Cheap Acoustic Treatment/Sound Energy

[Eat.A.Tron]

Okay, not technically a gear question here: I just moved into a new house in which my band can practice in the basement. The basement's about 30 ft. x 20 ft., with concrete walls and floor, and ceiling rafters covered with a cheap particle board. The first band practices were like playing in a cave. Since then, I've done a lot of work to deaden things as much as possible. The drums are in one corner, and I've put up folded blankets, styrofoam pads, etc. on those walls to kill off those reflections. MUCH improved. Putting a drum rug under the drums helped a lot, too, to deaden the downward reflections (esp. from the snare and floor tom) In addition, I've begun collecting bulk egg cartons (about 1 ft. x 1 ft. in size) from my work and screwing them into the ceiling. I think this is helping, but it's hard to tell. My logic is that it's useful as a diffuser, but any difference isn't as obvious as with the absorption.

So, tell me: Am I wasting my time with the egg cartons? Should I use a different strategy? My goal isn't necessarily to make it a great-sounding room, but more to make the sound clearer for band songwriting and rehearsal, as well as making things a little more bearable for my non-band roommates who are home during practice.

Thoughts?

[abell1234]

egg cartons are a waste of time IMO. Try building some bass traps, that will help with the sound inside the room. Then try anything cheap like blankets etc. to help with the sound outside the room. Egg cartons will do nothing, you would be better of getting a bookshelf and putting various things inside it to diffuse sound. Check out Build a Better Bass Trap Ethan has very useful information on sound treatment.

[Ethan Winer]

Originally Posted by abell1234

egg cartons are a waste of time IMO ... Check out Build a Better Bass Trap

This too:

Acoustic Treatment and Design for Recording Studios and Listening Rooms

--Ethan

[abell1234]

Hey Ethan you rock
The information on your sites have help me out so much.

[Glenn Kuras]

Originally Posted by Eat.A.Tron

So, tell me: Am I wasting my time with the egg cartons? Should I use a different strategy? My goal isn't necessarily to make it a great-sounding room, but more to make the sound clearer for band songwriting and rehearsal, as well as making things a little more bearable for my non-band roommates who are home during practice.

Thoughts?

Egg crates will work for holding eggs but that is about it.

Glenn

[bitflipper]

Somebody actually published the acoustical properties of egg cartons, but I don't remember where I found it. What I recall is that they were only absorbent over about 1KHz and did not make good diffusers because of the uniformity of their pattern. About all they do is absorb the frequencies most essential for speech intelligibility, which is why they sound like they're doing something, but in reality they're making your room worse, not better.

703 rigid fiberglass, on the other hand, is cheap and easy to work with. Just one inch of 703 does more than egg cartons, and 4 inches (spaced 4 inches from the wall) will make an inexpensive bass trap. 703 is actually more effective than commercial treatments costing many, many times more. If you don't have the budget for Ethan's products (which are more reasonably priced than any of his competitors'), DIY traps are almost as good.

[Eat.A.Tron]

Okay, great, I'll check out the article. Real quick, though, while I have internet access, if I were to throw in bookshelf-type bass traps, where would I put them? The instrument configuration of the room is basically a circle, drums in the corner and amps arrayed in a 20ish-foot semicircle, facing the drums.

Should such a trap be close to the "bassiest" sources (i.e. bass amp)? Or does it matter?

Secondly, any idea on how much #703 insulation costs?

Thirdly (I forgot to ask this in the initial post), if absorption methods are reducing the total sound energy in the room, is that then reducing the volume heard outside of the room? Or is that totally wrong-headed?

Thanks, everybody, this has already been very helpful.

[theblotted]

Originally Posted by Eat.A.Tron

Thirdly (I forgot to ask this in the initial post), if absorption methods are reducing the total sound energy in the room, is that then reducing the volume heard outside of the room? Or is that totally wrong-headed?

no and yes.

only way to reduce volume effectively, is to seal the band room, and build a few layers of different materials on the walls/ceiling, so you get a room within a room. even better, float the inside room.

or you can work out a schedule with your housemates, so you don't bother them.

[abell1234]

I just spent $300 and made 4 2'x8', 1 2'x4', and 2 4'x4' traps. They made a huge difference in my room. In Arizona where I live you can buy a pack of 6 2'x4' panels of rock wool (which is the same as 703 just not pink) for $36, the rest is materials and sweat. It will be the best money you will spend. Check out Ethan's site there is a forum somwhere in it and you can post your room specs and he or someone else will tell you the best places to put your traps. Or if you have money buy some traps from Ethan.

[Glenn Kuras]

Should such a trap be close to the "bassiest" sources (i.e. bass amp)? Or does it matter?

Bass is going to build up in all corners. Some corners pick up more then others, but if you focus on putting bass traps in the corners you should be fine.



Glenn

[Bob Ross]

Originally Posted by bitflipper

Somebody actually published the acoustical properties of egg cartons, but I don't remember where I found it.

