Processing
The internal processing stages of the IM5 surround input module are the hi-pass low-pass filter, the equalizer and the insert.

In addition, the surround console system offers the choice to add an additional processing device in the meterbridge.
back to top

External processing
The wiring of the console frame includes a special frame pcb in the meterbridge. The channels insert inputs and outputs and the external meter sends are available on the plugs of this frame board. If no module is installed, a blind connector bridges the lines to connect the insert to the connector panel.

It is possible to install one additional processing section in the meterbridge, that can be pre or post the insert. Since the wiring includes the stereo channels, there are many of possible combinations.
back to top

See the External Processing Page for details about the modules. The most common device is a dynamics processor. The big advantage of this principle is, that the dynamics section is not part of the channel and adds no cost to the module itself. It can be installed at any time. The amount of dynamic units and the channels they are assigned to depends on your needs.

We will offer different, compatible versions of dynamics processors and other processing devices in the next future. A combined dynamics section and meter will also be available soon.

A high resolution peak meter can be installed alternatively. See the Meter section for further details.
back to top

The Filter
The filter section combines a hi-pass filter and a low-pass filter. The sweep range of the high pass is from off to 600 Hz. The low pass ranges from off to 2 kHz. The filters are of the maximum type. The FILT switch insert the section into the signal path. The Filter is first processing element in the chain.
back to top

The Equalizer
The 4 band equalizer is an originally adt-audio EQ that is used in many 5MT audio console channels. The design of the very favored EQ has been optimized for many years. The circuitry is based on the phase coherent, active Vienna Robinson's bridge. The enormous range of +/- 20 dB, and the transparency make extreme interventions of tonal surgery possible. Even with extreme setting this EQ remains crystal clear and clean.

The HI EQ has two possible settings. In the 15 kHz position of the switch it works as a soft shelf EQ at the upper end of the transmission band. This setting produces clean, silky sounds. The 8 kHz setting changes the characteristic to a very soft bell with the center frequency of 8 kHz. With this setting soft soundings highs with full pressures can be produced.

The LOW EQ operates always as a soft bell, centered to the most important frequencies for music production in the low band, 60 and 100 Hz. The bell characteristic avoids the problem of a shelving low EQ, that unwanted subsonic components are raised with a low band gain. The optimized bell curve excludes automatically the subsonic components from the signal and eliminates the need of using an additional high pass filter for boosting low frequencies.

The two fully parametric mid bands have very wide frequency control and Q-factor ranges. The lower mid band can be tuned from 60 Hz to 3 kHz. The range of the high mid band is from 300 Hz to 15 kHz. The range of the Q factor is from 0.3 (more than 3 octaves) to 5 (less than a third) for both bands.

All 4 bands have a gain control range of +/- 20 dB. The EQ switch inserts the entire equalizer.
back to top

The Insert
The switched Insert section is normally post EQ and can be switched between the output of the filter section and the equalizer with the PRE switch. Both input and output are electronically balanced and fully buffered. Unless the INS switch is pressed, the insert input is not active but the insert output is driven normally. The insert is also used for the integration of internal additional processing sections.
back to top

PFL and Metering
The IM5 Channel has a build in LED Peakmeter with 10 LED's and a Range from -24 dB to + 12 dB. The meter reads the input of the main fader in parallel to the main PFL if no other function is active. The METER GROUP switch redirects the meter to the output of the group master / channel out section. In addition, the meter is switched to the PFL-R (Record PFL) line, if this PFL function is active. The PFL Record tap is fixed to the position of the Record Insert send, which depends on its Pre switch.

The PFL system operates always in adding mode. The locking switches are not affected by a central reset or a reset caused by the anoather function as we use to build up a PFL system with a live sound or broadcast console, but there is a PFL Off function, the blocks the entire PFL system and makes it possible to toggle between PFL and normal operation. This funtion is part of the control room module.
back to top

Optional Meters
In addition to the internal meter, there are two meter sends that can drive optional meters installed in the meter bridge. Apart from the Dynamics modules and other audio processing gear that can be installed in the meter bridge, it is of course possible to install meters as well. Mono and Stereo LED peak meters with 40 LED's and a display range from -45 to +10 dB are available. A mono meter can be assigned to the meter send 1 or 2; a stereo meter will display either the calibrated monitor or group input or the selected input, after the input gain controls. This is determined by a jumper setting. The second meter displays the channel / group output.

In the next future we will offer additional units for the meterbridge that include one or two meters and a compressor / expander.

The importance of a console metering decreases, since most of the DAW system include a digital system that reads the digital level. As the headroom of the analog system is much higher than the limited headroom of the digital system it is more important to take about the digital level than about the analog system. All the outputs of the SRC51 surround console can handle levels of at least + 26 dBu into a load resistance of 600 Ohms and more than + 27 dBu with a higher load resistor, which is the normal operation. This is more than any A/D converter can accept. The only possibility for a clipping inside the console channel is that the internal level relations are totally wrong. This might be the case, if the setting of the equalizer produces a lot of additional gain and the main fader instead of the input gain is used to reduce the excessive level. This situation is covered with internal meter very well, since the fader input is displayed in normal operation mode.
back to top