The mixer controls of sound cards using the snd_ice1712
module are not complicted per se, but without
explanation they are very hard to understand.
This section describes how envy24control
represents the hardware.
This VU meter on the left, labeled “Digital Mixer”, shows the signal that comes out of the mixer in the sound
card hardware. This is not neccessarily what comes out of the speakers! It is
the sum of all signals mixed in on the next two tabs (“Monitor Inputs” and “Monitor PCMs”).
In the two monitor tabs there are two faders for a single audio channel. The faders determine how much of the
(mono) input signal will be mixed into the left and right channels of the mixer. If both faders are up at the
same time the stereo signal will be wrong – a mono signal mixed into the wrong channel. If all four
faders for the two stereo channels have the same value, the signal that comes out of the mixer will be mono
for this input.
The VU meters on this tab show the raw input signals of the input connectors on the sound card hardware (line in,
microphone etc.). Nothing except the physical level of the input signal affects the levels of this meters.
The faders control how much of the signal gets into the hardware mixer. The result is shown in the “Digital Mixer” VU
meter). They can only reduce the level, not make the signal louder. It is safe to pull the faders all the way
This tab is the same as “Monitor Inputs”, but for the PCM controls. These are the signals that are generated
on the computer in software. The controls are labeled “Out” here instead of “In”. The functionality is
nevertheless the same.
Patchbay / Router
The radio buttons select which internal audio source (label on the radio button) will be routed to
which output (label on the column). Some examples
- “PCM Out” routes the signal of the selected PCM output to the output represented by the column
- “Digital Mix” routes the signal (output) of the digital mixer to the output represented by the column
- “Line In” routes the signal from the “Line In” connectors of the card directly to the output
represented by the column
“H/W Out 1 (L)” and “H/W Out 2 (R)” are connected to the speakers. So the radio buttons select what you hear.
I'm not sure what the “H/W Out” 3–6 outputs are for, but I think they are channels for the 5.1 sound.
There are two ways to hear sound: directly or via the hardware mixer.
This faders control the levels of the outputs (DACs – digital to analog converter) and the levels of the
input connectors on the hardware (ADCs – analog to digital converter). A level of 127 leaves the signal
If you want to record from Line In, the “Line In Selector” must be set to the appropriate hardware.
- “Front Input” for the connector on the breakout box
- “Internal” for the connector on the card (?)
- “Rear Input” for the connector on the back of the card (?)
- “Wavetable” for the wavetable module
In the same spirit phono and microphone share the same channels. Which one is active is defined with the
“Phono Input Switch”.
- “Phono” activates the phono cinch connectors
- “Mic” activates the” jack plug of the microphone
Recording in audacity
By default audacity only records two channels (stereo). To capture the inputs of the card more channels have
to be added. Phono/Mic is on channels 5 and 6.
DMX 6fire 24/96
- The gain control on the breakout box (front module) controls the pre-amp for the microphone
- The level control on the breakout box controls the volume of the headphone output
Controls and their functionality
|0 ||front left
|1 ||front right
|2 ||rear left
|3 ||rear right
|5 ||LFE (subwoofer)