Audiotec Fischer Tech Talks
Audiotec Fischer's new multi-stage "Virtual Channel Processing", in conjunction with the recognized user-friendly DSP PC-Tool software makes it easy to realize even highly complex system configurations. Besides that, it allows to freely assign our proprietary FX sound features such as "RealCenter" or "Augmented Bass Processing" to every output channel.
The main advantages of this concept are:
-Cross-channel group equalizers that affect several output channels simultaneously
- Multi-way speaker configuration of DSP Sound Effects (SFX))
- Additional features such as Rear Attenuation
- And more…
Tech Talk #5
If an input signal (e.g. front left) is first routed to a virtual channel (Front L Full) and this signal is then routed to an active multi-way system (e.g. front left – tweeter, midrange and woofer), the group equalizer of the virtual channel will influence all assigned output channels in their tonality. The advantage of this concept is that any amplitude and phase shift of the group equalizer is applied to all channels of the multi-way configuration simultaneously, thus avoiding any negative impact on the interaction of the individual speaker channels.
Cross-channel group equalizer
Multi-way configuration of the DSP Sound Effects (SFX)Example application: 2- or even 3-way center speaker
After activating “Virtual Channel Processing”, the DSP sound effects, such as RealCenter management or Augmented Bass Processing, are also available. These are no longer linked to the outputs but tied to specific “virtual channels”.
Front Processing: virtual channels Front L Full and Front R Full
Center Processing: virtual channel Center Full
Augmented Bass Processing: virtual channels Subwoofer 1 and Subwoofer 2. The subwoofer volume is also tied to these channels.
This makes it possible to route the DSP sound effects to any number of outputs, for example to realize 2- or even 3-way center speaker configurations. There are hardly any limits to flexibility here.
Operating concept of the VCP
In addition, the VCP enables the implementation of further new functions. One of these is, for example, the “Rear Attenuation”. With the help of a remote control, the volume of the virtual channels “Rear L Full” and “Rear R Full” can be controlled separately. So it is possible even without switching the sound setup, to adjust the volume of the rear speakers (or any other channel, which is routed through these channels) independently.
For further Information about the workflow check the user manuals of VCP supporting devices
Products with Virtual Channel Processing
Virtual Channel Processing
In many cases, a replacement is no longer possible, so that only an amplifier with the same number of high power highlevel inputs can be considered for upgrading the system.
Especially in fully active multi-channel OE sound systems in which the speaker configuration remains unchanged, it doesn´t make sense to generate a full-range signal out of individual channels first and subsequently separate it afterwards into individual frequency ranges.
Here it is way more clever to directly route all input channels one to one to the output channels and to optimize each channel individually by using all possibilities of the integrated signal processor.
Therefore, all Audiotec Fischer amplifiers with 1 to 1 channel routing option provide at least a minimum of 8 high power highlevel inputs and just as many amplifier channels.
Tech Talk #4
1 to 1 channel routing option
Products with 1 to 1 channel routing option
In these cases our Input Signal Analyzer (ISA) with its integrated InputEQ comes into play – It allows to analyze and compensate such a manipulation of the input signal before the signal is processed by the DSPs sound optimizing functions.
In addition the InputEQ provides amplitude-linear allpass filters to ensure an in-phase addition of the left and right channel which is especially important if subwoofers shall be added to installations where the OEM head unit is using allpass filters for their manipulations.
But why should I set an amplitude-linear allpass filter?
Allpass filters are often used in French and American vehicles instead of a time alignment to realize a wider stage image.
If the channels are summed up, typically the summation of the channels leads to a broadband cancellation in the lower frequency range and therefore a poor bass reproduction.
This issue can be solved by using an allpass filter as a correction in the InputEQ and can directly be verified through the ISA.
Tech Talk #3
Input Signal Analyzer
The ISA and InputEQ benefits at a glance:
Input Signal Analyzer:
- Tool for the frequency response measurement of an analog input signal.
- Adjustments of the InputEQ can be seen in the measurement with the ISA as well. This allows to instantly verify all InputEQ adjustments.
- Multiple input channels can be summed up before measurement to detect phase differences between each input signal.
- The summation can be adjusted in level and polarity for the optimum summing ratio in multi-channel active speaker systems. The result of the summation is directly visible in the ISA.
- The proportional summation of the measured signal can be transferred as "routing" directly into the IO channel routing to optimize the work-flow.
- Used for the correction of the frequency response of input signals which have already been manipulated (generally in OEM head units). The goal is to linearize the frequency response before the signal is processed in the DSPs sound optimizing functions..
- Allows the use of amplitude-linear allpass filters to ensure an in-phase addition of the left and right channel for subwoofer integrations e.g. in special applications where Peugeot OEM head units are used.
Die Features des ISA und InputEQs auf einen Blick:
Products with Input Signal Analyzer
Tech Talk #2
ADEP.3 - Advanced Diagnostics Error Protection
- Error messages stored in the car‘s CPU
- Features are missing like the fader function
- Speaker outputs will be switched off (= no more sound)
An often proposed solution:
Take a couple of high-power resistors (min. 10 Watts load)
and connect them in parallel to the highlevel speaker inputs of your amplifier / signal processor.
- Reduced sound quality due to higher signal distortion of the OE radio
- Requires additional space
- High installation effort
- Additional heat dissipation
- Unnecessary load for your radio and high current draw – bad if you like to use the original harness
for powering your Plug & Play amplifier!
The intelligent solution: ADEP.3
The ADEP.3 benefits at a glance:
- Avoids failure messages in the car´s error memory
- Keeps features e.g. fader function
- Ensures best possible sound quality
- KNo unnecessary load of the OE radio´s speaker outputs
- Perfect OEM integration without additional installation effort
Products with ADEP.3 circuit
ACO - Advanced CoProcessor
Products with Advanced CoProcessor