Difference between recording room and console room acoustics?

[DarkestDreaming]

Is there a difference between recording room and control/listening room acoustics? The articles that I have come across online mainly deal with setting up an ideal listening enviroment, speakers, bass traps etc.

I am moving into my new house soon and I plan to do some fairly decent acoustic treatment, mainly for recording acoustic guitars. My monitor speakers would be in that room as well, but my main emphasis is a fairly decent recording room.

The room is rectangular, approximately 12X8', no large windows, brick walls, tile floors and plaster ceiling.

The treatment available to me are px43 acoustic foam and partitioned rockwool. How should i go about doing this?

I can purchase some Auralex foam as well but i intend to keep it to a minimum since they are pretty expensive over here

[Doug Young]

Originally Posted by DarkestDreaming

Is there a difference between recording room and control/listening room acoustics?

Yes, I'd say so. For monitoring, you want accuracy, to be able to hear what's really there, so you want to minimize any reflections or any contribution of the room to the sound. For a tracking room you want the sound to be "good", which may mean more lively. An acoustic guitar in a totally dead room sounds pretty bad, for example. But often we have to compromise, in home studios. Mine for example, is all one room, so I just tried to strike a balance when I built my space. I wanted the room to be a pleasant place to play as much as I wanted it to be appropriate for recording.

[DarkestDreaming]

Hi Doug, I recalled you said the same thing here:

http://www.dougyoungguitar.com/studio.php


I was wondering if you could share your approach to room treatment here, as well as what you would have done differently given the chance.

I was thinking of omitting the bass traps due to the limited budget and was wondering if it were as significant for recording rooms (I normally see them in control rooms)

Also I was concerned about making the room too dead after treatment (the initial soundproof guy quoted foam and rockwool floor to ceiling every wall). Can anyone advise?

[moon]

In a small room like that, standing waves (for which you need bass traps) will usually be a problem. On the other hand, if you play solo fingerstyle guitar, that's not such a bass-heavy source like a full rock band with kick drums and bass guitars would be. Here's a test which is usually a bit of an eye-opener.

"Good" reflections will be airy and diffuse. They'll be staggered in time, and won't emphasise any particular frequencies over others. Bad ones are more focused and spiky, and can cause comb-filtering and phase problems which can suck the tone out of the instrument. If you hear a ringing sound when you clap your hands, that's a bad sign.

Room size matters a great deal. Small rooms mostly have all the bad kinds of reflections and so have to be made pretty dead.

I'd maybe start out by making a small number of movable panels (easy to DIY). A close mic position, and a V around the mic which will at least block out first reflections would probably give you a decent result for solo fingerstyle type music. You're kind of stuck with that one, close-in mic position though which might not sound so good with hard strumming.

I'd happily entomb my own small room in rock wool though, and bass trap every corner I could find. I can add some reverb in the DAW.

[DarkestDreaming]

Hi Moon, thanks for the reply.

Here's what I plan to do.. 4' thick rockwool bass traps on all four wall corners, and rockwool insulation on the rear wall. The side walls lined with acoustic panels, except the back end where I want to leave bare walls for tracking.

I am unsure of what to do with the rear wall (behind the speakers). Also I have foolishly commisioned for wall lights and a fan in the ceiling which pretty much makes it difficult to treat the ceiling so I was thinking of treating the floors instead with carpeting.

I was hoping that you guys can advise on this

[DarkestDreaming]

For those of you who are interested, this is Rod Gervais' reply to the same question I posted on Gearslutz:



There are a couple of pretty large differences between the 2.

The first is the design concept..

In a control room you are designing to create a balanced stereo sound field where the source and ears are always located in the same place (ears within reason of course)

In order to create the best sound field possible we design for acoustic symmetry.

Now - a tracking room is a totally different animal........

The source of sounds might be anywhere (or anything) within the space...... amps, drums, acoustic guitars, horns etc., etc., etc.

The "ears" in the room (which are now the microphones) might also be anywhere in the space.

The concern here is not creating a uniform stereo sound field for a relatively small area - but rather a more diffuse sound field that will enable us to put those sources as well as the ears wherever they might best suit us.

In these rooms I always lean towards asymmetrical room geometry........

Now - this can be both problematic and helpful to you from a design point of view, depending on what you have to work with.

We know it is very challenging to come up with (in small control rooms) the necessary room treatments to achieve a good sound field for even a small area - the "sweet spot" of the room....... in a tracking room you are really looking for a "good sound" anywhere in the room - which is next to impossible......

But - you have an advantage in a tracking room that you do not have in a control/mixing room.

You have the chance to play with different locations for both the sound sources and the "ears"

You can close mic and assure some level of clarity on a particular sound source....

You can use locations of peaks/dips to play into your favor with problematic frequencies.

You will still have to treat the room to the extent that you get ringing under control - but that challenge exists equally in either situation.

One of the other great differences between the 2 is testing...

Again because you are dealing with set locations for both sound source and the listening position in a control room it is easy to provide meaningful tests within those spaces.

But it is my contention that this is virtually impossible in a tracking room.

I cannot see any way of setting up a series of tests in a room when the microphones and sound sources might be set anywhere within the space.

And those sound sources might be anything - the "ears" might be any one of hundreds of different mics......

Rod

[Doug Young]

Originally Posted by DarkestDreaming

I was wondering if you could share your approach to room treatment here, as well as what you would have done differently given the chance.

