[Asterisk-Users] RX gain TX gain

[Robert L Mathews]

At 10/30/03 12:21 PM, Jared Smith <jsmith at drgutah.com> wrote:

>It's my understand that they are db levels.  (And, if I remember my
>electrical engineering classes from college, a 3db increase effectively
>doubles the volume.)

As a slight aside on the subject of gain....

It seems that most people asking about RX/TX gain want to increase their 
volume. I have the opposite problem: I have a Digium TDM10B FXS card that 
generates sound far too loud (in the earpiece) with the RX gain set at 
0.0, or commented out.

That is, routing an analog line => X101P => Asterisk => TDM10B => analog 
phone is MUCH louder than if I just plug the same phone into the same 
analog line directly.

Some people have suggested that using a negative gain will make it 
quieter, but I haven't had any luck with this. I *can* make it even 
louder by increasing the gain -- if I use "rxgain = 10" on the TDM10B, 
for example, it's so loud it sounds like the phone is going to explode -- 
but using things like "rxgain = -3.0" or "rxgain = -10.0" doesn't make it 
any quieter. I can't get it below the "rxgain = 0" value.

I've been meaning to dig around the source and see what's up, but since 
it's being discussed... anyone know how to use rxgain to lower the 
earpiece volume?

-- 
Robert L Mathews, Tiger Technologies      http://www.tigertech.net/