any other "speaker in a room". In other words, there is no such thing as a "soft soffit". It's a contradiction in terms If the front baffle is not hard, solid, massive and rigid then it cannot remove the speaker from the room, so it isn't a soffit. It's just a porous absorber, that happens to have a speaker mounted in it. Yes, that insulation does serve a useful purpose to some extent, but as was also noted on that thread in another comment, you'd need to make the absorption about a meter thick (over three feet thick!) to get a good effect from it. And if you have three feet to spare at the front of your room, then it would be better to NOT do that entire process, and just put the speakers on stands, three feet away from the wall. One of the big things that the soffit does, is to correct the power balance. With any speaker, the high frequencies are projected forward sort of like light rays, in a roughly cone shaped pattern, while the low frequencies are propagated more like a sphere expanding out around the speaker in all directions. So if you have (for example) eight watts of power going to your speaker, with four hitting the tweeter and four hitting the woofer, then all four of the tweeter watts are turned into energy that goes forward into the room, while the four woofer watts are turned into sound energy that radiates around the speaker in all directions, with only half of it going forwards into the room. The other half wraps around the sides of the speaker and ends up at the back, where it hits the front wall of the room and is reflected back again, interacting with itself and causing SBIR, comb filtering, and other forms of phase cancellation. In other words, only half of the power fed to the woofer goes into the room. The other half is lost. This is known as "power imbalance". So for this speaker, youd need to send 8 watts to the woofer, not just four, to account for losing half of the energy in the other direction. (To the speaker purists: Yeah I know! Such a speaker crossover would never work, and would sound terrible if it did, but I'm just using simple numbers to illustrate the point, so please don't beat me up for using invalid numbers!) So in effect, your woofer needs to have twice as much power fed to it so that the sound level coming out of it towards the room matches the level of the tweeter. The circuitry to do that is built into the speaker, which introduces another set of problems. The point where the behavior of the sound cross over from "cone" to "sphere" is determined by the dimensions of the speaker cabinet: the smaller the box, the higher the frequency. Actually, the point is set mostly by the shortest dimension of the front panel of the speaker, technically called the "baffle", and for this reason the entire issue is called "baffle step response", because there is a noticeable 6 dB "step" in the graphs for the sound energy emitted by the speaker plotted against frequency, and the middle of that "step" is set by the width of the speaker baffle. More technically, the tweeter emits sound into half-space, and the woofer emits sound into full-space. If you put the speaker into a soffit then what you are basically doing is making the baffle much larger, so you force the baffle step response way down the spectrum, hopefully below the lower cut-off for the speaker, where it doesn't matter any more. But to accomplish that, the baffle obviously must be hard, rigid, solid, massive surface that "forces" the sound to all go forwards, and prevents any of it from wrapping around the sides and back of the speaker. Insulation batts fall hopelessly short of being able to do that! They cannot prevent the low frequency sound from wrapping around and still hitting the front wall, so they do not solve the power imbalance, or the baffle step response issue, and neither do they have much effect on edge diffraction or SBIR.After some research, many people suggest making the baffle as rigid and massive as possible, but some ... have a completely soft baffle (just 703 with cloth on top) with a bit of diffusion.
:) :!: It's not a "bad" idea per se, but it wont accomplish what a soffit would. In other words, it won't make your room as good as it can possibly be, by removing the speakers from the room. The issue with soffit mounting in my (limited) experience is that some engineers don't like it because they are not used to hearing pure, clean, unadulterated sound coming from their speakers! All of their lives they have heard those nasty artifacts from having speakers in the room, so the first time they hear a properly soffit mounted speaker in a well treated room, they miss the dirty imperfections.. it doesn't sound right, because the artifacts that they have always heard just aren't there, so something seems to be missing from the sound. But give them time, let them get used to the pristine sound, and it starts making sense. Their mixes translate better and more cleanly, since they are no longer subconsciously dialing in unneeded EQ, and after working like that for a while, the "get it" and don't want to go back. Imagine that all your life the only meat you ever had to eat was McDonalds burgers: the first time you tried prime beef fillet steak, you'd say that it tasted "wrong", simply because you didn't know better. But after eating a few steaks, you'd never really want to go back to burgers! :) So that's the issue here: if you are happy with your room sounding like "hamburger", then by all means, stick the speakers in the corner and wrap them in pink fluffy. But if you want it to sound like prime beef steak, then soffit-mounting is the way to go. IMHO, of course... :) At least, my clients who have built the soffits I designed for them seem to prefer steak to hamburger! And forum members who have gone the soffit-mount route and done it right, have nothing but good things to say about the outcome. Below is a link to a forum member's studio build that was just finished today (Bigsby), where soffit mounting was done exactly right and turned out incredible. As he says, with the soffits completed he started hearing things in recordings that he had never heard before, because they were no longer being masked by the artifacts that non-soffit mounted speakers create. viewtopic.php?f=2&t=15430 An interesting read! On the other hand, I can't think of a single thread where someone did a "speaker stuffed in a superchunk" room, and then waxed eloquent about how well it turned out... - Stuart -Does this seem like a bad idea?
