Huge Double Garage Production/Mixing Room - HELP!!!

[syotheproducer]

Hello everyone,

This is my first post on John's forum, so please be understanding!

I've been into music and production for almost 12 years and have started studying more acoustics in the last couple of years, although I'm no pro in studio building..
I've read through many fantastic threads on this forum over the years (amongst others like the John Sayers one for example!!!) and have been so fascinated by other people's studios and designs, which eventually led me to this point.

A friend of mine (whom I work with) has this huge, double garage in which we'd like to build our production/mixing room.
We mainly focus on vocal recordings and music production, with the occasional recordings of acoustic drums or amps etc.

The room will of course be used for mixing as well but because of budget, we are unable to build a full-out, critical listening environment. The point of this room is for us to produce in a common area which has decent enough listening capabilities and to basically get out of our tiny, tinny bedrooms.

The room needs to be decent enough for good vocal recordings, but without creating extra small booths and whatnot. I just prefer the sound of "bigger", well-treated rooms for vocals (or any other instrument for that matter hittt ).

Noise coming from outside or leaving the room is absolutely not an issue as the garage is situated in a private area far away from neighbouring houses, roads etc - very quiet!

The size of the room is 640cm (length) x 500cm (width) x 240cm (height). I know, very low, garage ceilings.. I also understand that it isn't an ideal room ratio, but I guess it is what it is.. :amaze:

The speakers are actually shooting down the longer side of the room, as I understand that for the size of this room it is the best way to set up the listening position.
Production-wise I would've preferred to have it shoot down the shorter side as I could've utilised the space better to set up perhaps a drum kit or percussion, synths, or for vocal recording etc - I'm open to suggestions though!

The entrance to the garage is situated on the longer side of the room, which means that it has this massive sliding door on said side. In the middle of this sliding door there is another door that opens independently from the sliding door (depicted as the small opening on the right-hand side). Basically, the large sliding door is always closed and we use the small one to enter the room. The big sliding door can't be closed up in case it needs to be re-opened..

The Sketchup mock-up was made with solid concrete walls all around, but on the right side there is actually the vertical sliding door with its independent door. We are unable to build a wall or whatnot over this sliding door, but my thought was to treat it with absorbers as for the other walls.

One of the biggest questions I have is this:

Am I going to consider the garage door (made of very thin metal and plastic/rubber pieces) as an actual wall or is stuff (lower frq) just going to pass through and not reflect back into the room as much? I mean, it is going to respond differently to the opposite concrete wall resulting in having asymmetry in my stereo imaging, thus making it more sensible to place the listening position the other way around to have symmetry in consistency between the two concrete walls?

The panels I thought of using are made of two 5cm-deep rockwool panels (70/80kg of density for each rockwool panel) stacked to create a depth of 10cm, spaced 10cm from the wall (the white and dark-grey ones). The size of the panels are 120cm x 60cm as this is the only size I found around where I live. I also plan on having corner bass traps made with the same concept but applied horizontally instead of vertically. All will be framed using wood and drilling holes in the sides to have better air flow.

I had problems designing the cloud in Sketchup but I'm going to use the same principal as used in the wall absorbers, meaning 10cm-deep traps spaced 10cm from the ceiling at reflection points.

Although I'm going to test and see what is the best position for listening, I took as a reference the 38% rule from the front wall and creating an equilateral triangle to the speakers. I'd also like to know if the 38% rule applies to the floor to ceiling height, meaning setting the speaker's tweeter at the 38% point in the vertical axis (I think I read something about it at some point, but don't remember where..cooge). Also, I gather that if the size of the room isn't too big and I'm not soffit-mounting my speakers, it is best to have them as close to the front wall as possible and trapping as much as possible both behind the speakers and around the room for phase cancellation, correct?

For the first-reflection points on the side walls, I thought of turning two of the vertical panels horizontally to have a larger listening sweet-spot - makes sense?
(In the mock-up, one is white and one is dark grey).

Although not depicted (or at least not in every corner), I'm planning on applying broadband absorbers to every corner I can, as the bottom wall-to-ceiling corners show.

I'm going to add absorption along the whole back wall (not shown in the mock-up). In general, do all panels necessarily need to be 10cm (or more) thick?
Is it best to have fewer thicker panels in strategic places or a larger number of thinner panels placed in more areas around the room?

