I see nobody answered markhamJohn's question about the JL Audio 500/1 - JL Audio 1 Ch 500 Watt Amplifier $409.99
Yes, it looks like a good amp. I find the ratings hard to believe, the same RMS output, 1.5-4 ohm? In therory, these new technology amps run a constant voltage out, independant of load (within limits). I suspect these amps are better for SQ at the higher impedence.
Rated Power: 500 W RMS @ 1.5 ohm-4 ohm (11V-14.5V)
THD at Rated Power: <0.05% @ 4 ohm
S/N Ratio*: >95dB below rated power
Frequency Response:
5 Hz-500 Hz (+0, -1dB)
Damping Factor:
>500 @ 4 ohm/50 Hz
Input Range:
switchable from 200mV-2V RMS
to 800mV-8V RMS
Dimensions:
13.4"L x 9.25"W x 2.36"H
Features:
Differential-Balanced Input Topology:
(1 pair of inputs)
On-board Crossover:
fully-variable (40-200 Hz),
selectable-slope LP (12 or 24 dB per octave)
Preamp Output:
2-channel (independent active filter, parallel with amp filter or full-range)
Bass EQ:
parametric with variable boost up to 15dB and Remote Bass Control (optional)
Infrasonic Filter:
fully-variable 24dB/octave from 15-60 Hz
Signal-Sensing Turn-On:
permits operation without remote lead
Dual mono speaker output connections:
accept up to 8ga. wire
+12V and Ground connections:
accept up to 4ga. Wire

I wouldn't pay more for that amp than a whole lot of other choices, but if someone is giving it to you, these's nothing wrong with using it.

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