The Corner Trap

I've been pondering the idea mentioned by a forum member about combining the properties of a hanger with the solid fill idea in the corner trap. I wonder what the properties of this kind of trap would be. just scroll through the pages to see construction. cheers john

part solid - part "hanger"? one concern would be the wire mesh part causing rattles with the "hanger" boards sitting on them... also, what are you trying to achieve with the "isolated" sections? a specific freq response? would having varying sets of insulation and dividers cause it to have more broadband response? does it become somewhat diffusive because of the solid board ends being exposed? assuming the plates are to resonate to bass frequencies, would angling the horizontal plates help? interesting....

I wonder about this. 1) It's still unclear how corner absorption, in this case SSC (Studiotips Super Chunks, not just solid fill) works. 2) It's unclear how the hanger principle really works. Hence it's more a question of feeling. At a first glance I see little room to improve on the Super Chunks than playing with density. One can make it partly membrane traps, but the question then is: is the enhanced resonant peak positive or negative? This idea assumes that sound waves incidence only/mainly happens in the horizontal direction (for vertical trap). A lot of modes will show velocity in the vertical direction roughly parrallel to the walls. Hence you disrupt this partly. Is that good? Bad? I don't know. Does this create overdamped 1/4 wave silencers? If so, does that work? Does this show some additional resonance absorption behavior? At the expense of, or complementary to the velocity resistance principle? I've compared and tested the hanger principle versus thick wool at a cavity, and the hanger principle did not show any advantage (I don't want to start a discussion about this, nor will I share this data, hence one can ignore this if wanted. I only mention this in function of this corner absorber design). The only way to know is making comparative measurements in very controlled circumstances. For corner absorption in itself are still a lot of question marks to be solved. My gut feeling, which can be wrong: I've question marks in the possibility to improve on the basic chunk principle, where I find linearity a defining important parameter. Also the Super Chunks, while more masked, seem to exhibit some resonance like behavior. The ones completely lacking this seem the Foam by Mail Copycat LENRDs (and maybe comparable stuff), because of their extreme low gasflow resistance. And the LENRD measurements in Rod's book I can't explain, but nothing is mentioned there in function of how and where measured. It gives me the feel that they either are measured in a smaller room, or that some kind of small cavity was still behind them, or ........, but I admit this is gambling.

Eric_Desart wrote:

I wonder about this. I've compared and tested the hanger principle versus thick wool at a cavity, and the hanger principle did not show any advantage (I don't want to start a discussion about this, nor will I share this data, hence one can ignore this if wanted. I only mention this in function of this corner absorber design)

just curious (without revealing your data...) is there a disadvantage? or are we talking roughly on par performance between hangers and super chunks? and do you perceive any frequency dependencies on the insertion of the dividing partitions in this design? (I ask since you are regarded by many as a leading expert in this field and perhaps will share, as you have generously in the past...)

Genn - Eric and Lovecow are the experts in this area - I'm just a selftaught amateur. :) I'm a damn good recording engineer though. I agree Eric - it came up when people were discussing the superchunk system and mentioned adding a hanger style component and I was concerned that the additional weight would eventually end up with all the insulation compressed on the floor, hence the wireframe divider suggestion. :)

It's unclear how the hanger principle really works.

yes -I remember and article way back in the 70s in Recording Engineer Producer Magazine that explalned the principle but I've been unable to find the article. The closest physical example I've seen is the Oyster Trays hanging down in my local river and watching a boat's bow wave dissipate as it moves the trays forward and back as it passes dissipating the energy so no wave actually reaches the shore. cheers john

John Sayers wrote:

I was concerned that the additional weight would eventually end up with all the insulation compressed on the floor, hence the wireframe divider suggestion. :)

maybe the "hangers" should hang to alleviate the potential weight issue and the combination of hanging and "super chunk" absorbtion provide some benefit in terms of construction cost and return on acoustics... :-)

:lol: :lol: super deal... the idea was to create a sort of "hanger trap" (bass hanger + broadband trap). what if we tried: neoprene rubber on the floor & ceiling of the corner. stand the fiberboard vertically(directly on the neoprene). full height of the corner add rockwool(etc) in between the vertical sheets of fiberboard. :?: like vertical super chucks on viagra Maybe...even leave an open space in the rear so that the corner(depth) is not completely filled??? it was just a thought...

found this too. Don't know how accurate it may be. http://forum.studiotips.com/download.php?id=970 http://www.avsforum.com/avs-vb/printthr ... e=15&pp=60 :roll:

no updates thoughts? What about cutting the superchucks across the full length(blue) vs the other way(red)? adding to the corners maybe even find a way to attach them where the wall meets the ceiling. :roll:

Eric_Desart wrote:

And the LENRD measurements in Rod's book I can't explain, but nothing is mentioned there in function of how and where measured. It gives me the feel that they either are measured in a smaller room, or that some kind of small cavity was still behind them, or ........, but I admit this is gambling.

I cannot quite follow this thread as I don't have an app that opens a SKP file. However, I can tell you that the LENRD (and MegaLENRD) data from Rod's book in Figure 9.41b (if that's what Eric is referring to) were obtained at Riverbank using a J-mounting configuration; eight LENRDs (or MegaLENRDs) standing upright in the test chamber.

lovecow wrote:

Eric_Desart wrote:

And the LENRD measurements in Rod's book I can't explain, but nothing is mentioned there in function of how and where measured. It gives me the feel that they either are measured in a smaller room, or that some kind of small cavity was still behind them, or ........, but I admit this is gambling.

I cannot quite follow this thread as I don't have an app that opens a SKP file. However, I can tell you that the LENRD (and MegaLENRD) data from Rod's book in Figure 9.41b (if that's what Eric is referring to) were obtained at Riverbank using a J-mounting configuration; eight LENRDs (or MegaLENRDs) standing upright in the test chamber.

These are Sketchup files. Download Sketchup (From Google) free: http://www.sketchup.com/ ~ Joel DuBay

lovecow wrote:

Eric_Desart wrote:

And the LENRD measurements in Rod's book I can't explain, but nothing is mentioned there in function of how and where measured. It gives me the feel that they either are measured in a smaller room, or that some kind of small cavity was still behind them, or ........, but I admit this is gambling.

I cannot quite follow this thread as I don't have an app that opens a SKP file. However, I can tell you that the LENRD (and MegaLENRD) data from Rod's book in Figure 9.41b (if that's what Eric is referring to) were obtained at Riverbank using a J-mounting configuration; eight LENRDs (or MegaLENRDs) standing upright in the test chamber.

Just a question Jeff, without any intent to discuss this in-depth here. Does this positioning relate to the related discussion we once had? Hence this are no corner mounts? No = no corner mounts. Yes = it are corner mounts.

Eric, No. J-mounting. Eight free-standing devices for each test. Spacing between units and from room boundaries in accordance with ASTM.

no other thoughts on this idea?

i would really like to download this files but all i get is file.php can anyone help?

do a "normal" click (with left mouse button) instead of rightmousebutten/save..as.

problem was mac... it works fine on pc...

tomislav wrote:

problem was mac... it works fine on pc...

Works fine on Mac tooo.... :wink: HOOK