Alpine PXE-H650

Product Details
Manufacturer: Alpine
Website: http://www.alpine-electronics.co.uk/
This is about the Alpine PXA-H650 processor and its family of kit it is really a story of the Imprint process and what it is derived from. This unit is the top model, the standalone processor and installation accessory package called PXE-H650. The CDA-9887R headunit incorporates the second level of the Imprint process internally. And by changing the preouts to preouts/preinputs there is an additional box called the PXA-H100 (£149.99) that enables Imprint technology to be used with many of the new range of Alpine 2008 headunits. (Your installer also needs the microphone and CD kit KTX-100EQ for calibrating the CDA-9887R headunit and the KTX-H100 microphone and CD-ROM kit for use with the PXA-H100 Imprint box) So Imprint can be applied to a major proportion of the new Alpine range.
Imprint is all about automatically tuning the system in your listening space to be smooth and dynamic by way of seriously accurate application of EQ and phase and time alignment technologies. It has at its heart an Algorithm devised by the academics working with Tomlinson Holman of THX fame. It was created so that Tom didn’t have to climb and descend stairs seventy times when tuning a theatre. When the academics’ algorithm’s resulting sound was indistinguishable from the tuning process that Tomlinson Holman could do by ear and measurement, it was signed off. I first reviewed this process in the Audyssey unit made for home use and then went to Alpine’s HQ in Coventry to audition the Imprint system within an OEM car installation in a five series BMW. In between I had a career peak. I interviewed Tom Holman for Home Cinema Choice. They will be putting it on their site.(Oddly, I cannot publish it here as they own all rights!)
Over and above the Audyssey MultiEQ process, this headline processor is also a re-equaliser and starts by taking whatever the car’s own amplifier’s output is and rendering it closer to flat again. As is often the case, the OEM system’s amplifier puts out a heavily equalised signal in order to best match the car makers’ sound designers’ ideals and their system’s crossover points. The Alpine BMW demonstration car has had a complex resistor and relay network built by their cunning artificer (Ross) so you can switch the whole system in and out of function so as to hear the difference.
As well as re-equalising and correcting the system, the Alpine Imprint version of the audio in the car actually eschews use of the factory centre channel and the rear door pair of the installed speakers.
– Advanced factory audio system integration and tuning processor
– High/Low level Auto-ranging & Auto-Summing input
– 24-BIT Digital To Analogue Converter
– AntEQ Sound correction
– Audyssey MultiEQ XT sound optimisation
– Time Alignment
– Phase correction
– Additional after-process Parametric EQ
– Highpass/Lowpass/Bandpass/Subsonic crossover filters
– Over 500 frequencies used for correction within process
– Eight positions used to measure and calibrate with microphone (Six with CDA-9887R)
Review by Adam Rayner
Put bluntly, this is a simply brilliant process. Tomlinson Holman is a gifted audio genius and the academics simply had to make their re-EQ programme more and more clever until it could do – in moments – what it took Tom all day (and major callisthenics) to achieve in a professional system. I can tell you that Imprint has been picked up by Denon, Onkyo and others and is being licensed into some very sophisticated bits of home kit. What Alpine have done to overlay a cunning OEM integration re-equalisation route into the processing path is inspired. I have seen graphs and can tell you that the BMW system’s bass was madly overblown from the factory indeed it has two under seat proper enclosed subwoofer drivers as stock speakers, so is a much better proposition than most OEM systems but even without changing their speakers (which are in fact Aluminium coned so are quite exotic) the sound was improved from what was a perfectly acceptable application of the Harman Kardon Logic Seven technology meant to please all the passengers front and back, to an audiophile experience.
The staging lifted and the image spread out from the Logic Seven Bubble that is intentionally created for each listener in the car into a wide and open stereo soundfield that the true sound aficionado will recognise as superb quality and smooth transition from band to band. The whole stage acts like a Wonderbra has been applied. Bigger, sexier, more enticing and yet still bloody wonderful to get your ears seriously wrapped around with it.
I would have loved to hear the system as a brutally high ticket full-on F#1 Status rig with Alpine’s finest kit and Imprint as that is something I suspect would be awesome. Just as a stock OEM magic wand this is still something very special, though.
Just as the home unit makes your chin quiver and make you feel teary when it gets switched off, once heard, you really won’t be able to go back. More than a mere equaliser, the eight different locations measured with PXE-H650 and even with the six locations measured for use with the CDA-9887R, the result is stunning.

And now, here’s what Martyn Williams, AKA Ed Unit thought of the PXA-H650
Martyn Williams says, “Gobsmackin’ sound stage”
Mr Editor Adam Rayner has given you a full run-down of the 650’s capabilities, so it only remains for me to add some comments
Before talking about the product, I feel that it’s relevant to mention Bob Hobson of Prestige Audio, who collected a ton of trophies back in the 90s for sound quality cars. The reason for his winning ways was all down to the stereo staging where singers and instruments were neatly arranged across the dash as you listened, spellbound, to the imagery created in his car.
Bob created his sound stage mainly with clever equalisation and then took things a step further for audiophile customers with dash-top midrange and tweeter installations on the windscreen pillars. The sound quality and staging using Dynaudio speakers represents a pinnacle of achievement in car audio.
For mere mortals who perhaps can’t afford this sort of installation, or more commonly, don’t want to alter anything including the original head unit in the listening area of the car, there is hope in the form of Alpine’s latest silver box, the PXE-H650.
The system, as Adam has explained, carries time correction and auto EQ to a new level for users who don’t want to change their original head unit and there is no doubt that it works.
It works so well that, instead of tossing aside the standard head unit from my newly-acquired car, I am going to patch the PXE-H650 into the speaker wires and drop in some amplification to suit.
The PXE-H650 has also changed my plans to add a centre speaker moulded to the dash. It may still happen, but mainly to compare the likes of Dolby and dts 5.1 to the Audyssey time and EQ correction of Alpine’s clever new unit.
The bottom line here is that the PXE-H650 works so well that, if you constructed a centre speaker pod with no speaker inside, you could easily convince someone that it was playing.
It should also add a new dimension to sound competition in the UK with installers entering with standard-looking cars with original head units. Step inside a PXE-equipped car and the sound staging should rival the guys who sweated over creating the sound quality winners of yesteryear.
Sound Quality 10.0
Ease Of Use/HMI 8.0
Flexibility 9.0
DSP Power 10.0
Value For Money 8.0
Overall rating 9.0