Help with treating my new control room

Hi Guys, I'm moving my studio, and am in need of some help deciding how to treat my new control room. (From Chicago to one of the western suburbs). I have read a number of sources, and thought I'd post here for additional thoughts. Here are links to a sketchup file, as well as exported images of the room with dimensions. The images on the page are a bit small, so I linked to the full size images as well. The room is fairly large for a home studio, approximately 13' by 20'. The north wall has a large window on it, and I think that's the wall I want to put my speakers on. As you can see, the south (rear) wall has a bar near it, as well as a recessed mirror. There is an air return on the ceiling that protrudes most of the way into the room. This is the only real asymmetrical part of the listening environment. In terms of acoustic treatment, I already have (7) 6" traps of 703, and (20) 4" traps of 705. I also have 4 corners worth of 36" face superchunks. I'm moving all this from my existing space, and am willing to get more treatment if necessary. In terms of speaker placement, it seems like putting the listening position 37% off the front (north) wall would be a bit far. This would put the listening posiiton at approximately 7.5' from the front wall. Does that seem like it's a bit far to anyone else? In terms of determining listening position, I know I should measure for low frequency response to make sure I'm not in a null. Should I set up both speakers, measure from a listening position, move speakers, measure from the same position, etc? Then move the listening position and measure from potential speaker positions? (necessitating probably 3-5 measurements and moving speakers/stands per each listening position) As you can see in the photos, the room is carpeted. In addition, there is 12"x12" ceiling tile that appears to be at least semi-porous. The tiles have some give when I push up, but it's definitely not a traditional grid that allows the tiles to be easily removed. They're likely glued onto something behind them. If anyone has any suggestions, I'd be very pleased to hear them. North wall: This is what I would like to use as the "front" of the studio. The window pocket is approximately 5" deep. South wall: Has a recessed area with a mirror behind and shelves. It is 16" deep. Also has the door to the room on this wall. There is a bar close to the wall. West wall: Mostly bare; has a door to a crawl space near the south wall. East wall: Has a window on it. The window pocket is approximately 5" deep. Please let me know if you have any suggestions for determining proper speaker placement, etc. The last time I set up a control room, I paid a consultant to take my sketchup rendering and determine this for me, but I ended up with my listening position in a null; it caused some issues as you might imagine. :-) Please let me know if I have forgotten to provide anything, or if anyone would like more information. I posted the images as links, because they're large, and I didn't want to annoy anyone with the way they render on the webpage. If you'd prefer, I'd be happy to shrink them and embed them. Thanks! Mike North Wall South Wall East Wall West Wall Bar From Above From Below Photo From NW Photo from SW Ceiling Tiles Crawl Space

Hi Mike, and Welcome! :) Please post your photos and SketchUp files directly in the forum, so that they can be seen in your post, instead of linking to them off-site.

The north wall has a large window on it, and I think that's the wall I want to put my speakers on.

Looks like the best plan to me! That will have your speakers firing down the long axis of the room, which is good.

The room is fairly large for a home studio, approximately 13' by 20'.

Height? That's necessary for calculating the modal response of the room. And that means the height to the actual solid boundary of the room, not to the soft ceiling tiles that you mention. The acoustic boundary of the room is the solid, hard, massive, rigid ceiling beyond those tiles. That's what low frequency sound waves "see", so that's what is important for calculating modes.

There is an air return on the ceiling that protrudes most of the way into the room. This is the only real asymmetrical part of the listening environment.

That's a problem. Symmetry in the front half of the room is critical, and that is going to mess things up. So you should be thinking about how to deal with that. There are a couple of options.

In terms of speaker placement, it seems like putting the listening position 37% off the front (north) wall would be a bit far. This would put the listening posiiton at approximately 7.5' from the front wall. Does that seem like it's a bit far to anyone else?

It's probably about right, depending on your speakers and your plan for setting them up, but 38% is just a guideline, a good starting point, and not written in stone. As long as you stay away from the really bad locations at 25% and 50%, and stay reasonably close to 38%, you should be OK.

In terms of determining listening position, I know I should measure for low frequency response to make sure I'm not in a null.

That's a good plan, but don't forget that treatment and furniture can also change the modal response of a room. And so can the way you set up your speakers. What speakers are they? (Brand, model). Do you plan to flush-mount them ("soffit mount") or are you just going to have them on stands?

