John Sayers' Recording Studio Design Forum Archive

Hi all,

After many delays for various reasons I still have not started my studio build. But finally this year is the year I will start it!

I've worked out that I need a TL of 60db down to 20hz if possible... now if my estimations are correct, I can just about achieve this with my current design but it may be closer to 24hz... I wouldn't be surprised if I have got that wrong though, I'm sure you guys will correct me if I am wrong. The nearest neighbours are about 50m away and we're out in the countryside.

I've decided due to the difficulty and man power required that a block and beam roof is probably not going to happen, which means both the internal and external walls will be timber frames, and each room will be built on its own concrete slab as well as the outer walls.

The internal walls will be a sandwich of plasterboard/OSB/plasterboard. I am yet to decide what the outer wall sandwich will be, but something similar and waterproof. The roof will be zinc sheets on top of this sandwich.

Before I get into all the details of the construction I come seeking approval of my design. All of this can be changed if necessary and I am open to suggestions and especially corrections. I want to build this right.

UK planning laws mean that I can either build a flat roof with a maximum height of 3m or a pitched roof with a maximum height of 4m and 2.5m at the start of the eaves. So needless to say I am going for a pitched roof for the two largest sections. It's also just a safer bet due to the amount of rain we get here. (BTW, sorry to mix imperial and metric)

The air gap in my design at the moment is 12" which means that my internal height will be quite a bit lower than what I am allowed, especially at the lowest point. If this can be changed to something closer to 6" then it will give me a nice little bit of extra height.

There will be a central control room sidewards facing with windows looking into the main live room which has 1 long iso booth which can be divided into 2. Above that booth will be a little nest area, the ceiling means it won't be high enough to stand in but high enough for storage or lying down and reading books.

On the left of the control room will be another room that can be used for tracking quieter sources as a type of overflow space, but mainly a lounge and kitchenette area which also connects to a toilet.

The reason the main live room is at an angle is because there is a stream along side it, so I have no option other than making everything smaller or coming off at a right angle from the control room forming an L shape... but this would not be ideal because there is an incline in the land there. So I thought I'd make use of that angle and splay the walls in the control room. The angle is 12 degrees.

Rather than continue explaining, I would like people's opinions on this layout. I have just roughly put in some areas where I think would be best for bass trapping (in grey) but haven't got enough info yet to design the acoustic treatment properly.

Thanks in advance,
Paul

It's awesome that you have so much space to work with!

A few questionable things I see are:

- Your speakers are shooting across the short length of your control room. As far as I've learned, it's best to have them shooting the the long length.

- Both the front of your control room and the entire width of your live room are less than 5% of their lengths. That is a no no. These are almost square dimensions. My guess is that they fall well within a "bad" room dimension.

- It looks like you're maybe trying to go for an RFZ control room. The front half of the room looks unique to me. Have you done ray tracing to see if the design works out? I'd like to see it just for fun.

- Like most us, you seem to be a bit limited with height. If you go with the 4.5m roof, what pitches will you have? Is there rules for that? I know due to insulating, the pitches for my 8/12 outside had to be 4/12 inside and it sadly lowered my ceiling height way more than I wanted. The reason I ask is because your design doesn't show your HVAC silencers. So I assume you'll have them in the ceiling and/or outside of the building? Remember they're massive. Especially for your rooms because you have nice big rooms. I also don't see things like hot water tanks, AHU, or electrical panel in your design. These are all things that need lots of space.

It looks like you have a LOT of potential for an absolutely killer studio here!

Greg

Gregwor wrote:It's awesome that you have so much space to work with!

A few questionable things I see are:

- Your speakers are shooting across the short length of your control room. As far as I've learned, it's best to have them shooting the the long length.

- Both the front of your control room and the entire width of your live room are less than 5% of their lengths. That is a no no. These are almost square dimensions. My guess is that they fall well within a "bad" room dimension.

- It looks like you're maybe trying to go for an RFZ control room. The front half of the room looks unique to me. Have you done ray tracing to see if the design works out? I'd like to see it just for fun.

