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[Chrysander 'C.R.' Young]

Short version: what low to moderate cost (think sub $500) power amplifier would you recommend to power some JBL MRX515 tops?  This would replace the existing inuke 3000 which, although it works well, is only putting out around 300W into 8ohms.

Back story: Built a PA in my buddy's club using a combination of gear leftover from another club and some of my surplus gear.  Club is a small (~2k sq ft) club/bar.  Ceilings are about 8'; carpeted floor, but reflective walls and ceiling.  We have begun to regularly host rock bands and EDM DJs.  Over the weekend, I was doing sound for a local metal band and noticed that the inuke 3000 driving the MRX515s was hitting limit more often than I would like.  I also could have used a few more dB from the tops to get the vocals out cleaner.  The subs are powered about right, but are outrunning the tops easily.  None of the other amps in my stable would likely yield any worthwhile increase in output (IPR 1600, XLS 2500) from the top cabs.

System:

Mixer: XR18
Processor: DCX2496LE
Sub AMP: iNuke 6000
Subs: 2 x Carvin TrX218N
Top amp: iNuke 3000
Tops: 2 x JBL MRX515
Monitors: several Mackie SRM450.

System is run stereo.  Crossover is at 90Hz; cannot remember the details for crossover slopes, but will see if I can get on site this week and verify.  The system overall sounds very good and gets a lot of positive comments.   However, I can tell that, when the system is pushed hard, the tops run out of gas before the subs.  Replacing the tops is not an option at this time.  We can trade/sell some other surplus gear to fund an updated power amp, but high-dollar gear is not in the cards.  The amps are rack mounted and are rarely moved, so the replacement amp does not need to be particularly light.  Reliability and high bang/buck ratio are the most important factors.

Thanks for any assistance and advice!

[Scott Gaines]

Well as an owner of a pair of MRX515s, I can tell you the more power the better. I've since graduated to SRX815s, but I have fond fairly recent memories of my old tops.
 
I had a Carvin 3800w stereo power amp that pushed a cool 900w per side, and they took it all in stride... And they sound better and better the more you feed them.
 
Don't kill em with anything below 80Hz, of course.
 
One of the big issues with those speakers, though, is the rattling of the cabinets under load. They need like a little help in the bracing department.

[Will Knight]

QSC GX7 would be a perfect fit for those speakers.  I owned a pair along with the M500 series subs (MX518s) and ran them off of 2 GX7’s in stereo. Amp’s rated @800w/8Ohm load which matches speakers’ RMS/Program requirements. Single 20A circuit, Class D power, built in crossover point & QSC quality and warranty. Worked like a charm for my purposes at that time.



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[Mike Santarelli]

These were my first decent pa speakers. I powered them at first with qsc gx5 and it worked well.  I found the gx7 to be a perfect match and that’s what I used  for years with no issues.

[Bob Faulkner]

Short version: what low to moderate cost (think sub $500) power amplifier would you recommend to power some JBL MRX515 tops?  This would replace the existing inuke 3000 which, although it works well, is only putting out around 300W into 8ohms.

I'm not surprised at the lack of output for the inuke.  There's several youtube videos showing tests/results/readings for the inuke amplifiers (various inuke models) being close to 30% less actual output than what Behringer's marketing materials show.

I do not own any inukes, but have mixed bands which do own the inuke models.  It was audibly evident those amps were not producing the output anywhere near what their marketing material indicated.

[Chrysander 'C.R.' Young]

I'm not surprised at the lack of output for the inuke.  There's several youtube videos showing tests/results/readings for the inuke amplifiers (various inuke models) being close to 30% less actual output than what Behringer's marketing materials show.

I do not own any inukes, but have mixed bands which do own the inuke models.  It was audibly evident those amps were not producing the output anywhere near what their marketing material indicated.

Bob, you are 100% right.  I found some bench tests results on the iNukes that provided me with the more accurate numbers that I used above.  The general rule is to take the claimed rating and divide by SQRT(2) to get the continuous power at ~1% THD.  Curiously, the iNuke 6000 tests out right at 2kW per side at 4 ohms for the subs, which has proven a great fit.  Sounds good and has been in service for 4 years now without complaint.  More than enough bass for this small space.

Thanks, everyone.  I will look into the GX7 and any other amps that are suggested to me. 

[Scott Gaines]

One thing I love about those speakers is how light they are!

[Rob Spence]

I use a PLX1804 for my MRX512 speakers. Light, not too expensive. Of course I don’t do serious rock & roll with them.


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[Steve Litcher]

+1 for the GX7

I don't think you'll find anything else with better performance for the same $$... We had a few GX7's prior to switching to PLD4.5 and they always worked well. If you shop around and are patient, you can find smoking deals on these on Craiglist and the like. We bought one of our GX7 used from a local guy for $300.

[David Winners]

Why not just use another iNuke 6000?

[ProSoundWeb Community]