Mastering studio construction

[Duffster]

A couple months ago I posted the designs for my mastering studio.
http://www.gearslutz.com/board/high-...ml#post1163255
The build has been going for a while but I didn´t get the photos off my camera until today so here it is.
The start:

[Duffster]

More:

[Duffster]

and more:

[DSD_Mastering]

Pretty cool... believe me, I know what you're going through. I just finished a 2 year build.

Good luck!
Bruce

[Dude Masters]

I can relate having finished mine about 6 months ago.......power conditioning is fun at 9500 feet........

[Duffster]

getting together the desk:

[Duffster]

The half assed setup. Missing the STC-8, and the rock block that the speakers will sit on. Next week I start the patch bay and cabling.
Setup will be:
Crane Song Avocet
Crane Song HEDD
Crane Song STC-8
Waves MaxxBCL
Weiss EQ1-MK2
Alesis Masterlink
Sonic Studio HD1
Rotel RB1092
B&W 804s
KRK V8
Pro Tools Mix+(will move to HD soon)

[bit mangler]

Duffster,

What's that thing with the circular cutouts..is it some kind of diffuser?

[balanceman]

is that a sterlingmodular desk? the plan D?
we are finishing drywall next week- then painting , floors, glass parts. . . . I started the demolition back in January.
I attached a pic from a few weeks back - before the first layer was finished. . .
I hope everything works out as nicely as seems to have for you!
edit:
-just realized there are different people's pics up in the thread!

[Duffster]

Originally Posted by balanceman

is that a sterlingmodular desk? the plan D?

The desk is custom built. I wouldn´t even want to know how much it would cost to import a sterlingmodular to Brasil.

[Duffster]

Originally Posted by bit mangler

Duffster,

What's that thing with the circular cutouts..is it some kind of diffuser?

The best expanation I have found in english is:
the perforated panels provide efficient acoustic absorption in the low mid frequency range, while proving a degree of scattering/diffusion at higher frequencies.

The absorption characteristics of the perforated panels vary depending on the distance they are supported away from a solid boundary. The closer to the boundary, the lower the overall absorption at higher frequencies.

The panels can be mounted at an angle to the room boundaries to reduce effects such as "flutter echo".

When arrayed in groups in front of a solid, flat boundary, the diffusion effect of the panels extends to the lower mid frequencies.

I don´t know if they do all this hu-hah quted above but the rooms I have sound great. For having a low ceiling I am really suprised how good my mastering room turned out so the diffusors must be doing what they are supposed to.

[Adam Dempsey]

Originally Posted by Duffster

... the perforated panels provide efficient acoustic absorption in the low mid frequency range...

When arrayed in groups in front of a solid, flat boundary, the diffusion effect of the panels extends to the lower mid frequencies.

Can something like that really both diffuse and absorb low mid frequencies? Or are those aspects not considered mutually exclusive? Honest question.

[lucey]

Diffusion below 500 is not possible afaik... certainly not with that panel.


Not to take away from the room, which looks great.

[planet red]

Originally Posted by lucey

Diffusion below 500 is not possible afaik... certainly not with that panel.


Not to take away from the room, which looks great.

The designer of my new room is expecting to get the diffusion down to about 300 using staggered rpg diffractals. They'll be arranged using the same formula the diffusors are built using. Since the diffusors are already a 2 way design and with how they're arranged itll turn them into a 3 way diffussor.

The diffusors are mounted 10 inches from the back wall which will be HEAVILY trapped with both compressed fiberglass and a membrane trap that covers the entire backwall. Above the diffusors there will be a soffit that spans the width of the room thats 3 feet deep of broadband absorption. So hopefully the only low mids coming back to the mix position will be what the diffusor sends back..

Cant wait to get started and post pics.

[lucey]

Sounds great ... or it should

[jayfrigo]

Originally Posted by lucey

Diffusion below 500 is not possible afaik... certainly not with that panel.

Quite possible to diffuse below 500; just not common in studios, and as you observe, not with that panel. As for simultaneous absorb and diffuse, yes, there are things that do that, and some that will absorb low and diffuse mid and high. Even wooden QRDs absorb low-mid to low frequencies to some extent. Some studios have very large QRD difffractals (essentially multi-band diffusors) which will diffuse low frequencies as well as mid and high, but they are expensive and difficult to build, and of limited use in the typical small room acoustics of most control rooms. However, they do exist and they have their place. Take a look at the back of Bob Ludwig's main room at Gateway for an example of a large diffractal.

[Greg Reierson]

Originally Posted by jayfrigo

Some studios have very large QRD difffractals (essentially multi-band diffusors) which will diffuse low frequencies as well as mid and high, but they are expensive and difficult to build, and of limited use in the typical small room acoustics of most control rooms.

I built a 8' x 9' DIY diffractal for my back wall with an effective range of about 300 to 14k (by the math anyway). It wasn't really that hard to do. Just took a lot of time on a table saw with a dado blade.

