Sony Xplod XM-4S

Along with the Kicker, this is amongst the smallest of the amplifiers on test yet has one of the most impressive build arrangements. It has a cover made of Chrome plated steel that has the word ‘Sony’ sunk into it and is held on with Chromed dual-headed short bolts. They have a wide Allen head with a cross head cut within them so you can use an Allen key or a crosshead screwdriver to remove them and you have to in order to install the amplifier. Once removed you can get at the crosshead grub screws used to connect all speaker and power connections. These are all Gold plated and are the screw down plate type best used with forks. I have two sets of tails for adding to the StreetWires power looms donated to Talk Audio for hooking up to the Odyssey battery and so I simply changed over for the amps with fork-compatible connection systems.
As well as four Gold plated RCA inputs, there is also a multi pin connector to use with speaker level inputs via the supplied loom plug. This input will sense speaker level in the system and will power the amplifier up, obviating the need for a remote turn on wire’s installation.
Unusually at this price point the heatsink is a casting and also I think is the only one in this group to have a fan for cooling itself a sign that this is a compact power house. There are relatively simple controls only featuring gain controls for front and rear pairs of channels and a simple on or off switch for a Highpass filter for the fronts and a Lowpass filter for the rears, both fixed at 80Hz. There is a lows boost potentiometer control able to add up to 10dB @ 40Hz and a switch to turn the blue LEDs on or off. There are two, nestling under the opposite edge on the cover to the controls and connections, which are all on one drop. The controls on the top sit within a smoky transparent plastic slab that looks well smart.
– Class AB
– 4 x 50w RMS @ 4 Ohms
– 4 x 60w RMS @ 2 Ohms
– 2 x 120w RMS @ 4 Ohms bridged
– Cast Aluminium heatsink with black textured finish and chromed Steel wrapper plate
– 8Ga. Power terminals with Gold plated screw-down plate connection
– High level connection via single multi pin socket loom supplied
– Gold plated 4Ch RCA input
– 18dB per Octave Highpass, 12dB per Octave Lowpass crossovers fixed @ 80Hz
– 0 to 10dB Bass Boost @ 40Hz
– Input sensitivity: Low level 300mV to 6.0V and high level 1.2V to 12V
– Top plate bears plastic panel with crossover controls and lit logo
– Stereo & bridged operation
– Frequency response 5Hz to 100kHz
– Signal to Noise Ratio 90dB
– Channel separation not quoted
– Fuse Rating 40A x1
– HxWxD(mm) 44 x 223 x 196mm
Review by Adam Rayner
For all that this amplifier is the most wee of all the ones we looked at in this price bracket, the sound reminded me of the ballsy SPL Dynamics 2604. It was a slightly tough yet analytical output with plenty of detail retrieval, making this small but sparkly in output. It does seem at first glance that this amp might be about bling more than performance but the only one in the group to have a cooling fan? And the only one to also use a casting instead of an extrusion? It was the only one built with this metal fan shroud affair as well.
The see-through plastic panel on the top is pretty but I couldn’t help but feel that while looking like your amplifier has an aftermarket lighting thing appended to it, having the innards light up in a sexy way is what I would prefer with the plastic panel all aglow. After all, it isn’t hard to find a cheap item with blue LEDs in it within Halfords shelves and fling it at your install. So I was a bit less than thrilled to find that this panel doesn’t illuminate visibly. I seriously dig the Chromed steel plate and Allen headed fixings and while all you can see are the engineering-flavoured hexagonal heads, you can use a bog standard crosshead screwdriver to actually get at it, which is important as every now and again it is crucial to unscrew this and check your wires are firmly fixed. (Look after the bolts, they are tiny and easy to lose!)
The XM-4S isn’t rated at huge power yet it managed to raise a maximum of 123.5dB without audibly ruinous distortion and the bass booster facility sounded fat rather than overblown or making the amp struggle. This feel of high efficiency was also carried over to the higher tones so the amplifier feels loud although it didn’t measure quite as air-shiftingly major as others in this group.
All in all a very satisfying wee power maker and truly more powerful than its size might suggest. As with all these amplifiers I ran it with the 10A marine power supply feeding the Odyssey battery so the volts to the amp’s power supply stayed as healthy as possible and although this was another that I got carried away with and simply sat and listened to my album for a bit, the fan never came on, nor did the XM-4S even get that hot. This is despite me working the poor charger so hard I could smell it’s cooking insulative compounds and rocking it. So I reckon this is also an amp for those who want to run the living heck out of it for long journeys.
A cute wee spud and good looking as well as highly power dense.
Overall 7.8
Sound Quality 8
Power Output 8
Features 7
Build Quality 8
Value For Money 8