Flush mounting plans review

How thick should my walls be, should I float my floors (and if so, how), why is two leaf mass-air-mass design important, etc.

Moderators: Aaronw, sharward

parnas
Posts: 4
Joined: Mon Aug 23, 2010 11:10 am
Location: Ukraine

Flush mounting plans review

Post by parnas »

Hi. I've managed to rent a larger building, adjacent to my current current studio, which I'm going to use as the new live room. So I'm converting my current live room to be a control room (and I'll turn my current control room + vocal booth into a project / vocal studio).

I've designed the old control room myself (that was about 10 years ago), after studying this form and Rod Gervais' book. And, while it also has the flush mounted speakers, the room layout is simpler (and smaller) than the new one.

Old control room only had one set of monitors (Quested VS2108). In the new room I want to flush mount KS Digital ADM1 ( https://web.archive.org/web/20040116025 ... adm_1.html ) as the main monitors. I also have Quested H108 lying around, which I was thinking to use as either the console-top or stand mounted nearfields.

The room at the right is the storage room (I'm thinking of putting my computer and converters there now). And I want to convert the room at the top left (the pink walls one) into a vocal booth. It doesn't have the door from the new control at the moment, so I'm going to make one.

Frequency response is nothing to look on, at the moment, since the room wasn't treated to be a control room before. We have big SBIR issues, which, I think, would be magically fixed by the flush mounting.

Anyway, let me know what you think. Thank you.
Last edited by parnas on Sun Apr 05, 2020 8:32 pm, edited 1 time in total.
Paulus87
Senior Member
Posts: 652
Joined: Sun Mar 02, 2014 8:42 am
Location: Wales, UK

Re: Flush mounting plans review

Post by Paulus87 »

Hi,

Are you able to build inner framing with drywall at all? Your room is a-symmetrical so would be nice if you are permitted to change it - let us know. You also may want the extra isolation?... although looks like you won't need it.

Your current layout has your listening position pretty much dead centre of the room which is one of the worst places for it to be. Ideally you'll want it to be 38% (or technically 37.5%) of the length from the front wall... however, if this is going to be a completely sealed hard flush then you'll measure from the middle section of your speaker wall.

If it's a soft flush or hybrid flush then you'll still measure from the existing front wall.

It's hard to make out your flush mount design based on that 3d sketch alone, it looks interesting but potentially problematic. Firstly your speakers are up high and angled down which is best avoided if possible. In your case it looks like it is easily avoidable due to you not having to worry about any windows underneath for example, I can only assume you have done it like this so that they shoot over your near fields as well as reaching the client couch ear height behind you? If those are the reasons then there are other ways of dealing with those issues without needing to put your monitors up high and angled down.

Can you upload a 2d top view of it? Have you done any ray tracing? Depending on the design concept for your room you may want to add "soffit wings". However if you're doing a non environment style room or relying purely on absorption to deal with your first reflection points then those wings are not necessary (there are some people on the forum that are convinced you cannot create a reflection free zone unless using geometry to achieve it, I disagree with this and say it's actually better to avoid unusual geometry IF it's not needed).

Also, what is the height of your room?

Paul
Paul
parnas
Posts: 4
Joined: Mon Aug 23, 2010 11:10 am
Location: Ukraine

Re: Flush mounting plans review

Post by parnas »

Paul,

Thank you for your reply.

We were definitely thinking about hard flush, and internal drywalls is not a problem. And, thankfully, we do not have to worry about sound isolation nearly at all.

In fact, before I'll go further, we even had an idea, which seems crazy on the first sight... but is it? Instead of building an internal wall, what if we cut openings in the one we already have, and then build a cover structure outside (we can do that, speaking legally and technically).

Something like this (but with speakers disconnected from the wall):
Studio. Hole.jpg
As for the monitors angle - you are completely correct, that was because of the nearfields placement. I've lowered them in my plans now (they are still angled in 3d visualizations of the wall, but those were made before).

The height of the room is 2.830m

We are not doing NE room, and I was planning on using absorption for the first reflections (that's what we did in the previous control room). However, we can do wings as well, or both (if I understand what wings are correctly :) )

Here is the top view at the construction, we currently have in mind (the superchunks in the corners are there already, we can, obviously, add much more trapping inside, if needed, or use it as a storage :D ):
Studio. 2D Flush Walls.jpg
And here is the one with some dimensions (from that flush wall):
Studio. Hard Flush Dimensions.jpg
Paulus87
Senior Member
Posts: 652
Joined: Sun Mar 02, 2014 8:42 am
Location: Wales, UK

Re: Flush mounting plans review

Post by Paulus87 »

If you're doing a proper hard flush then there is no need to put super chunks in the corners behind the hard flush wall... when you do a hard flush the new wall in which you flush the monitors becomes the new fully sealed front wall, therefore your room dimensions/volume change and all treatment should be inside the room instead of behind the walls.

Your idea to cut sections out of the bricks in order to wedge in the monitors could work, I would cut the holes a lot larger (within reason) than your current monitors just in case you get bigger ones in the future. This would enable you to move your listening position out of the centre of the room, which is definitely a good thing. Bit of a big job though...