Should I set up both speakers, measure from a listening position, move speakers, measure from the same position, etc? Then move the listening position and measure from potential speaker positions? (necessitating probably 3-5 measurements and moving speakers/stands per each listening position)

One really good way of doing it is to set up one speaker only, in one of the front tri-corners of the room, play loud sine sweeps and also music through that, then listen/measure at several potential listening positions down the centerline of the room, at a height of 1.2m above the floor, to find the one with the least objectionable response. All modes terminate in corners, so setting up a speaker in a tri-corner is guaranteed to excite all of them. With that done, then set up both speakers with correct geometry and play music, to fine tune the location. But once again, don't forget that furniture and treatment can change that, so you might need to refine once again, after everything is in place.

As you can see in the photos, the room is carpeted.

Ouch! First order of business: get rid of the carpet. It ain't doin' ya no favors!

Please let me know if you have any suggestions for determining proper speaker placement, etc. The last time I set up a control room, I paid a consultant to take my sketchup rendering and determine this for me, but I ended up with my listening position in a null; it caused some issues as you might imagine.

some consultant! :!: :shock: Modes are fairly predictable, totally measurable, and can be treated / compensated somewhat. There are general guidelines that I have posted many times on how to set up your speaker geometry, and I'd happily post it again, except that I'm in a hurry to leave right now, so you might be better off searching for it on the forum.

If you'd prefer, I'd be happy to shrink them and embed them.

Yep! :) That's one of the forum rules. In the past we have had problems with images disappearing due to off-site hosting services going off-line, out of business, changing their structure, etc. If you post them here, at least they'll always be available for as long as the forum exists. If you want, also post the links to the larger versions, in case anyone wants to see something in more detail. - Stuart -

Thanks much for the response! I have replied per point below.

Hi Mike, and Welcome! :) Please post your photos and SketchUp files directly in the forum, so that they can be seen in your post, instead of linking to them off-site.

The north wall has a large window on it, and I think that's the wall I want to put my speakers on.

Looks like the best plan to me! That will have your speakers firing down the long axis of the room, which is good.

I have posted the files directly. Links to larger versions are still there.

The room is fairly large for a home studio, approximately 13' by 20'.

Height? That's necessary for calculating the modal response of the room. And that means the height to the actual solid boundary of the room, not to the soft ceiling tiles that you mention. The acoustic boundary of the room is the solid, hard, massive, rigid ceiling beyond those tiles. That's what low frequency sound waves "see", so that's what is important for calculating modes.

I will double check this, but I think the tiles are glued to a hard boundary; they're approximately 7'6" above the finished floor.

There is an air return on the ceiling that protrudes most of the way into the room. This is the only real asymmetrical part of the listening environment.

That's a problem. Symmetry in the front half of the room is critical, and that is going to mess things up. So you should be thinking about how to deal with that. There are a couple of options.

I'd love to hear what those options are, since I definitely can't move it! :-) The measurements are listed in the sketchup file as well as the images I posted.

In terms of speaker placement, it seems like putting the listening position 37% off the front (north) wall would be a bit far. This would put the listening posiiton at approximately 7.5' from the front wall. Does that seem like it's a bit far to anyone else?

It's probably about right, depending on your speakers and your plan for setting them up, but 38% is just a guideline, a good starting point, and not written in stone. As long as you stay away from the really bad locations at 25% and 50%, and stay reasonably close to 38%, you should be OK.

That sounds reasonable.

In terms of determining listening position, I know I should measure for low frequency response to make sure I'm not in a null.

That's a good plan, but don't forget that treatment and furniture can also change the modal response of a room. And so can the way you set up your speakers. What speakers are they? (Brand, model). Do you plan to flush-mount them ("soffit mount") or are you just going to have them on stands?

I am using JBL LSR4328's on stands. The stands are 34" tall. I also use monitor isolation pads which add about 1.5" to the height.

Should I set up both speakers, measure from a listening position, move speakers, measure from the same position, etc? Then move the listening position and measure from potential speaker positions? (necessitating probably 3-5 measurements and moving speakers/stands per each listening position)

One really good way of doing it is to set up one speaker only, in one of the front tri-corners of the room, play loud sine sweeps and also music through that, then listen/measure at several potential listening positions down the centerline of the room, at a height of 1.2m above the floor, to find the one with the least objectionable response. All modes terminate in corners, so setting up a speaker in a tri-corner is guaranteed to excite all of them. With that done, then set up both speakers with correct geometry and play music, to fine tune the location. But once again, don't forget that furniture and treatment can change that, so you might need to refine once again, after everything is in place.

