Author Topic: Soundwaves/vibra's-absorb then block  (Read 3750 times)


  • Guest
Soundwaves/vibra's-absorb then block
« on: April 12, 2005, 12:25:52 AM »

If a sound travels from  A to D  and  i am thinking of using an absorbtion layer and MLV/soundproof mat layer in between,
then where does the MLV/sound proffing mat go, at B or C?

Normal pratice for a concrete floor suggests putting the MLV ontop of the concrete 1st  and creating an airtight layer,then the absorption layer then your floorboards/or carpet however this is usually to stop impact noiselike footsteps  travelling down below,that is, originating from the room itself, not the other way around in my case. I want to block impact noise originating below me.(And i don't have access to the celing below me btw.)

Therefore, because i wish to block the noise orgininating below me from level 14 travelling up to my level on level 15 i have been speculating that maybe i should have an absorption layer 1st to deal with the inital vibrations  as it's iompact noise and then have my soundprooofing or MLV-type mat ontop of this as an end noise block (after the absorbtion medium has done it's job bouncing all those vibrations about)..

Is this the correct analysis bearing in mind the direction of the noise and that i wish to block noise comuing from below me, and not the other way around, if you see what i mean?

Excuse the repetition,please.

Thanks in advance for any replies? :o


  • Guest
Re: Soundwaves/vibra's-absorb then block
« Reply #1 on: May 14, 2005, 09:58:46 PM »
Sometimes we don't reply promptly to postings with complications and potential pitfalls, but we should.

Instead of taking your issues one at a time, I'll try to answer them all this way:

The importance of the mix of materials is somewhat important, but usually not.  It usually doesn't matter which material faces the noise, etc.

This would be important when vibration damping is involved, though.

You mentione MLV over concrete.  One thing you need to be aware of is that concretes alkali will leech into the MLV and eventually degrade it.  To prevent this, use a sheet of plastic as a barrier.

In your case, I'd recommend the MLV with a closed cell backing down for vibration damping.  Carpet pad and carpet should take care of the problem.