- Like most us, you seem to be a bit limited with height. If you go with the 4.5m roof, what pitches will you have? Is there rules for that? I know due to insulating, the pitches for my 8/12 outside had to be 4/12 inside and it sadly lowered my ceiling height way more than I wanted. The reason I ask is because your design doesn't show your HVAC silencers. So I assume you'll have them in the ceiling and/or outside of the building? Remember they're massive. Especially for your rooms because you have nice big rooms. I also don't see things like hot water tanks, AHU, or electrical panel in your design. These are all things that need lots of space.

It looks like you have a LOT of potential for an absolutely killer studio here!

Greg

Hey Greg, thanks so much for your reply and for pointing out some things I haven't yet thought of.

Yes, the live room especially needs more work, as it is too square... above the iso booths on the right there will be a platform, so the front walls of the iso booths don't go all the way to the ceiling, it will leave a little space for chilling/storage, so that will make the live room less square by a little bit at that end, but I think I will just redesign it completely.

That's interesting about the 5% rule, I didn't know that...hmm I will need to go back to the drawing board then. The funny thing is I based my CR design on one by John Storyk (which I've attached) so either he was limited and did the best with what he could or he's done something differently to me that I haven't seen?

As for the HVAC, well I am planning on having two multi split systems, which are small and only require two holes for each pipe, the noisy fan units are outside. They also provide heating as well as cool fresh air. It's more common to see these types of AC units in the UK rather than full on industrial ones.

Regarding the speakers firing down the shorter wall rather than longer wall... well I've read that as long as the rear wall is atlas 10' away from the listening position then it is not too much of an issue. The necessity to have a sideways facing, wider rather than longer CR is due to my desk being over 3m long and 1.5m wide. It would be crammed into the space if it was on the shorter wall and due to the width of the desk it would bring my listening position back to pretty much dead centre of the room, which is also a no no right? Also, I prefer just tilting my head to the side to get a full view of the live room rather than trying to look over the desk/screens that are always in the way from sitting. Also, I'd like to be able to see the room to the left of the CR, and for them to be able to see right through into the live room. However, if it really is a big issue then I will just have to change it somehow.

ray tracing? is that to show where the sound from the speakers will hit the walls? If so, yes I have done that and so long as the rear wall is treated correctly I should have a great listening sweet spot.

Well, I'll go back an adjust my design, in the mean time if you have any other suggestions please let me know!

So I've done a complete redesign:

Forwards facing control room, longer than wider, based roughly on a Sepmeyer ratio. Lots of space at the rear and ceiling for bass trapping, as well as a little at the front if needed. Iso room on the side.

I've roughly divided up the rest of the space for now but am looking for opinions on how I should do it? My idea is to have the main live room with a biggish iso next to it. Doing it like this means that the iso and live room both have independent entrances in the hall way leading to the control room, W.C. and exit.

A few questions:

The hallway is my airlock, so I'll be walking into my air. Is this acceptable? If so, should I put plasterboard on both sides of the wall or leave it off the hallway side of the wall?

The smaller iso next to the C.R. is constructed with just a single wall rather than double walls, will this create a third leaf? If it is not a good idea then what is usually done in this situation as I have seen many studios that only have a single door into the next room. Same with built in cupboards etc.

Thanks for your suggestions

I just drew this up for you to show you how you will have to do your two leaf system properly. I hope this helps. It's not the perfect dimensions as you didn't include every dimension or indicate how thick your walls were. That's one thing I did change. I used 6" exterior walls (assuming siding on the outside) and only 2x4 interior walls (actually only 3 1/2" thick) with 1" gap between the 2x6 outer leaf and the 2x4 inner leaf.

I also attached the .skp file for you. In order to import this into your SketchUp Make version, just google SketchUp 3D warehouse and sign in. Upload the file from your computer. Then open your SketchUp Make program and in the menu, go to "window" "3D Warehouse". From there, you should be able to import the .skp and it will convert to your version.

If you noticed, I put another wall to "seal" your hallway, making it a proper sound lock. So, you always have to go through 2 doors between rooms.

This layout isn't bad. I see why you have to have your control room rotated that way, essentially giving your inner leaf 21 feet of length (which is great by the way). The machine room is pretty small though. And will get much smaller with any amount of acoustic treatment in there. If it is purely a machine room/ second escape route, cool. But I wouldn't count on having it sound very good or be useful for anything short of maybe miking up a guitar amp. The good thing about this design is that you have sight lines between the vocal/ISO room, the live room and the control room. Also, this does allow someone in the control room to go to the bathroom without interfering with any recording going on. Maybe your machine room could have a coffee maker/microwave/other supplies in it which would utilize it's space.

