Studio build in Wales, UK...again!

[John Steel]

Hello & howdo' Paul?
I have been following your build with great interest although I haven't contributed to the discussion (this is simply because I don't think I have any thoughts of value to offer on the specific topics you mention and I've been up to my armpits in tanking compound for the last few days)! However, I'd like to say that for someone who is beginning their own build, it's massively helpful and informative to see and read about how your studio is progressing, so please know that it's appreciated!

. . . the more I researched interstitial condensation the less risk I wanted to take

- Not a phrase you hear every day! This information will be invaluable as part of the body of knowledge, so thanks for your thoroughness.

it's a lot of work for a temporary solution.

I'm sure it will pay off for you in the long run, your full attention to detail is a good indicator that it will.

hopefully my condensation woes will be behind me.

Plus one for that sentiment! John.

[Paulus87]

Hi John, fellow brit, I am doing good thanks, howdo' you? (btw, I'm not actually welsh, I'm originally from Bristol )

Thanks for your kind comments and encouragement, it means a lot to have people show interest in my build and I am glad that I can help others learn what not to do

Paul

[Paulus87]

Update:

Got the other soffit vents finished today, now I can *hopefully* get on with finishing the interior.

Has anyone come up with a way to make thick treatment walls covered in fabric less "squidgy" and more resilient without compromising the absorption behind?

Do people find that the stretched fabric is strong enough of a barrier to stop menacing clients from accidentally damaging the walls e.g. picking, leaning up against, tearing, putting headstock through etc...

Paul

[Gregwor]

Has anyone come up with a way to make thick treatment walls covered in fabric less "squidgy" and more resilient without compromising the absorption behind?

Do people find that the stretched fabric is strong enough of a barrier to stop menacing clients from accidentally damaging the walls e.g. picking, leaning up against, tearing, putting headstock through etc...

At a theatre located at Disney Land in California it looked like they had a metal mesh (think 1 square inch openings) all over the walls probably for this exact reason. Personally, I will probably just include a note in my studio contract asking people not not lean against the fabric covered walls. It is a real concern but hopefully it never becomes an issue. . .

Greg

[Paulus87]

Has anyone come up with a way to make thick treatment walls covered in fabric less "squidgy" and more resilient without compromising the absorption behind?

Do people find that the stretched fabric is strong enough of a barrier to stop menacing clients from accidentally damaging the walls e.g. picking, leaning up against, tearing, putting headstock through etc...

At a theatre located at Disney Land in California it looked like they had a metal mesh (think 1 square inch openings) all over the walls probably for this exact reason. Personally, I will probably just include a note in my studio contract asking people not not lean against the fabric covered walls. It is a real concern but hopefully it never becomes an issue. . .

Greg

Good tip Greg, I also had the idea of using a metal mesh but behind a layer of Dacron and fabric, so that it is not visible, seems about the only reasonable way of achieving it other than using slats everywhere, which I don't know if I want on my rear wall.

Seems Disney land probably took a leaf out of the BBC's book and built a version of the absorbers found here:
https://www.bbc.co.uk/rd/publications/r ... OACQKqLKgg

Now that I have finished all the temporary vents I've been making my ceiling hangers better. It's clear that Homasote does not keep it's form very well at all if not properly supported at anything other than a completely vertical angle when hanging, and even though they are not that heavy they seem to bow under their own weight.

Ideally I would like to have used chipboard or ply for the hangers, just like Newell does, but I didn't want to add extra weight to my ceiling so I decided to continue using the Homasote but strengthen it with some thin scrap battens I had. This seems to be just enough to stop them bowing, but also keep them lightweight.

I'm also going to make them easy to take down if I ever need to in the future (like when I build my outer shell and can put back the extra insulation behind the hangers without risking condensation again) so I am going to screw eye hooks into the hangers and the ceiling and use little carabiners to hang them. Just waiting for the carabiners to arrive and then I can get on with putting them back up again.

I have an exciting and slightly inconvenient delivery arriving tomorrow; A very much in need of TLC Trident 80C console. I bought it a few months ago since the guy was going to just throw it in a skip, it needs a huge amount of work as it has suffered water damage and most of it is corroded. The work is not the issue though, it's the fact that I can no longer afford to keep it in storage, and the only place I have room for it right now is the unfinished studio.

Ideally I would have liked to have got the room to the stage where it just has basic treatment, but empty, so that I can measure the room. I was almost at that stage when I noticed the water dripping down from the ceiling, so had to stop everything and sort that out.

Now the floor is down and the basic treatment is almost complete but I'll have a big console in the room! So, not too sure what to do about that at the moment. Any ideas? I can still measure the room, but would have been nice to have it empty first.

And to top things off, the cheap calibration mic that I decided to risk buying doesn't have a calibration file and doesn't seem to even work! so I'll need to wait until I can get a decent one in order to make the first measurements. Any recommendations? I was looking at the Dayton Audio EMM-6.

