Control Elements
M/S Direction Mixer with elliptical EQ for Stereo Mastering and M/S Microphones
ToolMod Pro Audio - TM130 & TM130m
The picture shows the recording version TM130
M/S Direction Mixer Home | MS Microphone Pre Amp Set Home | Stereo Mastering Home

M/S Direction Mixer with elliptical Equalizer

Control Elements Details and Specials
1 Stereo Base Width Control Recording Version
0 % = mono
100 % = stereo unchanged
300 % = extended stereo base
Stereo Base Width Control Mastering Version
50 % = reduced stereo base
100 % = stereo unchanged
150 % = extended stereo base
- see Details and Specials for more
Base Width
Settings of more than 100 % stereo can interfere the mono compatibility of the signal. Please make sure that you check the signal in mono when using such settings.

M/S format Direction Control
The direction control in the M/S stereo format works entirely different from the conventional stereo balance regulation. While a stereo balance control cuts off one of the two channels in the 'Left' and 'Right' positions, the M/S direction control converts the signal to a mono signal from the left or right output channel, when the pot is set all the left or all to the right. In all other positions but center the stereo base width is reduced while the left- right level balanced is modified. The great advantage of this method is that no signals are lost when the control is used.

With the mastering Version TM130m the range of the direction control is limited to +/- 6 dB, since with mastering and mixing the direction pot is only used to compensation the possible shifting of the stereo balance when using the overbase features of the module.

elliptical Equalizer
The elliptical equalizer generates a frequency dependent crosstalk between the stereo channels. The scale shows the frequency where the crosstalk is 15 dB. With lower frequencies, the crosstalk value is lower; higher frequencies cause a higher crosstalk value. The steepness of the curve is 6 dB/oct. Setting the control to 300 Hz causes no audible changes in the stereo base width.

The elliptical eq improves the mono compatibility in the bass frequency range and can reduce problems caused by base width settings of more than 100 % stereo.

2 Input Mode Select, Left/Right (default) or M/S (pressed)
makes possible to decode M/S format input signals as well as the opertion of stereo microphones in M/S mode.
3 M/S Direction Control Recoding Version
Control range from 'Mono from Left', over
Stereo unchanged at center (C), to
'Mono from Right'
M/S Direction Control Mastering Version
+/- 6 dB L/R Balance
Stereo unchanged at center (C)
- see Details and Specials for more
3 EEQ activates the elliptical equalizer ein
(the bypass switch 8 must be pressed for the operation)
5 Frequency control of the elliptical Equalizer
range from < 40 Hz to 1000 Hz
center detent at 300 Hz
the control is calibrated in 'frequency for 15 dB crosstalk'
- see Details and Specials for more
6 Bypass switch für the entire unit