Acoustics First

[wrgkmc]

I used ceiling tiles coverd them with rug undermatting foam on a converted 2 car garage. Put it on the ceiling and walls. Its a total dead zone like being in a coffin when you walk in. When we rehurse its completely directional with no reflection at all. You can pick out someone making a mistake instantly. I eventually put up reflective pieces around the drums and on a wall or two. Records a bit more live now. The stuff is cheap about $2 a Sq yard or so and it comes in a few different colors and thickness. I'm tempted to paint it white to brighten it up in there but I've been pretty busy. It also cut the sound leakage into other rooms quite a bit. My buddy used ceiling tiles and carpet on his which is better for live recordings.

[Eat.A.Tron]

Originally Posted by wrgkmc

I used ceiling tiles coverd them with rug undermatting foam on a converted 2 car garage. Put it on the ceiling and walls. Its a total dead zone like being in a coffin when you walk in. When we rehurse its completely directional with no reflection at all. You can pick out someone making a mistake instantly. I eventually put up reflective pieces around the drums and on a wall or two. Records a bit more live now. The stuff is cheap about $2 a Sq yard or so and it comes in a few different colors and thickness. I'm tempted to paint it white to brighten it up in there but I've been pretty busy. It also cut the sound leakage into other rooms quite a bit. My buddy used ceiling tiles and carpet on his which is better for live recordings.

Yeah, that sounds ideal. I assume you're referring to the cheap white styrofoam-type ceiling tiles used in office buildings and such? And any specific type/thickness of undermatting? Do you put any air space between the tiles and the real ceiling/walls, or just tack it in directly?

Also, with bass traps, since bass builds up in corners, would it make sense to stick a trap in the corner, to make a flat spot there? Or would you simply conform the traps to the existing walls and keep the corner intact? Reason being, I read Mr. Winer's article (excellent, by the way), and I'd like to test one out by sticking a deep-bass trap in the corner against which the amps face, and maybe in each corner of the basement. Thoughts?

Thanks again, everybody.

[willsing]

Here's a good link for getting good product (mineral wool, rigid fiberglass insulation)

Insulation World - Thermal Insulation Products for Pipes, Equipment, Ducts - Asbestos and Lead Abatement Products for Industrial, Commercial and Residential Applications - Hopewell, Virginia

Took me a while to sift around and find some. Good luck,
Will

[Ryuben]

Originally Posted by abell1234

...In Arizona where I live you can buy a pack of 6 2'x4' panels of rock wool (which is the same as 703 just not pink) for $36...

Would you mind letting me know where you found this in AZ?
Somewhere in the Phx area?

[fcorl]

Glenn,

I'm building solid (cut and stacked triangles) 703 traps. What is the best dimension across the front? My Room is roughly 10X15.

Frank

[Paul Woodlock]

Originally Posted by fcorl

Glenn,

I'm building solid (cut and stacked triangles) 703 traps. What is the best dimension across the front? My Room is roughly 10X15.

Frank

2 feet. Ideally 3 feet if you can spare the space.

1 foot wide won't hardly do anything. Yo ucan save a bit of rockwool by makign it a trapezoid shape instead of a triangle. The area very close to the corner won't do anything anyway

[junya-eskimo]

hi mate,

this may have been covered by the people who posted before me here...but these 2 items helped me ALOT...

Read this:

Acoustic Treatment and Design for Recording Studios and Listening Rooms

and download this:

Auralex Acoustics - Literature and White Papers.

(download Acoustics 101 - Now 52 Pages! )

The 1st its a little more complicate to get your hrad around at first, but the AURALEX ACOUSTICS 101 MANUAL is simple to the point and can point you in the right direction very fast without the head banging maths part...Best of both worlds here)

Good luck mate. message m if you need some other stuff..

jun

[Glenn Kuras]

Originally Posted by fcorl

Glenn,

I'm building solid (cut and stacked triangles) 703 traps. What is the best dimension across the front? My Room is roughly 10X15.

Frank

Paul is right on the money!!

Glenn

[fcorl]

Originally Posted by myfipie

Paul is right on the money!!

Glenn

Thanks! I jumped the gun a little on this one.... As I was asking you I was also figuring out what size would get the most out of a 2'X4' piece of of 703.

Since I started before I read these replies, I went with 16"X16" squares (which gave me 22.5" across the front of my corner trap). It's less than 2 ft. but may still be alright. If not I can always take a extra 2" panel and add some to the front to increase the width. This was only the first corner anyways......

[Glenn Kuras]

Originally Posted by fcorl

Thanks! I jumped the gun a little on this one.... As I was asking you I was also figuring out what size would get the most out of a 2'X4' piece of of 703.

Since I started before I read these replies, I went with 16"X16" squares (which gave me 22.5" across the front of my corner trap). It's less than 2 ft. but may still be alright. If not I can always take a extra 2" panel and add some to the front to increase the width. This was only the first corner anyways......

24" will work better, but I would think (talking DYI) that if you took a 22.5" and a 24" into a test lab that the 24" would win, but not by all that much.
I think your fine, but for the rest of them make them 24".

Glenn

[s.d.finley]

Check out my DIY bass traps and panels!!

I used mineral wool. The corner bass traps are done al a superchunk. 24" across. The panels have 1/4" louann board for the backing. The three 4" panels in front on the desk have no wood on the sides, so more surface area for acoustics.

These were so inexpensive to make, that it was silly!!

[andy roberts]

200 kg of toilet paper ...by far the best absorber