Reducing "noise" from output

Reducing "noise" from output

[Bryan Scaringe]

Hello all,
	I have a SB-AWE64, and it works fine under Linux, but I was
wondering if there is any way to reduce the noise from the speaker-output.
It sounds like a tape hiss, only less so.

Thanks,
	Bryan

Re: Reducing "noise" from output

[Paco]

Hi, Bryan.

I wanted to ask you what kernel/distribution/drivers you are using.  I
also have the AWE64 in my box, but I have no problems with hiss.  I *do*
use the line-out instead of the speaker-out, so that may have something to
do with it, but it seems unlikely.

-Paco

On Tue, 22 Jun 1999, Bryan Scaringe wrote:

> Hello all,
> 	I have a SB-AWE64, and it works fine under Linux, but I was
> wondering if there is any way to reduce the noise from the speaker-output.
> It sounds like a tape hiss, only less so.
> 
> Thanks,
> 	Bryan
> 

Re: Reducing "noise" from output

[ljp]

It might be due to power connections and other connections in close
proximity to the card, and/or the cord for the speakerOut. If the main power
cord to the computer must cross the outputs, put them at a 90 degree angle
to the power cord. or better yet, dont cross them at all. 110, or 220 power
cords have a large magnetic field that generates noise on speaker cords.


> Hi, Bryan.
>
> I wanted to ask you what kernel/distribution/drivers you are using.  I
> also have the AWE64 in my box, but I have no problems with hiss.  I *do*
> use the line-out instead of the speaker-out, so that may have something to
> do with it, but it seems unlikely.
>
> -Paco
>
> On Tue, 22 Jun 1999, Bryan Scaringe wrote:
>
> > Hello all,
> > I have a SB-AWE64, and it works fine under Linux, but I was
> > wondering if there is any way to reduce the noise from the
speaker-output.
> > It sounds like a tape hiss, only less so.
> >
> > Thanks,
> > Bryan
> >
>
>

Re: Reducing "noise" from output

[Bryan Scaringe]

Yep. The hiss is gone using line-out.  I guess this next question may be
a bit off topic, but here goes:

speaker-out is considerably louder at a given volume level than
line-out.  speaker-out also seems to have better quality bass.
line-out however, seems to be much cleaner, lacking the hiss.
So:  What is the difference between line-out and speaker-out,
specificly from a functional standpoint.  Is line-out expected to
be sent to an amplifier that will control bass/treble/vol?
Is this why line-out is less responsive to bass/treble changes
using "aumix" than speaker-out?

Thanks,
	Bryan
 


> 
> Hi, Bryan.
> 
> I wanted to ask you what kernel/distribution/drivers you are using.  I
> also have the AWE64 in my box, but I have no problems with hiss.  I *do*
> use the line-out instead of the speaker-out, so that may have something to
> do with it, but it seems unlikely.
> 
> -Paco
> 
> On Tue, 22 Jun 1999, Bryan Scaringe wrote:
> 
> > Hello all,
> > 	I have a SB-AWE64, and it works fine under Linux, but I was
> > wondering if there is any way to reduce the noise from the speaker-output.
> > It sounds like a tape hiss, only less so.
> > 
> > Thanks,
> > 	Bryan
> > 
> 
> 

Re: Reducing "noise" from output

[Paco]

On Wed, 23 Jun 1999, Bryan Scaringe wrote:

> So:  What is the difference between line-out and speaker-out,
> specificly from a functional standpoint.  Is line-out expected to
> be sent to an amplifier that will control bass/treble/vol?

Exactly.  For line-out, you have minimal control over the amplitude of the
signal.  "Line-level" voltage is (I believe) 2.2V, peak-to-peak.  Volume
control of line-out allows you to change this peak-to-peak value, but not
significantly.

Line-out signals are meant to go to another device which will control the
bass/treble/volume.  (ie, your stereo)

Speaker-out signals are amplified *on-the-card* and provide enough juice
to power speakers themselves.  This on-card amplification may be the cause
of your hiss.  (I'm not too sure if the on-card amplifiers are very
high-quality on an AWE64.)

> Is this why line-out is less responsive to bass/treble changes
> using "aumix" than speaker-out?

BINGO!  Bass and treble controls function just like the volume control for
line-out; they *do* cause changes in the signal, but not significant ones.
You can think of bass and treble controls as "turning up the volume" of
the low or high EQ bands.

regards,
Chad "Paco" Walker