# Drywall or cement sheeting for internal wall.



## sfdoddsy (Oct 18, 2007)

*Taming a huge room.*

Hi, I was wondering if I could get some advice.

I have a very large basement/warehouse space which I am converting to a listening room (mostly 2 channel). The area is 10m x 9 m (32 x 28) opening into a similar sized space.

The construction currently is double brick walls, a brick tiled floor and a timber beamed ceiling. For aesthetic and hopefully acoustic reasons I am planning on building an internal stud wall on three sides, using furring channels, insulation then either drywall or fiber cement sheets (like HardiePanel).

Which would you recommend. I am hoping that the new internal wall acts a bit like a giant bass trap as I have a few issues down low.

I've attached a plan of the room and some quick measurements. The FR is L&R and R.

Thanks in advance.


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## sfdoddsy (Oct 18, 2007)

Sorry, DP


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## bpape (Sep 14, 2006)

Where are you planning to build the walls? 

Ideally, you'd not be off to one side like that unless you're planning on one of the walls separating the listening space from where you show the car now.

Bryan


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## sfdoddsy (Oct 18, 2007)

The interior walls would be built inside the exterior walls, so on the left, front and right.

The car is actually in the room.


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## bpape (Sep 14, 2006)

Ideally you'd put a wall separating the car area from you - or - turn the setup so you can be more symmetric in the room left to right and have the car behind you.

Bryan


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## erwinbel (Mar 23, 2010)

Since drywall is very cheap and cement panels very expensive, the return on investement is far superior if you go with drywall. Use 2 sheets ofcourse. 

What I keep wondering is whether the very low bass (50 Hz and lower) isn't simply muted somewhat but by no means effectively damped with the MSM systems? The graphics I see everywhere start @ 125 Hz (okay for speech, not for music and movie-sound), so who knows what the performance is below 125 Hz? 

I assume low bass is reflected by concrete, but what about drywall etc? So I understand your thinking here: _I am hoping that the new internal wall acts a bit like a giant bass trap as I have a few issues down low._ so if drywall is "transparent" (not reflective) for this sub bass, can a drywall construction be a bass trap?


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## bpape (Sep 14, 2006)

The graphs you see are showing NRC, not STC. NRC is pretty useless for isolation as it's a limited range and also an average. 

Given enough mass, decoupling, and cavity depth, you can certainly do a good job well below 50hz.

Bryan


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