My plan right now is to get the basic treatment in and cover it with some removable frames covered in Dacron, take some measurements and then move the gear in. Then, gradually add the extra treatment and build the speaker wall. The reason being, firstly I do not know what extra treatment it will need without measuring, and secondly I just cannot decide on what design criteria I want to follow in terms of the environment. I'm working on 4 different designs at the moment which I'll upload soon, and then I'll make a decision based on room measurements and feedback from you guys, and whichever one makes most sense to me. It will help me decide once I have a basic environment to work in, so I can test out different layouts and workflow ideas and build the treatment and wiring layout around that.

The other reason is I just don't have enough money coming in right now to do much! I think we're all in the same boat with that one though.

That's all for now,
Paul

[John Steel]

Good to hear about your progress Paul.

I just don't have enough money coming in right now to do much!

It's truly terrifying how quickly building burns cash - despite being an optimist it's hard not to worry!

I have an exciting and slightly inconvenient delivery arriving tomorrow; A very much in need of TLC Trident 80C console.

Congratulations - that'll be a great desk when it's restored. I used to record on one of those in the 1980's and remember it sounded tremendous. I'm looking forward to seeing your photos and designs. ATB John.

[Paulus87]

Good to hear about your progress Paul.

I just don't have enough money coming in right now to do much!

It's truly terrifying how quickly building burns cash - despite being an optimist it's hard not to worry!

I have an exciting and slightly inconvenient delivery arriving tomorrow; A very much in need of TLC Trident 80C console.

Congratulations - that'll be a great desk when it's restored. I used to record on one of those in the 1980's and remember it sounded tremendous. I'm looking forward to seeing your photos and designs. ATB John.

Hey John,

Yes it was hard to resist for the price I got it (about 10% of current market value) and I'm lucky in that an ex trident engineer lives just down the road from me, I teach his kids, he used to build these things so he's excited to help me restore it.

I've also got a DDA AMR24 basically in mint condition, which is another huge desk, bigger than the Trident actually, so my control room is going to be more like a storage container for a while I'm either going to end up using both, putting one in the tracking room once it's built, or selling one. I'll use the DDA for doing work and repair the Trident as and when, then I intend to play with both for a good while before making a decision.

Thanks for the encouragement and interest in my project!

Paul

[John Steel]

I've also got a DDA AMR24 . . .

That's a great desk as well, I know some people rate them along side the very best.

. . . I'm lucky in that an ex trident engineer lives just down the road from me.

That is fortunate! When I had my (infinitely more modest) Soundcraft desk restored a few years ago, the engineer who did the job had worked for Soundcraft in the early 80's. He was slightly dewy-eyed when he saw mine and said that, in all probability, he'd assembled the desk 35 years earlier. Sounds like you are accumulating an embarrassment of riches Paul! ATB JS.

[Paulus87]

Hi guys,

I'm just playing around with a space saving concept here. Has anyone thought/done this before?

After much thought about hangers, I've come to the conclusion that as well as them having a slight, loose membrane effect, the main way in which they work is through redirection. The waves of all frequencies hits the hangers, the highs and high mids are absorbed by the insulation, any frequencies which the insulation does not absorb are reflected off of the angled panel, attenuated and away from the listener into more hangers/absorption. Any lows that creep around the hanging panels find themselves at the rear of the hangers where they are absorbed in more insulation; then, they either pass through the walls/ceiling or reflect back through the labyrinth highly attenuated. That is my theory anyway.

There's 3 main ways I've seen of doing hangers/waveguide absorbers. There's the way most common on here using homasote, there's the Philip Newell way of using heavy particle board with deadsheets, then there's the John Brandt way of using non hanging waveguides, rigidly attached to the framing with the insulation stuffed between the panels.

All three have their pros and cons in my opinion.

But, what about condensing the amount of space these waveguides often take up? and relying on the deflective properties of dense rigid waveguides to deflect all unwanted reflections to the rear of the room?

I've drawn an incredibly rough diagram of what I mean; the side walls have lots of narrow, rigidly fixed waveguides at an angle of ~40 degrees (this angle would vary depending on the room, speaker angle) with insulation stuffed in between, then this can be concealed with fabric. This version only takes up 90mm (the width of 4x2s) but produces an incredibly wide and long sweet spot.

If you were to ray trace this room, you will see that all of the rays that do not get absorbed will be deflected by the many narrow waveguide panels, either they will ping pong around between the waveguides passing through the absorption each time, or they will be deflected completely away from the listening position to the back of the room where they can be absorbed more efficiently, or diffused. This is really combining the concepts of RFZ and NE but in a fraction of the space, since the side walls do not need to be very thick at all.

This would mean that the energy is largely left in the room so that it doesn't feel overly dead, but a wider sweet spot can be produced than a typical RFZ room.

What do you think? Will this work?

