PCM equalisation (eq) and ASK amplifiers
#1
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PCM equalisation (eq) and ASK amplifiers
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?
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?
Last edited by jbatchelor; 12-19-2017 at 05:54 AM.
#2
Base radio 981 GT4
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?
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
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morice antar (04-02-2021)
#3
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?
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?
Hi, did you ever get the answer to this?