Using a 3-way crossover in a 2 way system

[malcatron]

I currently run my Peavey UL115 subs ( UL115 spec ) from a PV1500 (PV1500 spec)using the amps built in crossover. The crossover is fixed at 150Hz and the HPF is fixed at 40Hz.

 

Now, the subs have a published freq response low end of 60Hz and my question is basically - is the 40Hz low cut on the amp sufficient to protect my subs?

 

If not I have been thinking about possibly adding a crossover, using it in 3-way mono, sending the high out (say > 120Hz) to the mains, the mid out to the subs and then setting the crossover freq between mid/low to act as a low cut for the sub. (i.e. nothing connected to the low output)

 

Is this a viable/worthwhile exercise or am I talking out my arse?

[Craig Vecchione]

I currently run my Peavey UL115 subs ( UL115 spec ) from a PV1500 ( PV1500 spec )using the amps built in crossover. The crossover is fixed at 150Hz and the HPF is fixed at 40Hz. Now, the subs have a published freq response low end of 60Hz and my question is basically - is the 40Hz low cut on the amp sufficient to protect my subs? If not I have been thinking about possibly adding a crossover, using it in 3-way mono, sending the high out (say > 120Hz) to the mains, the mid out to the subs and then setting the crossover freq between mid/low to act as a low cut for the sub. (i.e. nothing connected to the low output) Is this a viable/worthwhile exercise or am I talking out my arse?

 

If your active crossover has the ability to do this, it's a very good idea, as 40Hz is almost certainly too low to adequately protect the sub.

[agedhorse]

I'll bet most 3 way crossovers will not allow this to work because the frequency point will not go down low enough.

 

Sounds like you are going to spend money on a solution so that you can be cheap elsewhere.

 

a 40Hz HPF will be ok with that amp, provided you use a little bit of reason and common sense. 150Hz as a crossover freq. is fine too.

[banddad]

How about an equalizer with a variable HPF on it? It may be a more elegant solution.

[malcatron]

The thinking behind this was really to keep things simple, I thought having something like a driverack and not really knowing what I'm doing with it could be a recipe for disaster.

 

Looking at the dbx 223 the frequencies will cover the ranges I'd need

 

Mono Mode: Low/Mid: 45 to 960 Hz or 450 Hz to 9.6 kHz (x10 setting) Mid/High: 45 to 960 Hz or 450 Hz to 9.6 kHz (x10 setting)

 

If I were to do this, would 60Hz be the best setting for the "HPF" or would slightly below be beneficial??

 

I do like the idea of an Eq with a variable HPF though, as I'd also be getting an Eq into the bargain any suggestions as to models that offer this feature?

 

Cheers

[agedhorse]

I would look at 50Hz because the x-over filter alignment is LR. I think you are over-thinking this though.

[banddad]

There are a few EQ's with a HPF.

Ashly makes a really good one, check out the GQX 3102.

Rane makes a nice one as well.

ART makes a lower priced unit, the HQ231 or others.

And I'm sure there is someone else's favorite I missed.

 

I have the ART and Ashly units, the Ashly has a better feel, lower noise, and will probably last forever. I find the ART works well for me as an ocassional 'weekend warrior' type who is in this for fun, not profit.