Hey as most of you know im the proud owner of a van with 36 10"s in it. I finally got to do some testing with a smaller amp I had laying around (crossfire xp1400d) and it was crazy loud for about 10 min and then the amp for lack of a better phrase exploded. 2 of the mosfets are no more and 2 more a really close. The board is destroyed. I wanted to know if anyone has experience with running this many speakers off of 1 amplifier. The voltage is constant at 16.3 and the speakers sit at around 1.1 ohms. Im planning on using an ab500.1 to run it and adding another in a month but Im not sure why the amp did what it did and I wanted to know if its because of the quantity of subs wired to it. Like I said it is a 1.1 ohm load and voltage isnt a problem.

 

sounds like maybe your amp might not be able to handle the 16v system?

 

It's a 1ohm stable amp, right ?

How did you come up with 1.1ohms.. measure the DCR with a DMM ??

Assuming the above I'd have to agree with hott-nix.... post a pic of the board so I can see which fets let out thier magic...

 

Back EMF is a killer, Seen it happen before but I would maybe check input voltage first.

 

Don... can you explain what back emf is?

 

no i have talked to him and this amp was on 16 volt all season last year

it was modded by crossfire before it was ever powered up last year

the voltage never dropped below 16 voltsand he measured the imp at 1.1 ohm

3 4 ohm woofers in series to 12 ohm then all groups of 3 parallel back down to 1 ohm

 

It was measured with a DMM and the amps can run on up to 21v after being modded I ran 8 last year in strapped pairs down to .7ohms per pair w/ no probs. I just need to know if it is safe to hook up my 500.1 or not because the damage it did to the crossfire isnt repairable and I dont wanna trash a $1000 amp

 

normally if the load is supposed to be 1ohm I'd expect to see around .7-.8 ohms DCR, 1.1 seems high (but whatever, thats not the problem)

If the amps are known to be stable at 16v+ and half an ohm I really don't see the problem...

The amp could have just gave up the ghost.... or maybe you've got an intermittent short going on somewhere ? (tinsel leads are notorious)

was it the power supply or output fets that smoked ?

 

Back EMF is 'back voltage' which is induced by a flow of current.... The inductance and capacitance of a voice coil make it a reactive load, which involves back EMF, and effects the impedance the amplifier sees...


I really don't see how it could be an issue... I would expect the back EMF and the subsiquent impedance to be the same between 4woofers or 36 woofers.... (with the only difference being much less power compression with 36woofers)

 

I think the amp just quit on you, if the Load is 1 ohm then thats what the amp sees , 4 woofers or 36 woofers 1 ohm is 1 ohm either way. ps check all your woofers to make sure none of them are rubbing the coils.