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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => LAB Subwoofer Forum => Topic started by: Benjamin Goulart on February 20, 2014, 12:00:24 PM
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So at moderate and higher power levels over about 20Vp the lab subs start to have some increasing rattles as the power ramps up. I thought it was the house before, but now that I'm facing them forward I've determined it's definitely coming from the horns themselves. I've narrowed it down to causing woofer distortion due to air leaking out of even the slightest gaps in the wood panels. I can feel the air escaping and hear the particular woofers behind those problem panels as creating much of the noise.
So I'm wondering what the best way to seal them is.
Should I remove the weather stripping type material and put new stripping on it? Maybe squishy thermoplastic? I'm not sure if that stuff exists as weather stripping.
I was also thinking about maybe a non-hardening putty. I don't want it to act as an adhesive too much and it definitely can't harden or dry. I need to be able to remove the wood panels later. My first thought was wood putty, but most of that does dry eventually. Blue tack will probably be too sticky and make it difficult to remove the panels. I'm worried that putty that will not act as a strong adhesive may lack the viscosity, I guess is the word for this, to prevent air from eventually getting through with enough usage.
Anyone done this before?
***Additionally, this will be like the second or third time I've removed the wood panels. What are some good screw fillers you've used that will make them tighter and potentially repair stripped holes if that occurs? I assume I'll need to let those applications dry first. I'm fine with that.
Thanks.
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***Additionally, this will be like the second or third time I've removed the wood panels. What are some good screw fillers you've used that will make them tighter and potentially repair stripped holes if that occurs? I assume I'll need to let those applications dry first. I'm fine with that.
Thanks.
Is it a possibility to set uo the panel screws with threaded bolts and t-nuts? Wouldn't have to worry about screw hole wear, nor over-tightening (within reason)
frank
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Is it a possibility to set uo the panel screws with threaded bolts and t-nuts? Wouldn't have to worry about screw hole wear, nor over-tightening (within reason)
frank
I wouldn't want to do that. I'd have to completely drill those screw holes out. Then deal with nuts on the other side (or maybe the screw end inside?) and then worrying about more air leaks.
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Should I remove the weather stripping type material and put new stripping on it? Maybe squishy thermoplastic?
***Additionally, this will be like the second or third time I've removed the wood panels. What are some good screw fillers you've used that will make them tighter and potentially repair stripped holes if that occurs?
I agree with Frank that the access panels should be attached with T-nuts or Hurricane nuts.
Since you have stripped them out, and wood screws are not keeping the panels air tight, they are a better solution.
I have not found gaskets needed when using T-nuts.
If your construction is such that it does need gaskets, you could use Mortite putty, it will be air tight and does not permanently set. Window glazing rolled thin like an earth worm works too.
Stripped holes can be repaired by mixing fine wood router dust with wood glue, and injecting the mixture with a large bore syringe, or simply apply glue on as many toothpicks needed to fill the hole and tap them in with a hammer.
If you have other leaking parts of the cabinets, you can pour in some paint and tip the cabinets around until it seeps in to the gaps. You may be able to find "oops" paints (mixed to some odd color) at some hardware stores.
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Stripped holes can be repaired by mixing fine wood router dust with wood glue, and injecting the mixture with a large bore syringe, or simply apply glue on as many toothpicks needed to fill the hole and tap them in with a hammer.
Back on the farm we used a few toothpicks as shims and put the screw back in. No glue, just friction fit. Of course, we made our own toothpicks by taking a pocket knife and whittling off a pointy piece from the corner of any handy 2x4 or the odd chunk of firewood...
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If you want to replace the weather stripping on the access covers with something that doesn't deteriorate over time then good old "rat fur" (http://www.parts-express.com/speaker-cabinet-carpet-covering-charcoal-yard-54-wide--260-765) works very well as a gasket. Use 3-m spray adhesive to attach it to either the cabinet, or the access cover.
A bead of strippable caulking (http://www.amazon.com/18324-Seal-Removable-Caulk-10-1-Ounce/dp/B0002YVNOQ) may also help you out here (although I wouldn't use it in conjunction with the rat fur)
+1 on gluing in toothpicks, then sand smooth. It'll hold screws stronger than the original plywood.