C-Media CMI8738-LX noise in recording from line in

C-Media CMI8738-LX noise in recording from line in

[Lars Schotte]

I have this Sweex Sorround sound card PCI and I want to use it for
recording / digitalizing / magnetic and other media types through
line-in. I have to use that card (or another) because the built-in
sound card doesnt work /is broken/.

The soundcard has following chipset - C-Media CMI8738-LX.

So I try to record from the line in input, which works for listening,
so line in input is played good through line out then. I dont know if
there is a passthrought or sth. however, when I record it, using
audacity, or even alsarecord / it doesnt matter / the sound is reported
and also actually is too silent and there is a lot of noise. So with
that noise, this card is for digitalizing useless.

this soundcard has physically no shared connector with the rear, or
bass or whatever. so there are 5 connectors, line in, mic in, front,
rear and cent/sub. each for himself. maybe thats the case, that the old
ones did have shared one and therefore it breaks the recording or
whatever, just a theory. because a few years ago i had an old cmipci
and that one worked fine.

just to be clear, there is sound, so it records, the problem is that
its too silent and there is a lot of noise in it. i write this note
because I saw some reports that suggest that it produces _only_ noise
in recording. thats not the case here.

-- 
-------------------
Lars Schotte @ romy

Re: C-Media CMI8738-LX noise in recording from line in

[Dan Chen]

From: Lars Schotte <lars.schotte@schotteweb.de>


> I have this Sweex Sorround sound card PCI and I want to use it for
> recording / digitalizing / magnetic and other media types through
> line-in. I have to use that card (or another) because the built-in
> sound card doesnt work /is broken/.
>
> The soundcard has following chipset - C-Media CMI8738-LX.

Please attach http://www.alsa-project.org/alsa-info.sh output (--no-upload)

Re: C-Media CMI8738-LX noise in recording from line in

[Clemens Ladisch]

Lars Schotte wrote:
> The soundcard has following chipset - C-Media CMI8738-LX.

This chip was designed before on-board sound devices were common, and
manages to have worse analog sound quality than many of those,
especially on its inputs.

> So I try to record from the line in input, ...
> its too silent and there is a lot of noise in it.

Even if your current mixer settings are suboptimal and can be improved
(please show the output of "amixer contents" or the alsa-info output),
be aware that this card never will have good quality.


Regards,
Clemens

Re: C-Media CMI8738-LX noise in recording from line in

[Lars Schotte]

OK. but the question is, does it put noise in recording in windows as
well? I maybe solved it w/ activating the old hd audio integraded snd
card, whichs broken, but line-in works and i tried it recording w/ it
and that works perfectly. you say, that the cards never going to have a
good sound quality. I am sure it doesnt, but what I am getting isnt
even good enough. there is written on the box that I can record with it
in 44khz and so on, cd quality and whatever, so is it a lie?

i tried out manipulating w/ the mixer, believe me, however, i ll post
some output later, but the settings can not be set better, because the
only relevant setting here is the line-in and that is already on
maximum. the second thing that i dont understand about this card is,
that when I play sth at line-in, the sound is perfect, but the
recording is crappy. so does it have a line-in to line-out passthrough?
but then hows that possible that I can regulate it on my mixer and even
mute line-in completely?

On Thu, 01 Apr 2010 11:52:38 +0200
Clemens Ladisch <clemens@ladisch.de> wrote:

> Lars Schotte wrote:
> > The soundcard has following chipset - C-Media CMI8738-LX.
> 
> This chip was designed before on-board sound devices were common, and
> manages to have worse analog sound quality than many of those,
> especially on its inputs.
> 
> > So I try to record from the line in input, ...
> > its too silent and there is a lot of noise in it.
> 
> Even if your current mixer settings are suboptimal and can be improved
> (please show the output of "amixer contents" or the alsa-info output),
> be aware that this card never will have good quality.
> 
> 
> Regards,
> Clemens
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel


-- 
-------------------
Lars Schotte @ romy

Re: C-Media CMI8738-LX noise in recording from line in

[Daniel Mack]

(please don't top-post)

On Thu, Apr 01, 2010 at 01:00:55PM +0200, Lars Schotte wrote:
> OK. but the question is, does it put noise in recording in windows as
> well?

Does it? Given that nobody else here happens to have the same audio
card, I believe you're on your own to find out whether this is a
hardware or driver issue.

> I maybe solved it w/ activating the old hd audio integraded snd
> card, whichs broken, but line-in works and i tried it recording w/ it
> and that works perfectly. you say, that the cards never going to have a
> good sound quality. I am sure it doesnt, but what I am getting isnt
> even good enough. there is written on the box that I can record with it
> in 44khz and so on, cd quality and whatever, so is it a lie?

"44khz and so on" just tells you how the ADC/DAC works, it says nothing
about the analog audio performance. So, vendors can screw the entire
analog path and still claim they operating on CD quality digitally, yes.
Welcome to the real world.

