First of all, I must admit, I was skeptical- a 4 x 125 amp for only $135? It's a Maxxsonics product, which most people take as "This amp could be really hit-or-miss." I asked around a bit, then ordered one, and it arrived today.
It's rated like so:
4x125 @ 4 ohms
4x250 @ 2 ohms
2x500 @ 4 ohms bridged
Here's how I have it set up:
Front channels- PG RSD comps, high pass @ 100hz, -18db/oct
Rear channels- Bridged to two MB Quart RWE-354s, low pass @ 100hz, -18db/oct
First, I ran it on just the subs because I was just happy to have a new amp, and didn't have the patience to wire it up to my fronts
I expected modest results, seeing that I was running a pair of 15s rated at 700w RMS apiece in a sealed box. I was blown away by the output. I mean, it's probably not in the 140s, but for 2 15s in a sealed box on 500w, I was certainly impressed!
So I went ahead and wired up the fronts to the front channels. I got the gains adjusted, then dialed in the time alignment and whatnot. Again, I was thoroughly impressed at the volume of the speakers, and the sick amounts of midbass. I had them on head unit power before (I know ) and the difference is night and day.
Final verdict: This amp is a force to be reckoned with for the power. I was very, very impressed at the price vs. the power you get. I don't know for sure if it's overrated or not, but the specs are certainly believable.
Way to go, Maxxsonics and MB Quart, that is a solid ass amp for the buck!