I wasn't super pumped on the design until I started thinking through the design more and realized that it is pretty functional. That long hallway feels like wasted space a bit, but I'm not able to think of another way of doing it while maintaining the orientation you need for your control room. Furthermore, I too have a long hallway about the same length in my personal design haha

Maybe one of the pro's can chip in some suggestions.

Greg

Gregwor wrote:I just drew this up for you to show you how you will have to do your two leaf system properly. I hope this helps. It's not the perfect dimensions as you didn't include every dimension or indicate how thick your walls were. That's one thing I did change. I used 6" exterior walls (assuming siding on the outside) and only 2x4 interior walls (actually only 3 1/2" thick) with 1" gap between the 2x6 outer leaf and the 2x4 inner leaf.

I also attached the .skp file for you. In order to import this into your SketchUp Make version, just google SketchUp 3D warehouse and sign in. Upload the file from your computer. Then open your SketchUp Make program and in the menu, go to "window" "3D Warehouse". From there, you should be able to import the .skp and it will convert to your version.

If you noticed, I put another wall to "seal" your hallway, making it a proper sound lock. So, you always have to go through 2 doors between rooms.

This layout isn't bad. I see why you have to have your control room rotated that way, essentially giving your inner leaf 21 feet of length (which is great by the way). The machine room is pretty small though. And will get much smaller with any amount of acoustic treatment in there. If it is purely a machine room/ second escape route, cool. But I wouldn't count on having it sound very good or be useful for anything short of maybe miking up a guitar amp. The good thing about this design is that you have sight lines between the vocal/ISO room, the live room and the control room. Also, this does allow someone in the control room to go to the bathroom without interfering with any recording going on. Maybe your machine room could have a coffee maker/microwave/other supplies in it which would utilize it's space.

I wasn't super pumped on the design until I started thinking through the design more and realized that it is pretty functional. That long hallway feels like wasted space a bit, but I'm not able to think of another way of doing it while maintaining the orientation you need for your control room. Furthermore, I too have a long hallway about the same length in my personal design haha

Maybe one of the pro's can chip in some suggestions.

Greg

Greg thanks so much for taking the time to do that for me, it's fantastic! Very kind of you.

I did originally draw up my design very similar to this with two doors for each room etc, but my reasons for changing it were on the basis of thinking about how much isolation I'll need/not need and weighing up the costs.

For example, the idea of the extra iso/machine room was for those occasions where you just need a little extra space and are recording something quietly such as vocals or acoustic guitar, where you may not be too worried about the sound of the room but just need to close mic something away from the rest of the band. But it's real function is a storage area/machine room. With this in mind, wouldn't one wall be enough between that room and the C.R. ? It would still have the external wall round it. Or by doing this am I going to compromise the C.R. isolation? I do not mind if it is compromised between the machine room and the C.R. but if it will compromise it between the C.R. and outside world then I can see that it is necessary. Also bear in mind that I live out in the country so I am not aiming for absolutely best isolation possible, just enough.

Secondly, the hall way. I have seen a lot of studios built this way where the corridor is the air. What are the disadvantages of this? From my point of view it would add more isolation due to the massive air gap between the two walls that would form the corridor. It might be compromised when someone opens a door, but that is only really a problem if it is the live room door, in which case recording would have to stop due to that person ruining a take. If someone opens the C.R. door it will not be so loud that it is likely to cause a problem, I do not monitor loud in any case. Secondly the cost would be double for that corridor, which I am willing to live with if it is necessary but if it is not then of course I do not want to pay for it. I am not suggesting at all that you are wrong, more that I do not understand why it is a problem?

It's difficult to see in my floor layout but I've drawn the live room smaller, the same width as the C.R. with the corridor extending all the way up to the larger iso booth. I did this because it would allow separate access between the live room and iso booth, so the two areas can be recorded without one disturbing the other when someone needs to exit. It also makes the room more rectangular than square if I do that, which should hopefully sound better, though in any case acoustic treatment will be needed.

Once again, thanks for your time and your input, it's really useful and appreciated. I just need a few clarifications before committing to a design.

