room acoustic set up question

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drabbish

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I have a duplex that I wanted to place some speakers in. I was wondering if i placed the speakers in front of the shared wall and placed some acoustic material behind the speaker would this give me the least amount of sound transmission through the shared wall? or does it not really matter?

the speakers are magico so the are also totally enclosed so there is no rear port firing.
 
I would say unless you treat a substantial percentage of the wall surface (100%!) you won’t notice an appreciable reduction in sound transmission. Acousticians will tell you even an untreated electrical recepticle will leak a lot of db across the boundary.
 
Placing the speakers in front of the shared wall should minimize the sound waves hitting the wall, but probably not make much of a difference what your neighbors hear. Then again, if the common wall is well insulated then you might be okay. My ‘office’ is in the room behind the wall with my speakers, and I have no problem listening to them while working. However, there is no insulation in this wall.
 
Most newer common wall structures (duplex, condo etc) have thicker studs (2x6) and acoustical insulation installed in order to provide a reasonable amount of sound attenuation.
With that said, why don't you just try the speakers and see what it's like on the other side during playback.
Hanging a carpet or other acoustical items on the common wall will only provide minimal additional attenuation.
There are several ways to do it right but all will require additional construction measures.
 
I would assume that use of acoustic panels etc. will affect the sound in the room, but do little to shield the apartment next door.

There is however a difference between sound damping/ absorbtion (e.g in a music room) and acoustic isolation (e.g. against traffic noise). Application and materials are different.

Latter might work, but results will be unpredictable, as it is hard to know what other sound transmitting properties the wall entails. This is a kind of acoustic isolation panel used earlier e.g. in telephone booths. But you’d have to treat the entire wall and there is no guarantee:

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If sound transmission reduction is your goal, and you don’t want to open the wall to deal with the space between the studs, you might wish to consider using something like “facric-wall” tracs and fabric. There are 1/2”, 1”, 1.5”, and 2” deep tracks and you can fill the space with damping materials. It will affect your room acoustics, but that can be mitigated with choice of materials. I had left over carpet pad that had mass-loaded vinyl bonded to one side—I put up 1/2”trac and used the carpet pad as the damping material, then place fabric over using the tracs. I did this on the wall opposite the glass wall of my wine cellar down the hallway adjacent to my music room. It totally stopped slap echo in the hallway and greatly damped sound in the adjacent bedroom. Also reasonable easy to do it yourself. Additionally, a fabric covered wall offers a nice alternative to sheetrock and of course a gajillion fabric choices are available. https://www.fabric-wall.com/ is but one of many companies offering this type of solution.
 
seems like two sets of studs in parallel and dry wall on each side, its an old duplex 1970 or older, there isn't even a fire wall between the two units in the attic. I was considering "green glue and a second layer of dry wall", I dont listen to music very loud and the neighbors are a nice older couple who probably dont care but trying to be as considerate as possible
 
Ok, LF bass will go through that wall like it isn't there. It will contain higher frequencies ok.
My suggestion would be, if possible, place speakers on wall furthest away. That way propagation distance will at least provide some attenuation of the soundwaves.
 
If the two sets of studs are staggered and you have opened up the wall then you can weave a sheet of mass loaded vinyl or rubber (such as used in pool liners or rubber roofing) through the studs in the wall. Then insulate. There are several methods of hanging the new drywall afterwards.
A search online describing acoustical barrier walls might prove to be of great value in your quest.
 
Having recently completed an acoustic remodel, if you are removing the sheetrock to treat the wall the above advice is good, but no need to weave the mass loaded vinyl just put it up last after filling the wall with recycled blue-jeans insulation. You can get some idea of that if you visit this blog http://www.whatsbestforum.com/showt...amp-ARC-for-me&p=416825&viewfull=1#post416825 and read through a few posts where there are some clear pictures of how to do it. You do have to do a few creative moves cutting the vinyl to overlap without doubling thickness (or your sheetrock won’t lay flat).

My acoustician said she found little appreciable benefit to using stuff like green glue between layers of sheetrock, and in your application of jst sound abatement a single layer of 5/8 rock over mass loaded vinyl will be plenty. In my space the sound in adjacent bedroom significantly reduced. If you listen at quiet-moderate levels your neighbors will hardly hear a thing. Be sure to treat behind electrical boxes or any pass through locations.
 
drabbish said:
seems like two sets of studs in parallel and dry wall on each side, its an old duplex 1970 or older, there isn't even a fire wall between the two units in the attic. I was considering "green glue and a second layer of dry wall", I dont listen to music very loud and the neighbors are a nice older couple who probably dont care but trying to be as considerate as possible
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This presents no barrier at all to low frequency waves and even if you were to add a second layer of dry wall your neighbours will still be disturbed by the bass but at least high frequencies will be attenuated. Pay careful attention to the ceiling too. This is a major point of weakness in sound isolation. Money spent on a second layer of dry wall is wasted if sound leaks via 1/4 inch ceiling boards...
 
I'm just wondering...does an insulator works to block the sound on the partition wall? I am planning to transform my garage to a music room.
 
chrispeddler said:
I'm just wondering...does an insulator works to block the sound on the partition wall? I am planning to transform my garage to a music room.
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Insulation will attenuate some frequencies passing through the walls (depending on construction/material), mainly mid-bass. Not the lowest. Are you trying to contain sound levels in all directions, including outside (neighbors), or mainly some isolation from inside house (family)?
 
AJ Soundfield said:
Insulation will attenuate some frequencies passing through the walls (depending on construction/material), mainly mid-bass. Not the lowest. Are you trying to contain sound levels in all directions, including outside (neighbors), or mainly some isolation from inside house (family)?
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Hi AJ. On one side (partition), it's my neighbor that I don't want to be bothered. I also don't want to bother the other house but there are 2 walls (one concrete, then the next wall is just plywood).

I was told that egg trays works better than an insulator. Is this true? I am on a tight budget so I am willing to DIY everything. Any recommendation?
 
chrispeddler said:
I was told that egg trays works better than an insulator. Is this true?
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Only if you sell eggs.

chrispeddler said:
I am on a tight budget so I am willing to DIY everything. Any recommendation?
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Sure, DIY some dipole or cardioid subwoofers (Google is your friend). They produce 6db less sound power and are directional. That helps mitigate the problem of excessive bass SPL leakage through walls from happening in the first place.
 
Lol on the egg trays:D...but seriously, there are stores that sells egg trays here...also I observed in some music practice studio that they have cardboard egg trays on their walls so I guess that works but idk if their walls have some other materials inside their walls aside from the trays.

Will do research on dipole and cardioid subwoofers.

Thanks AJ!
 
chrispeddler said:
I observed in some music practice studio that they have cardboard egg trays on their walls
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That's for diffusion (albeit a poor mans version/limited bandwidth), not attenuation of bass. It would only affect higher frequencies.

chrispeddler said:
Will do research on dipole and cardioid subwoofers.

Thanks AJ!
Click to expand...
https://kimmosaunisto.net/CardSub/CARDSUB.html
http://www.linkwitzlab.com/frontiers.htm
http://musicanddesign.com/u_frame.html
http://musicanddesign.com/A_B_C_Dipole.html

You're welcome
 
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