I think I understand the placement of the immediate reflection points, but what about the rest of the room? What would be the best spots to place extra panels on the parallel walls?

The flooring will be laminate parquet with a fairly decent, thick rug at the listening position.

The speakers I plan to use are 8-inch Yamaha HS80 monitors, and planning to add a sub in the future.

I do not own any measuring equipment as of now, but I'm going to have think about investing in some at some point.

I'll post actual pictures of the space once the garage is all cleared!!!

Anxiously awaiting any response!!!

[Soundman2020]

Hi there " syotheproducer". Please read the forum rules for posting (click here). You seem to be missing something iimportant!

The room will of course be used for mixing as well but because of budget, we are unable to build a full-out, critical listening environment.

Why not? You have the space for it...

The room needs to be decent enough for good vocal recordings, but without creating extra small booths and whatnot. I just prefer the sound of "bigger", well-treated rooms for vocals

So you basically want a single-room studio? CR and LR in one? Many forum members do that.

Noise coming from outside or leaving the room is absolutely not an issue as the garage is situated in a private area far away from neighbouring houses, roads etc - very quiet

It never rains where you live? No wind, hail, thunder or other sounds of nature? No aircraft flying over? Nobody else around outside while you are recording? No phones ringing, people talking, dogs, birds, etc?

The size of the room is 640cm (length) x 500cm (width) x 240cm (height). I also understand that it isn't an ideal room ratio,

Correct: the section is nearly square, meaning that you will have modal issues where the modes in the 1,0,0 direction will line up with the modes in the 0,1,0 direction almost perfectly. Not a good situation.

The speakers are actually shooting down the longer side of the room, as I understand that for the size of this room it is the best way to set up the listening position.

Correct.

The Sketchup mock-up was made with solid concrete walls all around, but on the right side there is actually the vertical sliding door with its independent door. We are unable to build a wall or whatnot over this sliding door, but my thought was to treat it with absorbers as for the other walls.

Treatment isn't isolation, and nor is isolation treatment. Those panels can help to improve room acoustics to a certain extent, but they won't do anything for room isolation, nor can they fix the problems inherent to a thn metallic plate.

Am I going to consider the garage door (made of very thin metal and plastic/rubber pieces) as an actual wall or is stuff (lower frq) just going to pass through and not reflect back into the room as much?

Both! It IS a wall, since it does have some mass to it, and it is a large, flat reflective surface, so it will certainly reflect back a large portion of the spectrum. It is also a resonant panel, so it will resonate at several different frequencies, implying that it could either absorb or re-radiate those frequencies back into the room, so it will have an effect on overall acoustics, and will skew the stereo image somewhat. The question is: how much of an effect will that be? That question is really hard to answer, without knowing all the characteristics of the door and of the rest of the room.

I mean, it is going to respond differently to the opposite concrete wall resulting in having asymmetry in my stereo imaging,

Correct. But the same question as above applies... The intensity of the effect, and the frequencies of the effect, are unknown.

thus making it more sensible to place the listening position the other way around to have symmetry in consistency between the two concrete walls?

That is a possibility, yes. Your room is borderline big enough to be able to get away with that, perhaps.

The panels I thought of using are made of two 5cm-deep rockwool panels (70/80kg of density for each rockwool panel) stacked to create a depth of 10cm

That's a bit too dense for bass traps. You'd need to go lighter than that. The normal density for mineral wool in acoustic cavity damping is 50 kg/m3, and even that is a bit heavy for serious bass trapping. See if you can get something a bit lighter than that. 80 kg/m3 would be OK for panels that only need to treat mids and highs, but it's too dense to get down to the lows.

... two 5cm-deep rockwool panels ... a depth of 10cm, spaced 10cm from the wall

If you do all your panels exactly the same, then they are all tuned to the same frequencies, so they will all be doing the same thing. It is better to have a few different types of panels, each tuned to do the job it needs to do, and placed in the correct location to do it.

The size of the panels are 120cm x 60cm as this is the only size I found around where I live.

