New Studio Build, Hello!

Hey what's up Andy! Have read your first build thread a few times already. Too bad you didn't buy in Gville, I could have just gone to your house to record! As far as the floor beef up goes I have pulled permits for building, electrical and mechanical, also my family are Class A licensed contractors in Va, they have been building houses, additions commercial and residential for 70 some years, I am checking with them in regards to how I'm building this money pit before I do anything. They said my addition to the subfloor would be fine. Hey, did you use all unfaced insulation in your previous build? I am wondering if it makes a difference or not? Will definitely keep in touch Allen

I used faced insulation only for the exterior wall cavity. All the other walls and ceiling I used unfaced as I recall. I did see in your earlier post that your family are class A contractors - that's gonna save you a huge chunk of change. It's definitely not a cheap project to enter into, but so rewarding to be able to jam out of the drums in the middle of the night without waking the babies, making the dogs bark, or upsetting the wife and neighbors! I'll be following your thread and don't hesitate to reach out to me anytime. Andy.

Ya having the family in construction is a definite bonus, I have access to about every tool you could think of. So far I've been doing it all myself which has been very time consuming.... I was going to hire a few subs and just manage the project, but decided to do it myself and save that money and put it into the studio. Did you ever think about soffit mounting your speakers? It looked like your original design had soffits in it but your final design you put them on the console. Btw checked out your site, good idea about the FM receiver, gonna try that out. And you hit the nail on the head with the late night drumming, that's the goal! Allen

I thought about soffit mounting but didn't really know enough about it and decided to see how the control room sounded and then treat problem areas instead. I guess it all depends just how pro you need to go. For my new build I hope to go all out (within the constraints of my budget of course). Glad you liked the fm receiver trick. The other approach I've been using is to upload the files to Dropbox and then play them in the car or elsewhere from my iPhone. So did you beef up with two layers of 5/8ths? Did you do that solo and How long did it take you? That is the part of the project I'm least excited about. I remember on my last build struggling to do it single handed. I'd def be interested to know more about your beef up process and experience. I've been a bit nervous about adding load to these TJI's.

Ya I've been back and forth and back and forth on the soffit thing, in order for me to do it I need to sell my JBL LRS28ps which I have been mixing on for 10+ years. They are rear ported and do not have enough LF roll anyway so I was thinking about going with some Adams A7, or F7s if I went that route. The thing is though I have never had my JBL's in a room like this so I am anticipating them sounding really really good in it. My major concern is whether something like the Adams are going to sound better and be more accurate than my JBL's in a well designed and treated room. This decision has been driving me nuts :shock:. My buddy keeps suggesting finishing the room, shoot some measurements and if I don't like how the JBLs sound sell them, buy something mountable and build the soffits. Stuart did have compelling reasons as to why go with soffits..... Sooooooo not sure yet. But my NS10s showed up in the mail today so there's that! As for the ceiling beef up yes, I have been doing it completely solo and it has been a GIGANTIC PITA! Not fun at all.... Some of my bays have nothing in them and some have a TON of plumbing, HVAC and electrical. I have been cutting, fitting and caulking the hell out of it, hopefully it will work well. I went with double 5/8s, backer rod and acoustic caulk. I did not GG between the double 5/8s and I'm hoping that wasn't a mistake. It's taken waaaaaaaaay to long to finish this part. I probably could have finished it in a couple of weekends but I slacked a little because of how unexciting of an endeavor it is.... I hope to finish this weekend. Allen

I have been cutting, fitting and caulking the hell out of it, hopefully it will work well. I went with double 5/8s, backer rod and acoustic caulk.

And the cleats? Don't forget the cleats to keep the drywall in place!

I did not GG between the double 5/8s and I'm hoping that wasn't a mistake.

That's fine. I would save the GG for the large drywall surfaces on the walls.

My buddy keeps suggesting finishing the room, shoot some measurements and if I don't like how the JBLs sound sell them, buy something mountable and build the soffits.

