John Sayers' Recording Studio Design Forum Archive

Hi Everyone,

I've been a long-time lurker but this is my inaugural post.

I am a professional engineer, sound designer, mixer, by which I mean that it's how I've paid my bills for the past 20 years. Half my time is spent on music projects, mainly as a mixer these days, while the other half is in post, as a sound designer and mixer. Like most people my age, when I started out it was unheard of for clients to not be sitting on couches behind you, but these days, very little of my work is done face-to-face with clients. I work a lot with David Bottrill, who is of the Daniel Lanois lineage, and have somewhat adopted their attitudes of not having to worry about a working space being perfect, so long as it feels good to work in... to a point, of course. I'm currently in a large, open loft space with minimal acoustic treatment and no isolation. It's not ideal, but it works. However, I am now moving to a house and will be occupying the basement, which is less forgiving and, as I'm sure you've inferred, why I'm here.

The room is essentially 23'8" x 11'7" with a 6'2" ceiling height (ugh... I'm just shy of 6' so it's cutting it close). I stumbled through the basics of Sketchup yesterday and cobbled together a somewhat accurate design, which I've attached, but my skills are limited. There are a few missing drops in the ceiling for ducts and a couple of windows (which I don't mind being covered), as you can see in the photos.



The room is drywall with carpeted floors. Two walls are to the outside (the wall with the windows and the wall opposite the door), one wall is to the furnace room (the wall with the door), and the last wall attaches to neighbours (the wall across from the windows). I'm not worried about isolation though. I'm just looking to tune the room as best I can given the circumstances. Other aspects of note:

• This house is a lease so I can't really do much structurally. Ideally, I'd love non-permanent solutions that I can remove and patch up holes when I leave.
• I work on an Avid/Digidesign D-Command and have a few racks of outboard gear.
• Most of the time I monitor quite low.
• I work in 5.1 half the time.
• I'd love to keep my budget under $2000 but I'm willing to spend what's needed to make the space workable... and cool. It's currently not cool. Ha Ha!
• I hope to have a couple soft chairs for clients but I don't necessarily need them to be in a good listening position. I just need the mixing position to be fairly accurate.

So, in closing, my question: What would you suggest I do to the room to make a good, relatively neutral listening position?

If that's an unrealistic, overly-simplistic question, please let me know. Thanks everyone.

Ryan

Hi Ryan,

Welcome!

With that budget and the restrictions imposed by the lease, you will be stuck doing very basic temporary type devices. I'd suggest setting up your speakers and run a REW test and post the mdat file for us to look at. Follow the REW measurement guidelines in the acoustics section of the forum.

Basic treatment would be floor to ceiling LARGE superchunk bass traps. 4" insulation behind your speakers. I'd personally build a super thick gobo type device (on wheels) that would cover your entire rear wall. The casters would allow you to move it and gain access to the furnace room. Also, panels at your first reflection points.

Is the ceiling a smooth paint finish? The reason I ask is because a cloud is important and if it's just a smooth paint finish, you could easily patch it when you move. If not, you might be screwed to repair the holes and have them undetectable.

As I'm sure you've seen on the forum, getting a baseline REW measurement is crucial. Add only ONE treatment device at a time and take a whole new set of measurements.

Greg

Thanks Greg!

I'll be moving in the first week of June and can start doing measurements then. I won't ask questions about that until I read the thread you referenced.

That said, yes, the ceiling is smooth and flat – it's just painted drywall. I've done loads of patching in my time, so I'm not worried about covering things up. I just don't want to knock down, or build, walls.

If upping the budget would make a significant difference, I'd do it. I'm just trying to minimize the amount I sink into this given that it's not a permanent space. At the end of the day though, I have to work there, likely for a couple of years.

Just a couple questions:

1) When you say "floor to ceiling LARGE superchunk bass traps. 4" insulation behind your speakers." – is that the same thought? As in, are the floor to ceiling bass traps basically just covering the wall behind the speakers?

2) I like the gobo idea, but – I should have mentioned this – there's a washroom back there too. Could they just be floor to ceiling, out from the wall 2', so the door can open, and then a bit of space on the sides so you can just walk around them?

3) I obviously don't want to give up too much height but I could definitely install a cloud. What thickness would you think?

I should also add that I need some sort of TV behind the speakers for the post work.

I'll obviously do the REW test before anything though, it's just good to get an idea of what I'm up against, particularly in trying to gauge my down-time.

Thanks again!

Ryan

Hi Ryan, and Welcome to the forum!

23'8" x 11'7" with a 6'2"

The total floor area is great! But the relationship between dimensions isn't so great... and the low ceiling is anything BUT great. It's a real problem, in fact.

First, the overall dimensions: There's some basic rules of thumb regarding dimensions, and the relationship between them. For example, the length of the room should not be more than three times the height or three times the width. In you case, the room is nearly four times longer than high. Next, none of the dimensions should be the same as any other, or a direct multiple of any other, or within 5% of being a direct multiple. Your length is almost exactly twice the width. If you plot all possible lengths and widths on a graph as multiples of the height, then there's an area within that graph, called the Bolt Area (named after the scientist who figured it out) which encloses all the "good" ratios. The "bad" ones are all outside of that. Your ratio is outside of the bolt area.

