Absorbant panel questions

Posted: Wed Feb 26, 2003 4:50 am

I'm in the process of finishing a basement studio and due to the fact of our house being built entirely of poured concrete, I'm going to need to install some wall absorbers. I've read Ethans construction article and like the idea of contructing the panels but don't like the involved process of the building the frame's. I'm wondering if there is a reason the absorbers(midhigh) can't just be attached to the walls directly without any frames or is there a reason there is an air space behind the panels as shown in the construction article? I would prefer not to drill four holes through 4" of concrete to set each panel, and go through the easy, but much more involved process of contructing the frames for the panels. I'm wondering if one of the Auralex foam absorbers or equivilant material from other manufactures, is nearly as good a material. Although costing more, it would be easier to install in this location. Sorry for the lengthy post-my first here!

Paul

Posted: Wed Feb 26, 2003 5:40 am

"fact of our house being built entirely of poured concrete"

Thats all the makings of a nice reverb chamber! Very Happy

Our home is also poured. Nightmare to drill into.

Some brief thoughts-
you wouldn't need to drill through 4" of concrete. Get some self-tapping anchors or similar from the 'depot. As for not wanting to build the frames/boxes- if you want to be able to trust your low end, you'll need bass traps. If you don't want to mount them with the wall as the 'rear', you can make sealed boxes. I'll let Ethan take it from here on that.

And as for the use of an acoustic foam- first, these do nothing for eliminating bass problems, which you surely have. If you're looking for some good broadband absorbtion using the fiberglass, here's 2 options. 1. Buy some of the 703, wrap it in burlap, secure it, and use velcro to stick it to the wall. And don't forget to use fire-retardant on the material! 2. pay someone to do it for you.

Oh, the air space. Spacing the absorber out from the wall incrases the efficiency/range of absorbtion down the frequency scale.

Jeff

Posted: Wed Feb 26, 2003 6:16 am

Paul,

> I'm wondering if there is a reason the absorbers(midhigh) can't just be attached to the walls directly without any frames <

You can absolutely do that. The frame is just for appearance, and to space the fiberglass away from the wall a little. If you have an easier way to attach 703 to the wall go for it. The air space helps, but is not strictly necessary. One easy way is to use Liquid Nails to glue some firring strips to the concrete. Then you can screw the fiberglass to the strips. The strips also provide some spacing.

> I'm wondering if one of the Auralex foam absorbers or equivilant material from other manufactures, is nearly as good a material. <

For a given thickness, foam is about half as effective as 703 below 500 Hz. and a little less effective than 703 above that.

--Ethan

Posted: Wed Feb 26, 2003 8:47 am

Thanks very much Jeff and Ethan for the quick and helpfull replies. Yes Jeff, you don't hang a picture on our walls without getting out the hammer drill. God help us if the plumbing fails, and you don't even think of running any additional wiring unless it can be exposed. It makes you appreciate regular house contruction and why builders have fine tuned this approach for hundreds of years. On the other hand we feel relatively safe from the occasional huricane that blows though here every couple of years. I realize I will have to address the bass buildup problem but since we have just spent alot of time reconditioning these walls (they had old walnut paneling stuck to the concete with liquid nails) we're ruluctant use this method again in case we want to use this room for something else at a later date. Ethan, I have thought of the furing strips and this may be the best option and less intrusive method of attaching several panels and possibly some of the bass absorber panels as well. I have not found 703 rigid fiberglass panels locally and am having a hard time finding them even in my southeastern geographical region, although I'm still on the hunt. I have found a rigid 1" and 1 1/2" thick fiberglass board made by Certainteed but not sure if this is a comparable product to 703. This particular Certainteed product has a silver backing material, but since Ethan has told me it is not absolutely necessary to mount the panels away from the walls, I'm assuming this backing material would be acceptable. Thanks every so much again for the help.

