Stupid PA questions

[theAntihero]

Ok, im not very knowledgable in the PA field so if i ask a stupid question im sorry.

 

So my band uses a powered mixer for our sound system, it has worked well for the very little we use it(most places provide a PA so this is used maybe 3 times a year and in small clubs) but since we have added subwoofers id like to power them seperatly from the mains and moniters to give them a bit more thump.

 

What im thinking of doing is this: Take the out from the powered mixer run it to a power amp and run it to the subs. The subs have an crossover but im not sure what happens if i dont connect another cab thru it to take the highs. Should i get an electric crossover and put it inbetween the power amp and th subs or between the powered mixer and the power amp?

 

thanks.

[theAntihero]

BUMP

[caseyjf]

More clarification as to what you're operating (amps, speakers, ratings, etc.) and how you are currently running it may make responses a little easier. But, just off what you've said I can't imagine why you would have an issue running an output to a power amp for subs that have an internal cross over.

[theAntihero]

 

More clarification as to what you're operating (amps, speakers, ratings, etc.) and how you are currently running it may make responses a little easier. But, just off what you've said I can't imagine why you would have an issue running an output to a power amp for subs that have an internal cross over.

 

 

Right now we are running a yamaha 800 watt powered mixer with a Peavey Neo12 and nady 18 inch passive sub(yes i know they are cheap but they work) on each side.

 

So if they have an internal crossover i should be fine? Stupid question, Where are the highs gonna go if im taking a line level out from the PA to a power amp into a sub only?

[Unalaska]

As it is now all speakers are getting full range amplified signal: bad. Mid/high speakers (Neo12's) are not going to be able to handle the extreme low end that a sub will, also subs sound plain bad run full range competing with the Peaveys. So, it's best to use a line level crossover DBX223XL to an amp and use that amp to power BOTH the peaveys and Nadys. CH1 subs, CH2 tops is the preferred method.

 

FWIW the crossover built into any passive sub is always too high, slope too gradual and still doesn't address the sub freq in the tops.

 

With the power amps in the powered mixer not being used, they can be used for monitor mixes or not at all really, doesn't hurt.

[theAntihero]

 

As it is now all speakers are getting full range amplified signal: bad. Mid/high speakers (Neo12's) are not going to be able to handle the extreme low end that a sub will, also subs sound plain bad run full range competing with the Peaveys. So, it's best to use a line level crossover DBX223XL to an amp and use that amp to power BOTH the peaveys and Nadys. CH1 subs, CH2 tops is the preferred method. FWIW the crossover built into any passive sub is always too high, slope too gradual and still doesn't address the sub freq in the tops. With the power amps in the powered mixer not being used, they can be used for monitor mixes or not at all really, doesn't hurt.

 

 

I was under the impression that connecting the tops thru the subs meant that the lows where handled by the sub and the crossover sent the highs thru to the tops, at least thats what i read somewhere.

[caseyjf]

 

I was under the impression that connecting the tops thru the subs meant that the lows where handled by the sub and the crossover sent the highs thru to the tops, at least thats what i read somewhere.

 

 

Thats right, but Unalaska was correct in what he suggested. Using an active xover (that DBX is a reliable and easy to use piece of equipment - you'll probably break even if you buy it on eBay and ever have to sell it) will give you a better tuning of frequencies to send to your sub and to your highs.

[WynnD]

DBX Driverack PX ($400 new) would provide electronic crossover, anti-feedback, auto-EQ and a bunch of other stuff that you might not ever get around to needing. If you ever think you might be going tri-amp, go at least to the Driverack PA. ($500 new)

 

Your current situation probably is providing a filter that sends the sub frequencies to the subs and the rest of the frequencies to the tops. In the very old days, speakers just had a capacitor to prevent low frequencies from getting to the horn. They didn't care about preventing the woofers from getting higher frequencies. I bi-amped a 60's pair of Kustom PA speakers. (Altec Lansing woofers and replaced horn drivers) Properly EQ'd they work pretty nicely. I still use them in smaller venues. My normal FOH speakers are 3' wide, 5' tall and 2.5' deep. Sort of fun playing with 40 year old equipment. (Except for the mixer, processors and amps. Looks vintage, but sounds much better.)

[dedmeet]

theAntihero -

 

Wow, had you asked this question before buying your gear, I would have suggested you get a powered sub like a Yorkville LS700P or similar. Your setup and configuration would have been far simpler.

 

What model of Yamaha powered board are you running? Mine can cross over the mono (sum) mix as a sub-out.

 

With your rig, I would do this:

 

1. Switch the internal amps to drive the monitors. Most powered Yammie boards can do this.

2. Take the L and R line outs from the mixer and feed them into a crossover, driverack, or similar. Use one amp channel to feed the tops and the other to feed the subs.

 

Mixer L+R -> Crossover -> AMP -> highs: channel 1, lows: channel2

Mixer internal amps -> monitors

 

Cross the PR12s no lower than 80Hz. Make sure you HP the NADY sub at a suitable point (I would guess about 45Hz) or you will unload the 18 and shred it.

 

Good luck and let us know how it works.