Here, I've removed the one wall in the hallway,

Yes, you could do this and still have isolation between all of the rooms. However, when it comes time to finish the walls, you will have a gap visible between every room and the ceiling. Cosmetically, and to save space, you might be best off making at least that hallway wall of your control room inside out so that there is drywall in the hallway. That would also keep the resonant frequency of that wall super low, all while saving you space.

Regarding a single wall between your control room and machine room, I wouldn't do it. Single walls offer atrocious transmission loss (relying solely on the mass law equation). It really is not hard to build a decoupled wall and won't cost that much more for a little room like that. You could build that inside out as well to maintain size and offer a good chunk of the acoustic treatment (insulation in the wall studs) you'll need to make it usable.

You can have that hallway extra long, but chances are, if someone is in the vocal booth, I doubt they're going to peace out mid take. Unless my measurements are wrong, it's not a square dimension without the hallway. If it is, you could build the wall out a bit and use it for storage or to put some HVAC silencer boxes.

Lastly, your most recent design shows speakers that are on stands, yet your design resembles more of an RFZ style control room. That means you should be flush/soffit mounting your speakers. The area behind your flush mounted speakers needs to be quite deep in order to accommodate the depth of the speakers. Also, once you start ray tracing, you'll see that that front wall may have to slide towards you in order to avoid first reflections from hitting your head. This isn't a bad thing though. The deeper that area is (between your inner leaf drywall and the front of your acoustic wall), the better your bass traps (which are in the lower portion of your soffits) will perform.

Having said that, with your wrap around type window (which will cost a crazy amount of money) will mean your speakers have to either 1) be on stands or on the dog house of your console -- they will block your sight lines and sound like crap because there is no broadband absorption behind them (as it's glass) so you will get front wall reflections, phasing issues, probably super bad SBIR, and almost guaranteed comb filtering. OR 2) be flush mounted up high above the glass which means the acoustic axis of your speakers will be much higher than the recommended 1.2m (~47") and have to be tilted down. You mentioned you have a large console. Any time you tilt down speakers, you have a very high chance of screwing with your midrange as you will be getting first reflections from the top of your console. The EBU 3276 states that you should avoid tilting your speakers down more than 10 degrees. A lot of people on the forum have spent (from what I can tell) years trying to determine the optimal or maximum angle of tilt for speakers and the general consensus is to not tilt them at all, but if you have to, to have it only a few degrees, preferably less than 5 degrees. Now, you won't have a massive control room. So, you don't have the luxury of having your speakers far away from you to allow you minimal tilt. I'd only have 1 center window if I were you and properly mount your speakers in floor to ceiling soffit walls at 47" off the ground. The only downside to this is that your sight lines won't be as good and your studio may not look as cool. You might be able to get away with some amount of wrap around type window though if you design it well. What I'm picturing in my head is that if you can maybe try to get your window flush with your soffit wall, the window could act as extension of your wall, ultimately contributing to the infinite baffle concept.

What do you think?

Greg

Gregwor wrote:Here, I've removed the one wall in the hallway,

Yes, you could do this and still have isolation between all of the rooms. However, when it comes time to finish the walls, you will have a gap visible between every room and the ceiling. Cosmetically, and to save space, you might be best off making at least that hallway wall of your control room inside out so that there is drywall in the hallway. That would also keep the resonant frequency of that wall super low, all while saving you space.

Regarding a single wall between your control room and machine room, I wouldn't do it. Single walls offer atrocious transmission loss (relying solely on the mass law equation). It really is not hard to build a decoupled wall and won't cost that much more for a little room like that. You could build that inside out as well to maintain size and offer a good chunk of the acoustic treatment (insulation in the wall studs) you'll need to make it usable.

You can have that hallway extra long, but chances are, if someone is in the vocal booth, I doubt they're going to peace out mid take. Unless my measurements are wrong, it's not a square dimension without the hallway. If it is, you could build the wall out a bit and use it for storage or to put some HVAC silencer boxes.

