passive crossovers / ohms question

[moody]

Ok, I seriously don't know enough about crossovers.

 

I have two 2x15" cabinets. (etone 1507 for the aussies). Huge fridge like things.

 

I know dual 15" cabs aren't thought well of here - but it's what I've got at the moment. I'm going to be using them for duo work with backing tracks and no subwoofers (again, not ideal but I'm working with what I have).

 

Each cabinet contains 2 8ohm woofers and a compression driver and are currently wired at 4ohms.

 

If I want to re-wire the cabinet in series (for 16ohms) will the crossover still work the same way or does it need to be changed?

 

I'll be running both cabinets of one side of a Peavey PV 2000 amp at 8ohms, which would give about 200 watts per cabinet - way less than the cabs are rated at but still plenty of power for my needs.

 

I'm not confident running this power amp at 2ohms - both due to the amount of power (500 watts per cabinet) and the heat the amp puts out (if it's hot to the touch at 8ohms, what's 2ohms going to do to it).

 

The other alternative is to keep the 4ohm wiring and run a seperate smaller power amp for both the mains and the monitors. However, I'd prefer not to carry more amps than I have to (little duo gigs).

[tlbonehead]

Originally posted by moody Ok, I seriously don't know enough about crossovers. I have two 2x15" cabinets. (etone 1507 for the aussies). Huge fridge like things. I know dual 15" cabs aren't thought well of here - but it's what I've got at the moment. I'm going to be using them for duo work with backing tracks and no subwoofers (again, not ideal but I'm working with what I have). Each cabinet contains 2 8ohm woofers and a compression driver and are currently wired at 4ohms. If I want to re-wire the cabinet in series (for 16ohms) will the crossover still work the same way or does it need to be changed? I'll be running both cabinets of one side of a Peavey PV 2000 amp at 8ohms, which would give about 200 watts per cabinet - way less than the cabs are rated at but still plenty of power for my needs. I'm not confident running this power amp at 2ohms - both due to the amount of power (500 watts per cabinet) and the heat the amp puts out (if it's hot to the touch at 8ohms, what's 2ohms going to do to it). The other alternative is to keep the 4ohm wiring and run a seperate smaller power amp for both the mains and the monitors. However, I'd prefer not to carry more amps than I have to (little duo gigs).

Yes,it will mess up the low pass side of the crossover.

[Centauri]

Adrian,

There shouldn't be any problem running the amp at 2ohms - it was designed to handle that. The 1507 boxes will be fine with that power - they can probably handle around 600W each.

 

The amp will generate a deal of heat, especially running at less than maximum, and I wouldn't expect much difference in heat with the lower impedence - the fan should step up to higher speed anyway when the temperature increases.

 

Cheers

Graeme

[moody]

 

Originally posted by tlbonehead Yes,it will mess up the low pass side of the crossover.

 

 

Can you tell me, in laymens terms, what would happen?

 

Is there a simple (and cheap?) way of matching up woofers and drivers with the appropriate crossover?

[moody]

 

Originally posted by Centauri Adrian, There shouldn't be any problem running the amp at 2ohms - it was designed to handle that. The 1507 boxes will be fine with that power - they can probably handle around 600W each. The amp will generate a deal of heat, especially running at less than maximum, and I wouldn't expect much difference in heat with the lower impedence - the fan should step up to higher speed anyway when the temperature increases. Cheers Graeme

 

 

Thanks. I didn't realise that heat was generated due to running at less than maximum?

[Mudbass]

 

Originally posted by moody Can you tell me, in laymens terms, what would happen?

 

 

Sure. I'm about as layman as they get. Changing the impedance by rewiring the drivers will also change the crossover frequency of the crossover to a value you probably don't want.