I have the equivalent of about 30 panels of OC703 in my room (13x15? I forget). The ceiling (10' tall) is all fiberglass, so very absorptive. Lots of pictures on that webpage. The floor is reflective, wood. I fine tuned a bit just by trial and error after I finished, and after I did that web blog. There are some rugs on the floor now, partially covering it, and I added some 2x2 hanging acoustic cotton panels to fill in some spaces on the walls. It's about 50/50 covered and hard on the walls. Corners are all filled as full as I could get them with OC703.

I'm breaking a lot of "rules". My mix desk is in a corner. It was just the only location that made physical sense, and that was at all symmetrical. Every other wall/location had some problem. My recent CD was recorded with me sitting facing a corner when I played. I thought it would sound bad, but it helped get the mics out of the way and let me keep them up all the time. After trying it, I thought the sound was good, so I stayed there.

What would I do differently? Given my current room, nothing. It's far from a professional studio, but I'm happy with the results. I'm a little tired of the color scheme, maybe I'll change that one of these days :-) In a perfect world, I'd have a bigger room, and/or a separate mixing room. I'd also make sure that my space wasn't located directly underneath my wife's office, where she likes to roll around in her office chair on a hardwood floor.

[DarkestDreaming]

Doug how did you fill the corners with OC703?

I was thinking of building it directly onto two of the four walls, by attaching it to the wall and then drywalling it, so it looks seamless. I was hoping that it would function as bass traps in all four corners as well as absorbers for both the front and back wall of my listening environment.. is this advisable?


Also, is the fiberglass attaached to your ceiling exposed? Doesn't it flake.. and isn't it unhealthy to breathe the particles?

[Doug Young]

Originally Posted by DarkestDreaming

Doug how did you fill the corners with OC703?

I just put a frame on each side of the corner, put pieces of 703 that spanned the corner, then stuffed the hollow space with smaller pieces. I used some wire across the 703 to hold it in place, then covered it with cloth.

Here's a photo of one of the corners:



Another way to do bass traps is with a vibrating membrane, just a really thin plywood that will vibrate with sound and absorb energy. I'm not sure an acoustic guitar generates enough sound for those to be all that useful, or needed tho.

I was thinking of building it directly onto two of the four walls, by attaching it to the wall and then drywalling it, so it looks seamless.

You don't mean you'd drywall over top, do you? The sound has to get to the fingerglass to be absorbed.

Also, is the fiberglass attaached to your ceiling exposed? Doesn't it flake.. and isn't it unhealthy to breathe the particles?

It's covered with cloth. Nasty stuff, tho, and putting it in overhead was a real pain. You certainly want to make sure it's covered and that you won't be breathing particles. If I had it to do over, I'd be tempted to use acoustic cotton everywhere, tho it's hard to find and costs more. Nice to work with tho, basically recycled blue jeans, I think!

[moon]

isn't it unhealthy to breathe the particles

I chose Knauf Ecose Universal Slab to make some panels partly because it's formaldehyde-free. You should wear a dust mask, and keep it out of your eyes, and if you handle it without gloves your skin gets a bit itchy, but it seems to be pretty safe - no more than an irritant.

Always check the health and safety advice for the specific material you're using though.

I used satin for the covering because there was a huge roll of white satin going cheap in the local fabric shop. Doesn't seem to leak fibres, so far anyway. You need something which you can blow through but with a fine weave to block the fibres. Use a double layer if you're really worried.

[DarkestDreaming]

Moon, thanks! That will come in handy.


Doug, I am thinking of building something similar. I was thinking of using rockwool since OC703's aren't that readily available here. Should that be fine?

Did you stuff the inside of the entire frame with OC703? Also how many inches from the corner did you install the frame? I need to know just how thick i need to make the trap.

[Doug Young]

Originally Posted by DarkestDreaming

M
Doug, I am thinking of building something similar. I was thinking of using rockwool since OC703's aren't that readily available here. Should that be fine?

Should be. This stuff is all hard to get. There are some places online that sell both OC703 and probably rockwool raw. Check GIK, for example. No idea if they can ship to you.

Did you stuff the inside of the entire frame with OC703?

Pretty much, I may have left some air in there, I don't remember. The front is 2 2x4 panels (stacked on top of each other), stradling the corner, so you'd have a right isosceles triangle, and the distance from the wall on each side would be 2/sqrt(2) or about 1.4 feet, if I remember my geometry. Or make something (piece of cardboard) 2 feet wide, place it across the corner and just see where it falls!

[DarkestDreaming]

Originally Posted by Doug Young

The front is 2 2x4 panels (stacked on top of each other), stradling the corner, so you'd have a right isosceles triangle, and the distance from the wall on each side would be 2/sqrt(2) or about 1.4 feet, if I remember my geometry. Or make something (piece of cardboard) 2 feet wide, place it across the corner and just see where it falls!

I'm sorry, Doug I don't understand this highlighted statement. Does this mean that the distance from the corner of the wall to your wooden frame is about 2 feet?

[Doug Young]

Originally Posted by DarkestDreaming

I'm sorry, Doug I don't understand this highlighted statement. Does this mean that the distance from the corner of the wall to your wooden frame is about 2 feet?

No, the panel is 2 feet across, and it spans the corner. The panel and the 2 walls form a triangle. The distance from the corner to where the panel joins the wall would be roughly 1.4 feet. But a lot will depend on how you build the frame. Just take a piece of cardboard 2 feet wide and place it across a corner, and you'll be able to measure and get an idea of what you need to create.

There are also pre-made corner traps you can get. They'd cost more than doing it yourself, but be a lot easier.

[DarkestDreaming]

Thanks Doug. My treatment guy is adamant on not using cloth for rockwool, insisting that it is carcinogenic unless covered with drywall.

I am deciding between buying the costlier foam bass traps and making one like yours. Did you draw a scheme before building yours? It will come in handy for me