Amp suggestion. Mono out, 400w, small, support 2ohm

[audtatious]

Doing some upgrades. Just purchased a JL XR650-CSI set to replace the crappy Infinity seperates I have. Thanks to another NICO member, I have a Diamond CM312D4 12" sub to replace the Infinity 12" I have. The issue I have is with my a/d/s PH15 supporting a 2ohm bridged load (only 4ohm stable bridged). So, I'm looking at adding another amp to push the sub.

Amp needs to be good quality, support a 2ohm bridged/mono load, capable of 400w, and is relatively small. I don't necessarily need internal Xovers, altho bass controls and subsonic filtering would be nice.

Suggestions?

[Rex]

Older Phoenix Gold amp M, MS or MPS they'll appear to be rated for less power than you need, but will drive that sub real well.

I bought a MS-275 last year to use when I put a project car together, if you want to try and see if it's strong enough.

[Florida240sx]

http://www.etronics.com/produc...d=306Look on that site looks liek they got the best deals around from what I can find anywayz.

[EW]

Alpine MRD-M605

[audtatious]

Older Phoenix Gold amp M, MS or MPS they'll appear to be rated for less power than you need, but will drive that sub real well.

I bought a MS-275 last year to use when I put a project car together, if you want to try and see if it's strong enough.

The problem with the MS-275 is that it is only stable to 4ohm bridged. The sub I have is a DVC-4, so I would want something that can handle a 2ohm bridged load (1ohm per channel stability).

Thanks for the suggestions. I'm still looking around. I wish my damn PPI A600 worked

[Rex]

The problem with the MS-275 is that it is only stable to 4ohm bridged. The sub I have is a DVC-4, so I would want something that can handle a 2ohm bridged load (1ohm per channel stability).

Thanks for the suggestions. I'm still looking around. I wish my damn PPI A600 worked

From the PG FAQ

"Minimum Impedance MS series 2 ohm bridged/1ohm stereo"."What might I need to run my amplifier to safely run into 2 ohm bridged?

The MS series has no "governor" or "limiter" circuits to restrict it's power supply when you run at lower impedances. This means if your careful and no what your doing, you can get a lot of performance out of your amp.

Bridging the MS series to a 2 ohm load is not a problem IF you pay attention to a few basic things:

1. If this were the only amp in the system, it would require at least 2 gauge wire from the battery to the rear of the car. Since it is very likely that you will have some amps for mids and highs, I highly suggest running 1/0 wire from front to rear. Then use 4 gauge wire from a distribution block to a minimum 1 farad capacitor. Finally, 4 gauge from the capacitor to the amp. Add more caps if you can afford them and fit them into your install. A 4 gauge ground wire to the rear frame assembly will provide a good ground.

There's no need for a dedicated fuse for any MS or MPS amp. However, for competition you may want one anyway to meet the "easy and quick access" judging rules. If the amp were mounted upside down under a quick opening Plexiglas panel or something, that would take care of it.

The reason for all the power wiring overkill is a matter of basic ohm's law. For example a MS2125, will TRY to double its power and make about 1,000 watts. However, the size of the amp's power supply will only allow it to make about 720 watts. To make that much power, the power supply MUST have adequate amounts of current. How much? At max undistorted output with typical music material, about 65 amps continuous with peaks (< 50 milliseconds) of around 100 amps. Any amount of resistance in the power or ground side of the circuit restricts current flow. If we restrict current flow then the voltage at the amp's B+ and B- terminals will sag when heavy bass notes hit. And when the voltage sags so does output power.

When everything is complete, you can check the voltage drop at the amp's power terminals with the engine idling and no electrical loads turned on. Then play the system at maximum and watch the voltage sag with heavy bass notes. Maximum allowable sag is about 1 volt. Ideally, it should be less than 1/2 volt.

2. You'll need cooling fans. Extra power means extra heat. The heatsink isn't large enough to naturally dissipate the heat generated from low impedance operation. This is another reason people like to put the amp upside down under Plexiglas. With an enclosed amp rack and a couple of 3 inch fans on each end (two pushing and two pulling), you can force the air through the heatsink fins."

Also, assuming you won't be pounding it at competition levels all day, you'd be fine. Watch on ebay for an MPS, they were bench tested by Car Audio Mag to 0.25 ohms stereo back in the day . Also, there's the HCCA line from Orion.

I'll look around for "new" amps that fit as well.

[audtatious]

Interesting. I had looked up specs and it stated 2ohm per channel and 4ohm bridged. I'll have to look closer at them.

Yeah, I liked the HCCA's. I had a USAmps 50HA "back in the day" which was similar to the 250HCCA. I also had a couple of the Adcom amps that could work at a dead short.

Still, my favorite was the PPI A600 until it started blowing mosfets. I replaced a couple and it worked for a while, but eventually blew more. Not sure if it is simply weak mosfets or if it has a power supply problem. It's been sitting in a box for the last 6 years.