5 Jul
2010
5 Jul
'10
10:25 a.m.
On Mon, 2010-07-05 at 10:15 +0200, Ralf Mardorf wrote:
-------- Forwarded Message --------
From: Ralf Mardorf <ralf.mardorf(a)alice-dsl.net>
To: Clemens Ladisch <clemens(a)ladisch.de>
Cc: Linux Audio Developers <linux-audio-dev(a)lists.linuxaudio.org>
Subject: MIDI jitter - Today for 4 of 4 tests my USB device did pass all
tests with success
Date: Mon, 05 Jul 2010 10:14:21 +0200
I'm very sceptic regarding to the ALSA MIDI
latency test, OTOH the PATA
might have caused 7 ms and IIRC 19 ms too and visually interpretation
might mistake because it's hard to find the start of waveforms in the
noise.
I guess (don't know), that 7 ms and 19 ms are caused by a broken HDD,
but when I did the visually test the HDD wasn't broken, I did it a long
time ago.
So the visually test around 4 ms and ALSA MIDI latency test around 4 ms
from today might be correct results for my computer and at least when I
got 4 ms for the visually test, the audible result was unusable for
music, anyway, I still have got some hope.
To be continued ASAP.
5 Jul
5 Jul
10:33 a.m.
New subject: MIDI jitter - Today for 4 of 4 tests my USB device did pass all tests with success
On Mon, Jul 05, 2010 at 10:25:23AM +0200, Ralf Mardorf wrote:
So the visually test around 4 ms and ALSA MIDI latency
test around 4 ms
from today might be correct results for my computer
That sounds pretty good then.
and at least when I got 4 ms for the visually test,
the audible result was
unusable for music, anyway, I still have got some hope.
You might have mentioned it before, but how exactly are you performing your
test of the 'audible result'?
Arnout
10:48 a.m.
On Mon, 2010-07-05 at 10:33 +0200, Arnout Engelen wrote:
On Mon, Jul 05, 2010 at 10:25:23AM +0200, Ralf Mardorf
wrote:
The hardest test is to record a MIDI groove for kick, snare and hihat.
I then used my Alesis D4 drum module that don't cause audible jitter
when using it with the C64 and Atari ST.
I did record the audio output of the Alesis D4 by Linux, but each
instrument one after the other, each instrument two times.
The result:
Playing one recording of the two recordings for each instrument and the
groove is broken. It doesn't matter if it's a beautiful McCoy Tyner or a
stupid Madonna like groove.
Playing two recordings, but just of one instrument the phasing is not a
constant phasing, but fluctuating. An early reflection similar effect
usually isn't the result, but in the worst cases even this is possible.
Ralf
So the visually test around 4 ms and ALSA MIDI
latency test around 4 ms
from today might be correct results for my computer
That sounds pretty good then.
and at least when I got 4 ms for the visually
test, the audible result was
unusable for music, anyway, I still have got some hope.
You might have mentioned it before, but how exactly are you performing your
test of the 'audible result'?
Arnout
10:51 a.m.
On Mon, 2010-07-05 at 10:47 +0200, Ralf Mardorf wrote:
On Mon, 2010-07-05 at 10:33 +0200, Arnout Engelen
wrote:
C64 synced by click and Atari ST synced by SMPTE and the recordings done
by a Yamaha MT44D 4-track cassette recorder a groove wasn't broken and
the phasing was fixed, absolutely constant. Using the same Alesis D4.
On Mon, Jul 05, 2010 at 10:25:23AM +0200, Ralf
Mardorf wrote:
The hardest test is to record a MIDI groove for kick, snare and hihat.
I then used my Alesis D4 drum module that don't cause audible jitter
when using it with the C64 and Atari ST.
I did record the audio output of the Alesis D4 by Linux, but each
instrument one after the other, each instrument two times.
The result:
Playing one recording of the two recordings for each instrument and the
groove is broken. It doesn't matter if it's a beautiful McCoy Tyner or a
stupid Madonna like groove.
Playing two recordings, but just of one instrument the phasing is not a
constant phasing, but fluctuating. An early reflection similar effect
usually isn't the result, but in the worst cases even this is possible.
Ralf So the visually test around 4 ms and ALSA MIDI
latency test around 4 ms
from today might be correct results for my computer
That sounds pretty good then.
and at least when I got 4 ms for the visually
test, the audible result was
unusable for music, anyway, I still have got some hope.
You might have mentioned it before, but how exactly are you performing your
test of the 'audible result'?
Arnout
11:29 a.m.
On Mon, 2010-07-05 at 10:33 +0200, Arnout Engelen wrote:
On Mon, Jul 05, 2010 at 10:25:23AM +0200, Ralf Mardorf
wrote:
FWIW to experience how steady the timing of even unknown musicians could
be listen to Roger Friedman playing McCoy Tyner on YouTube.
There is no human touch that is comparable to MIDI jitter.
So the visually test around 4 ms and ALSA MIDI
latency test around 4 ms
from today might be correct results for my computer
That sounds pretty good then.
and at least when I got 4 ms for the visually
test, the audible result was
unusable for music, anyway, I still have got some hope.
You might have mentioned it before, but how exactly are you performing your
test of the 'audible result'?
Arnout
5214
days inactive
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days old
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Arnout Engelen -
Ralf Mardorf