I have been reading the forum for well over 6 months in preparation for my home theater project. I have learned a great deal and it has helped me immensely.

Some background. The dedicated HT room is 15 feet wide x 18 feet long with 8.5 foot ceiling (after framing). The room is in a corner of the basement surrounded by concrete on three sides. The framed walls are not touching the concrete walls and are have batt insulation in the stud cavities in addition to typical "blanket" type insulation that was over the concrete.

The fourth wall that faces into the finished basement area is a completely separate wall and does not adjoin or touch any walls in that space.

The ceiling of the HT is below a sunroom which is connected to the house but at a side. My biggest concern is sound going up through the ceiling, through the sunroom, through another wall and into the bedrooms. It is a pretty good distance but a concern. Once the room is done, it will be difficult to change.

I am really not sure if the walls and carpet etc. would allow the sound to travel that far, but I don't want to take any chances.

Here is the dilemma. Drywall is getting close, and after reading over and over about different soundproofing techniques, I am second guessing my original plan.

Thinking that the room was fairly remote from the rest of the house, I was not overly concerned about sound, but now I am re-thinking.

A friend owns a large insulation company and raved about GP Hushboard. He sold it to me for half price and it is sitting in my garage. The plan was the hushboard and then drywall.

After reading thread after thread... I am not sure whether or not to use it. It would not be fun to take this product back, not only for the labor, but out of respect for the friend who did me a favor.

Is there any use for this product? Does anyone like it?

My options appear to be:

1) Use the Hushboard and drywall as planned.

2) Use the GP Hushboard and then buy Quiet Rock. Very expensive at $70.00 per sheet for 525 though.

2) Double drywall and green glue.

I know the prevailing opinion on this forum is DD and GG. Does anyone have experience with the Hushboard. The Georgia Pacific website claims a decent STC rating with proper construction.

Also, with STC, how much will I notice an STC of 49 versus one of 53.


Any suggestions would be appreciated, but I was interested if anyone sees any value in the GP Hushboard.

I know there are lots of threads on soundproofing, but I wanted to hear about any specific experience with Hushboard and if the soundproofing techniques I read so often really make a big difference.

Ken

I had never heard of hushboard. So I googled it:

Here is their pitch"
Hushboard® sound-deadening insulation board is a non-structural, fiberboard panel that provides an economical component for sound isolation systems in residential and commercial construction. These lightweight, low-density panels dampen sound transmissions in higher frequencies within our hearing range and can reduce sound transmission through interior or exterior walls.

The result is quieter, more enjoyable living spaces, and more productive classrooms and work places. These panels are also well suited to help provide sound isolation in home theaters.

http://www.gp.com/BUILD/product.aspx?pid=1071

A few comments, when isolating, efforts are more extreme to address low frequencies (LFE), moreso than the highs and mids. This almost seems like a product that trys to do sound treatment/absorbtion (accoustics) than isolation.

I still can't figure out what its made of and does.

The standard approach around here is 2 layers of sheet rock and green glue between. This generally comes out cheaper than quiet rock, and depending which flavor of QR, more effective. It does this by having a lot of mass (2x drywall), and constrained layer dampening. I don't think the "light weight" hushboard is likely to operate on either of those principals. I think it is some kind of sheetrock bonded with insulation that is designed to absorb (different than isolate) sound and treat the room. Might be an easy way to add some degree of accostical treatment, so might not be without benefit.

Bear in mind STC ratings do not address LFE, so that can be a misleading yardstick for HT purposes.

Check out the primer with the green glue guys (even if you don't want their product).

http://www.greengluecompany.com/understandingSoundproofing.php (lots of other good links on their site).

And good luck!

If you care about speech only - use STC ratings. If you care about low frequency HT - use TL curves. Ask your suppliers for TL curves if you are in an HT. Since unlikely to get that for soundboard - GG has hired a certified third party lab to test similar products http://www.greengluecompany.com/greenGlue-vs-Soundboard.php

If I understand you correctly your insulation friend dumped some soundboard on you when someone else realized there was more effective bang for the buck materials for the HT and he got stuck with a load? That will certainly improve the soundboard bang for buck depending on the price you paid...but it cannot improve its pure performance.


