Investigation Into Effects Of PC load On DAC Analogue Output

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Turns out that it's quite easy to see differences in the waveform, where it counts, which is the sound waves in the room -  @manisandher recorded what was happening when he altered settings of Peter's player; which had clearly audible variation, and this was quite distinct in the recordings when examined with DeltaWave. We were promised a more thorough version of this exercise, to overcome those who went into a mad thrash about microphone technique and everything else they could think of - but this has not eventuated.

 

Interesting how all investigations into things like this either bog down, or die a slow death - an instinctive reluctance not to rock the boat too much, perhaps ... ?

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Any clues as to how any of this is related to this paper or the experiment? Was Mani or DeltaWave or Peter involved in the process somehow? Didn't see them mentioned, I'm afraid.

 

Ahem. Alan uses one setup and measures nothing changing; Mani uses another setup, and a different technique for exercising the PC, and measuring - and records a significant difference ... who is correct?

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Just now, pkane2001 said:

 

What does this have to do with the experiment at hand? Mani's test was nothing like the test Alan performed.

 

I do appreciate that Alan's test has almost nothing to do with how people actually use their audio setups; and that Mani's is about a real life situation of listening to an actual recording ... yes.

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8 minutes ago, March Audio said:

As discussed elsewhere recording with a microphone in a room is hopelessly insensitive and will pick up all sorts of irrelevant background noise.

 

With all respect to Mani, unfortuntely Its a hopelessly flawed method.  Of course you will see differences in the waveform.  However these differences will have nothing to do with the PC or audio system.

 

First of all, the background noise can be made to be relatively consistent - to test this, merely record the same playback, with no changes, several times to establish the consistency of the recording space.

 

Secondly, what you are looking for are patterns in the waveform which consistently register as being different at certain points in the music - say, a treble crescendo, or transient. These are the "tells" that one's ears are sensitive to, and which are meaningful.

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1 hour ago, pkane2001 said:

 

So the real world is about using an obscure setting in XX High End software? How curious!

 

 

The real world is that the electronics which retrieves the source music file may impact the analogue part of the chain, by their operation - vast tracts of conversation have been laid down, in people's pursuit of finding answers to this. That particular  player just happens to make it easy to play with settings which the author has found to be effective in altering the electrical patterns which can disrupt, in subtle ways, the following components - for fussy listeners.

 

So, either all these people are delusional about hearing differences - or it may be that not all electronics are designed and implemented to behave perfectly, when faced with various forms of electrical noise ... now, which do you think is more likely?

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7 hours ago, manisandher said:

 

 

I think @pkane2001's DeltaWave software is the most promising approach. But at the moment, there's just too much variation between the analogue captures... without changing a thing, let alone varying any bit-identical parameters. Matching the captures against the original anywhere near as well as is necessary is just really, really difficult to achieve. (Matching captures against captures gives much better results.)

 

I still hold the belief that if we can hear a difference, then it should be measurable... somehow. The key is, I believe, in using dynamic content (i.e. real music) and not constant tones (including IMD test tones).

 

Mani.

 

I for one would very much appreciate if you could do several consecutive captures of some piece playing, without changing anything in between ... and post them. That would start to give me a benchmark to work with, in terms of what the natural variability of the playback plus recording behaviour is like ...

 

Thanks!

 

 

I've looked at few instances of where the natural versus playback waveforms are caught in a single track, and what's obvious is the poor transient, and treble behaviour of the reproduced version - no matter how good the conventional measuring gear proclaims the parts of the system are, the end result still shows quite obvious, visual shortfalls - if the eyes can see it, then the ears should have little trouble picking it happening.