JL Audio XD 400/4 Amplifier Review

Product Details
Manufacturer: JL Audio
Distributor: Celsus Ice
Website: link
Typical Selling price: 400/4 £369.99 (CAD £351.49)
A new amplifier range from the maker that others now look to when designing their products, using their NexD„¢ Class D technology. This is one of a new generation of better sounding Class D amplifiers and has resulted in very small footprint amps, with a high efficiency of 80%, or nearly double what a decent Class AB can manage. This is a very small amplifier but can output a top wellie of a true 400W RMS from its four channels.
Tested with the Pioneer DEH-P88RSII resident reference head unit and used to drive a set of Pioneer TS-A171Ci components and a set of Pioneer TS-A6913i speakers. It features two high/low pass crossovers that live under a brushed Aluminium panel, fitted with two Allen headed bolts after these controls are set, to seal them out of the way of fiddling.
Last of all, the connections are also all Allen headed bolt type with bare-wire gripping terminals and the badge is supplied separately in a little baggie to ensure it is perfect when finally placed in the finished install.
– NexD„¢ 80% efficient new ultra fast class D switching power supply
– Crossover: 12dB/octave Butterworth with continuously variable cut-off frequency selection from 50-500Hz
– Configurable as Low-Pass or High-Pass, Defeatable
– Rated Power 14.4V Stereo: 75W RMS x 4 @ 4 Ohms/100W RMS x 4 @ 2 Ohms
– Rated Power 14.4V Bridged: 150W RMS x 2 @ 8 Ohms/200W RMS x 2 @ 4 Ohms
– Rated Power 12.5V Stereo: 60W RMS x 4 @ 4 Ohms/90W RMS x 2 @ 4 Ohms
– Rated Power 12.5V Bridged: 120W RMS x 2 @ 8 Ohms/180W RMS x 2 @ 4 Ohms
– THD at Rated Power: <1% THD+Noise (20Hz - 20kHz)
– S/N Ratio: >104dB referred to rated power (A-weighted, 20Hz-20kHz noise bandwidth)
– S/N Ratio: >84dB referred to 1W (A-weighted, 20Hz-20kHz noise bandwidth)
– Frequency Response: 12Hz – 22kHz (+0, -1dB)
– Damping Factor: >150 @ 4 Ohms per ch./50Hz
– Damping Factor: >75 @ 2 Ohms per ch./50Hz
– Input Range: 100mV – 4V RMS
– Dimensions: (L x W x H): 8.52in. x 7.09in. x 2.05in. 217mm x 180mm x 52mm
– Black coated Aluminium heatsink with brushed Aluminium panel and final-piece badge
– 4Ga. Power Terminals with Allen headed grub screw bare wire socket connection
– Socket for optional HD-RLC remote level control knob
Editor Review : JL Audio XD 400/4 Four Channel Amplifier
This amp was central to the best sounding overall assembly of kit on my test rig in absolutely ages and ages! The P88RSII sent a pure signal and the Pioneer speakers I was using worked very well and the JL Audio bass enclosure was of incredible quality. But the perception of the music in all its detail really does have to come through a high signal to noise ratio amplifier to be perceived as high end or ‘˜HiFi’. And these new class D tech amps, called NexD„¢ by JL, are solidly in the Stupefaction Zone. You hear the sheer rich loveliness and then look down at Stumpy-Knickers The Spudly-Amp and wonder how in hell it isn’t all huge and Megabuck to do that stuff like previous experience would have you believe.
It is so damn good, it’s stupefying.
In the same way that Alpine’s new digital amplifiers turned out to be amazing, this JL Audio XD400/4 is a fabulously miniaturised, absurdly strong and yet talented piece of kit. It does scale, power and nuance. It does ‘˜space’, weight and drive. All the true HiFi stuff that class D was never ever supposed to do and this does it all and bloody well. They are not mad-end price but you just try and compare that serious 104dB signal to noise ratio and you will not find many amps that can actually offer that at any price.
The quality of the music reproduction almost erases any perceptions of the kit you are listening to. The XD, despite being a class D amp, does that truly disappearing straight wire with gain thing so beloved of the SQ hounds.
All that and some serious muscle for its size, too. A weeny footprint and the thick end of a half kilowatt of serious purity of audio amplification. All of which adds up to a tremendous amount of Value For Money and an easy Talk Audio Recommended status.
Overall 8.8
Sound Quality 9
Power Output 8
Features 8
Build Quality 10
Value For Money 9