There's a couple of on-line calculators that figure all this stuff out for you, and plot it on graphs, so you can understand it more easily. Here's one, with your dimensions already plugged in: https://amcoustics.com/tools/amroc?l=70 ... 3&r60=0.23

This is all about the "modal response" of the room. So your's basically does not have good modal response. That doesn't mean it is a terrible room from that point of view: it just means it will be hard to treat, and won't be as good as a room with a better ratio.

Now for the biggie: Ceiling height. 6'2". Wow! That's LOW! Very. Low ceilings are not good for studios.

There's one possibility here, which you probably won't like very much, but it would help: take off the drywall on your ceiling. That will expose the joists for the floor above, which I assume will be at least 2x8, perhaps 2x10, maybe larger. So you could hopefully gain a lot of acoustic height there. The headroom won't change, of course, as the joists will still be there, but the acoustic height will change. Having the joists exposed would also allow you to fill the stud bays with insulation, and the joists themselves would be good for some diffusion. You could then put up fabric on the joists, so it looks nice again. That insulation would go a long way to treating the modal issues associated with the ceiling and floor.

If you did that, when you leave all you'd need to do is to put up new drywall on the ceiling, and paint it. Done!

1) When you say "floor to ceiling LARGE superchunk bass traps. 4" insulation behind your speakers." – is that the same thought? As in, are the floor to ceiling bass traps basically just covering the wall behind the speakers?

Bass traps go in the room corners: they are triangular, and run about 36" along each wall. The 4" insulation behind the speakers is different, not related to the bass traps. 4" isn't enough for bass trapping anyway, and in this case the purpose is to help kill the reflections coming off the BACK of the speaker, hitting the wall, bouncing back, and then interfering with the direct sound coming out the front of the speaker. That creates problems such as SBIR, and the 4" panel can help with that, if it is up tight against the all and the speaker is up tight against the panel. You will certainly need those superchunks in the vertical corners, and I'd suggest putting some in the horizontal corners as well. You are going to need as much bass trapping as you can possibly get in there!

2) I like the gobo idea, but – I should have mentioned this – there's a washroom back there too. Could they just be floor to ceiling, out from the wall 2', so the door can open, and then a bit of space on the sides so you can just walk around them?

Yep, that's fine.

3) I obviously don't want to give up too much height but I could definitely install a cloud. What thickness would you think?

With only 6'2" to play with, I don't think there's going to be room for a cloud. However, taking off the drywall and filling the entire depth of the stud bays with good. light insulation would go a long way towards simulating a cloud.

I should also add that I need some sort of TV behind the speakers for the post work.

Between the speakers, not behind them. Your speaker have to go against the front wall, so there won't be much "behind" the speakers! Just the depth of the speakers and the 4" for treatment.

I'll obviously do the REW test before anything though

Great! Here's how: How to calibrate and use REW to test and tune your room acoustics


- Stuart -

Stuart, this fantastic. Thanks you so much for taking the time.

Soundman2020 wrote: This is all about the "modal response" of the room. So your's basically does not have good modal response. That doesn't mean it is a terrible room from that point of view: it just means it will be hard to treat, and won't be as good as a room with a better ratio.

I'm not sure if this is ridiculous but is it possible to "fake" the dimensions with floor to ceiling gobos? So, "move" the back wall using gobos, thus making the room a little shorter?

Soundman2020 wrote: Now for the biggie: Ceiling height. 6'2". Wow! That's LOW! Very. Low ceilings are not good for studios. ... There's one possibility here, which you probably won't like very much, but it would help: take off the drywall on your ceiling.

Oh, I know. It's brutal and was a serious concern of mine. The real estate market here in Toronto is in dire conditions, so in the grand scheme of life, a low ceiling is just something I have to live with for the time being, unfortunately. If I owned the place I'd dig out the floor but that's a couple of years off, so in the meantime, here I am. Unfortunately, I don't think I can cut out the ceiling. The landlord would be so, unbelievably pissed off, and I wouldn't blame him. Physics or not, I have to make it work – even if it means double-checking critical mixes elsewhere. But I really do appreciate the creative suggestion. Admittedly, it may come to it but I want to try everything I can, and assess how bad it is, before even opening that can of worms.

I understand we're talking about things that are pretty fundamental here but what would be the next best option? I recognize that just shoving absorption on stuff doesn't fix these fundamental problems, however, would some sort of cloud-like panel on the ceiling above the mix position help – even if I couldn't stand up? Or diffusion? Or... anything? Ha Ha!

Soundman2020 wrote: You will certainly need those superchunks in the vertical corners, and I'd suggest putting some in the horizontal corners as well.

I haven't looked at the building section of the forum yet but I'm going to assume that there's some sort of explanation on how to suspend bass traps that run on the horizontal corners?

Soundman2020 wrote: Between the speakers, not behind them. Your speaker have to go against the front wall, so there won't be much "behind" the speakers! Just the depth of the speakers and the 4" for treatment.

