"Air leak" from Cornwalls. How do I fix?

[jwc]

I was crankin my Corn's last weekend for a party and my brother in law noted there was "air" blowing on him when He stood behind one of my Corns. He was right. The top right corner was puttin out air when the bass would hit. I didn't think much of it since I new I was about to overhaul these babes.

Anyway, at the end of the party, I noticed that speaker had some disortion from the woofer. Now, It was still cranked and I turned it down just a smidget and it didn't do it any more. It then played fine w/o distortion. By distortion, I mean the "flap" like noise from a woofer when someone turns your stereo too loud.

Can I assume the leak of air caused the woofer to do this?

Ay any rate. My back covers are off while BEC upgrades the capacitors on the networks. I am also painting them. Before I put the back cover back on, any suggestions on getting a better seal on the back cover?

I have considered some weather window sealing, silicone or just cranking down harder on the screws.

jc

[3dzapper]

I used some of that thin (1/4") 1/2" wide stick on foam window insulation tape on the backs of my Heresys. Works great.

[jwc]

Did you put the strips over the screw holes and just screw through em. Or did you put the strip at the outer ot inner most edge?

[joessportster]

hello dont just tighten up the screws likely as not you will end up with stripped screws much better idea to use some weather stripping sylacone will act as a glue after it drys if you use that and when you attempt to remove the backs agian you will probaly damage the finish and or veneer joe

[WMcD]

When a vented system hits resonance the pressure in the box and against the back of the diaphragm is relatively high. If you have an air leak it will probably make an odd noise through the leak.

Thomlinson Hulsman (sp - Mr. THX) once wrote of port noise complaints (ahem) when the ports are small . . . so I'd think you'd hear air chuffing through a leak.

Also, the woofer motion will be higher than normal and it might bottom out, just like non-vented systems at high drive levels.

I would not use silicone sealant. It is a fairly good glue and you might not be able get the back off in the future.

I've used rope-type window seal (Mortite) to seal hatch covers. Same people use to damp horns. It comes off the roll in strings about 1/16 wide.

Best,

Gil

[3dzapper]

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On 3/24/2005 9:36:00 PM jwcullison wrote:

Did you put the strips over the screw holes and just screw through em. Or did you put the strip at the outer ot inner most edge?

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I put it along the outer edge of the lip in the cabinet. The screws go right through it.

[mike stehr]

I did the same thing as Rick.

[colterphoto1]

if a screw hole gets stripped, just insert a toothpick in the hole and break it off flush, that will give the screw something to grip.

DO NOT use silicone or any glue on the back, a thin foam or felt weatherstrip or a single thread of the mortite should suffice.

A slight air leak should not damage the woofer as it's a vented cabinet to begin with. If woofer is blown, you've overdriven it. Send to BEC>

Michael

[jwc]

Thanks for the replies.

jc

[D-MAN]

Felt is an old-style gasket sealer. It is not permanent and can be stapled down. You can't go wrong with felt, especially if you don't use glue on it.

Door weather stripping (with adhesive on one side) is a modern alternative available at Lowe's and such, and can be found in many different widths and thicknesses.

DM

[Mark Hardy]

"Port noise complaints" tee-hee... most of y'all are probably too young to catch this allusion!

BTW, the THX guy is Tomlinson Holman (also father of the relatively renowned APT/Holman pre and power amps of the late 1970's).

[colterphoto1]

"Port noise complaints"

very literary Mark, yer right, 10% of us will understand. Keep the kids in suspense for a while, okay?

Michael