How did this happen

[carshateme]

My friend had 2 rockford subs. The brand new p3 series. These subs were brand new. He hooked it up to a concept ca505 300rms amp
.

He somehow blew both subs. My suspicion is that he didn't warm up the subs. What's your guys thought?

[kevinkr]

Bad amp, wiring mistake, too much power, inappropriate enclosure if we're talking raw drivers.

FWIW I've never heard of sub woofers needing warm up..

Many more details are needed to know the answer.. (Burned voice coils, VC formers run into the pole piece due to over excursion, shredded/mangled cones, ripped surrounds, shredded spiders?)

[carshateme]

Yeah I don't know all that.. He's a friend from work. So I'll have to look at the speakers next time I see him at work. He said smoke was coming from the speakers..

Since he's new to all the speaker stuff.. I'm sure he did something wrong with the wiring. Sub warming is when you get new amp...and you slowly turn the knobs up to figure out the standing point of how much your subs can handle...also warming up new ones...you don't just pop in subs and blast your music...that'd be asking for trouble. There is a ton of stuff I can think of how they blew...but they were being seriously under powered...so I'm stumped on how much information I know now.


Will update when I learn more.

[tomchr]

Perhaps he wired the speakers to the battery... That would cause smoke to come out.

[carshateme]

Originally Posted by tomchr

Perhaps he wired the speakers to the battery... That would cause smoke to come out.

Lmao. That'd be a stupid thing to do xDD

[brandes.cm]

He cranked the gain and ran clipping audio into the subs, somehow the amp made it unmolested.

[Perry Babin]

Can you post an example of any piece of documentation where the manufacturer suggest warming up a woofer as you described?

Before you connect any other speakers to the amp, you need to measure the DC voltage across the speaker terminals to confirm that there isn't an excessive amount of DC present.

[AKHeathen]

actually, perry, i recall clearly that rockford outlines a "break-in" procedure that thay suggest. just look up a cheap rocford sub manual pdf and it should be in there....that being said, tha point of a break-in is to loosen up the spider and surround a bit, which is not really a science on proven effectiveness, becuase break-in is going to happen, it's just a cover your bum insurance-piece of mind thing. i've done it before....couple times, and even blew a house reciever, so gave up bothering. i completely agree thet the problem lies in either clipping, wiring, or both. when you check it out, make sure he has sufficient power wire to handle the current that the amp is fused at, and the same size, or larger ground (don't need larger) and ask him to crank the stereo "loud" in front of you....leave it thaere and walk a few feet away from the car. if it does not sound clear, then he was likely clipping it. you can definately over-power many subs many times over, and even daily, if you really know what you are doing, but you can blow them allot easier under-powering them and clipping, or "distorting" think of it as putting the speaker at a much higher duty cycle, and diminished cooling movement.

[kevinkr]

Maybe I am too literally minded but "warm up" and "break in" connote two very different things to me. I always (the very few times I done this) break in a driver before measuring the TS parameters for example if I want to do a box design for a new driver, but otherwise just let them break in with moderate use..

I don't tend to push things nearly as hard though as they in the auto audio world..

Smoke seems to imply the VC burned out, and IMHO an inadvertent connection to DC (battery?) or a bad amplifier seems quite likely.

[Perry Babin]

The test for that is... Have they continued to recommend that for every woofer from that point (when I assume that they learned that it helped speakers in some way)?

If EVERY manufacturer gave specific guidelines for breaking in woofers, that would make me believe that there was something to it. If only half would recommend it, it would likely mean that there's no proof that it does anything. Since very few recommend it, I can't see that it's anything that needs to be done.

The materials should not change in their physical properties in any significant way. If they did, the woofer would wear itself out relatively quickly.