Attic Studio

Green House · Post by **Green House** » Tue Apr 08, 2003 4:47 am

Hi there,

I am interested in improving the acoustics of my studio space. I am primarily interested in its use as a mixing room. I intend to build some of the wall units, but would like some advice for bass managment.

Attached is a gif of the space which is basically 20'x16'x7'

There is an alcove on the west side of the room that is 8'x4'

I face west when I mix and I am seated just forward of the halfway point.

I don't mind losing the west alcove to some sort of hanger/trap situation. In fact, I don't mind even a little bit more of the floorspace on the west side if it meant better sound.

BTW...there is also a small alcove to the south and a long alcove to the east.

barefoot · Post by **barefoot** » Tue Apr 08, 2003 6:26 am

GH,

Apart from the 7' ceiling, this is quite a nice space.

With all of the volume in those alcoves you could achieve some pretty high performance bass response in this room. What's the situation above the ceiling? Any space up there?

Thomas

Green House · Post by **Green House** » Tue Apr 08, 2003 11:26 am

The space above the ceiling is the peak of my roof. It is about 8 feet from ceiling to peak (just unused space). Also...I need more info on how to use the volume of space in the alcoves to my advantage. Are acoustic hangers appropriate in this situation? I am willing to give up several feet of space on the west side of the room.

Simply asked, what would you guys do with this space? Short of massive reconstruction...

Thanks

Post by **John Sayers** » Tue Apr 08, 2003 12:32 pm

How about something like this??

cheers
john

Green House · Post by **Green House** » Tue Apr 08, 2003 1:14 pm

John,

Wow...I never would have thought of that design. I guess that is at least part of why you are doing what you are doing...and I am not doing what you are doing. I am also EXTREMELY gratified that you took the time.

I had considered using your design that I have attached below...but revesing it so that the control room is to the west...It was going to have sliding glass doors on both sides...one to the studio to the east, and the other into that western alcove which was going to house my noisy computer and stuff.

On the short term though...I am not in a position to do this kind of construction yet, so I am looking for an interim solution. If you were going to use the room for mixing, with some wall units put up...how would you configure the room without any construction besides the modular wall units?

Since I don't mind losing some floor space to the west, would some sort of monster bass absorber be called for?

Thanks much,
Richard

Green House · Post by **Green House** » Wed Apr 09, 2003 1:57 am

I have considered that these questions might be more suited for the acoustics forum...if you need to move me feel free.

Here is what I am considering so far:

1: I have placed my desk back from the wall to allow maximum distance so as not to get bad bass reflections.

2. The space in front of the desk can be used for any treatment...including building a cloth facade wall with a bunch of hangers behind it.

3. I intend to build some of John's slot resonators on each side

Some Questions:

1. I have shown my monitors on stands behind the desk...am I right in thinking that this would be better than right next to the computer screens on the desk?

2. Is the lack of symmetry toward the back of the room likely to cause a big issue?

3. How can I best use my alcove areas for bass management?

4. How wide do I have to make my rear absorber? If it is too wide it will cover the stairs

Thanks guys

Post by **John Sayers** » Wed Apr 09, 2003 8:56 am

I'd turn the desk around and face the other way - then you can use the rear 8' section as a bass trap.

cheers
john

Green House · Post by **Green House** » Wed Apr 09, 2003 11:53 pm

If I turn the desk around will the lack of symmetry in front of the mix position be an issue?

Also, and I am not very educated here, couldn't I use the western alcove as a bass trap even if it was behind the speakers?

Post by **John Sayers** » Thu Apr 10, 2003 7:04 am

The idea is to have the direct sound from your speakers to go pastyou and not come back. With the bass trap behind you, that's what will happen.
I'd build some gobos to place in front of you that will give you symmetry and will break up the parallel walls.

cheers
john

Green House · Post by **Green House** » Thu Apr 10, 2003 2:59 pm

That is great info...thanks a bunch

I am thinking that filling that alcove with acoustic hangers might be the way. Should I just create a cloth cover over fiberglass for the alcove or should I close it in with something more substantial (making a big panel trap out of it)?

