Re: [LAD] Tests directly routing pc's midi-in to midi-out

From: Arnout Engelen <lad@email-addr-hidden>
Date: Thu Jul 15 2010 - 12:48:00 EEST

On Thu, Jul 15, 2010 at 10:40:53AM +0200, Ralf Mardorf wrote:
> On Thu, 2010-07-15 at 09:57 +0200, fons@email-addr-hidden wrote:
> > Until you try it you won't know, and your claim that 2 ms of jitter
> > 'destroys the groove' is pure conjecture.
>
> Who knows? Perhaps 2ms shown by Audacity are 20ms, because Audacity has
> a bug?

Sounds unlikely - but if you post the recording we can check.

> Perhaps 2ms shown by Audacity are 2ms, but when playing JACK, the
> sound card or what ever will add additional jitter?

You claimed the latency/timing was obviously noticably broken without needing
'golden ears' even without JACK, right? Let's first try to get this reliable
without JACK, just ALSA, then we can add other things to the mix later. If
this is not possible, anything 'on top of' this is doomed, too. I doubt it
though.

Arnout

> I can't test the list, because on my machine there is something audible.
>
> On Thu, 2010-07-15 at 09:56 +0200, Arnold Krille wrote:
> > On Thursday 15 July 2010 01:14:45 Ralf Mardorf wrote:
> > > On Thu, 2010-07-15 at 00:46 +0200, fons@email-addr-hidden wrote:
> > > > Apart from that, it remains to be seen if *real* timing errors of
> > > > +/- 2 ms do 'destroy the groove'. To test this, make the same
> > > > recording
> > > >
> > > > - without jitter,
> > > > - with 1 ms jitter,
> > > > - with 2 ms jitter,
> > > > - with 3 ms jitter.
> > > >
> > > > and check if listeners are able to identify which is which,
> > > > or at least to put them into order.
> > > I know very gifted musicians who do like me and they always 'preach'
> > > that I should stop using modern computers and I don't know much averaged
> > > people. So the listeners in my flat for sure would be able to hear even
> > > failure that I'm unable to hear.
> >
> > You really should do that test first before speculating about the outcome and
> > your audience.
> >
> > You would expect Audiophiles to spot the "super sounding" denon cables by
> > listening, right? Yet a blind test showed the opposite. The test was to
> > identify which audio take was played with denon-cables, el-cheapo cables from
> > walmart and a bended cloth-hanger. If they where as good as they claimed, the
> > denon-cable should get hits with probability significantly better then 1/3,
> > otherwise its just luck.
> > Guess what the outcome was: There was a significant hit: But they spotted the
> > cloth-hanger as the denon-cable. Thats what real experts do...
> >
> > Do the listening test with as many people as possible and then show the
> > results. And only afterwards start the speculations what the reason and the
> > effects might be. (Thats called science btw.)
> >
> > Have fun,
> >
> > Arnold
>
> Perhaps it's not that 2ms, but here are audible issues. As I mentioned before. Audacity shows 2ms, but JACK, the driver the hardware might add jitter.
>
> FWIW blind tests aren't scientific,just double-blind studies are meaningful. And if you wish to test cables you need to test the quality after one year, after two years etc.. Anyway, a bad cable might cause a bad sound quality, but not bad timing.
> Timing is the meat and potatoes to music.
>
> Regarding to my Linux computer such studies aren't needed. A bad timing is a bad timing.
> At least for the USB MIDI that I'm not using anymore, I made tests with a Windows install (I don't have this install on my machine anymore, so I can't test the PCI card with Windows).
> The USB MIDI was much better on Windows, even better than the PCI cards at the moment are on Linux. So I guess, yes I don't know, that the hardware is ok.
>
> - Ralf
>
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Received on Fri Jul 16 20:15:17 2010

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