Your buddy must really hate you! :) Either that, or he doesn't realize that you'd likely have to take the entire room apart and rebuild it from scratch, since soffits change the acoustics completely... :) (not that I'm trying to push you towards soffits or anything... Just sayin' ... :) ) - Stuart -

Quote: I did not GG between the double 5/8s and I'm hoping that wasn't a mistake. That's fine. I would save the GG for the large drywall surfaces on the walls.

In my last build I did GG on the beef and the inside leaf on my live room. I'm not sure if that was overkill but I'm all for saving next time around given how expensive that stuff is! I will say that the isolation was much better in there than in my CR and I've been going back through my build thread trying to remember if I did anything different with the CR Ceiling. The footfall noise was noticeable in the CR - I could hear my wife walking through the kitchen in her kinky boots when she came home. Perhaps it's just because the kitchen floor was vinyl tile where above the live room was laminate.

Soundman2020 wrote:

And the cleats? Don't forget the cleats to keep the drywall in place!

Yup definitely going to put the cleats up!

andy_eade wrote:

Quote: I did not GG between the double 5/8s and I'm hoping that wasn't a mistake. That's fine. I would save the GG for the large drywall surfaces on the walls.

In my last build I did GG on the beef and the inside leaf on my live room. I'm not sure if that was overkill but I'm all for saving next time around given how expensive that stuff is! I will say that the isolation was much better in there than in my CR and I've been going back through my build thread trying to remember if I did anything different with the CR Ceiling. The footfall noise was noticeable in the CR - I could hear my wife walking through the kitchen in her kinky boots when she came home. Perhaps it's just because the kitchen floor was vinyl tile where above the live room was laminate.

Ya, I bought 5 gallon buckets of that stuff, enough to do the entire inner leaf including the inner leaf ceiling.

andy_eade wrote:

Your buddy must really hate you! :) Either that, or he doesn't realize that you'd likely have to take the entire room apart and rebuild it from scratch, since soffits change the acoustics completely... :)

Ya know this is interesting? Couldn't I build the room like this where the black corners indicate superchunks, and if it did not sound up to snuff build soffits in place of the front chunks? Am I missing something in terms of how the room should be constructed that would drastically change the acoustics if I did this? I'm not ruling out the soffits, because lets be honest, even if the acoustic results were the equal between soffits and stands, the soffits look sexy as hell. Just want to make sure I do the right thing. BTW did you do yours in poured concrete? Do have the original A7s or the A7x's.... I haven't really found anything else in that price range that looks suitable for mounting. Allen

Am I missing something in terms of how the room should be constructed that would drastically change the acoustics if I did this?

The soffits ARE the new wall! If you start out with just superchunks in the corners to visually represent the soffits, then the front wall of the room is the hard, solid, drywall beyond that. All room acoustics is taken relative to that solid, rigid, massive, hard boundary, not considering any treatment that might be in front of that. So when you then build the soffits, you displace the position of that boundary, and your entire front wall has now effectively moved to where the soffit faces are: So the modal response changed, big-time, and so did everything associated with the front wall. In fact, everything changed, because the original front wall was flat, but the soffit faces are mostly angled with some flat. SBIR is now very different too. So since all that has changed the room probably needs very different treatment. For example, if you do your soffits right with a full RFZ design, then your need for first reflection point treatment is now gone, or greatly reduced, since there ARE no first reflection points (or they are much weaker). Any tuned treatment needs re-tuning since the entire modal response signature is different: changing the front wall to soffits affects ALL of the modes, of all types: axial, tangential and obliques are all now at different frequencies. Etc. If you subscribe to Wes Lachot's musical room tuning ideas, then the tuning scale is now very different, so other things need changing to accompany that. Etc. :) So if you might want to have soffits later, I would suggest building them now anyway, and facing them with 4" of 703 if you don't actually use them as soffits to start with, then removing that if you do decide to use them. That way, your acoustic changes won't be so drastic, and you won't need to re-tune the entire room so differently. - Stuart -

Do have the original A7s or the A7x's.... I haven't really found anything else in that price range that looks suitable for mounting.

