Absorption Or Diffusion?

[Derrick]

Hi, As stated in another post, I just purchased a house where I will be building a studio in the basement. I am looking into accoustics and treatments. It occurs to me that there are many options and that I need to understand my needs better... For example, there are options for absorption and diffusion. How do I figure out what I need for my space?

I will be tracking and mixing rock instruments such as drums, bass, and guitar. I like an open, sound but don't expect miricals as my ceilings aren't more then about 7.5 to 8 ft. The room tends to sound thin as opposed to bassy so maybe I don't need bass traps? I like the room sounds Albini and BBC/Peel got. I want to control my issues while trying to keep as much of that character as possible.

Thanks!!

[DrummerMan]

The room tends to sound thin as opposed to bassy so maybe I don't need bass traps?

Low frequencies canceling each other out is as much a low frequency problem as hearing too much low end. Bass traps are where I always start when it comes to treating a room. This can be done as cheaply as stacking still-in-the-wrapping pink insulation, floor to ceiling, it each corner.

If you've heard the following advice before, that's ok because it's good advice: Get Rod Gervais' book. It'll answer most of your basic questions in an easy to understand way and probably save you money in the end. I'm not trying to cop out of answering your direct questions, it's just the book says everything and more that I'd say, and so much better than I would.

[iC]

re:Low Ceilings
ABSORBTION!!! LOTS OF IT! Superchunks are a great start.
My reasoning comes from opening a rehearsal studio mini-complex that had been already built out by the previous tenants. While skilled carpenters, i'm pretty sure these guys knew NOTHING of acoustics.
Now i'm just a beginner, and it took some hand holding and encouragement from a local acoustician, but as simple as $150 worth of rockwool (approx. 200 2x4 sheets from the local fiberglass dealer) and a bunch of wood and screws for frames, i've outfitted 3 rooms with framed bass traps, superchunks, first reflections and clouds - and i'm ready for more:).
The rooms sound thousands of times better, not perfect and not like Studio B at Electrical either (that's not gonna happen unless i tear down this build and blow up my woodworking and marble cutting neighbors). Its so easy too. i am a shitty carpenter - can barely cut a straight line- and i averaged about 8 traps a day once i figured out my method.
The absorbtion may make your space "dead-ish" but once you've controlled some of the low end (doubtful that it will ever be a "perfect" space), you can add in reflection and scatter points with wood panels and such....
i'd say first things first? Superchunk your corners and put a bunch of clouds in your ceiling.... i'm heading out today to grab wire and eye hooks to build a modular cloud system for all my low ceilings. I'd like an almost full ceiling of absorbtion to see how that helps the vocal monitoring in the rooms....
As far as reverberant room sounds, get control of the acoustics first, then work on maybe creating a live end -dead end style studio....
cheers, kevin

[Ethan Winer]

How do I figure out what I need for my space?

First you have to tell us the size of the space, not just the ceiling height. Generally small rooms do well with absorption only, and larger rooms benefit from a mix of absorption and diffusion. But that's not set in stone. See the video All about Diffusion on the RealTraps Videos page.

The room tends to sound thin as opposed to bassy so maybe I don't need bass traps?

As DM said, thin bass is caused by the same reflection that cause bloated bass. So bass traps are the solution for thin bass too.

--Ethan

[Derrick]

I see... well, my basement is 25X32. I haven't yet designed how I will put up the walls to block off furnace, washer/dryer, etc. But I plan to dedicate as much space as possible to the tracking and control rooms.

[johnchuckalumba]

hello.. check out phillip Newall's book on studio design...Focal press I think....It's pricey but totally worth it It's a good resourse.
john

[JWL]

I also agree on the Gervais book. I've heard good things about Newall book, but haven't actually seen it in person.

In a basement studio like that, depending on what your isolation needs are, I'd put a ton of absorption on the ceiling (ie, Ultratouch cotton between the ceiling joists), add bass traps to corners, and if you have the budget for it, use diffusion in the tracking rooms or on the rear wall of the control room. If you are planning a one-room design (which I generally recommend, depending on your needs), you can combine the diffusion for both needs with room arrangement.

Generally, I see diffusion as icing on the cake in a great room, rather than an essential component of room treatment. Mostly because it's expensive, diffusors are very complex and labor-intensive to build. If you are on a limited budget, you are much better off focusing on absorption (bass trapping, RFZ, managing reflections for tracking).