It's been mentioned many times but distance is very important. I'm about 8' from the diffusor, which is just slightly too close, but that's the compromise of a small room. Any closer and colorations from the rear wall become audible.


Greg Reierson
Rare Form Mastering

[Duffster]

Today the Mogami cables, audioquest speaker cables, and many assorted goodies arrived along with the stc-8 so I started the patch bay. Just waiting for the wood rack, the computer rack and the speakers stands and I will be in business.

[finetuner]

Hi Duffster,

Nice room and console man. Thanks for sharing your efforts with us.

Seems like you care for the slightest detail too.
Those curved, thick wooden panels for the back of your desk are .. tres chique!
How did they build that? You said the desk is custom made, right?

Take care.
Peter

[Ethan Winer]

Originally Posted by jayfrigo

Quite possible to diffuse below 500; just not common in studios

I'm not convinced diffusing low frequencies is even desirable. To my way of thinking, you want as low a "reverb time" as possible below around 300 Hz, to avoid the muddiness of some bass notes overlapping into others that are played later.

some that will absorb low and diffuse mid and high.

Right, and that's a huge feature of the RealTraps Diffusor.

--Ethan

[bob katz]

I think very few of you have ever experienced a room with genuine RPG-designed bass difussors! The purpose of good bass diffusion is to widen the sweet spot, to even out the bass response in the room regardless of where the listener is located. I built a control room in Guadeloupe and hired acoustic architect Doug Jones who designed what at the time was only the sixth installation of RPG (authorized and designed) bass diffusors on the entire planet. Our carpenters did the construction to Doug's plans. The back wall behind the mesh screen contains giant-size RPG diffusors, the depth of the largest piece of wood is, if I recall correctly 4 or 5 feet!

In this room you can stand just about anywhere and get extremely even bass response. The very common phenonomen of standing at the rear wall and getting bass buildup---just doesn't happen in this control room. I've rarely (maybe never) experienced bass response like this. Usually there's one sweet spot and that's it...

BK

[donsolo]

Nice to see you again Bob, how's the second release of the book coming along?

[Duffster]

The granite speaker stands arrived today.

[Ethan Winer]

Originally Posted by bob katz

The back wall behind the mesh screen contains giant-size RPG diffusors, the depth of the largest piece of wood is, if I recall correctly 4 or 5 feet!

That's a great point, Bob. I've experimented with several rooms that have a multi-tiered stepped rear wall, which is sort of a poor man's QRD diffusor.

In all cases the quarter-wave peaks and nulls were less than expected. However, to my way of thinking, a room design like this is more about reducing bass problems than "diffusing" in the same sense as when scattering mid and high frequencies to retain liveness. At low frequencies sound doesn't travel in rays as happens at mid and high frequencies, so diffusing behaves differently. I should revisit this again and do some more testing - not only the improvements in raw LF response, but also how LF decay times change (or not).

--Ethan

[Duffster]

Hopefully this coming week I will run a couple tests and see how the acoustic treatment of the room turned out. I have the original tests before the room was even treated so it will be interesting to see how much the treated changed things. Did my first master in the room yesterday and the client phoned this morning happy as hell with the result so looks like the room works.

[bob katz]

Originally Posted by Ethan Winer

That's a great point, Bob. I've experimented with several rooms that have a multi-tiered stepped rear wall, which is sort of a poor man's QRD diffusor.

In all cases the quarter-wave peaks and nulls were less than expected. However, to my way of thinking, a room design like this is more about reducing bass problems than "diffusing" in the same sense as when scattering mid and high frequencies to retain liveness. At low frequencies sound doesn't travel in rays as happens at mid and high frequencies, so diffusing behaves differently. I should revisit this again and do some more testing - not only the improvements in raw LF response, but also how LF decay times change (or not).

--Ethan

Ethan is correct that at these wavelengths a giant RPG might not really be a "diffusor" but more rather a staggered set of low frequency resonators? Since each of the segments of the RPG has a different length the overall front to back wall resonance is completely broken up modally.

[Ethan Winer]

Originally Posted by bob katz

Ethan is correct that at these wavelengths a giant RPG might not really be a "diffusor" but more rather a staggered set of low frequency resonators? Since each of the segments of the RPG has a different length the overall front to back wall resonance is completely broken up modally.

Exactly. This is an often-overlooked feature of "regular" diffusors too. Most people consider the main value of a diffusor to be scattering sound waves. But it also staggers the reflection times. When a microphone or instrument is near a reflecting sheet rock wall, the reflections are coherent and return as a single wavefront. This creates the peaks and deep nulls we all know as comb filtering. With a QRD well or skyline diffuser the reflections arrive at different times, which reduces their effect. I realize you know this Bob! I'm just clarifying for others here.

--Ethan

[frank lyon]

Congrats!


(I like your dog)

[Ethan Winer]

Nice kitty!

[Duffster]

DONE: