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View Full Version : L/R channels sometimes reversed when using optical output



Mitch Harding
2005-01-17, 13:27
I recently got a new A/V reveiver, with digital audio inputs. Prior to that I had been using the analog outputs of my Squeezebox. When I got the new receiver, I attached the SB to it using a TOSlink cable. Shortly after moving to the digital audio connection, I played a song with very clearly differentiated left and right channels, and I noticed they were reversed. I verified that speaker cabling wasn't the problem. Then I attached a CD player to my receiver using an analog connection, and I played the same song. The channels played correctly. I then unplugged the power from my SB, removed the optical cable, reseated the optical cable, and restored the power. This time when I played the song, it played correctly.

So for some reason, the channels were reversed, but they were restored after I power cycled and reseated the optical cable. I haven't yet tried power-cycling again to see if I can get them to flip-flop back to the incorrect state.

I remember someone reporting a problem similar to this early in 2004, but then I never heard about it again. Is this a known problem? Is it a flukey thing I shouldn't expect to see again? I don't see any Bugzilla defects open on it. Is it worth opening one, or should I first try to reproduce it?

I'm running server version 5.4.0 on Windows XP, and my firmware level is 40. I do have the graphical display.

Thanks,
Mitch
www.mitcharf.com

Mike Reeve
2005-01-17, 15:13
Mitch Harding <mitcharf@...> writes:

> So for some reason, the channels were reversed
>
> I remember someone reporting a problem similar to
> this early in 2004, but then I never heard about it again.
> Is this a known problem?

Hi Mitch

Yes, it is a real bug.

I and several others were plagued by it ...

In the end Sean tracked it down to a bug in the DSP chip
used in the Squeezebox.
As it is a fault in the chip there is nothing that
SlimDevices can do about it for themselves
and, as I understand it, they are still waiting for their supplier
to resolve the issue ...

[BTW while 'lurking' on the Roku Labs forum :-O I noticed that
they seem to have the same bug ...]

Regards

Mike

Michel Fombellida
2005-01-17, 15:13
Yes, that's a known problem. Sean mentionned that it could be related to a DSP
firmware issue that is also related to another issue reported in Bug 416:
http://bugs.slimdevices.com/show_bug.cgi?id=416

Since then, I did not hear anything new, I don't know if it is fixable...
doesn't seem easy. Perhaps Sean could give us some hints.

Michel

Mike Reeve
2005-01-17, 15:22
Mike Reeve <reeve_mike@...> writes:

> Yes, it is a real bug.

Mitch

I forgot to say ...

The known-about bug only affects PCM not MP3 playback
- if you have had the problem with an MP3 track then that's new :-O

And it only happens sometimes!

You can 'fix' it by soft resetting the Squeezebox
(i.e. hold down the power button on the remote until it restarts)
- keep doing this until the channels are the correct way round.

Once the channels are correct then they will stay that way until
an MP3 track is played (or the Squeezebox is restarted),
after which they may or may not be the correct way round ...

Mike

Robin Bowes
2005-01-17, 16:50
Ralph Edington wrote:
> I managed to work around this problem by navigating to
>
> /Ralph%20Edington/Brain/Preferences/
>
> and selecting the "I don't care which channel is which" checkbox.
>
> Of course, note that selecting this checkbox will automatically de-select
> the "I'm an Audiophile" option...
>
> ;o) Sorry, couldn't resist.

Humour appreciated, but you don't have to be an audiophile to find this
irritating. For example, listening to classical music with the Orchestra
the "wrong" way round is most disconcerting! Also, jazz recorded with
instruments panned fairly hard left or right sounds odd.

R.
--
http://robinbowes.com

Robin Bowes
2005-01-18, 02:30
Ralph Edington wrote:
>>Humour appreciated, but you don't have to be an audiophile to find this
>>irritating. For example, listening to classical music with the Orchestra
>>the "wrong" way round is most disconcerting! Also, jazz recorded with
>>instruments panned fairly hard left or right sounds odd.
>
>
> Well, maybe audiophile isn't the right word. Then what is? Aficionado?
> Enthusiast? Devotee?
> Someone-who-can-tell-which-side-of-a-jazz-ensemble-is-the-right-side?
>
> I'm kind of serious here -- I know there are some people who actually sit in
> front of their stereo and listen to the music while facing the speakers.
> I'm not one of them. I'm always walking around, doing chores, cooking, or
> generally whirling like a dervish, which is why whole-house audio is way,
> way, WAY more important to me than correct left/right orientation. (Thank
> you Slim Devices for supporting whole house audio!)
>
> So what is the right word for these true listeners, who can tell when the
> music is backwards? If they're not one-and-the-same as the people who
> subscribe to "Stereophile" magazine, I think we should have a word for them.
> If there's not a word out there already, I think we should make up a new
> one.
>
> :o) RE

:)

Ralph,

if you can't hear it, don't worry!