Lastly, your most recent design shows speakers that are on stands, yet your design resembles more of an RFZ style control room. That means you should be flush/soffit mounting your speakers. The area behind your flush mounted speakers needs to be quite deep in order to accommodate the depth of the speakers. Also, once you start ray tracing, you'll see that that front wall may have to slide towards you in order to avoid first reflections from hitting your head. This isn't a bad thing though. The deeper that area is (between your inner leaf drywall and the front of your acoustic wall), the better your bass traps (which are in the lower portion of your soffits) will perform.

Having said that, with your wrap around type window (which will cost a crazy amount of money) will mean your speakers have to either 1) be on stands or on the dog house of your console -- they will block your sight lines and sound like crap because there is no broadband absorption behind them (as it's glass) so you will get front wall reflections, phasing issues, probably super bad SBIR, and almost guaranteed comb filtering. OR 2) be flush mounted up high above the glass which means the acoustic axis of your speakers will be much higher than the recommended 1.2m (~47") and have to be tilted down. You mentioned you have a large console. Any time you tilt down speakers, you have a very high chance of screwing with your midrange as you will be getting first reflections from the top of your console. The EBU 3276 states that you should avoid tilting your speakers down more than 10 degrees. A lot of people on the forum have spent (from what I can tell) years trying to determine the optimal or maximum angle of tilt for speakers and the general consensus is to not tilt them at all, but if you have to, to have it only a few degrees, preferably less than 5 degrees. Now, you won't have a massive control room. So, you don't have the luxury of having your speakers far away from you to allow you minimal tilt. I'd only have 1 center window if I were you and properly mount your speakers in floor to ceiling soffit walls at 47" off the ground. The only downside to this is that your sight lines won't be as good and your studio may not look as cool. You might be able to get away with some amount of wrap around type window though if you design it well. What I'm picturing in my head is that if you can maybe try to get your window flush with your soffit wall, the window could act as extension of your wall, ultimately contributing to the infinite baffle concept.

What do you think?

Greg

So, I think it's important for me to say that I'll have to build this whole studio in stages. Right now what will be the C.R. structure is basically built. It's an old timber framed outbuilding that just needs the height extending and a new roof. The walls are built though, and is standing on a concrete slab. The dimensions just happen to be around 15' x 21', so I am going to try to make that work as it is, all I need to do is insulate and board it. Once I've done that and I have more money I will build the external walls as well as the other rooms. This means that my first stage will only be a single wall construction, and at a later date i'll remove the roof, put it to one side and then reattach it to what will be the outer shell. I am not expecting much isolation at this first stage, and that's fine as it will just be enough to function as a mix room/storage for all my gear.

I see what you mean about the hallway, I think I could find a solution to the gaps though by using a similar method to dealing with the gaps between windows, or I could just put the wall in like you suggested... it would just be cheaper if I could do without it, and it's always nice to not have to open loads of doors to get from room to room Provided that I build it properly, are there any disadvantages isolation-wise to not having the extra wall in place?

Yes the live room would not be completely square if I made it bigger, due to the iso booth cutting off the corner and the bottom wall being longer than the top wall etc, but if I average it out it's a little squarish... it's hard to work out what the room ratio would be in order to work out potential modal issues, especially with vaulted ceilings. I am undecided as in some ways it would be nice to have independent access for each room just in case I decide to use that iso booth as a green room as well. I like your idea about having a little kitchenette in the iso next to the C.R. that's a great idea.

Flush mounted monitors: yes, originally I was planning on doing that and I would adjust my layout to accommodate that but I've been put off doing it recently because I think it is quite hard to get it spot on, and it's not the kind of thing you want to get wrong. Granted, those issues you mentioned with stand mounting against glass are also not good. One of the main reasons for not doing it right now is that I don't have any large full range mains, so even though I'd like to get some in the future, at present it's hard to design to accommodate speakers that you don't have, or even haven't chosen. I suppose to future proof it I could leave enough space behind my front treatment so that if I did want to invest in some I could just take the frame down. I do have a load of nice rough cut stone that would make a beautiful front baffle. If I was to flush mount then you are right, I would need to either redesign or sacrifice the wrap around window and sight lines, which would be cheaper and still functional. The best place for the speakers to be mounted is where the shorter angled panes of glass would be.

