Amp to supply 2 ohm mono power

[Loamy]

This has bad idea written all over it, but here goes... I have a dual 1 ohm voice coil speaker that my friend sold me for next to nothing (RE Audio 18") that can handle 5000 watts RMS. I've been contemplating building a box for it and wiring it up to my home system. I have an extra output I'm not using on my crossover. The problem I'm having (aside from how much overkill this is) is that I can't figure out how to properly power it: if the voice coils are in series, I get a reading of 1.7 ohms. I'm looking at feeding it 2000 watts ideally and I can't find the right power amp. Nothing seems to be stable below 4 ohms in bridged mono. Does anybody have any creative ideas?

[mosfets]

I'm looking at feeding it 2000 watts ideally and I can't find the right power amp. Nothing seems to be stable below 4 ohms in bridged mono. Does anybody have any creative ideas?

Take out all fuses and any circuit-protection, then increase rail voltage to desired level and enjoy the show! Have fun!

[tinitus]

ReAudio says 1500watt thermal powerhandling

Your best chance is to NOT bridge your amps
Besides, they promise 87db, so I dont think you need that much power

Crown XTi promise 700watt in 2ohm

[dangus]

Use a transformer? A 240VAC to 120VAC isolation or autotransformer could convert 1 ohm impedance to 4 ohms. That's how I run my Contrabass which has a 1 ohm voice coil.

Or, there's the brute force chip amp approach: use enough LM3886es in parallel or bridged to handle the load. They're almost as cheap as power transistors. This'll need a substantial power supply; maybe a rewound microwave oven transformer, or one from a car battery charger or arc welder.

And, something I've speculated about: take a stereo amp, disable one channel's driver section and add its output devices to the remaining channel. This may be least problematic with a MOSFET amp, since presumably at low frequencies the added capacitive load on the drivers won't be a factor. People who know something may shoot this idea down in flames.

Or trade the speaker for something that's easier to use.

Or, yeah, settle for much less power. Due to issues with the NAD2200, I'm currently running one Contrabass and a 1259 from a little 40 watt/channel DIY amp (Reg Williamson's 40/40). I haven't noticed any shortage of bass, but then I have been exercising some self-control with the volume knob ever since a neighbour informed me her house was shaking.

[Loamy]

For a low cost option, I suppose I could run a Behringer EP4000 on one channel at 2000 watts to 2 ohms (but it seems like a waste to leave that other channel just sitting there).

Where do I find more information about using transformers? I'm interested to see if I could make that work.

[djk]

"Behringer EP4000 on one channel at 2000 watts to 2 ohms"

The EP4000 is only rated at 1250W/2R RMS, the 2KW rating is 'peak'.

It won't run very long at 2R before overheating.

[Glowbug]

I wouldn't use the Behringer, but there's a lot of pro amps that fit your needs.

Look into QSC & Crown, you can mod the amps' fans with quieter ones if need be.

Or you could always get it re-coned with new soft parts and higher impedance VCs. If it's an older RE driver, Scott @ Fi can still work on them Dual 1 ohm with 5kW power handling sounds like you have an MT 18", meant for SPL competition.

[event horizon]

What model 18" is the RE Audio driver? They do make more than one The driver with the highest power rating i know of is the "XXX" & there are two flavours of these. The earlier model had an xmax of about 35mm & had a glued on dustcap, the later model had a one piece cone & a 54mm xmax & higher power handling I believe the later model would handle 2000W RMS, not quite sure about the earlier one but it'll be less.

The voice coil resistance doesn't sound right either as they are 2 ohm per coil, so again, what model is it?

If it's one of the custom jobs that they can supply like the MT series it might explain things.

[Glowbug]

Actually, now that I think about it...some of the MTs came with much tighter gap tolerances in the motor, so they weren't able to be reconed with different coils...for the purpose of maximizing performance for SPL "burps".

A good friend of mine in college (who works at Fi now, incidentally) ran a 15" BTL - basically an updated MT - as his home theater sub with a QSC RMX series amp. Thing had some attitude when playing Xbox, that's for sure

[Loamy]

I believe it's an older MT with the glued on dust cap. I got it off of my friend 4 years ago and he had it for a while so it's got to be around ten years old. Supposedly it was a preproduction test speaker before he got his hands on it. It's a dual 1 ohm coil setup. The magnet is about 3" deep and 9 inches in diameter. He was powering it in his car with a 2400w RMS amp into it at 2 ohms. He was actually using 8 gauge as speaker wire. It's absolutely massive. Aside from that, I don't have that much info on it.

I'm not looking at breaking the bank to power it, because it will see pretty limited use (I have a feeling the neighbors may complain).