jbatchelor

Does anyone know for sure whether the line-level (low-level) analogue signals out of a PCM 3.1 (or 3.0 for that matter) are flat, or linear, or whether there is any processing and equalisation applied? These are the audio signals that typically come out of pins 1-8 on the Quadlock connector on the back of the PCM.

If the PCM outputs are processed with some eq so that they are not flat then presumably the ASK amplifier (Sound Package Plus, etc) also has a corresponding tailored response curve such that the output from the amplifier, to the speakers, is restored to be nominally flat? In which case, replacing the ASK amplifier with an aftermarket amplifier would reproduce the uncorrected eq applied in the PCM so that, for instance, there might be an excess of low-end and high-end and a relative absence of mid-range sound.

If, on the other hand, PCM output is relatively flat then an aftermarket amp would be easier to integrate into a modified system and still retain the PCM head-unit...

This isn't a quaetion about MOST optical connections or Bose; it's the analogue side of things on a non-Bose (SPP) installation.

Any knowledge or insight?

Steve Whit

So after a few years since this thread took place initially and my resent purchase of 2016 GT4, can I install Apple CarPlay or any other infotainment system into my base radio. I do see some gadgets that make it work apparently along side your iPhone 5 or higher. Or do I install a new stereo as in a pioneer or other ? that will fit the existing screen opening that is in the car now. Again it is as base as they come as far as the radio is concerned.
Steve

Plek

Hi, did you ever get the answer to this?