I'm also quite inspired by Frank Zappa's old studio at his house, which has the wrap around window and no soffit/flush mounted mains. Granted, it probably isn't the best design though. See here: https://cdn.vox-cdn.com/uploads/chorus_ ... 6329.0.jpg

I totally understand. With your dimensions (somewhat close to my own) for your control room, your front acoustic wall will probably be far enough back to accommodate future speakers. Also, note, you don't need massive speakers. You can mount 4" driver speakers if you really want!
Rough stone wouldn't be the best for the soffit walls because you're basically needing to make an infinite baffle, and I'm pretty sure there's a reason the fronts of speakers aren't all jagged and such!
To future proof, you could make a removable square/rectangular bezel around the speaker that you could size accordingly depending on the speaker model you have installed. That way you don't have to entirely rebuild the wall. Also, I don't think it's too hard to make the soffit situation. There are lots of pictures to reference, and if you design it stud for stud in SketchUp, you should be good to go!

I don't think there's any harm in having a single wall in your hallway like you suggest, and yes, you could totally fill the gap the same as you would a window or a two door gap. Also, doors are very expensive, even homemade super doors (the hardware).

Greg

Gregwor wrote:I totally understand. With your dimensions (somewhat close to my own) for your control room, your front acoustic wall will probably be far enough back to accommodate future speakers. Also, note, you don't need massive speakers. You can mount 4" driver speakers if you really want!
Rough stone wouldn't be the best for the soffit walls because you're basically needing to make an infinite baffle, and I'm pretty sure there's a reason the fronts of speakers aren't all jagged and such!
To future proof, you could make a removable square/rectangular bezel around the speaker that you could size accordingly depending on the speaker model you have installed. That way you don't have to entirely rebuild the wall. Also, I don't think it's too hard to make the soffit situation. There are lots of pictures to reference, and if you design it stud for stud in SketchUp, you should be good to go!

I don't think there's any harm in having a single wall in your hallway like you suggest, and yes, you could totally fill the gap the same as you would a window or a two door gap. Also, doors are very expensive, even homemade super doors (the hardware).

Greg

Okay... i've played around with the idea of keeping the wrap around glass but also fitting flush mounted monitors. (see attached) It's not easy because of the small width... The only way I could do it is by angling the monitors at 90 degrees instead of 60. I don't think I like this design too much, I did play around with doing it a different way too (basically having 3 front windows with the monitors at each side of the middle pane) but there's not really much to gain in terms of sight lines by doing it like that.

I think i'll either have to have the monitors up higher angling down or do away with the wrap around window and just have a single window in the middle. The only thing that did make me think was if I ended up getting some barefoots (in my dreams) then I wouldn't want to flush mount them but would still end up with the problems of stand mounting.

I like the idea of flush mounting but with the monitors hidden. Or perhaps even on stands within the acoustic wall with the acoustically transparent fabric covering them. I think it would help me focus on the sound with my ears rather than my eyes.

Any other ideas about the control room window?

The only way I could do it is by angling the monitors at 90 degrees instead of 60

Well, your drawing sure looks cool anyway!
Try putting your head at the recommended ~38% depth within the room (from the inner leaf drywall). And instead of angling the glass at 45 degrees like you have in your drawing, set those walls to 30 degrees. Like I had to in mine, your acoustic wall may have to shift towards your mix position (my room is 23' long, yours is 21' so they should be pretty close in what's required to get the RFZ ray tracing happening properly). Draw that up and let me see how it comes together. Also, when you ray trace, set the junction point of the traces behind your head slightly as to get the traces grazing past your ear tips, not hitting your nose

Regarding Barefoots, I talked to Thomas because I am thinking about getting rid of my NS-10's since I probably shouldn't be flush mounting those and my Dynaudio's have a rear port and a weird shaped baffle. He did say that you can flush mount the MM45's. He also gave me a 2nd order low shelf circuit to build and put in line with a variable attenuator potentiometer to dial it in. I'd maybe modify the circuit a bit once I calculated the exact size of my soffit/baffle walls.

This is awesome that you're taking such care and putting so much thought into your design BEFORE you start building onto the existing structure. Exciting!