Paul

[DanDan]

Random thoughts:- The 'Sawtooth' concept pops up now and then. You can see some examples on Newell's website.
They are usually big areas of slanted wall though. I don't know if they have HF absorption on the surface or not.
The BBC CID system didn't have HF absorption. I used simple angled plasterboard with a foot of fibre behind in a recent venue refurb. No flutter, no loss of HF and MF energy, and great VLF absorption.
90mm treatment will not address Width Modes and non resonant LF reflections.
The 'Sweet Spot' for stereo can only exist in a small area unless radically different types of loudspeaker are used.
Indeed many to most Pro speakers have HF Wave guiding.
Auralex Space Couplers placed under fibre treatments, e.g. clouds, seemed to increase LF dramatically, up to 45% in the 125 Octave if I remember rightly.

[Paulus87]

Random thoughts:- The 'Sawtooth' concept pops up now and then. You can see some examples on Newell's website.
They are usually big areas of slanted wall though. I don't know if they have HF absorption on the surface or not.
The BBC CID system didn't have HF absorption. I used simple angled plasterboard with a foot of fibre behind in a recent venue refurb. No flutter, no loss of HF and MF energy, and great VLF absorption.
90mm treatment will not address Width Modes and non resonant LF reflections.
The 'Sweet Spot' for stereo can only exist in a small area unless radically different types of loudspeaker are used.
Indeed many to most Pro speakers have HF Wave guiding.
Auralex Space Couplers placed under fibre treatments, e.g. clouds, seemed to increase LF dramatically, up to 45% in the 125 Octave if I remember rightly.

Dan, thanks for your thoughts...

I should have said RFZ instead of sweet spot, or even ray free zone...

A couple of ways to deal with modal resonances, the first being the walls are lossy enough to act as membranes and so the low end goes out into the surrounding areas around the control room - not ideal for everyone I’ll admit but for me it’s not an issue in my design.

Secondly the walls could be made thicker, indeed my first concept of this was with 350mm thick walls and the wave guides were about 2’ wide once angled. This is more similar to the NE concept.

I thought I’d try to push it to try and get it as thin as possible, and as simple
As possible. Option 1 of using lossy walls is probably the only feasible way of doing it, with very rigid wave guides.

Effectively, the idea is to have many, many “soffit wings” instead of just the one pair at the front of the room, but this concept could be used as well as the traditional RFZ soffit wings, for example to increase the reflection free area. It would be useful for rooms where more than 1 critical listening area is desired.

Paul

[DanDan]

It is an interesting idea. It would make most sense with more omnidirectional loudspeakers.
I wonder what are the pros and cons of such tiny reflectors versus the huge ones used by Newell and others.
Would the room feedback to human noises be HF only, a bit odd?
Wasn't there a sawtooth in the MHOA?

[Paulus87]

Design concept 1

Did some more research on sawtooth designs, there's a couple of threads on gearslutz (such as this one: https://www.gearslutz.com/board/studio- ... esign.html ) as well as a section in Newell's book - thanks to DanDan for pointing this out.

Now I know these designs are not anything new - back in the 70s, studio designer Wolfgang Jensen used such an approach in his rooms. From what I can ascertain, they seem to work very well and are in many ways similar to the non-environment concept - the main difference being that the Jensen rooms are not as highly absorptive, the sawtooth panels are reflective one side and filled with insulation behind.

I am having a hard time finding fault with the design... it seems that such a design would work even better for reflection control than a typical RFZ style room. The only potential difference I can think of is the focus on a diffused return of energy from the rear found in RFZ style rooms. But, a Jensen style room seems to kick the butt of an RFZ for wide reflection control in the ray region.

Here's a diagram of how a Jensen style design approach could work in my space:

Screenshot 2020-06-06 at 14.04.47.png

I horizontally ray traced the extremes of each change of angle for each surface on one side of the room, the grey shaded area shows where the rays combine with the white area showing the reflection free zone (at least in the frequency range of concern)

I first drew the room, then marked the listening position, then spaced the speakers with the desired toe in and distance from the listener. Then I drew the side walls angled at 6 degrees either side and then divided them up every 2' and drew the diagonal panels of the sawtooth.

The reflections from the saw tooth side walls hit the rear wall where they can either be absorbed and/or diffused. I have drawn in some slatted poly traps in the rear corners and an air transparent fractal diffuser in the centre of the main wall. The angled sawtooth panels could either be completely solid or could be slatted as well to provide more/less reflectivity, depending on what was desired.

What do you guys think of this concept?

Paul

[Paulus87]

Just an update to my previous post, in reality it would probably look more like this...

Screenshot 2020-06-06 at 16.02.02.png

I'm thinking BAD panels to front the angled reflective parts of the sawtooth side walls would be a nice option.

The walls could either be concealed behind fabric so the sawtooth is hidden and appear to be just "normal" walls, or just left exposed which might look quite cool.

Here is a link about CID rooms, prototyped by the BBC for anyone interested in a similar concept http://downloads.bbc.co.uk/rd/pubs/reports/1995-04.pdf

Paul

[Paulus87]

Here' some basic 3D images of this concept...