Understood. [quote[

As you can see in the photos, the room is carpeted.

Ouch! First order of business: get rid of the carpet. It ain't doin' ya no favors! [/quote] Unfortunately, it's a rental, so I don't have the liberty of removing the carpet. I could put a laminate down or something over the top of the carpet, if you think that would help.

Please let me know if you have any suggestions for determining proper speaker placement, etc. The last time I set up a control room, I paid a consultant to take my sketchup rendering and determine this for me, but I ended up with my listening position in a null; it caused some issues as you might imagine.

some consultant! :!: :shock: Modes are fairly predictable, totally measurable, and can be treated / compensated somewhat. There are general guidelines that I have posted many times on how to set up your speaker geometry, and I'd happily post it again, except that I'm in a hurry to leave right now, so you might be better off searching for it on the forum.

I'll do a search and let you know if I can't find the correct information.

If you'd prefer, I'd be happy to shrink them and embed them.

Yep! :) That's one of the forum rules. In the past we have had problems with images disappearing due to off-site hosting services going off-line, out of business, changing their structure, etc. If you post them here, at least they'll always be available for as long as the forum exists. If you want, also post the links to the larger versions, in case anyone wants to see something in more detail. - Stuart -

That's been done. I should also mention that I don't care about sound transmission out of the space. I'm only concerned with treatment inside the space. This will be a 2 channel (with sub) mixing room. I will occasionally use it for other purposes, but that is the primary focus. I'm really just looking to create a space in which I can make translatable mixes. :-) I suppose just like everyone else that tried to treat a room. :-) Thanks again, Mike

I have posted the files directly. Links to larger versions are still there.

Much better! :)

they're approximately 7'6" above the finished floor.

That's a pretty low ceiling, and I assume you are talking about the higher section (the ceiling itself), not the part under the HVAC duct? That must be several inches lower. But with such a low ceiling, the room wont sound as good as it could, and there is very little space for suitable treatment up there. For example, hanging a cloud could be problematic. You might have to live with just those "acoustic" tiles on most of the surface.

I'd love to hear what those options are, since I definitely can't move it!

Well, "move it" was the #1 option! :) Number 2 is to duplicate it on the right side (build a fake soffit the same way). Number three is to drop the entire front half of the ceiling to that level, but I think that is out, as the ceiling is so low already.

I am using JBL LSR4328's on stands. The stands are 34" tall. I also use monitor isolation pads which add about 1.5" to the height.

That sounds like it might be ending up too high. "Standard" height is 1.2m above the floor (47.25"), but that refers to the acoustic axis of the speakers (not the top or bottom of the cabinet). So you should check that, and see if you can figure a way to get the acoustic axis to the correct height. Also, the stands should be massive, heavy, and very solid. If they are hollow metal frames, then you could fill them with dry sand to gain the mass that you need.

Unfortunately, it's a rental, so I don't have the liberty of removing the carpet. I could put a laminate down or something over the top of the carpet, if you think that would help.

The issue with carpet is that it is "randomly selective high frequency absorption". What all small rooms need is lots of bass trapping (and I mean LOTS of it), a bit in the mids, and probably little to nothing in the high end. What carpet gives you, is plenty in the high end, fading out through the mid range, and nothing at all in the lows. In other words, it does exactly the opposite of what you need for a small room. Also, the general rule in studios is "hard floor, soft ceiling". Of course, rules are made to be broken, but take a look around high-end professional studios and you'll see that very, very few of them have carpet on the floor. There are several reasons for that, and many of those reasons are related to acoustics. So a hard floor is preferably You could cover your carpet with a layer of thick plywood (say 3/4" OSB, MDF, etc) and then laminate on top of that. You normally cannot lay laminate directly on carpet, as the carpet "gives" to much, and doesn't provide the firm surface that laminate needs. So that would be an option, but it does mean losing probably an inch of your precious room height. However, if that is your only option, then that's what it will have to be!

I should also mention that I don't care about sound transmission out of the space. I'm only concerned with treatment inside the space.

I thought that might be the case, and you don't really have enough space in there to isolate properly anyway, so "treatment only" it is!