What is the small external room with a door to the top left? Can you utilise it as part of your studio OR block it off? Can you block any of the doors off?

If it were me then I'd arrange the room like this, red is where I'd add drywall to keep the room symmetrical and add the hard flush. I'd get rid of the two other rooms and have the speakers shooting down the length of the room. This is of course if you can block off doors.
parnasstudio.jpg
Paul
Paul
parnas
Posts: 4
Joined: Mon Aug 23, 2010 11:10 am
Location: Ukraine

Re: Flush mounting plans review

Post by parnas »

Hello Paul.

Unfortunately, making it like this is not really possible. Otherwise, we'll have quite a bad isolation between two studios.

I've created the full building plan, with all the rooms and dimensions.
Studio. Full.jpg
Paulus87 wrote:If you're doing a proper hard flush then there is no need to put super chunks in the corners behind the hard flush wall
They are just already there. Would, probably, be more trouble to move them, than to leave them :)
Paulus87 wrote:What is the small external room with a door to the top left? Can you utilise it as part of your studio OR block it off?
Just a small empty room. I was thinking of using it as a storage / computer room.
Paulus87 wrote:Can you block any of the doors off?
We can, if needed. Those are all "our" doors, it's a free standing building.


We've measured and experimented a bit, and it seems, that we can cut just a part of the wall, to put the speaker corner there, which will place listener at quite a good position (if I'm not mistaken): 1.87m from the front wall, 3.4m from the back wall.
Studio. Wall Cut.jpg
Studio. Wall Cut Top View.jpg
(it's not clear on the picture, but, obviously, the hard flush wall wings would extend to the walls on the left and right.

What do you think about that? Any better? :)
Paulus87
Senior Member
Posts: 652
Joined: Sun Mar 02, 2014 8:42 am
Location: Wales, UK

Re: Flush mounting plans review

Post by Paulus87 »

I think your plan looks a little better, the only thing I wish you could change is making the room symmetrical, and since you are constrained by that factor I am not sure how to continue as I have never worked in or designed an asymmetrical room before, so I just don't have the experience dealing with the potential challenges that will bring. It's good that the room is symmetrical from the listening position to the front wall, and it's good that you have moved your listening position from dead centre.

Flush mounting the speakers in your front wall is going to help with reducing the SBIR, though I should imagine it will be very strong coming from your rear wall; not only are you shooting down the short dimension of the room but your walls are also very rigid and massive, which means you'll have strong reflections to deal with, more low end reflections than a typical stud wall. You'll have peaks and nulls related to your speaker/listener position, not just modal issues.

The only advice I could offer you now is to make your rear wall very absorptive, you might need to use some membrane or Helmholtz traps to save space, but you'll also need some broadband absorption there too. You'll know better if you can measure the room and see what issues you'll have at the listening position.

Regarding your baffle wings, are you going for a geometrically controlled reflection free zone? Personally, especially in rooms which are wider than they are longer I would consider saving some space and relying on absorption instead of deflection to control first order reflections, so your baffles could either extend all the way to the side walls, or you can angle them back on them selves a little, for example if your speaker baffles are angled at 30 degrees, your wings could be angled at 25 degrees. just some thoughts.

Looking forward to seeing the rest of your design progress!

Paul
Paul
parnas
Posts: 4
Joined: Mon Aug 23, 2010 11:10 am
Location: Ukraine

Re: Flush mounting plans review

Post by parnas »

Hello Paul,

We have "spooned" up part of the wall to mount the speakers, and, of course, even without the additional treatment, the sound is noticeably (and measurably) better, than when they were pointed to the middle of the room.

Here is how it looks ATM:
Studio. Speaker Holes Closeup.jpg
Studio. Speaker Holes.jpg
So now we need to decide about the form and the construction of the wall.

Here are the two form options. The simpler one (we cannot make the wings fully straight, since then the left one would end inside the door):
Studio. Simple Wings Top View.jpg
Studio. Simple Wings 3d.jpg
And the better looking, but "anglier" one:
Studio. Anglier Wings Top View .jpg
Studio. Anglier Wings 3d.jpg

Do you see any potential problems with the "anglier" version?

Now, about the construction. Am I right in my understanding, that we can build most of the construction from the drywall, but the baffle itself needs to be heavier? In that case, my question is how large should the baffle be? The black zone around the speakers in the current drawing is about 20cm each direction, is this is enough, or should the baffle be larger?

Another question, just out of the simplification of the construction, can we do Drywall->insulation for the wings, instead of the drywall->insulation->drywall? Or even second wouldn't be enough, and we need to do two leafs?

As always: thank you :)
Paulus87
Senior Member
Posts: 652
Joined: Sun Mar 02, 2014 8:42 am
Location: Wales, UK

Re: Flush mounting plans review

Post by Paulus87 »

Fred, have your your listening position at 37.5% (if it isn't already) out from the front wall, toe your speakers in at 25 degrees instead of 30, but have the listener still be at 30 degrees to the speakers. 5 degrees off axis will have almost no audible effect for the listener and will provide a wider dispersion. This should allow you to have your baffles extend straight to the walls.

If the listening position needs to move a little closer to the front wall then that's fine, just avoid 25%.

Paul
Paul
Post Reply