Cutting slots into a splayed wall... Helmholtz effect?

Started by Antho on 1 October 2006. 7 replies.

Originally posted at johnlsayers.com, topic 7186.

This thread is in regards to my studio build diary thread... http://www.johnlsayers.com/phpBB2/viewtopic.php?t=6863 I have hung several large 'bass hangers' into the cavities created by my splayed walls, as you can see in the images of the above thread. I drywalled and covered up everything and my intent was to cut slots into the faces of these splayed walls to create a slot resonator. I am planning on covering these slots that I cut (because they will look bad) with a broadband absorber pannel that will sit off the wall by about 1". Am I on track here? I have calculated my three main problem modes and have also calculated the slot arangment that I believe will put me 'in the ballpark' of these frequencies'. Should I just cut open a hole in these walls and cover with fabric or is my plan appropriate? I put those big hangers back there... I should make use of them somehow! :lol: Any thoughts, suggestions, or general 'pointing-in-the-right-dirrection's would be very helpful!
Any one?
Antho - you could remove the bottom 1ft of the drywall creating an access at the floor/wall junction to allow low frequencies into the cavity. As far as making a slot resonator your design is flawed as there should be a sealed chamber behind but you omitted the joining wall. see attached pic. cheers john
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John, Thanks for the feedback! Is there any acoustical benifit to cutting the bottom portion? Since I was planing on putting broadband absorption on the front walls, could I just cut an opening where my asorption will be covering? thnks again.
is there any acoustical benifit to cutting the bottom portion?
Most definitely - that space behind will all the hangers is a bass trap if you allow the sound into the cavity. The front walls are part of the geometry so cutting into them, other than at the wall/floor join would change that factor. cheers john
Ok, so is the objective to keep the oppening that I cut from effecting the dirrect reflection in the room that my splayed walls are designed to redirect? If so, would I be ok to cut an opening below the height of the speaker (say about 2 ft below the bottom of the speaker) but not all the way to the floor? My plan was, simply for asthetics, to keep my absorption pannels only covering about a 5 ft. high portion on the front walls with about two feet of the painted drywall above and below exposed. So basically I would like to keep that very bottom portion still painted and not cut into it. Although, at the end of the day, I need a good sounding space. Here is what I am now thinking... Is this acceptable in your opionion? Thanks!
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No - the point is to open the wall to floor join where the low end builds up. cheers john
Ok then, fair enough. I will try to do that then. I will post pictures on my build diary of the finished product. Thanks once again for the helpful insight!