I too listen around the house, and when I do even *I* don't care about
L/R orientation and sound stage balance.

It's one of those things that, once you've noticed it, niggles.

Afficionado is probably a suitable word.

R. (Sound Engineer, Degree in Electroacoustics, Musician, Music-lover)
--
http://robinbowes.com

Mitch Harding
2005-02-12, 16:44
Thanks for all of the responses about this. Even though this appears to be
a known problem, I could find no bug report for it. Accordingly, I opened
up bug 839 on it:
http://bugs.slimdevices.com/show_bug.cgi?id=839

I am sending out a note to the list just to let everyone know that it's now
officially documented (in case it wasn't before). Also, if this problem is
bothering anyone else out there, you can vote on this bug (for whatever
that's worth).

Thanks again for the replies. As always, this list is extremely helpful.

Mitch

----- Original Message -----
From: "Mike Reeve" <reeve_mike (AT) hotmail (DOT) com>
To: <discuss (AT) lists (DOT) slimdevices.com>
Sent: Monday, January 17, 2005 4:13 PM
Subject: [slim] L/R channels sometimes reversed when using optical
output


Mitch Harding <mitcharf@...> writes:

> So for some reason, the channels were reversed
>
> I remember someone reporting a problem similar to
> this early in 2004, but then I never heard about it again.
> Is this a known problem?

Hi Mitch

Yes, it is a real bug.

I and several others were plagued by it ...

In the end Sean tracked it down to a bug in the DSP chip
used in the Squeezebox.
As it is a fault in the chip there is nothing that
SlimDevices can do about it for themselves
and, as I understand it, they are still waiting for their supplier
to resolve the issue ...

[BTW while 'lurking' on the Roku Labs forum :-O I noticed that
they seem to have the same bug ...]

Regards

Mike

momerath
2005-02-12, 19:43
Does this only happen with the optical out? Is the coaxial plagued as
well? I havent run into it yet that I've noticed, but I just got my
SB yesterday. Does the channel swap happen in the middle of playback?

~Michael

On Sat, 12 Feb 2005 17:44:51 -0600, Mitch Harding <mitcharf (AT) tmbg (DOT) org> wrote:
> Thanks for all of the responses about this. Even though this appears to be
> a known problem, I could find no bug report for it. Accordingly, I opened
> up bug 839 on it:
> http://bugs.slimdevices.com/show_bug.cgi?id=839
>
> I am sending out a note to the list just to let everyone know that it's now
> officially documented (in case it wasn't before). Also, if this problem is
> bothering anyone else out there, you can vote on this bug (for whatever
> that's worth).
>
> Thanks again for the replies. As always, this list is extremely helpful.
>
> Mitch
>
> ----- Original Message -----
> From: "Mike Reeve" <reeve_mike (AT) hotmail (DOT) com>
> To: <discuss (AT) lists (DOT) slimdevices.com>
> Sent: Monday, January 17, 2005 4:13 PM
> Subject: [slim] L/R channels sometimes reversed when using optical
> output
>
> Mitch Harding <mitcharf@...> writes:
>
> > So for some reason, the channels were reversed
> >
> > I remember someone reporting a problem similar to
> > this early in 2004, but then I never heard about it again.
> > Is this a known problem?
>
> Hi Mitch
>
> Yes, it is a real bug.
>
> I and several others were plagued by it ...
>
> In the end Sean tracked it down to a bug in the DSP chip
> used in the Squeezebox.
> As it is a fault in the chip there is nothing that
> SlimDevices can do about it for themselves
> and, as I understand it, they are still waiting for their supplier
> to resolve the issue ...
>
> [BTW while 'lurking' on the Roku Labs forum :-O I noticed that
> they seem to have the same bug ...]
>
> Regards
>
> Mike
>
>

kdf
2005-02-12, 20:01
Quoting momerath <michael.warnock (AT) gmail (DOT) com>:

> Does this only happen with the optical out? Is the coaxial plagued as
> well? I havent run into it yet that I've noticed, but I just got my
> SB yesterday. Does the channel swap happen in the middle of playback?
>

it is on digital outputs, usually caused when switching between PCM and MP3
output to the squeezebox. It is a known bug, and has been reported back to the
vendor of the hardware involved in hopes of a solution. In the meantime, there
is a workaround if you add this to your convert.conf:
mp3 wav * *
[lame] --mp3input --decode -t --silent $FILE$ -

make sure you have LAME installed.

