[oris98]

Hi all,

I have a 17' x 17'x8' room for my HT and 2 channel setup.  The room right above my HT/2 Channel audio room is the master bedroom with wall to wall carpet.  My wife lately been requesting to replace the carpet with hardwood or liminate floor.  With carpet on between my HT room and master bedroom (MBR), the sound travelling level to the master bedroom was acceptable (according to my wife).  If I replace the carpet with hardwood floor I am afraid that the sound will travell even faster and have bigger impact to the noise level to the MBR.  I do a lot of late night music listening and would like to keep the sound level unchanged without sacrifying too much with my sound volume when I listen at late night. 

Would you guys have any suggestions or options for me to do any treatment to the floor for sound proofing purposes ?  Someone suggesting to put a layer of 3/8" MDF as subfloor (glue it on top) and lay the hardwood or liminate floor on top of the MDF will improve sound dampening effective ?   Any comment on this suggestion ?  Is there any sound absortion or dampening paint / coat that can be sprayed on top of the bear floor before laying the MDF subfloor for better sandwitch effect ?   Or should I better off to treat the ceiling of the HT room that may give me  a more effective solution ?

Thanks

[bpape]

Not only will sound transmit more readily out of the room, but impact noise from the bedroom will travel MUCH easier into your room.  If you want to do it the right way...

- Pull up the carpet AND the subfloor upstairs.
- Insulate the joists between the rooms
- Lay 2 layers of subfloor upstairs with Green Glue between
- Use a dampening mat between the subfloor and the wood floor.

Bryan

[oris98]

Hi Bryan,  thanks for suggestion.   How to insulate the joists on exiting floor ?  Are you referring to putting insulation (rockwool stuff like normal room insulation stuff ?

What is the green glue stuff ?  Is it a kind of acoustic paint or coating ?  Sorry, I am pretty green in room treatment here..  

Pulling out the subfloor to reach the joists is quite a bit of work.  If I lay the sound dampening mat between the subfloor and a second MDF subfloor then put another layer of sound dampening mat between the MDF and the wood floor will it work ? 

Since the HT room has 4 pocket lamps up on the ceiling, if I enclosed these 4 4" holes and repatch it with dry wall (I can install some track lights for lighting instead, will this help too ?   Unfortunately, there is a heat vent on the ceiling of the HT room too, I will not able to enclose it as this room will be cold in the winter time...

Thanks again.

[bpape]

You can use standard wall insulation so long as you completely fill the cavity.  Not sure how you're going to fill the cavities without pulling the subfloor.  You could bore holes at each end of each cavity and blow it in.  I guess I didn't figure it was that big a deal since you already have to pull up the carpet and move all the furniture out to do the floor anyway - jsut another layer of plywood to pull up - unless they used adhesive between the joists and the subfloor.

Green Glue is a viscoelastic damping material that helps the 2 layers keep acting like 2 layers but turning some of the vibration into heat and having them vibrate NOT in unison.  It takes about 30 days to setup. 

Your idea of a mat between layers of subfloor and between subfloor and wood floor will work - for impact  noise.  For full range isolation, it's no better than just adding another layer of subfloor.

Lighting - closing the holes will reduce transmission.  On the down side, track lighting is the devil's work    I've yet to see one that when the bottom end gets going, doesn't rattle and buzz like mad.  That would drive me nuts. 

Bryan

[richidoo]

http://www.greengluecompany.com/

[saygrr]

Oris98 I am in the middle of a big project to resolve the same problem you are having. I am using Green Glue and Mineral wool. However I ripped out the ceiling in the listening room and put in ceiling joist so nothing is touching the floor truss. If isolation is not possible for you spend extra time examining your options. Just like you when I am listening to music I want silence. Look at sound isolation companies web sight you might find some help there. That is where I got the Green Glue from.  Here is what I am doing. The 18 inch floor truss was already filled with cellulose. I just finished putting in 5 inch tall microlam ceiling joist. Almost done insulating them with rigid batts of mineral wool. Rigid batts are more condensed considerably heavier. Next half inch mdf, green glue, half inch mdf, green glue, half inch sheet rock. I am positive the room will be very close to silent under normal living conditions. The isolation will be the biggest benefit. Will know more when I'm done and moved back in. Hope what ever you do works for you.

Jeff