Greg

Gregwor wrote:

The only way I could do it is by angling the monitors at 90 degrees instead of 60

Well, your drawing sure looks cool anyway!
Try putting your head at the recommended ~38% depth within the room (from the inner leaf drywall). And instead of angling the glass at 45 degrees like you have in your drawing, set those walls to 30 degrees. Like I had to in mine, your acoustic wall may have to shift towards your mix position (my room is 23' long, yours is 21' so they should be pretty close in what's required to get the RFZ ray tracing happening properly). Draw that up and let me see how it comes together. Also, when you ray trace, set the junction point of the traces behind your head slightly as to get the traces grazing past your ear tips, not hitting your nose

Regarding Barefoots, I talked to Thomas because I am thinking about getting rid of my NS-10's since I probably shouldn't be flush mounting those and my Dynaudio's have a rear port and a weird shaped baffle. He did say that you can flush mount the MM45's. He also gave me a 2nd order low shelf circuit to build and put in line with a variable attenuator potentiometer to dial it in. I'd maybe modify the circuit a bit once I calculated the exact size of my soffit/baffle walls.

This is awesome that you're taking such care and putting so much thought into your design BEFORE you start building onto the existing structure. Exciting!

Greg

Thanks for the encouragement, and the help! I am putting so much thought into it because I want to get it right... I am only going to get one chance to build it so it's worth as much effort as I can muster.

I would love to see your place? Do you have a website or design thread?

I would love to see your place? Do you have a website or design thread?

I'm still in the design stage like yourself actually! Obviously I'm a bit further along than you, but still scratching my head problem solving haha I'm just sharing any knowledge I acquire along the way.

Once phase 1 of my design gets closer to completion, I'll create a design/build thread. I too am working hard on things. The foundation is pretty much done on the house now and I'm doing my best to coordinate with the trades guys so that they don't leave me with a mess to build around! It sure is hard with kids and so much paying work to find time to design. I should get keys to our house in October - December depending on build progress so I have until then to work out bugs and build for sure items like doors and buy things like HVAC registers/glass that might take a while to be delivered.

Greg

Gregwor wrote:

I would love to see your place? Do you have a website or design thread?

I'm still in the design stage like yourself actually! Obviously I'm a bit further along than you, but still scratching my head problem solving haha I'm just sharing any knowledge I acquire along the way.

Once phase 1 of my design gets closer to completion, I'll create a design/build thread. I too am working hard on things. The foundation is pretty much done on the house now and I'm doing my best to coordinate with the trades guys so that they don't leave me with a mess to build around! It sure is hard with kids and so much paying work to find time to design. I should get keys to our house in October - December depending on build progress so I have until then to work out bugs and build for sure items like doors and buy things like HVAC registers/glass that might take a while to be delivered.

Greg

Look forward to seeing it

Been playing around with my room again. If I am going to flush mount the monitors then I want to use some that are fairly hefty, something like Tannoy DMT15s or Ardens. It also occurred to me that they will only really be used for the client's benefit, when they want to crank their music, not really for me while mixing though they will come in handy for checking the low end. With that in mind, I should be aiming the speakers at the couch rather than my mix position. Now, I could do this quite easily and still have a nice big wrap around window, but it would put the main monitors right in the corners of the room (due to the narrow width of the room). I've read that the monitors should not be right in the corners though I have not yet found out why. I'm just guessing it will have something to do with modal build up in the corners and also being right next to a boundary from the side walls.

This lead me to the following main options:

1. Mount them in the corners anyway
2. Mount them in a better position and make the window smaller
3. Mount them above the window and tilt them down

Option 1.
If I mount them in the corners I can aim them at 60 degrees so that they reach 38% of the room from the REAR wall. This will be just in front of the sofa and probably good enough for the clients. But they will be mounted in the corners.

I could mount them at 90 degrees and they would be aimed at MY mix position, but they would still be in the corners.

I could bring them in from the corners slightly but then they would aim close to the 50% mark of the room, which is also a no no. (See left diagram in attached image)

Option 2.
(See right diagram in attached image) This in theory should sound best, and they would be aimed at MY mix position, but would also sacrifice a portion of the available sight lines, but it does meet the following criteria (found in this forum):

1) The speakers should not go in the corner, nor on the line that divides the corner. In other words, if your walls intersect at 90°, then draw a line out from each corner at 45°, and stay away from that: don't put your speaker exactly on that line, since it implies that you'll be getting the same artifacts from the side walls as from the front wall. Put your speakers either outside or inside of those lines. More commonly you'll want your speakers "inside" those lines (more towards the center line of the room).

