attic the bass trap?

I have 20 m2 dedicated listening room. over this room there is an attic/loft. I have been woundering if should try to use the attic to treat my bass. I am thinking four 50cmx100cm holes in the drywall. use som windstopper to hold insulation in place.

Anybody seen ore tryed anything like this?

the Idea is that I can lower the bass energi in the room.
I also use dsp under 200hz.
 
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Hi,
Yeah good idea. I know some ( professional) control room using same strategy.
One of the most famous is the 'A' of Steve Albini's Electrical Audio, Chicago Illinois : they use the basement as a gigantic bass trap for this room.

The only drawback i see is if you've done a 'very serious' soundproofing it'll kill most of what you achieved ( or will need some serious afterthinking to counteract the eventual noise leaking into your listening place from outside - and vice versa).
 
The idea was to unload a small and sealed room. But I dont know if it helps for standing Waves.
If I open up to the attic. the room volum dobbles. But there kneeds to be some barrier because it gets realy cold in the attic in the winter .
I dont know if drywall is a good absorber because it probbably has an resonance and then it acts as a trancduser and smears everything.
 
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The idea was to unload a small and sealed room. But I dont know if it helps for standing Waves.
If I open up to the attic. the room volum dobbles. But there kneeds to be some barrier because it gets realy cold in the attic in the winter .
I dont know if drywall is a good absorber because it probbably has an resonance and then it acts as a trancduser and smears everything.


It will change the behavior of modes for sure*. Don't worry about a barrier as the wavelength involved won't 'see' the insulation even if 50cm deep.

Yes Markbakk comment is right, drywalls acts as absorbers and are used to this effect in pro control room. It won't smear anything, they are just large membrane absorbers tuned low ( often they use multiple plasterboard sheet of different thickness and resilient material in between ( eg: Auralex's 'soundbarier', MLV in general) to form a constrained layer damping to increase efficiency and lower effective freq and at same time increase soundproofing) .

That said if you want your attic to be an helmotz resonator it have to be sealed. If not it will act more or less like an open window ( which isn't bad by itself if you don't have neighbour too close).
The issue with Helmotz resonator is they are effective in a narrow range and if i had to choose between an open window and an helmotz res i would choose the window as it is 'wideband' in effect.

I have a leaky roof ( wrt low end) and i like this as it lower the mode issues i could have in my listening space.

Adason advice should be considered too imho.

* their location within the room.
 
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