BTW waffles make very good sound isolating material. They form a damping layer with organic materials - the voids in the surface material form air pockets that vibration currents rotate in. Their performance is enhanced with geniune maple syrup - the sucrose is well know to be an effective counter to the bulkiness of the waffle, and the stickiness ensures that heat will be dissolved. The manufacturer takes no responsibility for insect infestations - please follow local codes when using this product if you intend to have it inspected.

You see anyone can write psuedoscience BS when they have something to sell and make it sound good.

Looking at the brochure it looks very similar to Celotex Soundstop.

http://www.knightcelotex.com/pages/soundstop.aspx?gclid=CNDK16HAhZACFQdlHgodkRqsZw

The celotex product is identical to the external sheathing product they make they just leave off the very light tar coating and put on a different label. General consensus has been it is actually less effective than two layers of DW.

Some guys just grab the sheathing product instead of the Soundstop board and use it for soundproofing purposes. They stock it at Lowe's and was less than $10 sheet last time I looked. I hope you didn't pay more.

Very good replies, thanks.

The insulation company sells quite a bit of it for similar uses and he told me it was very good and was not really "dumping it" on me. The carry it as a regular stock item. He sort of got me believing in it with his explanation of it, but I don't think he was trying to unload it.

I did not pay very much for the soundboard but I was hoping there would be some application for it in the HT so as not to deal with taking it back, etc. Its light compared to drywall, but a pain to move.

If there are no members who have had any positive experiences with it (or have anything positive to say), I think I am going to scrap the idea and go with the DD and GG. I was a little concerned about the application part of GG and whether or not the drywall contractor would be interested in using it.

I want to get it right (or as close as I can) the first time...but I don't when to go overboard if the benefit does not justify the cost.

It looks like it might be useful for accoustics (making the room sound better) moreso than isolation (keeping noise in/out).

I was cautioned that the material needs to be covered with drywall because of its fire rating, so I am not sure you could use it as an absorber, like linacoustic or some other insulation as it seems like it would be unsafe to do so.

The room is in a corner of the basement surrounded by concrete on three sides. The framed walls are not touching the concrete walls and are have batt insulation in the stud cavities in addition to typical "blanket" type insulation that was over the concrete.

The fourth wall that faces into the finished basement area is a completely separate wall and does not adjoin or touch any walls in that space.

The ceiling of the HT is below a sunroom which is connected to the house but at a side. My biggest concern is sound going up through the ceiling, through the sunroom, through another wall and into the bedrooms. It is a pretty good distance but a concern. Once the room is done, it will be difficult to change.

That describes my house/theater EXACTLY. Holy crap thats scary. Did you get a hold of my plans or something?!?! :) Mine is bigger though, with web floor trusses above and a bunch of HVAC and plumbing running within the trusses. My fourth wall has staggered studs. Yes, sound will travel thru the ceiling, vents, the floor, and get into the rest of the house. I didn't drywall originally for access to mechanicals. In hindsight, I would have done what you are considering (DD, GG). But please consider insulation between the joist before drywall, and acoustic panels on the ceiling to control reflections.


What I did is different but satisfy the need for mass, decoupling, some high frequency absorption, and esthetics.
1. insulation between joists (Roxul, Pink Fiberglass)
2. two layers of 3/8" OSB to cover ceiling
3. 3/4" MDF cut into approx 2'x2' tiles
4. each tile is wrapped in a marine carpeting. The carpet is very short pile, much like felt, and black in color. It wraps around the back by 2". I screw each one into the OSB with four black drywall screws, in a grid config. It takes 88 tiles to cover my ceiling. I still have close to 30 to go. I can email pics if you're interested. It is decoupled a bit because the MDF doesn't touch the OSB. It's separate by a rim of carpet.