Gotcha. So you're suggesting the speakers be right up agains the 4" insulation? No space between the speakers and the 4" panels?

There's also always the awkwardness of dealing with the center speaker. Does it make matters worse to have a TV just above the center channel?

I also just assumed to set up facing the wall opposite the door. Does that make the most sense?

Thank you again.

Ryan

Thanks you so much for taking the time.

I'm not sure if this is ridiculous but is it possible to "fake" the dimensions with floor to ceiling gobos? So, "move" the back wall using gobos, thus making the room a little shorter?

It's not ridiculous to suggest i! But unfortunately, it won't work. Room modes occur between the hard, solid, rigid, massive boundary surfaces of the room, not the things inside the room. You would have to build a physical wall across the room to change the modal distribution.

That said, putting a ton of gobos back there will help with the modal issues, to a certain extent. But it won't move them up in frequency. In fact, it would move them DOWN in frequency a little: sound travels slower through the absorption in the gobos, so it makes the room "appear" even longer, form the point of view of sound waves... which means that the modal frequency will go down just a bit more... Ain't acoustics fun?

Unfortunately, I don't think I can cut out the ceiling.

Maybe just the part of it over your mix position and speakers? Even just doing that area would make a difference.

I understand we're talking about things that are pretty fundamental here but what would be the next best option?

With such a low ceiling as that, there really aren't any "second best options"! It would be nice if there were, but you do still have to walk around inside that room, so there's no place to put anything useful on the ceiling. If you can't take out the drywall, you might just have to live with the artifacts of having a low ceiling.

would some sort of cloud-like panel on the ceiling above the mix position help – even if I couldn't stand up?

Here's what typical ceiling clouds look like, in room with roughly your floor area: Clouds are big, and thick, and angled... the lower the ceiling, the more they need to be angled.

It might be possible to design something with a sot of saw-tooth shape to it, angled in sections (same principle as a Fresnel lens), but it would be complex... and it would still take up a lot of space. Probably your only real choice here is 6" of insulation in a rectangular frame with slots or holes in the frame, to get just a little bit of diffusion. Maybe with a space-coupler under it.. a very SMALL space coupler...

Or diffusion? Or... anything?

A numeric-sequence based diffuser has to be at least 10 feet from your ears, to avoid the lobing patterns that it creates... so putting one over your head, a couple of inches away, isn't a good idea!

I haven't looked at the building section of the forum yet but I'm going to assume that there's some sort of explanation on how to suspend bass traps that run on the horizontal corners?

Your wish is my command! :

Gotcha. So you're suggesting the speakers be right up agains the 4" insulation? No space between the speakers and the 4" panels?

Exactly. Your room is actually long enough that you probably could space them away from the front wall enough to push SBIR down low, but that would put your head in the middle of the room... in the worst possible spot for modal issues! So they have to go up against the front wall. And especially with that low ceiling....

There's also always the awkwardness of dealing with the center speaker. Does it make matters worse to have a TV just above the center channel?

That's fine. As long as the speaker sticks out past the front face of the TV, you should be OK. However, your speakers should be mounted such that the acoustic axis is 47 1/2" above the floor (120cm), as that's the "standard" height, for a very good reason: that's the height of your ears above the floor, when seated! (OK, the average height for most people). If you set your center speaker that high, the TV would have to be way up high. What you can do, is lower the center speaker a little, and tilt it upwards a fraction, so it still points at your head. You can't move it down a huge amount, but a few inches should be fine. Cinemas solve this issue by mounting the speakers behind the projection screen, which is acoustically transparent...

I also just assumed to set up facing the wall opposite the door. Does that make the most sense?

Right!


- Stuart -

Thanks a million, Stuart. This is all incredibly helpful.

Soundman2020 wrote: It might be possible to design something with a sot of saw-tooth shape to it, angled in sections (same principle as a Fresnel lens), but it would be complex... and it would still take up a lot of space. Probably your only real choice here is 6" of insulation in a rectangular frame with slots or holes in the frame, to get just a little bit of diffusion. Maybe with a space-coupler under it.. a very SMALL space coupler...

This is interesting. I'm up for a construction challenge! Ha Ha! I would think that the next step is to do some measurements when I get in the space in a couple of weeks and go from there. But I like this creative thinking.

Out of interest, what will a lower ceiling do, sonically speaking? As in, how will it affect the sound? Are we talking comb-filtering, imaging issues? What part of the spectrum would it affect?

Thanks again.

Ryan

Hi Everyone,

The moment of truth has arrived for me. I got in my room and did the REW tests. Here are the results:

https://www.dropbox.com/s/muzph9ik6wqoq ... .mdat?dl=0

I wasn't entirely sure if I did it correctly with my sub. Calibrating all the speakers to as close to 77 as possible was incredibly loud on the sub. That said, the collective was still about 86. If that is really messed up, we can disregard the sub altogether and just go with the L/R. I tend to keep my crossover really low anyway so the L/R speakers are doing the bulk of the work.

I set up where I thought was comfortable, so the tip of the mic ended up being 49" from floor, 69.5" from the side walls and 61.5" from the front wall (the one opposite to the door).

Any advice would be much appreciated.