Stuart, thank you kindly for the detailed response. I hope some other people benefit from this thread in the future as a clarification of the issue.
So, first off, I'm sold on the 'true baffle' (even though I'm a vegetarian). The only thing that still confuses me is how soffit mounted speakers interact/change room acoustics when there are also nearfields (or multiple pairs of nearfields) involved.
Let me clarify. Our studio has numerous pairs of speakers so that we can check translation. The list includes NS1000's, NS10's, HS80's and Genelec 1029A's (with a separate sub). My original plan was to soffit mount the NS1000's, sell the HS80's, and put a mono NS10 and the pair of Genelecs on rigid stands so that they could be used in the 'near' field.
Here lies my conundrum...if I've just put up a large rigid surface to mount my NS1000's, then all of the back and side speaker output from my near fields is going to have to deal with a rigid, non-diffuse surface. I've seen in some of John's designs that he uses 2" rock wool on the bottom half of the soffit baffle (backed with a rigid surface and covered with cloth), and other designs where the bottom half is a bass trap with hangers. I've also seen designs where nearfields are mounted lower in the soffit baffle, with the midfields mounted higher up pointing down. Is there a preferred method for multiple speakers?
Great! Glad I convinced you to go for a "real" soffit (high-fat, high-protein, and non-vegetarian! :) ).
OK, about the multiple-monitors thing.
It mostly depends on how you use all those monitors normally. For most places, the top notch mains are for mixing and critical listening, while the lower quality "near-fields" are for checking how the mix will sound on typical consumer monitors that are typically badly placed (eg, on the meter bridge... :ahh: ), or perhaps for getting another perspective on the mix.
If that's how you use yours, then the idea is to mount your very best monitors in the soffit, and perhaps one other pair if you can fit them in usably (more on that later), then put something like NS10s on stands for the "consumer" testing. Since the mains are the critical guys here, those are the ones that have to be mounted best, in the optimum location, etc. And since the near-fields aren't really used for critical listening, they can be mounted in non-optimum locations, outside of the path of the mains where they won't get in the way of the direct sound from mains to ears, preferably on stand located further apart than the mains, and angled more steeply.
With this scenario, yes the low quality near-fields will still be suffering from all of the "speaker in a room" artifacts... but that's actually what you want! Since their purpose is to give you an idea of what the mix sounds like on typical consumer speakers in typical consumer environment, it makes sense that they suffer the same way as a consumer setup would. Most consumers don't soffit-mount their speakers! The reason why you want the mains mounted in soffits is so you can hear the absolute total pure unadulterated truth of your mix, exactly as it is, so you can be certain it will translate well to all other systems and locations. The "NS10s on a stand" are there to tell you how it will sound in a typical "other" location, just to confirm that your mix is translating well, and also in case you want to tweak something to sound better on that setup. I always check my mixes on a cheap smartphone with ear-buds and in my car too, to make certain the mix works for those locations as well. Since ear-buds are so lousy on the low end, and cars are so small inside, checking on those three gives you confirmation that your mix will work pretty much anywhere.