Anyway, i've noticed a tremendous reduction in sound leakage. Not completely, but enough. Our bedrooms are at the other end of the house and I can let'er rip when my fiancee is sleeping.

Kraz ... you made a spelling error. You wrote:
please follow local codes when using this product if you intend to have it inspected.
It should be:
"please follow local codes when using this product if you intend to have it insected".
I'll let your transgression slide...this time :)

Kraz ... you made a spelling error. You wrote:

It should be:
"please follow local codes when using this product if you intend to have it insected".
I'll let your transgression slide...this time :)


Does this product in some way attract insect infestations??? That would make the decision very easy not to use it. (Although maybe I just need to read between the lines if it would not be appropriate to make such a statement.)

That was tongue in cheek referring to Kraz's comments about waffles.

I keep my tounge in cheek when I eats my waffles...except of course when I needs to lick my syrup! :D


"He sort of got me believing in it with his explanation of it, but I don't think he was trying to unload it"

I guarantee your insulation guy will say the exact same thing about his soundboard manufacturing rep....but I somehow don't think any of them has a clue what a TL plot even is...but I bet right now there probably is a soundboard manufacturing rep going - "waffle soundboard you say? - damn! - less raw materials that we can get even more money for!"

Therefore I hereby claim the WaffleBoard(TM) as a trademark....:p

I keep my tounge in cheek when I eats my waffles...except of course when I needs to lick my syrup! :D


"He sort of got me believing in it with his explanation of it, but I don't think he was trying to unload it"

I guarantee your insulation guy will say the exact same thing about his soundboard manufacturing rep....but I somehow don't think any of them has a clue what a TL plot even is...but I bet right now there probably is a soundboard manufacturing rep going - "waffle soundboard you say? - damn! - less raw materials that we can get even more money for!"

Therefore I hereby claim the WaffleBoard(TM) as a trademark....:p


I appreciate all the fun you are having with this. I am sure you have forgotten more about Home Theater than I ever will know. I am just trying to get a little advice from the "experts" on this forum about about a product that someone informed me was good. Instead of jokes about insects and waffles, how about a little advice instead. DD and the magical green glue I would assume.

I'll keep it simple. Don't use soundboard or a similar product (Hushboard, Homosote, etc.) for sound isolation purposes in a music, media, or film reproduction (playback) space. It is ineffective and, in many cases, more expensive than more appropriate materials and construction techniques.

The use of STC ratings to make product/construction decisions for these spaces is ill advised and will lead to decisions that will adversely impact your desired end goal.

I appreciate all the fun you are having with this. I am sure you have forgotten more about Home Theater than I ever will know. I am just trying to get a little advice from the "experts" on this forum about about a product that someone informed me was good. Instead of jokes about insects and waffles, how about a little advice instead. DD and the magical green glue I would assume.

I have to say that that is exactly what I used back in the day before I knew about GG. and overall the results have been excellent BUT my theater is not attached to the house other than by a long hall. it is about 20 feet from the house and used to be it's own free standing struckture, it is built on a concrete slab.
In my case most of the walls were already there and so I put the soundboard over the drywall that was there then a layer of drywall over that.
As I say I have had good results with it and with the acoustic treatments I made within the theater itself. BUT if I were doing it now I would have used the green glue instead.

So you could use it and have decent results but I think for your isolation needs the DD GG would be a better route.

My theater has a similar plan with three walls concrete and one "existing" wall. I read for several months before starting and made the decision that I would use DD and GG. I can say that I am very pleased with the results, and that there is very little leakage from the room, even in the rooms directly overhead. LFE is reduced greatly, so much that there is little if any heard or felt upstairs. The high frequencies are almost totally non-existent outside the theater. Many times my wife has to come down to the theater to see if I am there, because she can't tell if a movie is playing or not.

I'm sorry that I can't answer your original question about the GP hushboard. But I can say that if you use the techniques talked about on this forum that you won't be sorry.