The size of the batts has no bearing on the size of the panels: you can make the panels as big as you need. The actual panel can be any size, wider or narrower than a single batt, and taller or shorter than a single batt, as needed for each specific location. Once again, if they are all the same size and all placed at the same height, then they are all treating the same frequency range: so you'll have one range that is heavily over-treated, while other ranges are not treated at all.

All will be framed using wood and drilling holes in the sides to have better air flow.

The holes are not there for air flow: there wont actually be any air flowing though your panels. The holes are there to increase the total area of porous absorber that is exposed to the room, and they also provide some diffusion. But no air flow.

I had problems designing the cloud in Sketchup but I'm going to use the same principal as used in the wall absorbers, meaning 10cm-deep traps spaced 10cm from the ceiling at reflection points.

It is normally better to angle the cloud, and making it hard-backed can also help in other ways, such as breaking up modes, to a certain extent. Also, the cloud you show in your model is waaay to small. It needs to be MUCH bigger than that.

I took as a reference the 38% rule from the front wall and creating an equilateral triangle to the speakers.

OK, as long as you understand that 38% is not really a rule: just a starting point. Also, it's not clear on your model if you have the apex of the triangle in the middle of your head, or at a point some distance behind your head?

I'd also like to know if the 38% rule applies to the floor to ceiling height, meaning setting the speaker's tweeter at the 38% point in the vertical axis

38% is the theoretical distance for minimum modal effects, and it applies in all 3 dimensions. However, for the width of the room, you do have to be on the centerline to get symmetry, so it does not apply there. For the vertical axis, it can apply if the ceiling is high enough: since normal ear height is 1.2m, your ceiling will need to be about 3.2 m high to achieve that. If you can't raise your ceiling high enough to do that, then you are stuck with having your ears at the 50% position vertically too, which implies that you need major treatment on the ceiling, and that angled, hard-backed cloud is now very, very important.

Also, I gather that if the size of the room isn't too big and I'm not soffit-mounting my speakers, it is best to have them as close to the front wall as possible and trapping as much as possible both behind the speakers and around the room for phase cancellation, correct?

Correct for the location up against the front wall, correct for the front wall treatment, and also correct for the bass trapping, but not for treatment spreading around the room. SBIR is normally associated directly with the front and rear walls, not so much with the side walls or ceiling.

For the first-reflection points on the side walls, I thought of turning two of the vertical panels horizontally to have a larger listening sweet-spot - makes sense?

Actually, no. First reflection point treatment does not define your sweet spot. The sweet spot is defined by the speakers themselves, and by the room geometry. The purpose of the treatment on your first reflection points is to attenuate mid and high frequency reflections, so that they only get to your ears at a much lower level. But they don't change your sweet spot.

Although not depicted (or at least not in every corner), I'm planning on applying broadband absorbers to every corner I can, as the bottom wall-to-ceiling corners show.

Broadband absorption doesn't make much sense in corners: broadband absorption should go where needed on the walls, particularly the rear wall: Corners need bass trapping, not broadband.

I'm going to add absorption along the whole back wall (not shown in the mock-up). In general, do all panels necessarily need to be 10cm (or more) thick?

For the rear wall, I prefer to go with 15cm if you can afford to do that (available space, aesthetics, money), in addition to the superchunk bass traps in the rear vertical corners. You can also make the treatment thicker in some places.

Is it best to have fewer thicker panels in strategic places or a larger number of thinner panels placed in more areas around the room?

That depends on the room response after you get the basic treatment in place, and do your first analysis.

I think I understand the placement of the immediate reflection points, but what about the rest of the room? What would be the best spots to place extra panels on the parallel walls?

See above: after you do your first REW test, you'll have a better idea about that.

The speakers I plan to use are 8-inch Yamaha HS80 monitors, and planning to add a sub in the future.

That should work fine.

I do not own any measuring equipment as of now, but I'm going to have think about investing in some at some point.

All you need is a reasonably good acoustic measurement mic, which should cost around US$ 100, and a reasonably good quality sound level meter, which will also cost about US$ 100. The rest you already have.



- Stuart -

[syotheproducer]

Hey Soundman!

First off, thank you so much for the knowledge - it's humbling and very much appreciated!

I've read through the forum rules and think I got things right - right? Please tell me if I'm still missing something!
I'm going to go through the FAQ later tonight.