Some folks wonder why studios bother going to all the trouble of having amazing speakers perfectly mounted in an absolutely neutral room, when consumers never, ever listen like that, and I'm sure you already know the reasons, but I'll repeat some of them here for others who might be reading your thread and wondering the same thing. Why not just mix using ear-buds? Or mix in a car? Or mix in a typical living room? That's the question
The answer is simply that each of those other scenarios masks, colors, and disguises the true sound in some way, so mixes done like that will never translate well. You could indeed mix on ear-buds if your mix will only ever be listened to on ear-buds, but if you then play it in your car it will sound terrible, because your car system will reveal things that the ear-buds never did. Ditto if you mixed it in your car: it will sound wonderful in your car, and probably most other cars too, but then when you play it in your living room, or a club, or a church, or wherever, it will sound terrible since a typical car system does not reveal things in the mix that those other systems do. With top quality reference monitors correctly soffit-mounted in properly treated control room, you hear everything. Nothing is masked, colored, distorted, disguised or hidden. It is all there, clear as a bell, and all perfectly balanced. So if your mix sounds good there, then it will automatically sound good on ALL those other systems: it "translates". That's why it is so important to get the control room as neutral as possible, so that it does not add anything false to the sound, nor take anything away: the engineer needs to hear the truth, the whole ugly truth, and nothing but the whole ugly truth.
There might well be reasons to do some minor tweaking afterwards if it is known that the mix will primarily be heard in a particular scenario (eg dance club, large church hall, car radio, etc) to enhance it for that specific use, but if it already sounded great on the mains in a good control room, then it would have sounded good on that system anyway! It's just an extra tweak being added for that specific system, which gets back to the original point: the reason why studios also have other sets of speakers that are of much lower quality than the mains, and not mounted optimally either.
So that's my long rambling rant about typical studio speaker setups! :)
Conclusion: Put the very best speakers you have (or ever plan to buy) in the soffits, then put the others in places that won't damage how the mains sound, even if it means that the secondary speakers will be in lousy locations... because that's the entire point of those anyway!
For some people, that actually means soffit-mounting a pair of good quality near-fields, and that actually works very well. Several of my clients have done that, with Adam A7s and A8s, for example, as well as Genelecs, Focals, and others. Small near-fields correctly soffit mounted can sound really big. Unexpectedly big, and very usable as mains. There are many examples here on the forum of members who have done that in their rooms, with very good results. In fact, I'd go so far as to say that soffit-mounted near-fields can outperform much larger, more expensive speakers that are not soffit mounted.
Now, that said: if you do want to mount a second set in the same soffits, it can be done. It isn't easy, and the second set obviously cannot also be placed optimally (there's only one perfect spot in a soffit), but even then it can greatly improve the sound of those speakers. I have seen that done where the second set is aimed at the client couch at the rear of the room, so the client can get to hear the mix almost as cleanly as the engineer does (obviously not at the same time! Only one set is used at a time.)
And for those speakers that are on stands in front of the hard, rigid, soffit surfaces: It's no ideal, but if the room is designed well (Eg. full RFZ), big enough, and the speakers positioned well, then the issues can be minimized. The reason John uses absorption on the lower portion of the soffit is more related to reflections coming off the back of the desk and console, not so much to do with secondary speakers, but it will help, of course.
Overall, its a matter of taking all of that into account in the room design, to make sure that each set of speakers can be set up so that it does what it is supposed to do as well as possible. That takes some doing, sometimes! :)
- Stuart -
I forgot to answer the other point: Yes it is possible to raise speakers up and tilt them down, but that introduces other issues. You can only tilt them an absolute maximum of about 10°, and preferably no more than 7°. Beyond that, you start creating psycho-acosutical issues, since your ears don't do so well for sound coming in from high angles above your head, and also the higher you place them, the more reflections you get off the console and/or desk, and at worse angles. Personally, I have never tilted speakers down more than 4.5°, and that was in a fairly big room where there was a good distance to the console.
If you do want to mount a second set, it's better to put them outboard of the first set in a separate soffit section that is angled more steeply inwards (toed-in at a higher angle, such as 40° instead of 30°). But that has to be done carefully too, so that it doesn't mess with the reflections from the main speakers...
Like all things in studio design, it's all about juggling a whole bunch of compromises to get the best fit that doesn't damage any one thing too greatly...
John normally does both, actually! :) The hangers go inside the lower section of the soffit (under the speaker shelf), and there's a solid extension of the soffit baffle just in front of the hangers, but set back a couple of inches from the main part of the baffle, with the absorption in there. So its sort of a "box" in front of the baffles that holds the absorption, with a large gap right at the bottom to connect the room to the hangers, acoustically (it acts like an acoustic coupler, actually). - Stuart -I've seen in some of John's designs that he uses 2" rock wool on the bottom half of the soffit baffle (backed with a rigid surface and covered with cloth), and other designs where the bottom half is a bass trap with hangers.