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<DIV><FONT size=2 face=Tahoma>Okay, no that doesn't sound like a buffer problem
at all.</FONT></DIV>
<DIV><FONT size=2 face=Tahoma></FONT> </DIV>
<DIV><FONT size=2 face=Tahoma>If the crackle continues during silent passages i
would say it is a hardware problem, most probably a power supply filtering
issue. (It could be, for example, a dried out electrolytic capacitor that cease
to perform sufficient filtering as it gets a bit warmer.)</FONT></DIV>
<DIV><FONT size=2 face=Tahoma></FONT> </DIV>
<DIV><FONT size=2 face=Tahoma>If the crackling disappears or changes greatly
during silent passages, which it sounds like it does, I would say it was
more likely a software problem. It does change a little as the sound gets
louder, but this could happen as power loading changes with the
volume.</FONT></DIV>
<DIV><FONT size=2 face=Tahoma></FONT> </DIV>
<DIV><FONT size=2 face=Tahoma>It could also be a 'rectifying contact' - usually
a dirty or tarnished one, or a cracked resistor among many
posibilities.</FONT></DIV>
<DIV><FONT size=2 face=Tahoma></FONT> </DIV>
<DIV><FONT size=2 face=Tahoma>There is very distinct almost continuous
series of spikes at 204Hz (4.88ms period) which ought to give a clue, but
doesn't immediately ring any bells, so to speak. </FONT></DIV>
<DIV><FONT size=2 face=Tahoma></FONT> </DIV>
<DIV><FONT size=2 face=Tahoma>
<DIV><FONT size=2 face=Tahoma>If it is software, it might be something happening
at high speed, for example if you are using the card to perform a sampling rate
conversion (eg 44.1kHz to 48kHz), and it is failing to keep up with the pace,
that could possibly produce crackle effects.</FONT></DIV>
<DIV><FONT size=2 face=Tahoma></FONT> </DIV>I don't think your hard drive
is implicated, but it is possible that the crackle is a manifestation some data
issues where the data is passing at a high rate beween the drive and the system
- maybe a problem with DMA interrupts/speed of access, but my gut feel is that
is not the most likely cause - it does sound more like audio hardware/power
problems to me (as i stab in the dark!).</FONT></DIV>
<DIV><FONT size=2 face=Tahoma></FONT> </DIV>
<DIV><FONT size=2 face=Tahoma>Alex</FONT></DIV>
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style="BORDER-LEFT: #000000 2px solid; PADDING-LEFT: 5px; PADDING-RIGHT: 0px; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="FONT: 10pt arial; BACKGROUND: #e4e4e4; font-color: black"><B>From:</B>
<A title=admin@londonhuayu.co.uk href="mailto:admin@londonhuayu.co.uk">London
Chinese Radio</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=tlr@gairloch.co.uk
href="mailto:tlr@gairloch.co.uk">Two Lochs Radio</A> ; <A
title=studio@ravensoundradio.co.uk
href="mailto:studio@ravensoundradio.co.uk">Tony Bailey</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Cc:</B> <A title=cma-l@commedia.org.uk
href="mailto:cma-l@commedia.org.uk">CMA-L</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, October 31, 2011 12:48
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [cma-l] Audio
crackling</DIV>
<DIV><BR></DIV>Hi,<BR><BR>Here is a sample of the audio. As you can see, it's
pretty bad!<BR>It doesn't solve it by disconnecting and reconnecting the audio
stream. But it does sound very software-y.<BR><BR>The HD is an old IDE drive,
but the motherboard, which has mostly SATA ports on it, had an IDE port, so I
installed it. So it could be that... I'm not properly trained,
only find out things by overcoming problems like this...!<BR><BR>Anyway, I am
attaching a small sample from the stream...
<BR><BR><BR>Peter<BR><BR><BR><BR><BR>
<DIV class=gmail_quote>2011/10/31 Two Lochs Radio <SPAN dir=ltr><<A
href="mailto:tlr@gairloch.co.uk">tlr@gairloch.co.uk</A>></SPAN><BR>
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class=gmail_quote><U></U>
<DIV bgcolor="#ffffff">
<DIV><FONT size=2 face=Tahoma>Does the crackle stop for a while if you stop
and restart the audio stream? If so, that would suggest a small bite rate
mismatch is not being properly handled and is resulting in repeated buffer
overflows, which depending on how well the software handles dumping the
excess data can sound like a crackle or a 'glitch'.</FONT></DIV>
<DIV><FONT size=2 face=Tahoma></FONT> </DIV>
<DIV><FONT size=2 face=Tahoma>But the description 'crackle' can cover a
multitude of effects. is it possible for you to post a little audio sample
of it somewhere we can access (or email me a small pice directly if you
want) in case the actual sound triggers any other thoughts.</FONT></DIV>
<DIV><FONT size=2 face=Tahoma></FONT> </DIV>
<DIV><FONT size=2 face=Tahoma>Alex</FONT></DIV>
<DIV><FONT size=2 face=Tahoma></FONT> </DIV>
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<DIV>
<DIV></DIV>
<DIV class=h5>
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV style="FONT: 10pt arial; BACKGROUND: #e4e4e4"><B>From:</B> <A
title=admin@londonhuayu.co.uk href="mailto:admin@londonhuayu.co.uk"
target=_blank>London Chinese Radio</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=cma-l@commedia.org.uk
href="mailto:cma-l@commedia.org.uk" target=_blank>CMA-L</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, October 31, 2011 10:41
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [cma-l] Audio
crackling</DIV>
<DIV><BR></DIV>Hi,<BR><BR>I wonder if anyone has had problems with audio
crackling? <BR>I have recently changed to a different streaming PC,
(because it was XP, and I had a Marian marc8 midi sound card which has 8
ins and outs, but doesn't support Win7), and it was fine for about a
month, until it started crackling. I put all the audio on a seperate HD,
and because they are quite close together, I also fitted a large fan next
to them, which delivers quite an icy blast across the disks.<BR>It starts
crackling after a few hours, and it ruins the stream. It is solvable by
rebooting. I originally thought it could be something overheating, but
since it is solved by rebooting, without the time for anything to cool
down, I don't think that is it. <BR><BR>System info: <BR><BR>Airmate out
into Soundcard in (channels 1 & 2)<BR>mAirlist (6 Channels) and
computer audio (2 channels) via Soundcard outs into Airmate
channels<BR>Asus P5K-VM motherboard with an Intel Core2 duo CPU. (it's a
Red Sub computer with a few extra things I've added) <BR
clear=all>The CPU cooler is a bog standard one but with a funnel that
directs the hot air out of a vent on the side. <BR><BR>Anyway, if you have
an idea, I'd really appreciate any advice. <BR><BR><BR>Peter
Vautier<BR>London Chinese Radio<BR>-- <BR><FONT color=#666666 size=4><SPAN
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