Ok so:

1) I will eventually try and slowly build a critical listening space, building more treatment as I go along, but yeah I'd definitely want that in a few months!! The approx budget of between 1000€ and 2000€ won't allow it as of now because of all the work that needs to be done (flooring, security etc).

2) Correct. Single-room for sure! Mainly for workflow, but also because of cost and the reduction of space that two separate rooms would create..

3) Hahaha it most certainly does rain and thunder where I live, it's just not an issue for me and to be honest, I've recorded other times in there and it wasn't really a problem. The garage is pretty much a 50/60cm-thick concrete bunker, stuck halfway into a hill and on a private road where there's only my friend's house (in the middle of pretty much, nowhere..). As I mentioned earlier, very quiet indeed. lol

4) Any idea of how (and if) it would be possible to correct it without building solid, angled walls? Does it make sense to build say extremely thick (but removable) front bass-traps at 30 degrees to act as "walls"? I might actually be talking out of my a**.. hahaa

5) Absolutely agreed that treatment isn't isolation!!! In fact I meant, since the garage door is on one side and concrete on the other, and since I can't build an inner wall on the garage door side, I thought of only treating it with lots of absorption. It was more of a descriptive statement than else.. hahaha Would it make send to put the absorption flat against the garage door in order to dampen a little bit its resonances?

6) Ok, so because of the different mass between the two side "walls", will modes be more difficult to calculate?

7) Ok, great! Any idea on what would be a good way of testing the intensity of the effect that the garage door (asymmetry between concrete and garage door) has on the stereo image, more than say just listening to the bare room? I wouldn't want to build the whole room just to find myself that the asymmetry is unbearable..

So assuming I fill the back wall (garage door) with ridiculous amounts of bass trapping, I could think of orientating the listening position horizontally? In that scenario and considering that because of its thinness the garage door will dissipate some of the sound's energy, would it be better to face the monitors towards the garage door instead of the concrete wall which has heavier mass?

9) Ok so, 50 kg/3 or less for thick bass traps - say 150/200mm thick? I had read that for very thick corner traps, it'd be better to go down to 14/16 kg/m3 and have them really thick - any truth in that?
Would 50 kg/m3 be still ok for first reflection/cloud panels?

10) Ok, so I should have different thicknesses of panels and perhaps densities in the room to even out as much as possible the response. What about the air-gap behind the panel? I've read about many people saying that the air gap helps, and some that say that it shouldn't be used. Confused..

11) By air flow I meant the capacity for the panel to be exposed to more "air", increasing as you said the area of exposed absorption. Is there a "rule" on this or is it just sort of "the more the merrier" ?

12) Ok so by hard-back cloud you mean having a piece of solid wood or whatever to close the panel on the upper side? Thickness of wood? Uhm, interesting! As I mentioned, the cloud being that small was more of a Sketchup design issue hahaha I was planning on doing sort of a 140x140cm or 120x120cm by 10/15cm.

13) Yeah no actual 38% RULE there, but I figured it was the best (or only) place to start for my experience level. If you notice in the top-view image, the listening position (ears) is displayed by a dot and a 60 degree angle forming the equilateral triangle to the speakers (do not pay attention to the chair for reference of course lol)

14) And good to know that it applies to all 3 dimensions; makes sense! duh hahaha And yes, definitely symmetry between left and right! I guess one could always decide to have either a lower or higher chair even with a lower ceiling to find that approx 38% distance - right?

15) Ok, so speakers as close to the front wall and thick traps at the front and back!

16) Ok, I must have misread info regarding the sweet-spot. The sweet-spot is the equilateral triangle position between your ears and your monitors, equidistant from left to right, correct? I thought that since you were making the first-reflection points larger, you'd be making the RFZ bigger, enhancing the sweet-spot. But I guess it is more of a confusion with terms that understanding.

17) Yeah I meant bass traps, not broadband in corners.. My bad! hahah

18) Ok, 15cm absorption for the back wall and superchunks in corners!

19) Ok, so I guess it more about fine tuning panel positioning and seeing what is needed, while we are safe to say that all the other things (especially bass traps) are probably going to be needed even without measuring, right?

20) Yeah, I was planning on buying one of those Beringher measurement mics that are quite cheap!


Well, this has been eye-opening in so many way for me!!! I can't thank you enough Stuart!!