HELP - How Hard is to Blow a Bass Driver

Dr. balance,

With a 70 watt amp - it's more likely that the upper frequency
drivers could be damaged if they overdrove the Exposure 18
into "clipping".

If the amp is driven into overload, and can't supply enough
voltage so that the peak voltage equals the peak input voltage
times the amp's gain - it will clip off the top of the wave
at its maximum voltage.

Because this means a sharp kink in the wave - that results
in a lot of high frequency distortion products which get
routed to the tweeters and high frequency drivers by the
crossover - resulting in fried tweeters.

Listen to your tweeters - if you can hear them OK - then
you are probably fine. Tweeters don't stand for abuse
very long - they just go "phht"

Sounds like you dodged the bullet.

Dr. Gregory Greenman
Physicist

Dr balance,

The fact that you heard distortion with deep bass only is what
you would expect if the amps were driven into clipping.

It takes a lot of power to do the deep bass notes - so they
are the most taxing for the amplifiers.

The distortion - which is often described as a "cracking"
sound is what you expect to hear from an amp that is clipping.

If that's what you heard - then the tweeters could have
been under some stress - but if they are still working -
then you probably corrected the problem in time.

The problem is basically too much power and hence energy
going to the tweeter which heats them up. The coils can
get so hot that they melt - and that ruins the tweeter.

However, if you correct the situation quickly, which is
what sounds like you did - then the coils just got hot
but didn't melt. So they'll be fine.

If they are damaged - you'll know it - the tweeters won't
work.

But if you don't notice a problem - then your speakers are
OK - and I wouldn't worry that there's some "hidden" damage.

Go back to enjoying your stereo system.

Dr. Gregory Greenman
Physicist