Here is a cool sidenote...I have a lot of space above me in the roofline that I can hang some traps in.

Thanks so much for the help...when the day comes for me to build a "real" studio I will have to hire you to design something awesome (like left bank...that's a sharp facility).

Have a great one!

barefoot · Post by **barefoot** » Sat Apr 12, 2003 2:22 am

GH,

I suggest the arrangement attached below.

The cloth covered bass trap in front will work well for dampening longitudinal room modes. Since you're not soffit mounting, having absorption behind the monitors is actually preferable especially for the upper bass range where reflections from that wall will interfere with direct signals from the monitors. The small rear alcove is also turned into a bass trap.

Longer individual midband slot absorbers or diffusors replace your sawtooth design on both sides of the listening position. At bass frequencies these structures, if solidly built and mounted, will appear to be sloped walls and help break up lateral room modes near the listening position. The smaller stepped design would be ineffective in this regard.

The gray rectangles represent cloth covered openings in the ceiling drywall. The corner openings will help reduce deep room modes and "bass lift". The openings above the listening position will help dissipate vertical room modes in that vicinity. The roof space can be filled with hangers, but just opening up that volume will help tremendously. Depending on your climate, heat lost or infiltration may be a big concern. In this case the cloth should be sealed with paint and airtight gaskets used to mount the frames. Fiberglass insulation can then be laid above the cloth. This will give you good heat insulation while still remaining acoustically transparent into the upper bass.

Finally the walls of the long rear alcove should be covered with some sort of drapery or other acoustic damping material to reduce flutter echoes from that space. Of course, the rest of the studio may also require some mid or high frequency absorption in areas to balance out the response.

Thomas

Green House · Post by **Green House** » Sat Apr 12, 2003 8:10 am

Barefoot,

Thanks for the design...that looks very much in my budget/time range. I have one additional question:

The acoustic hangers in the alcoves...should I

1. Make them as big as possible
2. Vary the size of each to cover more frequencies
3. Size them specifically for certain frequencies

Thanks,
Richard

barefoot · Post by **barefoot** » Sat Apr 12, 2003 10:09 am

That's sort of a tricky question, because I'm a bit skeptical about the "resonant panel" absorption mechanism attributed to hangers. How can a relatively thin layer of absorptive material glued to the outside of a panel have any real absorptive effect at that panel's resonant frequencies? Personally I'm more inclined to believe that the primary mechanism behind hangers is that they 1. provide convenient support to stuff a lot of absorptive material in a given volume, and 2. provide a "tortuous path" such that the effect of the absorptive material is maximized.

I'm also more inclined to believe that loose flexible hangers like asphalt roofing, linoleum, of some other such material would be more effective than rigid panels. Unlike rigid materials these loose materials have good internal damping properties and would be far more likely to absorb acoustic energy via a flexion mechanism. And since they're loose they can flex any which way at practically any wavelength, so just make them as big as possible. I also recommend attaching the insulation only at the top of the hangers so the insulation and panels (membranes in this case) are free to move relative to one another. This provides for a frictional mechanism which might also improve absorption (also makes them faster to mount).

If covered with a thin fabric, these traps will act like black holes across the entire audio spectrum down to their low frequency limit - which I think is more a function of volume and packing density than specific panel size. But if size does matter, then bigger is better. All that insulation will take care of the higher frequencies regardless of the panel size.

Thomas

Post by **John Sayers** » Sat Apr 12, 2003 11:32 am

Just bare in mind that breaking through the ceiling will break any sound isolation from the roof so when it rains??

cheers
john

Green House · Post by **Green House** » Sat Apr 12, 2003 2:07 pm

Not to mention that I can hear street noises through the big vent hole in my roof. If I punched through the ceiling I would have to finish out the inside of the roof...which takes me to a considerable cost and effort for a space that isn't that convenient to begin with...arrggh!

But I am still grateful for the help. I am going to incorporate these changes one at a time...as each one will improve my situation.

I intend to post on another thread about a different wild idea I am having

Richard