MQN testing/experimentation thread

[DaveF]

I don't think we have explicitly tested bit-perfectness as such - really it's a given really considering what Gordon's software is doing. Maybe Gordon has checked this. But you are correct that any testing should establish this fundamental first. It's relatively easy to do this - play a HDCD file through MQN into a HDCD compatible DAC which has a HDCD indicator. If the HDCD indicator lights we have a bit perfect stream (the HDCD indicator is a single bit indicator, AFAIR)

I'd be inclined to do this on every release of new version of MQN. Just from a QA point of view. I dont know the encoding used in HDCD but I wonder if its possible to post alter the data(or some of it) but still be HDCD compliant? Unlikely I would think but if so that could lead to a false assumption.
Not sure how rigorous the decode mechanism is either. Is it like a CRC check?

[sbgk]

I don't think we have explicitly tested bit-perfectness as such - really it's a given really considering what Gordon's software is doing. Maybe Gordon has checked this. But you are correct that any testing should establish this fundamental first. It's relatively easy to do this - play a HDCD file through MQN into a HDCD compatible DAC which has a HDCD indicator. If the HDCD indicator lights we have a bit perfect stream (the HDCD indicator is a single bit indicator, AFAIR)

I'd be inclined to do this on every release of new version of MQN. Just from a QA point of view. I dont know the encoding used in HDCD but I wonder if its possible to post alter the data(or some of it) but still be HDCD compliant? Unlikely I would think but if so that could lead to a false assumption.
Not sure how rigorous the decode mechanism is either. Is it like a CRC check?

DF, didn't get a response to the question of do all players sound the same ?

[DaveF]

DF, didn't get a response to the question of do all players sound the same ?

Sorry, just saw that question now.

Are you refering to software players or hardware(DACs)?

[sbgk]

DF, didn't get a response to the question of do all players sound the same ?

Sorry, just saw that question now.

Are you refering to software players or hardware(DACs)?

not sure how dacs can be equated to players

[DaveF]

DF, didn't get a response to the question of do all players sound the same ?

Sorry, just saw that question now.

Are you refering to software players or hardware(DACs)?

not sure how dacs can be equated to players

Just trying to be helpful here.

DAC's as in those found in CD players, thats what I meant by hardware.

[sbgk]

not sure how dacs can be equated to players

Just trying to be helpful here.

DAC's as in those found in CD players, thats what I meant by hardware.

not sure how dacs can be equated to players

given this thread is about software players, the context of the question was software players and your own replies are about further testing of software players I'm wondering what you thought I mean't by "do all players sound the same ?"

[DaveF]

given this thread is about software players, the context of the question was software players and your own replies are about further testing of software players I'm wondering what you thought I mean't by "do all players sound the same ?"

Well given that MQN appears to affect what's happening at a hardware level(through noise or otherwise), both the software and hardware have to be considered together here.

My suggestion was to test at a hardware level (inputs to the DAC) to see if anything in the data samples changed due to changes in the software player, i.e different MQN versions. Whether any such changes where introduced in SW or HW, who knows. This is one test out of several that could be done. From what John says, this test hasnt been done?

In the industry whenever a new version of anything in a system is released be it software, hardware, FPGA etc, a regression test or test suite is usually run, sometimes on a nightly basis. This is a net to catch any issues. Just a form of QA, traceability and a record of testing done on all releases.

I havent heard any differences between different software players, MQN, JRiver or Jplay but I never spent much time with it to be honest.