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Sound proofing first floor


Justink

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I just installed 5 CDT 2650-C speakers and they sound great. The issue is they are on the first floor and the sound is traveling to the second floor. I can't buy a metal enclosure without ripping up all the sheetrock which I don't want to do. What can I do to help dampen the sound?  Remember the sound is traveling between the  two floors. The solution needs to prevent me from tearing out the existing sheetrock.

 

Thanks in advanced.

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Sorry you didn't get a response on this.  One reason you didn't, IMHO, is that soundproofing requires a lot of work on the rooms and you seem to have ruled that out at a starting principle.

 

Sound is transmitted when the wall in one room is physically connected to the wall in another.  The sound, to some extent, is transmitted through the studs (therefore a space between studs is usually recommended).  The same applies to ceilings and floors.  This is mostly bass.  Thin doors do this too.  A real soundproof room is a room within a room.

 

Another means of transmitting sound is simply air passages.  These include gaps in sheetrock, ventilators, electrical outlets, non-airtight doors.  If there is a stairway up to the second floor that is going to be an effective passage, just as when you yell downstairs, "Honey have you seen my purple socks?"

 

One thought is that it might be a smaller production to soundproof a bedroom on the second floor than a living room on the first.

 

As you can imagine, this sort of work is better done during initial construction.

 

Metal cage?  That is for electronic signals, not audio.

 

Let us know what you find you can accomplish within your restraints. You really need an architect to advise you.

 

WMcD

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You can hire an insulator to blow in shredded newsprint or maybe white cellulose.  He will drill 2+ one inch holes between each stud and blow the stuff in.  It is a very good heat insulator and does offer a little sound insulation, but by no means soundproof.  I had this done to my garage.  In that environment, the plugs are unobtrusive; in yours, you could reinstall the sheetrock plugs, mud and refinish.  Did I ever tell you I HATE finishing sheetrock?  Shredded newsprint creates dust.

 

You might install a dropped ceiling with acoustic tiles and a fiberglass bat on top of that.  It will reduce the physical connection to the studs and transmit less vibration. 

 

Ultimately, you will have to live with the sound transmission, or remove the ceiling and build another one that has no direct connection to the floor joists and then stuff the space with insulation, like fiberglass, to get close to soundproof. 

 

In my old house I had fiberglass between the floor joists and a suspended acoustic tile ceiling.  She Who Squawked still carped about her china buzzing from bass sounds.  I was threatened with violence if a piece broke.  :unsure: 

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I enjoyed reading JohnA's comments and agree.

 

For the record:  There are two different issues which might get confused.

 

The first is the treatment of rooms to affect how sound bounces around within.  Absorbers and diffusers (reflectors) are often used.  This is not soundproofing though.

 

The second, soundproofing, is keeping the sound pressure from getting out, or in.  

 

For example: In my humble apartment there is little transmission though the walls floors and ceilings because they are six-inch reinforced concrete.  It is not a matter of sheet rock and studs, just massive sealed barriers. 

 

OTOH, voices pass though the ventilation system.  I hear vague conversations and a microwave oven cycling.  People passing though the outside hall can be heard because of the lightweight door (no mass) which has a gap at the bottom threshold and no sealing at the edges.  It is just a matter of sound passing though gaps.

 

It is interesting to watch old James Bond movies with Sean Connery.  We see that Bond passes from Moneypenny's anteroom into M's office (where he is criticized for using a .22 Beretta and ordered to use a Walther .32.  IIRC.  Smile. 

 

There is a double door system, between the anteroom and the office presumable to prevent sound transmission.  But ventilation for M's pipe, it could compromise soundproofing and security.

 

WMcD

 

 

 

 

 

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Welcome to the forum!

 

There are some home solutions in Jeff Cooper's book shown below.  Check out the section on how to soundproof a room.  The space behind your ceiling speakers should be airtight, with rigid, relatively high mass barrier material to prevent sound from going through.   As you play more and more modern movies I fear you will find that all the other speakers also provide sound that leaks into the room above.  All your regular speakers will be pounding away at about 80--250 Hz, and your sub will impartially deliver the powerful and largely non-directional frequencies below 80 Hz to the sound room ceiling and all walls.

 

One problem is the term "soundproofing."  Too many contractors and some architects are used to thinking of "soundproofing" in terms of keeping human voice frequencies from traveling to another room.  You have a larger problem.  You have to deal with BASS, down to about 30 Hz for orchestral music, lower for electronic music, 16 Hz for pipe organ, and (increasingly often) to 10 Hz for movies.

 

You could put a floating floor in the second story, as well as a high transmission loss ceiling treatment in the sound room.  No guarantees.

 

Make sure this is the room you really want to use for your sound.  Some people add a free-standing room in the back yard, with optimum construction, a la Cooper, as well as favorable size, shape, ceiling height, etc.

 

Good luck!

 

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Not sure how far you're willing to go with this but as Gil & John suggested - blowing more insulation in between the ceiling joists would help.

 

There is a second alternative - if you're willing to put on an additional layer or two of sheetrock. Use Green Glue (not actually a glue) between the sheetrock layers and Green Glue Sealant along all the seams. Recent studies have shown Green Glue to substantial reduce bass transmission not just as a sound barrier, but also reduce vibration transmission laterally. I can act to some extent as a sort of bass trap. Make sure you follow the manufacturer's directions!!! It's important for instance to secure the first green glue sheetrock layer all the way through to the stud/joist.

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  • 1 month later...

I put a 13 gallon trash bag in the speaker hole then sprayed expanding foam into it and sealed it with a rubber band.  I tucked a pillow into the hole to achieve a convex void until the foam hardened.  It's not perfect, but I got good results.

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  • 1 year later...

With in ceiling speakers, you are obviously using that joist space as the speaker “box”.  You won’t stop sound transmission easily. You can make a smaller, insulated box with the foam idea but results will depend on what you expect. You could think about thicker padding under any carpet on the second floor too. As well as thicker carpet.  Never heard of using MLV on the floor but who knows? Might work.

Are those speakers just for ambience? 

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  • 2 weeks later...
4 minutes ago, babadono said:

Yea but...aren't the Klipsch in ceiling speakers using the air space on the back side of the woofer cones as an infinite baffle? Sealing it up, it's still gonna work but not as designed. Or am I way off base?

Great point

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