boosting a boost..

awhile ago i finished a diy sub project. 2 jbl12gg01 12" subs in individual 3 cu. ft boxes ported @ 32hz powered by a home receiver amp i had.

at first i had ran into alot of clipping problems at medium to high volumes, i eventually fixed the clipping problem by lowering bass amplication created by the computer soundcard, but at the cost of very little lower-end bass response

last week, i ended up adding an active subwoofer crossover between my computer and the receiver that powers the subs.

after trying trying out different settings/setups. i had found the final setting. after doing so i had noticed a huge diff, the bass response was unbelievable and the best part was no clipping.

on the crossover i set the xo frequency @ 90hz and turned on the 12db boost @ 45hz, along with the five band equalizer on the receiver set with [email protected]+10 db, [email protected] and everything else @ -10db.

basically the question im asking with a 10 db eq boost @ 50hz on top of a 12 db boost @ 45hz.
am i risking damage to the subs?
 

pinkmouse

diyAudio Moderator Emeritus
2002-04-03 7:15 pm
Rotherham, England
Hi Chester

It mostly depends on how loud you are playing them...( sorry to be obvious).

By boosting the bass at low frequencies you are increasing the excursion of the driver, the way to check this is to play your sub at the maximum volume you will use and listen closely to the driver- if you hear any clicking or grating noises you are bottoming out excursion on your driver and could damage it.

at first i had ran into alot of clipping problems at medium to high volumes, i eventually fixed the clipping problem by lowering bass amplication created by the computer soundcard, but at the cost of very little lower-end bass response

I suspect what you were hearing was the soundcard overloading the inputs of the receiver, rather than the amp overdriving the sub.

By boosting the bass frequencies you are sucking power out of the amp, as bottom end needs much more power than hi or mid, by using 22dB boost you are increasing the power needed to drive the sub at this frequency by roughly 16 times, so unless you have a really meaty amp you are more at risk of taking out your amp than your speakers,as unless you know what to listen for, amp clipping at sub frequencies can be hard to determine.