I'm really just looking to create a space in which I can make translatable mixes. :-) I suppose just like everyone else that tried to treat a room. :-)

Naah, only about 99.999% want that! :) - Stuart - - Stuart -

Thanks very much for the response! I'll consider the stuff you laid out, particularly the flooring. I realize the ceiling height isn't optimal, but we do the best we can with what we have, right? :-) I've had it suggested to me that I do something like this: This makes a cloud at the listening position that hugs the HVAC duct. I know that would help with comb filtering, etc, but how do you feel about it? You can see that the first reflection side wall points are treated as well, and there are chunks in the front corners, as well as bass traps along the front wall/floor junction. This does make the bottom of the "cloud" (the face of the 4" panel) at 6'3.5". I know that's low, but is it workable in your opinion? I will definitely mass load the stands with sand, as you suggest. In the event that I decide to do 3/4" plywood with laminate on top, would I practically need to do the entire studio floor, or just a section around the listening area? Thanks again, I really appreciate it! Mike

Soundman2020 wrote:

I have posted the files directly. Links to larger versions are still there.

Much better! :)

they're approximately 7'6" above the finished floor.

That's a pretty low ceiling, and I assume you are talking about the higher section (the ceiling itself), not the part under the HVAC duct? That must be several inches lower. But with such a low ceiling, the room wont sound as good as it could, and there is very little space for suitable treatment up there. For example, hanging a cloud could be problematic. You might have to live with just those "acoustic" tiles on most of the surface.

I'd love to hear what those options are, since I definitely can't move it!

Well, "move it" was the #1 option! :) Number 2 is to duplicate it on the right side (build a fake soffit the same way). Number three is to drop the entire front half of the ceiling to that level, but I think that is out, as the ceiling is so low already.

I am using JBL LSR4328's on stands. The stands are 34" tall. I also use monitor isolation pads which add about 1.5" to the height.

That sounds like it might be ending up too high. "Standard" height is 1.2m above the floor (47.25"), but that refers to the acoustic axis of the speakers (not the top or bottom of the cabinet). So you should check that, and see if you can figure a way to get the acoustic axis to the correct height. Also, the stands should be massive, heavy, and very solid. If they are hollow metal frames, then you could fill them with dry sand to gain the mass that you need.

Unfortunately, it's a rental, so I don't have the liberty of removing the carpet. I could put a laminate down or something over the top of the carpet, if you think that would help.

The issue with carpet is that it is "randomly selective high frequency absorption". What all small rooms need is lots of bass trapping (and I mean LOTS of it), a bit in the mids, and probably little to nothing in the high end. What carpet gives you, is plenty in the high end, fading out through the mid range, and nothing at all in the lows. In other words, it does exactly the opposite of what you need for a small room. Also, the general rule in studios is "hard floor, soft ceiling". Of course, rules are made to be broken, but take a look around high-end professional studios and you'll see that very, very few of them have carpet on the floor. There are several reasons for that, and many of those reasons are related to acoustics. So a hard floor is preferably You could cover your carpet with a layer of thick plywood (say 3/4" OSB, MDF, etc) and then laminate on top of that. You normally cannot lay laminate directly on carpet, as the carpet "gives" to much, and doesn't provide the firm surface that laminate needs. So that would be an option, but it does mean losing probably an inch of your precious room height. However, if that is your only option, then that's what it will have to be!

I should also mention that I don't care about sound transmission out of the space. I'm only concerned with treatment inside the space.

I thought that might be the case, and you don't really have enough space in there to isolate properly anyway, so "treatment only" it is!

I'm really just looking to create a space in which I can make translatable mixes. :-) I suppose just like everyone else that tried to treat a room. :-)

Naah, only about 99.999% want that! :) - Stuart - - Stuart -

This does make the bottom of the "cloud" (the face of the 4" panel) at 6'3.5". I know that's low, but is it workable in your opinion?

It's not ideal, but if that's the height you've got, then that's the height you've got! One of the basic philosophies of home studio design is that if you have a choice of "something that works but is not ideal" against "nothing at all", then "something" beats "nothing" every time! :)

In the event that I decide to do 3/4" plywood with laminate on top, would I practically need to do the entire studio floor, or just a section around the listening area?

I would try to do as much as possible, but at least the front half of the room. - Stuart -