Dirt Cheap PA Amplifiers

[mdcdesign]

Okay so I've just got a new Saturday night residency at a small venue, and it's PA system is a MESS. They've got an old NSM jukebox (one of the first CD ones, I think it's a debadged Heritage) and a Blackbox-AV MPA150 amplifier, along with a bunch of Wharfedale Force 2180 speakers.

The setup is one of the most whack ones I've ever seen; 4 or 5 of the speakers are wired up to the jukebox, and another pair are wired up to one channel of the MPA150, and the other channel is driving a single speaker outdoors. It's not exactly the ideal setup, as the NSM keeps (I think) going into protect mode which also stops it from outputting via RCA to the MPA150. The wiring is all mains cable (yep - wtf?) and there's wires not connected to anything as well.

Basically, it needs a complete re-think and re-wire. Ideally, I'd like to add another PA amplifier to drive the main speakers and just use the MPA-150 to drive the outdoor speakers. So basically, here are the main questions:

1) Why the hell are modern PA amps rated so much higher than stuff from the 80s/90s? Is it literally just a case of manufacturers playing silly buggers with their rated specs, or are they ACTUALLY higher output?

2) Does anyone know of anywhere - aside from Gumtree and eBay - I can pick up something sub-£70 which can drive 6-8 of those Wharfedale Force 2180s effectively. Volume is NOT an issue here, the reason there are so many speakers is one of coverage, so tbh running each cabinet at 20W RMS would probably do the job nicely.

I'm guessing pretty much any 1U or 2U PA amplifier would be fine, although I'm somewhat worried about picking up one of these Skytec/Soundlab/Powertronic/etc "1200W" units for £60. I just have a feeling that am 80s/90s unit would be more reliable, even if it's cheaper.

Before anyone mentions impedances, I know how to calculate series/parallel setups in order to match the impedance of each channel's load to the amplifier rating, so that won't be a problem Just need some advice about the gear itself.

A little more background; this venue is (mostly) a square, aside from a couple of little side-areas, and has a capacity of no more than 150, and is primarily a pub/bar; NOT a club. The idea isn't to deafen the audience or even to completely immerse them in music, I just want to provide even, full-range coverage so they can appreciate the music without being dominated by it, hence the lack of subs etc.

[makar1]

1. Obviously technology has progressed so higher ratings are more easily achieved, but as you said there are manufacturers like Behringer who at some point decided to change all their ratings to peak. I would assume that Skytec etc. will do the same as they have no reputation to worry about.

2. I've seen several main-brand home theatre receivers that quote 100W per channel, which go up to 8 channels for 7.1 surround.

[mdcdesign]

1. Obviously technology has progressed so higher ratings are more easily achieved, but as you said there are manufacturers like Behringer who at some point decided to change all their ratings to peak. I would assume that Skytec etc. will do the same as they have no reputation to worry about.

The thing I'm wondering is just how far they've taken this peak nonsense... for example, the Wharfedale Force speakers are rated 100W "programme" aka "peak" aka "music power" etc; but 75W RMS; now, a 33% decrease from the specified wattage isn't too bad for RMS, but if one of these modern amps is 1600W peak and only 250W RMS, that'd give me cause for concern lol.

2. I've seen several main-brand home theatre receivers that quote 100W per channel, which go up to 8 channels for 7.1 surround.

I did consider just going down the hi-fi route since they're 8 ohm speakers and you can get - as you said - late 90s AV amps for around £75-100, but the problem with that is the ability to SUSTAIN that for long periods of time. I mean typically these amps are going to be running every night with a relatively constant input signal (and resulting output) for 6-7 hours in a less than ideal environment, so I need something designed for that.

[sss18734]

The cheapest amp I could really recommend is the Behringer EP2500. I have four and they have never let me down, and they really do put out good power. Crown XLS, Peavey IPR, and QSC G series amps are also solid budget amps.

Most will run a bit over your price tag though.

[SumthinJumpin]

I picked up a second hand Numark Dimension 3 in a flightcase for £80, and a Dimension 4 for about £120, I run 4 Wharfedale EVP X12 off the dimension 4, so far so good.

[funke]

Marathon amps are good copies of the qsc rmx line. I'm going to get the ma 4050 for sub duty.

[mdcdesign]

New amp arrived today after a NIGHTMARE with the first one I ordered (guy promised to deliver then went back on his word and 2 weeks later still haven't got it, so bought another one).

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Tested it at home on a pair of Mordaunt Short MS5.30s, and I'm pretty happy with it Not sure if it's really the quoted 900W RMS (bridged), but I suppose I'll find out once I've got it hooked up to the 10 Force 2180s we'll be using.