[TerryO]

I have a friend that is remodelling his bedroom and would like to isolate the sound of the Living Room TV which is on the other side of the wall. He likes to watch the tube at night, but the sound in the next room keeps his wife awake. I would think that fiberglass insulation would provide some isolation at least cavity resonances. A double layer of drywall is also feasible. Green Glue works well, but is pricey...so is there a lowtech economical substitute. Would for instance, Aleene's tacky glue work if spread with a notched trowel before attaching the second layer of drywall? Aleen's never completely hardens but I may not be aware of other considerations.

Any ideas would be appreciated.

Best Regards,
TerryO

[rodge827]

Hi Terry,

How about a good set of headphones ?

Chris

[MaxCast]

For starters put the new wall on it's own studs.  Insulate between the walls with fiberglass.  I guess you could put some sort of un-pieced poly between the walls??  That's about all you can do besides attacking the flanking noise/vibrations.

[TerryO]

Hi Terry,

How about a good set of headphones ?

Chris

Thanks Chris!

I'll even pay for the shipping, it's the least I can do to compensate you for your generous gift.

Best Regards,
TerryO

[rodge827]

Hi Terry,

I work in the trades and have done this kind of thing in the past only to come up with marginal results at best. If your buddy wants to do this right. He must I mean MUST consider doing the attached bedroom walls as well as the floor and ceiling too. One wall will not be enough to sound proof the TV noise.

When you figure in all the extra work, mess, and money, a good set of headphones seams quite reasonable.
 
Don't ya think ?

Chris

[Big Red Machine]

Yes, flanking noise will defeat you.  If a separate wall is put up, make sure it does not touch the existing wall, even the insulation can transmit vibrations.  One or the other rooms needs to be isolated completely.

[Nick77]

Yes, flanking noise will defeat you.  If a separate wall is put up, make sure it does not touch the existing wall, even the insulation can transmit vibrations.  One or the other rooms needs to be isolated completely.

I was hoping to do the same in a new construction situation. I was hoping to fill the wall with either blown cellose or cotton insulation which has better noise reduction and then double layer drywall with green glue.

You guys make it sound like its more complex than I realized.

Am I off base also? I dont know if OP has the option of insulation or not but isnt there much better choices than fiberglass?

[bpape]

Flanking can certainly be an issue.  However, when we're talking about TV sound (unless it's really really loud), the flanking won't be as much of an issue.  Insulating the cavity will certainly help.  Green Glue is very effective but even moreso at lower frequencies which, again, are not the issue with simple TV watching.  More mass is the answer (coupled with the insulated, damped cavities).  Even using simple Liquid Nails and another layer of drywall will help in this situation.  The idea is simply to drop the resonant frequency of the structure thereby getting the center of the resonance lower than the frequencies which would be in question. 

The next step would be to remove the existing drywall and put up RSIC-1 clips and hat channel and then double drywall on top of that (and insulate).

All of that said, you really need to look at the HVAC setup first and see what's happening there as that's generally the biggest culprit.  If the 2 rooms are sharing a tin trunk and are tied to it relatively closely, doing the wall will not overcome what is basically a direct path between the rooms.

Bryan

[rodge827]

Hi Nick,

If you are in the pre construction phase there are many options you can consider. It all comes down to the level of sound proofing that you want to achieve.

If you are looking for studio level, be prepaired to open up your wallet and reduce the size of the house you plan to live in.

If you want to just reduce noise to a very quiet and livable level try this. My friend built his house on the oceanfront here in NJ. All his walls were 2x6 studs, yes even the interior walls were 2x6's. What this means is that most doors, windows' etc. are configured for 2x4 walls. Extension jams are the answer for that. Then before the 5/8's sheetrock went up all the walls were insulated with either interior or exterior fiberglass insulation. All spaces were filled including the space between the floors, his are all hardwood floors due to an allergy issue with 2 of his 6 kids. All of his duct work is insulated through out the whole run from supply to register. He did this about 15 years ago since then better and more environmentally conscious products are available.

Net result is a much quieter house, more fuel efficient, and economical to boot. The kids run around in the play room upstairs and we have the privilege of watching our Iggles struggle valiantly.

Chris 

[bpape]

If I missed that the shared wall is still under construction, you can build staggered stud walls with a 2x6 bass and alternating studs each side so they're not shared.  This is a very effective yet cost conscious way to reduce structural transmission. 

Bryan

[John Hile]

Another tip that would help would be to build you walls at 24" OC so the panel has more flex.

Depending on how much sound isolation you require and can afford, you may want to consider using 1 tube of Green Glue per 4'x 8'. You would be introducing damping and you will get about 70% of the performance than you would get from 2 tubes per 4'x 8'. And with a decoupled wall, that may get you to what you need.

John