Paul

Posted: Wed Feb 26, 2003 9:54 am

Paul,

> I have not found 703 rigid fiberglass panels locally and am having a hard time finding them even in my southeastern geographical region <

It's readily available. Look in your yellow pages under insulation and call some of the suppliers listed. If that fails, call Owens-Corning at 800-GET-PINK and ask for some dealers in your area.

There are also other manufacturers that make the same basic stuff for less money. Other products are called rigid fiberglass, rock wool, or mineral wool. Also, 703 has a density of 3 pounds per cubic foot. So that's yet another way to make sure you're getting something equiavalent.

--Ethan

Posted: Wed Feb 26, 2003 10:08 am

Here's a source of info on the 700 Series:
http://www.owenscorning.com/comminsul/documents/Fiberglas700Series.pdf

Hey Ethan-
"Other products are called rigid fiberglass, rock wool, or mineral wool."

Are you saying these 3 products are equivelents? Obviously they are 3 different compounds, but are the properties similar for absorbtion and other uses?

JZ

Posted: Wed Feb 26, 2003 11:53 am

Jeff,

> Are you saying these 3 products are equivelents? <

They are according to John Sayer, an acoustician who definitely knows his stuff. And they're spec'd the same way, with similar absorption graphs, and also with density rated as pounds per cubic foot just like Owens-Corning's specs for 703 and 705. We'll be ordering some samples from a few different manufacturers soon, and I'll let y'all know what we find.

--Ethan

Posted: Wed Feb 26, 2003 12:22 pm

I have a question for Paul and Ethan.

Paul,
What did you do with all that wood paneling? hehe

Ethan,
What are some or your ideas about using wood paneling in a tracking room. Problems/advantages, etc.
A lot of pics of tracking and control rooms show the extensive use of wood paneling (mixed with absorption/diffusion et al.) I'm wondering if it's a way to go.
Jason

Posted: Wed Feb 26, 2003 12:39 pm

Jason,

> What are some or your ideas about using wood paneling in a tracking room. <

Wood looks nice, but acoustically it's no better than linoleum or other inexpensive materials that are similarly hard. If that's what you're asking.

The key for most rooms is a mix of hard and soft surfaces, preferably with no one large area all hard or all soft. How live a sound you get depends on the ratio of hard to soft. Recording rooms are often more live than dead, and control rooms are often the opposite. Again, it's mostly a matter of personal taste.

--Ethan

Posted: Wed Feb 26, 2003 12:52 pm

Ethan, thanks for the info. That was exactly what I wanted to know.

Jason

Posted: Wed Feb 26, 2003 1:04 pm

Jeff and Ethan, I have been to the Owens-Corning website and gone through the requisite zip-code search for "703" dealers in my area and alas, although their database pulled up many dealers for insulation/hardware-building supply dealers, none carried this in stock and several said they could not get it. I thus called Owens Corning to get some telephone numbers of dealers beyond the 100 mi maximum search area provided and even the dealers she provided me in the Atlanta area said the distributor for this area did not carry this product. Before I posted this question here, I did a search for any previous posts concerning this issue and was able to find two references to dealers in the New York area that either stock the 703 or have access to it. I called the first dealer who told me they could not ship to me here in the south, so I did not give the other source (Kamco) a try until today. Kamco has told me they can get the product but, since the purchasing agent is out until 2/27/03 they cannot make a determination if it is ok to ship to me. I think the problem is the small amount I'm ordering of 256 sq. ft. is just not worth the trouble. I was quoted $62.50 per 128 sq. ft. I did call Certainteed and was told their product was equivalent to the 703 series product if the 300 series was purchased (3lb. density). I'm still on the hunt though. Threw the old paneling away Good Texan, would have saved it for you though. It really was not too bad looking as paneling goes but looked bad old and, since we only have windows in one room of this basement(my control room now) made the room very dark. Thanks again for your replies and help here Ethan, and Jeff.

