EQ question (blown speaker)

Hi there everyone.

I managed to blow a mid-range driver in one of my speakers. I've never run my system at maximum volume for extended periods of time, and I've never heard any distortion at high volumes either (until I broke a speaker). So, now I'm scared of doing it again, and I'm wondering how I can prevent it.

I don't know enough details about what actually damages a speaker to be certain about any corrective actions. I'm assuming that it was caused by the amplifier clipping, but it's possible that the volume on the empeg has (very briefly) been into the positive region, should the resulting clipping do any physical damage to the speakers?

I've got one amp for all four in-cabin speakers, with signal from the empeg front, and a separate amp for the subwoofer with signal from the empeg rear. If I use the EQ to get rid of all the low end going to the in-cabin speakers, it seems that I would be much less likely to be working the amp at anything close to its maximum power or signal amplitude, so I should be pretty safe. Is this true?

Does anyone have other advice?

I'm a little bit peeved that the guys who installed everything didn't set the gains so as to avoid damage, but I didn't explicitly ask them to, so I can't get too indignant. The only advice they had afterwards was "turn the gains down a bit". I could figure that much out myself!

Richard.

Remember that it's possible that it had nothing to do with you or the empeg. It could have been a short in the amp, a faulty speaker, etc.

Sure, it could have been caused by turning it up too loud. But unless I was there and I was seeing what happened exactly, I can't give an opinion. But the usual advice of adjusting the amp gains so that empeg->0db is as loud as you'd ever want to listen to it still stands.

Damage to speakers can be:

- Too much juice through the speaker coil (i.e, wiring or amplifier short, amp too loud).
- Too much amplitude/excursion of the cone (turn it up too loud)
- Hard-clipped signals going through the speaker for too long (bad amp, too much bass for the speaker, etc.)

Anyone have any other possible causes of speaker damage?

Also, when you say the speaker was "blown", can you be more specific? Did you remove the speaker and find out exactly what's wrong with it? Fused coil? Torn surrounds? What?

I'd pretty much assumed that it was basically due to something that I did, but I guess you're right that it could have been an equipment fault. Perhaps I should investigate that avenue further...

I did have the gains at a fairly reasonable level, which is why I'm scared of doing it again! 0db is pretty bloody loud, by my standards, and if I'm the car by myself, it doesn't usually get above -10db. When some friends are in the car they sometimes crank it all the way to 0db. But I never noticed any distortion. Mind you, the distortion caused by the damaged speaker was inaudible in many kinds of music as well.

Also, when you say the speaker was "blown", can you be more specific? Did you remove the speaker and find out exactly what's wrong with it? Fused coil? Torn surrounds? What?

It sounded strange playing brass quintet music. Stranger than it ought to, that is! Seriously, I don't know exactly. After some experiments, I figured it was the medium sized driver (the one about 60mm across, in a 3way 6x9), but I haven't pulled it to bits, and there was no damage I could see with a casual visual inspection. Maybe I should just send it back to the manufacturer and hope for a refund, rather than dissecting it.

Richard.

0db is pretty bloody loud, by my standards, and if I'm the car by myself, it doesn't usually get above -10db. When some friends are in the car they sometimes crank it all the way to 0db.

Ah. See, that's why I love being able to set the amp gains and have the player cap out at 0db. Even if my friends do that sort of thing, they can't hurt it.

Yes, well, I thought I was pretty safe too, until this!

Richard.

I had a 75w amp driving 4 stock seakers. They were configured for high pass or band pass, I don't remember. But then I sold my box. To get bass back, I opened up the amp to the lower end bass. Within days I had blown a 6x9.

Moral of this story: Don't run speakers bast their specified wattage without first limiting their frequency range.