Clarion launches New Full Digital Z3 Sound System

[Feb 2016] Those of us who've been in the industry longer than we care to admit know Clarion's pedigree, but outside of the business few probably realise that the Japanese company is a member of the huge Hitachi Group and was founded way back in 1940.

Clarion full digital car audio system
Today it is classed as one of the 100 largest global OEM suppliers (that is, supplying to the car makers) and generally considered amongst the world leaders in car audio, car navigation and camera systems. As well as manufacturing, they have the kind of research, development and design engineering facilities and expertise that put Japan number one in hi-tech well before other Far East producers. So it wasn't such a surprise when I heard of the launch of a new in-car "full digital" sound system made up of a digital processor and "full digital" speakers.

I immediately knew it would be a serious product, but the term "full digital" speakers made me pull a slight frown. No one has managed to find a way to get the sound to come from speakers as a digital stream that our ears can interprete as music! And I doubt they ever will, unless we all have USB ports fitted to our heads! But the "Z3" system, comprised of a processor, tweeter and commander, the "Z7" 'full digital' speaker, and the "Z25W" 'full digital' subwoofer - about to be released this spring in Japan, the USA, Europe and Australia - promises to take the digital line just about as far as it can practically go.

Back in 2012, Clarion in Japan released the world's first in-car 'full digital speaker audio system', essentially a system that took the digital signal as far as it could go, all the way to the inputs of the amplifiers. And since the amplifiers used Class D switching technology, the signal could be converted from a digital form to analogue just ahead of the output stage. Better yet, since the amplifier module was built into the speaker itself, there was no longer the need to send the converted analogue output through lengthy speaker cables where losses can occur.

Diagram of conventional car audio system

For this latest system, Clarion have achieved even higher quality by using the latest custom-developed LSI ('Large Scale Integration') integrated circuits. High-resolution digital signals can be fed all the way to the speakers, with (in practical terms) no sound deterioration (through cables etc), and very low (may as well call it zero) susceptibility to interference. The system performs oversampling and digital modulation, delivering the digital stream right up to the speaker, where a small and very efficient embedded Class D power stage controls the speaker's voice-coil and cone assembly. Embedding the amplifier stage within the speaker module provides benefits in terms of cost, less mounting space and reduced weight.

Developed with the aim of providing full digital playback quality, the system also offers a lot of connectivity options and features an intuitive sound tuning function. There's huge potential for very sophisticated tuning of the sound to the automotive environment - Clarion claim the system "can create an optimal audio environment intuitively using smartphones and tablets", presumably using those as a programmer. We'll find out more on that, but all us 'tweak heads' will rejoice at the thought of being able to setup our systems with an app on our smartphone! Clarion is currently in the process of developing a new head unit with digital output, fully compatible to get the best out of the new system.

Clarion digital car audio system

The high output LSI, custom developed by Clarion, will accept digital input signals of 96kHz resolution, and by combining 256x oversampling, it's the world's first 24MHz multi-drive type D-class ultra-high speed driver (try saying that after a couple of bevvies!) , achieving performance claimed to be over twice that of conventional 'full digital' systems. For the power output stages, Clarion have optimised the efficiency of the Class D module, providing power claimed to be four times that of conventional 'full digital' systems, with half the power consumption of typical analogue systems. We look forward to seeing the measurements because the first of those claims is a biggy - Class D amps are generally already around 50% more efficient than conventional Class B or AB, but 4x the typical Class D output would be quite something. Either way, it means less power being drawn from the vehicle's system, less weight being carried down the road, and the promise of superbly accurate audio reproduction, so there's little scope to find fault in that!

The 'full digital playback' extends to direct connection to external audio devices and high-resolution compatible smartphones (currently those using Androidâ„¢, which will disappoint the hordes of iOS users but that may follow), but this versatile system can also be connected to a wide range of devices regardless of a car's head unit or interface standards (digital or analogue). Smartphones can also be easily connected to the digital processor using a USB cable (supporting high-res signals with sampling up to 96kHz).

That's all very well, you ask, but what happens when the signal gets converted and leaves the speakers as an analogue sound wave? Well, you wouldn't really expect Clarion to have gone to so much trouble and then stick a dual-cone paper driver on the end of it, would you! The speakers are equipped with "six-layer multi-voice coils" that lets you use a digital signal processing technology (Dnote) to "directly transmit multiple digital signals to the voice coils"... hold on. Play that back again; "directly transmit multiple digital signals to... a six-layer multi-voice coil". Now that does sound unique, but we've yet to get a definitive explanation of it. Clarion GB have promised to fill us in on it in the near future. All we have so far is that "Multiple digital signals are sent directly to each speaker and the digital to analogue conversion takes place within the speaker via means of the LSI chipset" which doesn't tell us quite how each layer of a six layer voice coil can be controlled. If it's not a simple case of poor translation from the Japanese tech notes, it will be fascinating to hear what it's actually doing. [ Kevin O'Byrne ]