The original A7s, plus a Sub-8 to extend the bottom end down lower. But I would recommend the Sub-10 instead of the Sub-8 if you want to add a sub: the Sub-8 is a little underpowered for my likings. Mine are not in concrete, but a guy I designed a place for in Canada is busy making concrete soffit panels for his A7X's right now, and they are looking good. He hasn't installed them yet (the concrete has not finished curing yet), but when he does we'll do a REW test and see how well they work as compared to wood. He has wood baffles on his soffits at first, but decided to switch to concrete when he had to take the soffit apart anyway, due to having used the wrong rubber to decouple. So we'll have "before" and "after" testing for you! - Stuart -

Cool, look forward to seeing the tests.... I found a pair of A8x's for a really good price and decided to get them. So the JBLs are going on the market. Also picked up some NS10s for reference so I'm thinking I should be good in the monitor department. Now if I only had a place to monitor something in.... :? So the plan is to soffit mount! That's what I'm doing full speed ahead! Could you possibly help me out on my angles for the room. I'm trying to achieve RFZ, but I am a bit lost in how to calculate the angles for my room correctly. Thanks, Allen

Question... So I have this trunk HVAC line going perpendicular under the joists in my room. This is the HVAC feed for the studio. I was originally thinking I would build a soffit around it with double 5/8s and have it occupy the space between the foundation wall and inner leaf for isolation purposes but then realized it would still be open on top so I think this might be pointless, so now I'm thinking that I will just leave it on the outside of the inner leaf and port it into the studio through a vent muffler which I was going to do anyway. Any idea on how to isolate the trunk line from sound any other way? This line runs about 12' and then goes straight into the house system. Just trying to eliminate as much sound into the house as possible.

I was originally thinking I would build a soffit around it with double 5/8s and have it occupy the space between the foundation wall and inner leaf for isolation purposes but then realized it would still be open on top so I think this might be pointless,

Your basic plan is correct, but you also need to fix that "open on top" part, by enclosing it 100%.

now I'm thinking that I will just leave it on the outside of the inner leaf and port it into the studio through a vent muffler which I was going to do anyway.

If you did that, it would be in between your two leaves, and become part of your air gap. You do not want to do that! The air gap is where all the serious resonance business happens, inside an MSM wall, and since your HVAC duct is basically just a resonant box itself, made with thin metal walls, it will gladly pick that up and send it all over your house! Not to mention that any noise that is already present in your HVAC system will now totally bypass your outer leaf, and be present in the air gap.... So you definitely do need to soffit up fully, to make it part of the outer leaf, not leaving it inside the air.

Any idea on how to isolate the trunk line from sound any other way? This line runs about 12' and then goes straight into the house system.

Is there any possibility of re-routing that line somehow? Can that room above (and your room) be fed by some other route? If not, then you are stuck with the not-very-delightful task of carefully cutting bits of drywall and/or OSB to fit into each of those bays between your joists, hold them in place with cleats (on both sides), then seal everything carefully with acoustic caulk. Rinse. Repeat. Not fun. Boring, time-consuming, but the only way to do it if you can't find a better route. - Stuart -

I was afraid you were going to say that. :cry: Oh well, I've gone this far with the ceiling beef up, which has been as much fun as going to the dentist, I'm not going to stop now. Soffit it is. What about flex ducts that are coming off of that trunk line? Do those need to be completely enclosed as well? I have already beefed the ceiling up above them...I have one more bay that I have been putting off until last because I wasn't sure what to do? I know it's not ideal but should this bay just be filled with insulation and enclosed as opposed to trying to beef the sub floor above do to the length of the flex duct and all of the other pipes and electrical in it?This is a vent from the microwave in the kitchen above. It is not tied into the house HVAC system and vents directly out the back of the house. Should I do anything to it? Thanks! Allen

:) I'm taking a wild guess here: I think you already know the answers to at least two of those, but you are really, REALLY hoping I'll tell you something different!!! :) But, unfortunately... :

What about flex ducts that are coming off of that trunk line? Do those need to be completely enclosed as well?