Ken

I have not used GG and DD before, and have no idea how will it perform, so
don't take my case seriously. I have used soundboard from local home depot, and Sheetrock on top of that in my current theater room. My theater room is under garage. I used soundboard on ceiling and wall adjacent to the rest of the house. Here is what the wall consists of: Sheetrock, soundboard, osb, 2x6 with (r19 or ??, it was part of new construction), and sheetrock. I have solid core door and overall very happy with results. I have very little sound transmission in the house, but in garage (concrete floor) sound transmission is noticeable.
I used soundboard because it was $9 a sheet, readily available and I didn't have much knowledge about other techniques, plus I think GG is quiet expensive.

Thanks for all the replies. I am thinking that the double drywall and green glue is the best way to go.
I think the sound board will probably do a decent job, but not as good as using the green glue.

Being as that I already had the Hushboard, I was trying to see if there was some way to make use of it before lugging it back to where I bought it.

I even thought about sandwiching it between two layers of drywall. Again, I know the green glue would be a better choice, but since I already have it...that is mainly the reason I was looking for anyone with experience using it and was happy with the results.

I suppose a possible compromise would be DD and GG on the ceiling (the only part touching another space) and using the soundboard on the four walls???

Before there was green glue, we used sound board doubled up with drywall, and MLV draped in the stud cavities behind that.

This was a staple of the isolation in early Acoustic Innovations rooms.
Trust me that it is a dramatic improvement over a traditional wall construction if you still follow the rules about sealing the penetrations and adding door sweeps and gaskets.

There is no doubt that the more modern rooms with multiple layers of drywall w/ GG laminating them are better isolated at the lower frequencies, but it's not the end of the world.

My theater has a similar plan with three walls concrete and one "existing" wall. I read for several months before starting and made the decision that I would use DD and GG. I can say that I am very pleased with the results, and that there is very little leakage from the room, even in the rooms directly overhead. LFE is reduced greatly, so much that there is little if any heard or felt upstairs. The high frequencies are almost totally non-existent outside the theater. Many times my wife has to come down to the theater to see if I am there, because she can't tell if a movie is playing or not.

I'm sorry that I can't answer your original question about the GP hushboard. But I can say that if you use the techniques talked about on this forum that you won't be sorry.

Ken


Ah... my situation.(sorry to hijack the thread a little).. Ok, how did you do the walls that were on concrete?
Completly isolate them? resilaint channels on studs? Or isolate from the wall with risc_4 and use DD hard attatched to the studs?

I've been thinking of disconnecting the top of the wall from the joists, use isolators to tie the top of the wall to the concrete, But leave the bottom of the wall bolted into the concrete floor. Hard attatch with 5/8 DD with GG in em.

Humm? :o

Gosh

Gosh,

My build isn't the most ideal one, because I was limited on budget and time (like almost everyone). The walls facing concrete were built with studs about two inches away from the concrete and filled with insulation (pink stuff). I had planned to isolate at the top, but didn't. The walls are two foot centers with the base bolted (nailed) to the concrete floor. I used DD and GG, fastened directly to the studs. It isn't totally isolated, but there is very little problem in my situation. The ceiling is isolated and I used DD and GG on it with two foot centers.

If I were to do it again, I would isolate the wall at the top, but as I mentioned, I am very satisfied with the results.

Ken

Hi all... quick question..

I am planning on using DD and GG in my theater room. My primary goal is sound isolation, not treatment. SHould I also be using a metal channel to separate the drywall layer from the wall studs.

Dave

Bump... anyone have a thought on this.

Dave

Metal channel + clips aka RSIC-1 or ISOMAX are good.

Metal channel as a form of resilient channel is bad. It helps with mid to high frequencies, but hurts LFE - which is the one you are trying to control. I believe this is what you were describing.

Take a look at this:
http://www.greengluecompany.com/greenGlue-vs-ResilientChannel.php

Don't forget to insulate all the walls/ceiling.

Great..thanks for the response DC.

Dave