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Martin, Electrical Engineer
Category: Home Improvement
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Experience:  Design, construct, fix and grow stuff around and in the home.
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Does anybody have experience with soundproofing techniques

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Does anybody have experience with soundproofing techniques such as double walls or staggered stud walls, use of channel & clip ceilings, green glue and/or roxul?

I'm looking at doing a drop ceiling of sorts and want advice if it will be as effective as I anticipate.

Hi, this is Ken,and I will hopefully be able to solve your problem, since I majored in audio engineering.

There are different techniques used for different purposes, for example music studios, annoying neighbors and busy streets, etc., and also for the type of construction.

Please tell me:

(1) The dimensions of the room, including ceiling height (without a dropped ceiling).

(2) Is the room a perfect rectangle with parallel walls?

(3) Wood/sheetrock construction?

(4) How many windows and doors, and their sizes?

(4) what is the source or the sound you are trying to squelch?

(5) In your own words, what are you trying to accomplish? Please be specific.

When I receive your reply, I will be able to help you.




p.s. It is late now, so please expect a reply tomorrow.

Customer: replied 3 years ago.

Room is kitchen about 12 X 12


Perfect rectangle

Desired sound reduction is almost 100% impact from above subfloor and joists


Trying to decouple the subfloor impact source from the lower floor ceiling




Hi, this is Ken again.

Sorry, I did not get a complete answer. Let's try one more time.

I'm going to bed now (really).

please be complete. Otherwise, I cannot help you.


Customer: replied 3 years ago.

Those were the relevant answers to the questions you asked. Impact noise from above, need to decouple and dampen below.

I graduated with a degree in Electrical Engineering 42 years ago. I retired just 4 years ago. At that time, my consulting rate was $130 per hour. I have already spent 20 minutes trying to get answers from you in order to earn $15. I'm sorry, but I do not wish to spend any more time, since without complete information, I cannot give you any specific answers, and any answer I give might be the wrong one for your situation anyway. Thus, I have opted out of this question.

Please re-list your question and perhaps someone else might be willing to help you.



Customer: replied 3 years ago.

Yes, we're not building an acoustical orchesrta hall here, it just a matter of dampening and decoupling the upper level from the lower level. No involvement with windows, or room rectangular orientation. Thanks for having a look.

Hello. How much space do you have available to lose on that ceiling?
Customer: replied 3 years ago.

It's 9 1/2 feet give or take for the ceiling hight. This When I did the clip and channel ceiling it came down not more than an additional 2 inches below the old plaster and lathe.


I'm thinking staggering new joists between the exiting but slightly lower than the orignials and not touching existing joists or subfloor above (but onlyt to the perimeter ballon framed walls) will effectively decouple. People who sell channel and clip though seem fixated on flanking noise and say clip/channel is superior.


My scenario would have perimeter connections to the structure instead of 40-50 clips direct to the joists where the impact occurs. And any impact in the field of the floor above would have to travel over to walls and plates down into the stud wall below, into the new joists, through the rock & green glue and then out into the room.


Seems like same or less money than clip and chanel for 10 2X10X14s which I could level independant of the above joists which was a huge pain in living room of this 1885 house with low points in the center of the joists, and other issues with settling.

This is a valid idea, if you still hear impact style of sound even after using roxul bat and sound isolation support materials. The only problem is a possible sagging of the ceiling in the middle if not enough tension is used (if all would be suspended to an horizontal wire). If you redo a whole framing it could be more rigid (that is why i asked if you have enough space). The beam could the sitting on rubber feet/pad.

If the problem is from impact sound, you can also work on it from the floor above. Using a cork mat or similar material to dampen it and prevent the sound to enter too strong in the joist. Ceramic and hardwood floor are really good to conduct sound. Note that sound can also come from vertical beam and dissipate from the wall.

Some sound like extreme bass need extremely thick sound insulation and are very hard to remove.
Customer: replied 3 years ago.

I could go the route of using a rubber impact absorbing underlayment in the future but I have to wait until the vinyl floor is ready to be redone, it has a few more years.


I had another expert advise that 2X10s should be strong enough to span a 12-13 ft room and carry 2 layer of 1/2 drywall (that would be unsupported and a complete spanning). The existing joists carrying all the weight of the up stairs space are only 2X8s but they are the growth true 2 inch stuff from 1885. Would you think 2X10s woul dbe sufficient? The only other weight would be a ceiling fan or something similar, or If I went with 5/8 drywall.

2x10 are absolutely enough for that area. You could even use engineered joist as you could fit more sound insulating material between the triangles withing the joist (they use lot less wood also).

If you have any water pipe or drain going trough the area, make sure to make it easy to access them in the future.
Customer: replied 3 years ago.

By engineered you mean the I beams made from particle wood, etc?


As far as access goes, I won't have direct access since this will be a rocked ceiling, the access will be limited to under the kitchen sink and in a linen closet.


Are you familiar with the clip and channel decoupling method used by many in this scenario and what are your thoughts on it vs mine (which should limit the noise to flanking which must travel a ways through surrounding structures to make it into the new ceiling?)

Engineered joist as in made from smaller wood part assembled in triangle with steel connection.

As for the access, do it like you want, i was just doing a friendly reminder :)

Yes i know the clip technique you mentioned. It work up to a certain extend as long as the impact of sound is not too strong. All the energy not absorbed will continue pass it. Your method is valid but a last resort solution as it involve more material and take more space from the room. Like i said it is a valid method and you can apply them both at once to really give it your best shot to solve the problem once and for all.
Customer: replied 3 years ago.

My numbers on the heavy duty RSIC rubber and metal clips and 20 guage hat channel is almost identical to 10-12 2X10s and the ease of leveling is what attacted me to this method. The clips are cool and everything but it killed me leveling the high and low spots in an old house.


I like the idea of putting drywall right on the wood as well.

What do you think about putting some strips of the rubber underlayment betwen the joist bottoms and the sheetrock? Not exactly clips but I can't see doing joists and the whole clip and channel system


Yes, that would work, as long as the sound can't directly go to the second ceiling easily.

If you want to do leveled things in an old house, a rotating laser level is very handy.
Martin, Electrical Engineer
Category: Home Improvement
Satisfied Customers: 4922
Experience: Design, construct, fix and grow stuff around and in the home.
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