Yup!

I know it's not ideal but should this bay just be filled with insulation and enclosed as opposed to trying to beef the sub floor above do to the length of the flex duct and all of the other pipes and electrical in it?

OK, on this one I can give you a "permission slip": your plan is fine: stuff it full of insulation, and soffit over the whole thing with abundant drywall, all around, and well sealed. You'd likely go nut-job crazy trying to beef up inside there! :)

This is a vent from the microwave in the kitchen above. It is not tied into the house HVAC system and vents directly out the back of the house. Should I do anything to it?

Yup, and we both know what you should do there... :) On the count of three: 1 --- 2 --- 3 --- "Soffit"! There, that wasn't so hard, was it? And just as much fun as root-canal with no anesthetic! One other thing: Where you have wires coming through, such as those next to the microwave duct, you need to put putty-packs around those penetrations, to add a bit of mass and get a better seal. Oh, and I don't see your caulking on that "beef"! Is that still coming? All of that needs to be sealed... - Stuart -

Ya that's what I thought... :x If I'm not going to do it right, why do it at all! So with that microwave vent and that other smaller flex duct, should I insulate and close the bottom of the bay up or build a tighter soffit just around the duct and vent? Also I was thinking in regards to the soffit mounting of the A8x's which I am still planning on doing, but this brings up the question about my second pair of monitors, the NS10s, since these will not be soffit mounted but rather on stands behind the desk aren't they going to suffer in that the room would not be treated the same as if I did not have the mains soffit mounted, ie more bass trapping behind them on the front wall etc... Or am I just be silly because the NS10s aren't known for their bass response anyway?... Stuart do you have any pics of your front wall? What method did you use for mounting... I have been all over the place as far as how to go about the soffits, and then I read a post by John saying people are really over complicating the matter. Build a big solid baffle and secure your speakers behind them... In Johns design the speaker box is attached to the bezel correct? But the entire structure is rigid enough that it doesn't matter... Is this right? Did you remove your amps? Do I build the inner leaf with the double 5/8s drywall all around and THEN frame and build another front wall with the soffits and middle section. Do the soffits need to be sealed or are they open to the drywall with just some insulation in them? I know there are various ways to go about it, but I am really not trying to experiment, I am looking for a known build that works. BTW how did you end up carving the angles out of your bezel for the A7s. Thanks Stuart!

Still wondering about what to do with with that microwave vent and that other smaller flex duct, should I insulate and close the bottom of the bay up or build a tighter soffit just around the duct and vent? Also, I did some tweaking of my RFZ design and finally got the angles worked out correctly "I think" I did angles for the ceiling too, I am still on the fence as to whether angle the ceiling or add a cloud. I have to angle the ceiling anyway because of the HVAC soffit that has to be built but the degree to which I do it depends on if I go the cloud route or not .My original plan was to splay the walls to create my RFZ, then I thought maybe slot walls would be better? After many many many hours of research it seems that it doesn't really matter which method I choose as long as either one is done correctly ie, angles right for splaying or enough absorption implemented correctly for the slot walls... With my space, which do you think would be better? 1. Splaying? 2.Building a rectangle and then adding angled slot walls later? 3. Does it matter as long as either one is done right... 4. What would be your personal preference? Thanks, Allen

-Bump- Still really wondering about the angled ceiling vs a cloud? And angled treatment in a rectangle vs splayed walls. Thanks, Allen

So with that microwave vent and that other smaller flex duct, should I insulate and close the bottom of the bay up or build a tighter soffit just around the duct and vent?

Do the easier thing: insulate and close off the entire stud bay. Much easier!

Or am I just be silly because the NS10s aren't known for their bass response anyway?...

