P5AD2-E Mic input too low / quiet.

  • Thread starter Thread starter Barry
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Barry

My P5AD2-E seem to have too little gain on the Mic input. I've the latest
drivers and tried several Mics but still too quiet. This is causing problems
with essential applications such as Counter Strike Source. Yes - I've turned
up the gain in windows and Counter Strike.

Any ideas?

Thanks for any and all help.

Barry
 
"Barry" said:
My P5AD2-E seem to have too little gain on the Mic input. I've the latest
drivers and tried several Mics but still too quiet. This is causing problems
with essential applications such as Counter Strike Source. Yes - I've turned
up the gain in windows and Counter Strike.

Any ideas?

Thanks for any and all help.

Barry
Click to expand...

Congratulate the "space cadets" at Cmedia for this.

On an AC97 chip, there is a 20dB "mic boost" button, to fix
your microphone problem.

In the Azalia spec, there is no provision for funny controls
like that. The gain/loss control is a simple continuum in the
new Intel spec. A company designing a new chip, would be expected
to preserve the feature set of their old chips (to meet
customer expectations), and that means mapping the old
specifications to suit the new standard's way of doing
things. (See PDF page 162 stepsize/numsteps/offset)

ftp://download.intel.com/standards/hdaudio/pdf/HDAudio_03.pdf

But, what the guys at Cmedia forgot to do, is add more gain
steps to the gain control, so that the customer could add
about 20dB more gain, in 1.5dB steps. I'm not convinced it
is impossible to do, and someone just forgot.

You may need to buy a preamp of some sort. The type of
preamp may vary, depending on whether your mic is
electret or a dynamic type.

While many chip bugs these days are fixed by a driver
update, something tells me this is truly busted, and a
new chip revision will be needed to fix it.

Best guess,
Paul
 
If you have a better head for numbers than I do, compare an
AC97 chip, to the CMI9880:

ALC650, an AC97 audio chip. Data sheet version 1.28 . Page 10
has microphone volume of +12dB to -34.5dB in 1.5dB steps. On
top of that, there is the 20dB boost button. Max gain in
that stage is 32dB.

ftp://202.65.194.18/pc/ac97/alc650/alc650_data5.zip

The CMI9880 seems to only have gain in the "input widget".
It has 32 steps of 1.5dB and an offset of zero. This
implies a gain of from 0 to +46.5dB, and the rest of the
spec doesn't seem to have any attenuation capability.
The microphone in the ALC650 has a range of +32 to
-34.5dB, or a total range of 66.5dB .

http://cmedia.com.tw/doc/C-Media CMI9880 Datasheet rev 0.99C.pdf

The CMI9880 just doesn't make a lot of sense to me.
Maybe someone else can explain this to me. A chip
that only has gain, doesn't make a lot of sense,
when you want to turn it down :-)

Paul
 
Well I've sent the problem to ASUS support. They came back quickly but with
the standard refer to this page in the manual for the level control. I've
replied yep, got that max'ed already. We will have to see what they can do.
Good news is that I googled and I not the only one that has noticed the
problem.

Thanks for the info

Barry
 
So what is ASUS's answer to one of their flagship boards having a problem.

1. Have your dealer test it. They know less than me.....I.T. professional
for 14 years.
2. RMA it back here so we can take a couple of weeks sending you the same
board version again. Oh, that's worth while!

Well I'm unimpressed. I wonder how long it will take for a clue to filter
down to the techies at ASUS from the users in the real world who actually
know it's a problem.

I'm guessing a USB based microphone will have none of these problems and so
I may try one of those next.

All the best

Barry
 
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