[Derrick]

In a basement studio like that, depending on what your isolation needs are, I'd put a ton of absorption on the ceiling (ie, Ultratouch cotton between the ceiling joists),

Does Ultratouch do anything for sound in the live and control rooms or just for isolation to/from outside?

If you are planning a one-room design (which I generally recommend, depending on your needs), you can combine the diffusion for both needs with room arrangement.

One room design as in control and live all the same room? Why do you recommend this?

[iC]

In a basement studio like that, depending on what your isolation needs are, I'd put a ton of absorption on the ceiling (ie, Ultratouch cotton between the ceiling joists),

Does Ultratouch do anything for sound in the live and control rooms or just for isolation to/from outside?

Turn that question around, friend. Fiberglass and such will do everything for sound IN the room and Less for "isolation".
Absorbtion in the ceiling will keep reflections from cascading back down into the space. As the sound passes into the fibers, they'll (the fibers) will move on a very small scale (microscopic?) and rubb against each other. This action of rubbing transduces the sound energy into heat (not enough to warm you up though:))
This same action will occur in your corner bass traps as well.
Sound isolation has to do with MASS. Like cinderblock and double/triple layers of sheet rock. MASS. Isolation is quite difficult to "build into" a space. its more of a "build OUT".
Just touching on the science here, but i think i'm right on this stuff. someone please correct me if i have erred.
bests, kevin

[JWL]

Does Ultratouch do anything for sound in the live and control rooms or just for isolation to/from outside?

Mostly for the sound inside. It'll help a bit with isolation, but mostly at higher frequencies.

One room design as in control and live all the same room? Why do you recommend this?

It really, depends on what your needs are, but in general I like it for home studios. For a detailed explanation as to why, see this article.

[Derrick]

Mostly for the sound inside. It'll help a bit with isolation, but mostly at higher frequencies.

How does something like Ultratouch or any other substance effect room sound unless it is is exposed in the room? If it's on the other side of drywall, shouldn't this effect bleed only?

It really, depends on what your needs are, but in general I like it for home studios. For a detailed explanation as to why, see this article.

Wait, I'm confused... It sounded like you were recommending the control and live all in the same room. When I asked you about that you directed me to an article discussing the lack of need for a vocal room.

[DrummerMan]

I think the point of the one room thing is that, unless you have a really huge amount of space to work with, and in these modern times of smaller home studios, alot of people are choosing to have one really nice sounding room for tracking and mixing, instead of breaking it up into two mediocre sounding rooms, neither living up to the music's full potential. The idea in the vocal booth article is the same concept as it would be for the argument against a control room/live room situation, and it comes, mostly, I think, from the perspective of acoustic treatment in that you have more flexibility, control, and possibilities for good sound the bigger the room you're treating. The smaller a room gets, especially with low ceilings, the harder it is to tame reflections until it's so small you're only left with one option, total absorption, which will leave everything really dead sounding, and it's especially difficult to mix that way and have the mixes translate onto another system, in my experience.

Some people also like and prefer the workflow of having the instruments and everything in the same room as the engineer, but that's more personal preference.

[Derrick]

Yikes. How big does a control/mix room have to be in order to get descent results?

[JWL]

Yes, DrummerMan has it right. Whether it's a vocal booth or a "live" room, if you only have a small amount of space to work with you are generally better off with a one-room design. Again, depending on what your needs are, mostly in terms of isolation.

And if you are putting up drywall, then yes the insulation between the joists will (mostly) help with isolation as opposed to the sound in the room. You might get a small amount of bass trapping depending on how much drywall (the more layers of drywall, the less bass trapping you'll get), and depending on whether or not the insulation comes into contact with that bottom layer of drywall.

If isolation isn't a concern, then I'd simply stuff the joists with insulation, cover with cloth, and be done with it. The only reason to add drywall to the ceiling is if you need isolation, and then you need to build it properly (a few different ways to do it) to actually attain isolation.

As far as how big a control room is, this is up for debate, but generally around 2500 cubic feet is a good place to start. But, use what you have.

[DrummerMan]

decent results?

you can get great results anywhere. I've both recorded and mixed in tiny, untreated, theoretically terrible rooms before and been thrilled with the results. Keep in mind, all these ideas and numbers being thrown out are about the ideal way, according to current generally agreed thinking, to setup a recording studio. You take that and do what you can with it. If you take any of this advice, you'll probably be in better shape than most people who currently have home studios.