2) The "38% of room depth rule" is not a rule, but it is a useful guideline for a starting point. You'll generally want to have your listening position a bit closer to the front wall than that location, but do be aware that you might be getting into problematic SBIR territory there. (You can treat that, to a certain extent).

3) Keep the mix position away from 25% and 50% of room depth, and try to stay between about 32% and 44%

4) You can angle your speakers differently than the "textbook" 30° angle: Anything in the range 25° to about 35° will work well under most circumstances.

5) Keep the speakers as far apart as possible, wile not violating rules 1 and 4.

6) Keep the mix position at a good distance from the speakers, within the range of about 1m to about 5m. Further away is usually better.

7) Don't put the speakers at 25% of the room width: that's a modal null for some frequencies, and a peak for others. Try something more like 28% to 34%.

8 ) Make the front baffle of your soffit as wide and tall as you can, within reason. The width should be at least three times the diameter of your low frequency driver. In other words, if you have a speaker with an 8" woofer, then you want the soffit baffle to be at least 24" (60cm) wide. Wider is better.

9) Do not put your speaker in the middle of the soffit baffle: Offset in both directions. In other words, the distances from the acoustic center of the speaker to each edge of the baffle should be very different, by at least 20%. So for example if your speaker axis is 30cm from one side of the baffle, it should be more than 36cm from the other side, less than 24cm from the bottom edge, and more than 44cm from the top edge. (Rough distances, for illustration only...). Larger differences are generally better.

10) Make the baffle as massively heavy as you can, and as rigid as you can.

11) Make the structure inside the soffit (the framing that holds the baffle and speaker in place) as rigid and massive as you can.

12) Mount the speaker inside an enclosure box that is either a very tight fit, in order to keep the speaker rigidly fixed in place, or mount it on suitable rubber pads, to completely decouple it from the the box. Carefully choose the properties and dimensions of that rubber, to make sure the speaker is still decoupled down to at least one octave below the speaker's low cut-off frequency.

13) Take into account that speakers need a lot of space behind them for cooling, and a path through the soffit for cooling air to flow.

14) Rear-ported speakers need special attention: Do not overload the rear port, acoustically, with an enclosure box that is too small, or un-ventilated, or un-damped.

15) Damp the hell out of the soffit interior! Fill it entirely with suitable damping if you want, except for the cooling path

Option 3:

If I mount them above the window and tilt them, then I could basically place them wherever I wanted on the front wall. I would be happy with this option as it would give me the biggest window, but I know that tilting them is not ideal neither recommended (despite the hundred of control rooms that have done exactly that) However, if they are for occasional 'party time' listening and not for precision mixing it would not be a big deal. If I wanted to try and make this option work for precision mixing then I have heard of studio designers positioning the console to minimise reflection. If I wanted them to be aimed at the clients on the couch then the tilt angle could be lessened. I could also do what I've seen John Sayers do as well as other designers and that is bring the height of the speakers down and use shorter panes of glass under the speakers, almost as if the speakers are cutting in to the window. This would be a nice compromise I'd be willing to live with. The complications of doing this lie in supporting the weight as they would need to be suspended.

So these are the options I am weighing up at the moment. Let me know your thoughts. I really need a soffit/flush mounting expert to chime in here before I go any further.

You're certainly on the right track here!

monitors should not be right in the corners though I have not yet found out why

You answered your own question in your post:

don't put your speaker exactly on that line, since it implies that you'll be getting the same artifacts from the side walls as from the front wall

I think those are your 3 options. Things I thought of while reading your post were:

- YOUR the mixing engineer, not the people sitting on the couch. No matter where you speakers are, they'll be able to hear them, it's YOU that needs to do the critical listening.
- You don't need massive speakers. Your room isn't massive. You can use tiny speakers if you want.
- Sure it's nice to have some sight lines, but you don't need a 180 degree view. I'm sure any of the options you listed would suffice.
- I like option 2 and 3. 3 would entail more work and more money. Also, having the acoustic axis of the speaker low enough in option 3 would render a window useless. Therefore, if this was my baby, I'd vote for option 2.

What are your questions about soffit mounting? I'm personally in the process of navigating the rabbit hole that is Sorbothane.

Greg