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Hi all
i am purchasing 2 Peavey PRO 15 speakers please see spec below

Specifications
300 Watts RMS continuous, 600 Watts program, 1200 Watts peak.
4 Ohms.
15'' (381mm) speaker with 3" (76mm) voice coil.
1.75" (44.5mm) compression driver.
Dispersion: 90° H x 40° V.
Frequency response: 50 Hz – 18kHz.
Efficiency: 98dB.

my question is what is the minimum and maximum amp requirements for these speakers.
i am only playing small venues 50-75 people max.
this way i may have a good choice of amps to choose from

cheers

The answer is you want an amp that can do 1200 W or so at 4 ohms bridged (to run in mono), or one that can do about 600W at 8 ohms.

That basically means an amp they would call a 2500, if you want to run in stereo.

If you want to run in stereo, then you can use a Behringer EP2500 or a Tapco Juice 2500. Or any of the more expensive models you can find out there (Crown, QSC, Mackie, etc.).

If you want to run in mono, then you can use a Behringer EP1500 or a Tapco Juice 1400, bridged at 4 ohms, with your speakers in parallel.

If you are sure they are 4 ohm speakers then i'd make sure the amp can push 600 watts into 4 ohms for those particular speakers.  You would not be able to bridge these speakers together like suggested above as this would drop the ohms to 2 ohms & most amps will not bridge to 2 ohms.  Some can't even handle 4 ohm bridged.  But as a stereo or dual mono set-up, look for an amp that will push 600 watts per channel INTO 4 ohms.

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Thanks guys
so a behringer pmh3000 powered mixer would suffice?

I missed the 4 ohm impedance. Are you sure about that? It would be unusual....



No, not really. It does 400W into 4 ohms, and no one would say it is understated. It would not be that great a match at all.

If the speakers are 8 ohms, as I suspect they really are, the PMH3000 only pushes 215w/channel.

I own a PMH3000 and use it as my main mixer, and I have a separate power amp for my speakers. It is not enough.

Nope they are 4 ohm speakers according to the stores that sell them.  
http://www.getinthemix.co.uk/Peavey-Pro ... agodcSGVog
Remember these particular Peaveys are only available overseas.

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is it my being stupid but the pmh 3000 says its 1200 watts
so wouldn't that be enough

I am guessing that a PMH3000 would drive them, but would not be that good a match. I would feel better with an EP1500 or J1400 amp pushing them.

Obviously stereo is required because driving at 2 ohms is problematic with most amps.

1200 watts MAX/PEAK & this is usually a 2 ohm rating.  Amp manufacturers tend to use these ratings to lure unsuspecting buyers into thinking they are getting much more.

The amp comfortably pushes 400 watts per channel into 4 ohms, even less into 8 ohms, but we're not worried about that rating.  Even for your speakers, this amp is not a good match.  It will work, make sound, even get loud, but the chances of blowing your speakers will be higher & they will not sound nice & full, they will almost tend to sound a little on the tinny side which you will need to adjust the eq further adding to possible speaker failure.

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any suggestion for mixer amps to buy then?

If you are happy with the mixer, an external power amp could be added like mcky suggested, the Behringer EP2500 would be fine.

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if i bought the ep2500 could i then make do with a non powered mixer instead

Sure. You could even run a subwoofer or monitor speaker on one channel, and your other two speakers in mono on the other channel, as the EP2500 is one of the few amps that will handle a 2-ohm load on a single (unbridged) channel. It puts out 1200 watts into 2 ohms, which is a perfect match for your two 600w speakers.

Or you could run stereo into the speakers separate, with a good match of 750w to 600.

Do you already own the PMH3000?  You wouldn't need to change the mixer unless you really wanted to.  You would just run the line out (or main out) on the mixer, this will send the main signal to the amp bypassing the internal amp of the mixer.

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Running a 2 ohm load, while can be done, it will put more strain on the amp.  Will heat it up faster & the THD (total harmonic distortion) level will be much more.

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According to the live sound pros on alt.audio.pro.live-sound, the EP2500 works well at 2 ohms, night in, night out.  But I think you are right about the distortion.

With regard to the PMH3000 in combo with the EP2500, that is what I do use. It actually works great, because I run the powered mixer in the mono/monitor mode. This allows me to have a monitor speaker from the internal amp of the mixer, along with a fill speaker if necessary. The mono out on the mixer goes to my crossover which then splits the signal to the two channels of the EP2500, which drive my mains and subwoofers.

A very good amp for the price would be the the QSC GX-5

4 ohms 700 watts - 26 lbs

http://www.musiciansfriend.com/product/ ... sku=481805