-kdf

momerath
2005-02-12, 20:15
Thanks kdf. I pretty much only listen to flac, so it doesnt sound
like it will bother me.

~Michael


On Sat, 12 Feb 2005 19:01:53 -0800, kdf <slim-mail (AT) deane-freeman (DOT) com> wrote:
> Quoting momerath <michael.warnock (AT) gmail (DOT) com>:
>
> > Does this only happen with the optical out? Is the coaxial plagued as
> > well? I havent run into it yet that I've noticed, but I just got my
> > SB yesterday. Does the channel swap happen in the middle of playback?
> >
>
> it is on digital outputs, usually caused when switching between PCM and MP3
> output to the squeezebox. It is a known bug, and has been reported back to the
> vendor of the hardware involved in hopes of a solution. In the meantime, there
> is a workaround if you add this to your convert.conf:
> mp3 wav * *
> [lame] --mp3input --decode -t --silent $FILE$ -
>
> make sure you have LAME installed.
>
> -kdf
>

Mark Graham
2005-02-12, 23:16
Hi all,

I downloaded a couple of CD's onto my harddrive (Velvet Revolver and
Silvertide) and were able to listen to them by either using the CD or
directly through the hard drive but they wouldn't play thru the slimserver.
When looking at each song thru the slimserver it stated that the songs were
protected by digital rights mangagement.

I thought I would delete the folders from the hard drive and attempt to
download them again and this time the CD didn't open and go to the internet
for the codes. It wouldn't do anything.

Both of these CD's are originals. Just to review both CD's at first played
either with the CD inserted or thru the hard drive after receiving the codes
from the internet. After reinstalling them they both seem to be dead.

Has anyone ran into this and are there any solutions to this?


Thanks in advance
Mark Graham

kdf
2005-02-13, 00:04
Quoting Mark Graham <graham_mark (AT) sbcglobal (DOT) net>:

> Hi all,
>
> I downloaded a couple of CD's onto my harddrive (Velvet Revolver and
> Silvertide) and were able to listen to them by either using the CD or
> directly through the hard drive but they wouldn't play thru the slimserver.
> When looking at each song thru the slimserver it stated that the songs were
> protected by digital rights mangagement.
>
> I thought I would delete the folders from the hard drive and attempt to
> download them again and this time the CD didn't open and go to the internet
> for the codes. It wouldn't do anything.
>
> Both of these CD's are originals. Just to review both CD's at first played
> either with the CD inserted or thru the hard drive after receiving the codes
> from the internet. After reinstalling them they both seem to be dead.
>
> Has anyone ran into this and are there any solutions to this?

I'm not completely following what you have done here. Have you downloaded songs
from an online store or taken files from a store bought cd? Depending on the
store, the files may be protected by Digital Rights Management, which means you
are only able to play the song in a format and location of the record company's
choosing. Slimserver is not one of those formats. You would have to burn your
downloaded songs to a blank CDR then rip those tracks back onto your hard
drive.

if you have ripped from a CD, what program did you use? I've found that EAC is
fairly good at getting clean tracks off any CD.

regardless, copy protected so-called CD's are a bad thing.

-kdf

Jason Holtzapple
2005-02-13, 07:06
Mark Graham wrote:
> Hi all,
>
> I downloaded a couple of CD's onto my harddrive (Velvet Revolver and
> Silvertide) and were able to listen to them by either using the CD or
> directly through the hard drive but they wouldn't play thru the
> slimserver. When looking at each song thru the slimserver it stated
> that the songs were protected by digital rights mangagement.
>
> I thought I would delete the folders from the hard drive and attempt to
> download them again and this time the CD didn't open and go to the
> internet for the codes. It wouldn't do anything.
>
> Both of these CD's are originals. Just to review both CD's at first
> played either with the CD inserted or thru the hard drive after
> receiving the codes from the internet. After reinstalling them they
> both seem to be dead.
>
> Has anyone ran into this and are there any solutions to this?

These CDs likely have 2 sessions - 1 with CD audio and 1 with
Windows Media DRM files. I think you've probably copied the
DRM files to your hard drive. You may be able to "work around"
the protection on the CD audio and extract it - I don't know
the exact method but suggest googling around a bit.