:thu: :shot: To my way of thinking, the purpose of having NS10's is so you can hear what the mix will sound like on a pair of typical low quality home stereo speakers or car speakers, that are set up poorly in a typical living room.... :) Now some folks might get upset with my view, but to me that's what I use them for. So I wouldn't be too concerned about having the NS10s set up "perfectly", when that isn't really their purpose.

then I read a post by John saying people are really over complicating the matter. Build a big solid baffle and secure your speakers behind them...

Have you seen this post by John, on the 3 (or 4) ways you can soffit-mount speakers? viewtopic.php?f=2&t=839&start=197

Did you remove your amps?

I always suggest doing that, as YOU WILL need to tweak those settings many times during the final room tuning, and pulling the speakers out to do that each time is a pain in the rear end! so pull them, extend the wiring, and mount them on the front/side of the soffit, or on a bracket, or some such. And of course, replace the rear panel on the speaker box with a similar piece of wood!

Do I build the inner leaf with the double 5/8s drywall all around and THEN frame and build another front wall with the soffits and middle section.

Yup!

Do the soffits need to be sealed or are they open to the drywall with just some insulation in them?

They don't need to be sealed: after all, there's a huge ventilation path running through them, to cool the speaker, so sealing the rest doesn't help at all.

Also, I did some tweaking of my RFZ design and finally got the angles worked out correctly

Looks good!

I am still on the fence as to whether angle the ceiling or add a cloud. I have to angle the ceiling anyway because of the HVAC soffit that has to be built but the degree to which I do it depends on if I go the cloud route or not .

Either way will work, but if you have good ceiling height then a cloud can add a really nice touch, both acoustically and visually. But if your ceiling is low to start with, then a cloud is probably out of the question.

My original plan was to splay the walls to create my RFZ, then I thought maybe slot walls would be better? After many many many hours of research it seems that it doesn't really matter which method I choose as long as either one is done correctly ie, angles right for splaying or enough absorption implemented correctly for the slot walls...

Right! But to be honest, I prefer to have those walls solid and use slots further back in the room. Slots are tuned devices, so they can change the overall perception of sound in the room, and you don't want that happening too close to your ears. - Stuart -

Hi Stuart, Thank you once again for the feedback! I think I have designed what I want to do finally! I feel like I want to do a slot wall bass absorber on the rear wall. I was originally going to just put a couple of superchunk corner traps in the rear but do to where the door is located in the room I thought this might work better for sound and most certainly look better. Basically I am just filling the slot walls with rockwool, covering with cloth and then adding the slats to reflect some of the highs back into the room so I don't lose the brightness. I have seen this done before, like in Javiers studio and it is my understanding that the distance between the slats does not matter since their purpose is to just reflect some highs and for the aesthetics of the room as opposed tos covering the rockwool with a plastic sheet and then applying the fabric. Does this sound right? Also, I was wondering if you think I should build the back inner leaf wall inside out to give me a bit more rockwool absorption behind the slats?...

Ok - there are three ways to mount your soffits. The first is the simplest which is as per my design at SAE and which we've further updated through drawings posted here in these forums. The idea is to make the whole soffit frame as rigid and solid as possible using double layers of MDF/plywood glued and screwed thus lowering the resonate frequency of the whole structure.

Does this mean that the speaker box does not need any rubber/neoprene material inside the speaker box decoupling the speaker from the box? Does it also mean the it does not matter if the baffle is touching the box because the point is to make the whole thing so rigid that it should not vibrate at all? The reason for the confusion is because of things like Simo's build where he made a very solid structure, then made sure not to have the speaker box touch the baffle or the finish piece of veneered MDF. John's design appears to have the speaker box coming through flush and touching the timber finish and the box does not have any springy rubbery material inside, just a very tight fit? Is this correct?

Does this mean that the speaker box does not need any rubber/neoprene material inside the speaker box decoupling the speaker from the box?

