tpaxadpom

I love when chrome get's stuck in calendar. I had to force close chrome to recover but my reply was erased. I dig up the document describing Logic 7 system as well as standard stereo setup.

Top HiFi Components
The Top-HiFi audio system differs from the HiFi audio system by higher grade speakers and
the addition of following components:
• Top-HiFi amplifier
• Front mid-range speaker mounted centrally in instrument panel
• Mid-range speakers in rear left and right doors
Higher grade speakers are used in the Top-HiFi audio system. The midrange speakers are
equipped with aluminum diaphragms, the tweeters with aluminum spherical caps. The
speakers were adapted corresponding to the higher output power of the Top-HiFi amplifier.
Top-HiFi Amplifier
The Top-HiFi amplifier is designed as an analogue 7-channel amplifier (LOGIC7). It features
7 bridge-type output stages with an output power rating of 7x40 W at 2 and a bandwidth
of 200 Hz - 20 kHz. In addition, two bridge-type output stages rated 2x70 W at 4 and a
bandwidth of 20 Hz - 200 Hz are available for the central woofers.
This amplifier is connected via the MOST bus to the M-ASK. All audio signals are transmitted
from the M-ASK via the MOST bus. The Top-HiFi amplifier is equipped with the LOGIC7
function.
LOGIC 7
LOGIC7 is a registered trademark of Lexicon, Inc., a company of the Harman International
Group. It was especially developed for applications in motor vehicles.
LOGIC7 is a sound system that creates a 7-channel surround sound from 2-channel audio
sources (radio, CD, CC). The incoming stereo signals are decoded in the digital sound
processor (DSP), distributed over 7 channels and remixed. The entire transmission width is
used on each channel, thus creating perfect surround sound that gives the listener the
impression of being in the middle of the space.
Mid-Range Speakers
The load rating of the mid-range speakers was increased to 40 W for the Top-HiFi audio
system. The mid-range speakers are equipped with aluminum diaphragms. aluminum
diaphragms are particularly lightweight and feature a higher rigidity. These properties result
in improved inherent dynamics and a clearer sound over the entire frequency range.
The effective frequency range is from 100 Hz to 10000 Hz. The Top-HiFi audio system was
extended by three mid-range speakers. A mid-range speaker was positioned in the center
of the instrument panel in order to realize the surround sound function in the vehicle. Two
further mid-range speakers were integrated in the rear doors.
Tweeters (High-Range Speakers)
The tweeters (high-range speakers) have also been adapted. The load rating was increased
to 40 W. The tweeters are equipped with aluminum spherical caps. They feature sealed
design. The effective frequency range is from 5000 Hz to 20000 Hz.
Central Woofers
Compared to the HiFi audio system, further modified central woofers are used in the Top-
HiFi audio system. The central woofers have a diameter of 200 mm and a load bearing
capacity of 70 W. The transmitted frequency is between 30 Hz and 500 Hz.
They don't talk about filters used to cross, but it looks like amps are bandwidth limited as well as additional filtering in tweeter according to your post (first order crossover - cap on the tweeter). As I expected woofers are crossed really high with midbass, I think this is the main disadvantage of this system ?(4" drivers cannot extend really deep in this acoustical environment, so they had to make a trade off). Naturally I want to drop the bass response by 3 clicks on eq at 100Hz eq setting but then the voices start to loose weight. Alternatively I can use Bass control that covers wider range but I haven't played enough to see if there is a real benefit.

Natural speaker response:
Highs [500; 20000] Hz - amp FR [200; 20000] Hz
Mids [100; 10000] Hz - amp FR [200; 20000] Hz
Woofs [30; 500] Hz - amp FR [20; 200] Hz