> i tried out manipulating w/ the mixer, believe me, however, i ll post
> some output later, but the settings can not be set better, because the
> only relevant setting here is the line-in and that is already on
> maximum. the second thing that i dont understand about this card is,
> that when I play sth at line-in, the sound is perfect, but the
> recording is crappy. so does it have a line-in to line-out passthrough?

Is there any software active to enable that pass-thru? Or is that a
hardare feature?

> but then hows that possible that I can regulate it on my mixer and even
> mute line-in completely?

Maybe you should provide the output you have been asked for, namely
your mixer settings and the output of the alsa-info.sh script.

And the information about how the same hardware performs under Windows
would also help you and other understand where the problem might be.

HTH,
Daniel


> On Thu, 01 Apr 2010 11:52:38 +0200
> Clemens Ladisch <clemens@ladisch.de> wrote:
> 
> > Lars Schotte wrote:
> > > The soundcard has following chipset - C-Media CMI8738-LX.
> > 
> > This chip was designed before on-board sound devices were common, and
> > manages to have worse analog sound quality than many of those,
> > especially on its inputs.
> > 
> > > So I try to record from the line in input, ...
> > > its too silent and there is a lot of noise in it.
> > 
> > Even if your current mixer settings are suboptimal and can be improved
> > (please show the output of "amixer contents" or the alsa-info output),
> > be aware that this card never will have good quality.
> > 
> > 
> > Regards,
> > Clemens

Re: C-Media CMI8738-LX noise in recording from line in

[Lars Schotte]

yes, I will post it, like I said, I am not on that computer now.

I dont have any windows now, so maybe I ll get some copy from
bittorrent or whatever, I didnt use windows for a long time.

I dont know if it has a passthrough. its only I cant otherwise explain,
why the sound card is working good on playback and the recroding is
such bad quality.

On Thu, 1 Apr 2010 13:14:04 +0200
Daniel Mack <daniel@caiaq.de> wrote:

> (please don't top-post)
> 
> On Thu, Apr 01, 2010 at 01:00:55PM +0200, Lars Schotte wrote:
> > OK. but the question is, does it put noise in recording in windows
> > as well?
> 
> Does it? Given that nobody else here happens to have the same audio
> card, I believe you're on your own to find out whether this is a
> hardware or driver issue.
> 
> > I maybe solved it w/ activating the old hd audio integraded snd
> > card, whichs broken, but line-in works and i tried it recording w/
> > it and that works perfectly. you say, that the cards never going to
> > have a good sound quality. I am sure it doesnt, but what I am
> > getting isnt even good enough. there is written on the box that I
> > can record with it in 44khz and so on, cd quality and whatever, so
> > is it a lie?
> 
> "44khz and so on" just tells you how the ADC/DAC works, it says
> nothing about the analog audio performance. So, vendors can screw the
> entire analog path and still claim they operating on CD quality
> digitally, yes. Welcome to the real world.
> 
> > i tried out manipulating w/ the mixer, believe me, however, i ll
> > post some output later, but the settings can not be set better,
> > because the only relevant setting here is the line-in and that is
> > already on maximum. the second thing that i dont understand about
> > this card is, that when I play sth at line-in, the sound is
> > perfect, but the recording is crappy. so does it have a line-in to
> > line-out passthrough?
> 
> Is there any software active to enable that pass-thru? Or is that a
> hardare feature?
> 
> > but then hows that possible that I can regulate it on my mixer and
> > even mute line-in completely?
> 
> Maybe you should provide the output you have been asked for, namely
> your mixer settings and the output of the alsa-info.sh script.
> 
> And the information about how the same hardware performs under Windows
> would also help you and other understand where the problem might be.
> 
> HTH,
> Daniel
> 
> 
> > On Thu, 01 Apr 2010 11:52:38 +0200
> > Clemens Ladisch <clemens@ladisch.de> wrote:
> > 
> > > Lars Schotte wrote:
> > > > The soundcard has following chipset - C-Media CMI8738-LX.
> > > 
> > > This chip was designed before on-board sound devices were common,
> > > and manages to have worse analog sound quality than many of those,
> > > especially on its inputs.
> > > 
> > > > So I try to record from the line in input, ...
> > > > its too silent and there is a lot of noise in it.
> > > 
> > > Even if your current mixer settings are suboptimal and can be
> > > improved (please show the output of "amixer contents" or the
> > > alsa-info output), be aware that this card never will have good
> > > quality.
> > > 
> > > 
> > > Regards,
> > > Clemens
> _______________________________________________
> Alsa-devel mailing list
> Alsa-devel@alsa-project.org
> http://mailman.alsa-project.org/mailman/listinfo/alsa-devel


-- 
-------------------
Lars Schotte @ romy