For John's method, yes that's correct. It's a very tight fit.

Does it also mean the it does not matter if the baffle is touching the box because the point is to make the whole thing so rigid that it should not vibrate at all?

Once again, for John's method, yes it can touch. However, you do need LOTS of mass and a very rigid structure to get good results here. So the front baffle will be at least a couple of centimeters thick, maybe more, and will probably need to be built up from two or three layers. The internal framing also needs to be tough, strong, rigid.

The reason for the confusion is because of things like Simo's build where he made a very solid structure, then made sure not to have the speaker box touch the baffle or the finish piece of veneered MDF.

Well, you always need a solid structure, no matter which method you use. But Simo also decoupled his, as far as I recall, using a variation on Barefoot's method. I may be wrong, but I seem to recall that he has the baffle decoupled from the speaker support itself.

John's design appears to have the speaker box coming through flush and touching the timber finish and the box does not have any springy rubbery material inside, just a very tight fit? Is this correct?

Right. You could use thin rubber if you wanted, to protect the finish on the speaker cabinet itself, but you'd need to make sure that you compress it enough so that it does not decouple, and holds the speaker firmly in place. - Stuart -

Awesome thanks for the clarification Stuart! I was planning on building the soffit baffles with a sheet of 3/4" MDF and a finish sheet of 3/4" Birch laminated plywood on top of that. Does this sound solid and thick enough to you? I saw something similar to this on the forum but cannot remember who came up with it, I thought this would be good in case I need to remove the speaker for any reason. The plan is to have a removable bezel that frames the speaker and then the bolt down top on the box holding the speaker for easier removal. The rubber on top is 8mm gym flooring rubber that I have left over from my workout room, very dense not springy at all, just figured it would be good to help protect the speaker. What do you think? One other question, from the floor to the lowest point on my front wall is 6'1", is this high enough to not cause any issues with the speaker soffits? The ceiling angles up to 8' as it goes back into the room. I know I have to cut the bezel to match the odd front of the A8X's, just didn't go to the trouble in SU. Almost done boxing in the duct work in the ceiling and finishing the soffit around the HVAC trunk line, will post pictures soon! Could you also comment on my idea for the rear wall absorption, after some more research I decided it might be better to get rid of every other slat so the wall is not too reflective. Does this look like a sound idea idea to you "pun intended" If I build the rear wall inside out I get 1'8" of absorption at the thickest point and 3.5" at the shallowest. The slats are 3.5" with 6" spacing between them. Thanks! Allen

I was planning on building the soffit baffles with a sheet of 3/4" MDF and a finish sheet of 3/4" Birch laminated plywood on top of that. Does this sound solid and thick enough to you?

That should be fine.

The rubber on top is 8mm gym flooring rubber that I have left over from my workout room, very dense not springy at all, just figured it would be good to help protect the speaker. What do you think?

Looks good to me. That should keep the speaker firmly and solidly attached to the soffit, but also make it easily removable. Good idea! :thu:

One other question, from the floor to the lowest point on my front wall is 6'1", is this high enough to not cause any issues with the speaker soffits?

Looks OK. If that's how low it has to be, then that's how low it has to be!!! :)

Could you also comment on my idea for the rear wall absorption, after some more research I decided it might be better to get rid of every other slat so the wall is not too reflective. Does this look like a sound idea idea to you "pun intended"

That does, indeed, "sound" like a very "sound" idea! :) In fact, you could start out with no slats at all, measure the room response with REW, then add a couple of slats at a time and check with REW after each addition, to see how it is doing.

If I build the rear wall inside out I get 1'8" of absorption at the thickest point and 3.5" at the shallowest. The slats are 3.5" with 6" spacing between them.

:thu: - Stuart -

Thanks once again Stuart! Is there a major advantage to using 703 vs Roxul for the treatment, I have seen people face their superchunks with 703 and then use rockwool or pinkstuff behind, is this necessary? What about the panel absorbers... Thanks, Allen