Paul

Posted: Wed Feb 26, 2003 3:04 pm

ah baloney,
There is a supplier up here who has it. Last price list :Owens Corning 700 Series Rigid Insulation (Clarke Insulation)

Type p.c.f kg./m2 Price sq/ft Price 2x4 sheet
701 1.5 24 1.5" $0.20 $1.60
702 2.3 37
703 3 48 1" $0.38 $3.04
2" $0.77 $6.16
704 4.2 67
705 6 96 2" $1.40 $11.20

I'd be willing to box it and ship it to you. FedEx is reasonable. Check into it and let me know. I've got to call them tomorrow to update, but this is probably right on, or darn near the current price. (It might not be 703, but the equivilent (how in the world is that word spelled!!?? E QUIV I or E LENT?). Max FEDEX shipping size would allow for home delivery of 9 one inch thick sheets. Maybe 5 2" sheets.

Let me know via PM.

Or email me
jeff@acidacoustics.com

Jeff

(this would mean that when I'm in Alabama I get to sleep in your couch..... Very Happy

)

Posted: Wed Feb 26, 2003 4:27 pm

That is mighty kind of you Jeff and you sure are a quick study on whereabouts and funny names. You are most welcome here if your ever in our neck of the woods. We'll make a beach trip to Panama City, Florida (In A VW BUS with bread, cheese and wine?) which is our local playground. I'm not sure yet of my material and I would like not to inconvenience you. The Certainteed Product I looked into further today seems close in spec to the 703 product. This is their duct series of rigid fiberglas. It does have a shiny silver backing to it and its sound absorbant efficiency is the same or better in the mid and high frequencies but slightly less in the 125 hz. range. It has a density of 4.2, probably more comparable to the 705 material. The cost is very similar-although I think you have given me the best prices regarding a similar or the same material to "703". Now if I can find a real Artsy type material like a Piccaso repro or etc. to cover these thing with-We'd Be Happe'nn! The Wife Acceptance Factor (WAF) would be very high.

Paul

Posted: Wed Feb 26, 2003 6:32 pm

My wife refers to my absorber panels as "those ugly things." granted, they are. Today when I was out I stopped at JoAnne fabrics and get this- plaid printed burlap. Fancy shmancy! I can just see Martha Stewart frothing at the bit to accesorize the studio that is adorned with these 'designer' panels. Heck, I bet I could wrap some fiberglass in plaid burlap and mark it up 500% and sell it as 'designer'. Some weenie newbie rich kid would grab hold of it and think he got away with something.
....meanwhile I'm buying used gear of of Fats with all my riches..... Very Happy

I noted you are getting 250+ square feet of fiberglass. That amount might not be worth the shipping. I don't know. Hey, its not too big of deal at this end to ship it- pending I've got you're money to pay for it with! Hey...have you heard of 'designer' absorbers? They are the latest thing......really fancy....anyone who's anyone is getting them....I'd get a really good deal on them...... Very Happy

Posted: Wed Feb 26, 2003 6:57 pm

You know you're not far off the mark on that artsy fartsy idea for absorbers covering. The whole reason I found out about this "703" thing was my wife and I were not seeing eye to eye on the foam treatment that I was proposing. Since I had been frequenting this website for a month or so gathering information on hardware, etc., I thought I'd check out the "studio and Control Room Acoustics" section and lo and behold, I come upon Ethans absorber plans and here I am. My wife is definitely happier with the idea of applying fabric to a panel in our basement than putting up foam, even if its burlap (colored preferred by her). I'm the one who would prefer something other than burlap. Nothing wrong with burlap mind you, if this were a commercial entity, thats what I'd use, but we really did this basement a sweet remodeling and I'd prefer something kind of cool.(Then we could drink our ripple in complete ectacy). Why not an interesting fabric, I call for all fabric aficiondos to the rescue! This may not be available though so-burlap it may be-but, maybe high cotton burlap. Jeff, I still may take you up on your offer for the "703".

Paul

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