Spider surgery - anyone?

[Jorge]

Hello,

I'm considering cutting slits in the spiders of my GR165 woofers used in a MTM TL to lower Qts (they are out of spec, bass is a bit boomy).
Qts has to be lowered from about 0.64 to 0.53, Fs from just over 50Hz to some 39Hz..

Did anyone do it? How likelly to damage a driver is it? (if I damage one, all 4 will be lost - they are no longer available!)

Thanks for your comments.

[454Casull]

How would it lower Qts?

[noah katz]

Lowering suspension stiffness lowers Qe, with the additional benefit of lower Fs.

But surgery sounds risky.

How about stuffing? I just happened to re-read the stuffing section in Dickason's LDCB 4th edition, and in some stuffing combos Qts was lowered from 1.1 to .7.

[noah katz]

Lowering suspension stiffness lowers Qe.

But surgery sounds risky.

How about stuffing? I just happened to re-read the stuffing section in Dickason's LDCB 4th edition, and in some stuffing combos Qts was lowered from 1.1 to .7.

[Jorge]

Thanks, noah katz

It's already stuffed - it's a TL, about 0.3 lb/ft3.
Heavier stuffing doesn't have much influence at 70Hz (that's where the peak is)...

[noah katz]

"Heavier stuffing doesn't have much influence at 70Hz (that's where the peak is)..."

Are you sure about that?

But more may screw up the TL action.

Anyway, LSDC densities were between 1 and 4 lb/cu ft.

[Jorge]

From all my WEB searches, the best on TL is on Martin King's site:

http://www.quarter-wave.com/

I use his worksheets, and increasing stuffing has a minor influence in the peak - or bass will be killed before the peak!