JL Audio 300/4

JL Audio is a long-time player in car audio, and these amps are a good example of great product at great price.

The amplifier is one of the smallest 4-channel 'SQ' amps, at only 340 mm x 235 mm x 60 mm.
With all the connections along the bottom, it makes for easy mounting and cable hiding.

These amps are quite heavy and certainly feel as solid as they look.

in the box you get: one amplifier, a hex-key tool for terminals, and a very comprehensive manual, including a great step-by-step guide to installing and setting-up the amplifier (even my mum could do it with these instructions).

Installation:
I installed a pair of these into my car, wired to a combination of 4 and 8 ohm speakers on various channels for an active front stage, and 8 gauge cables for power.
No problems here, power fits up to 4ga and all the speakers go up to 8ga.

The RCA inputs are good quality, mounted firmly in the amp's chassis, and the outer (ground) of each RCA is isolated to allow running fully balanced inputs. This works too, as you would expect.

Listening:
the first thing I noticed about these amps was their noise - there almost isn't any - no pops on turn-on, and the hiss is well below normal hearing level.
ok, so for some tunes.
the amp has a clean sound, not harsh at all. Frequency response is good all the way from sub to high. You could use these for anything.

The rated 75W RMS per channel is, I feel, a bit conservative: My 8-year old Pioneer amps were rated at 65W/ch and these JL's are easily twice as loud while retaining composure, and nice clean sound.

Also of note was the temperature of the amps - I haven't been killing them with power, but they stay really cool - even with moderate loudness.

Conclusion:
Nice amps, I think I'll keep them for a while.

The more I read about them the more I want them....October.....its not that far away....I'm so impatient!

I wrote that sooo long ago, and I'm still happy with them.

I have a 300/2 and have exactly the same sentiments. Quiescent noise is wicked, output is very clean, and probably a little conservatively rated. I was running my current splits from a Jaycar amp bridged to 2x160 watts, and the JL at 150 watts x2 is much louder, and much cleaner at the upper volume limits where blood starts coming from my ear canals. My only negative notes is that it isn't very sensitive in the gain department (I have weak outputs at the moment) and that the highpass filter hasn't quite got the lower end that I'd occasionally want (stops at around 50Hz whereas 40 would be nice.)

Sound quality (particularly SN) is simply awesome.

i have dreamed of these amps forever...

just installed my 300/4 and 500/1...

cant hear em yet as HU isnt in, but will advise when there in....

first saw these amps in ca&e in about 2003. and dreamed of owning them aswell.

in about the middle of 06 the dream became a reality and i installed the first 300/4, and gave my piponeer amp to my g/f. i ran the front and rear pioneer tcs165 splits off it at 75rms each channel. instant improvement in volume and clarity...

i then upgraded to kps165 focal splits up front and had them running on 75rms, i was told to do away with the rears and send 150rms to the focals, and boom, they came alive. the midbass was insane,the detail was obvious in the midrange at lower volumes where as before it lacked a little untill turned up. (thats more to do with the speaker then the amp id say, the gain was set with multi meter and test tone as advised).

sticking to just the jl product, i got w3 subs, and upgrade from the pioneers i had. then i upgraded the sub amp to a 1000/1 and the result was amazing, i never thought a sub could be MUSICAL just BOOM, but found out that it complements the midbass and brings warmth to the sound.. i was stoked with the set up.

all in all, ill be sticking with jl subs and amps for a while, it would take something very special to get me too change from these amps. (maybe the new jl hd )

i have a second 300/4 already installed and hooked up. just waiting on the kbe midbass extension kit for my splits, and ill send 150rms to those aswell. need $$$ for those.

good value and great product for any one shopping for amps... my 2c, actually 10c,

BRAD..