The original 10-speaker system sounded dreadful--bloated, boomy, ill-defined bass at too-high level, shrill, harsh treble at too-high level, and all the sound coming from everywhere and nowhere but none from in front of me. My fellow-audiofool-goodbuddy commented that initially, he thought the system sounded not too bad with the bass and treble at full cut, but after a half-minute or so, he too realized that even so adjusted, the bass, treble, and 'soundstage' sounded terrible. The system's only sonic aspect that was OK was the quality and quantity of low bass from the SW.
So we started the audio rebuild with a new JVC DVD receiver, model KW-ADV65BT. It cost about $370 including some installation hardware from Crutchfield, and I bought the PAC adapter-cable system that does not 'power' the steeringwheel controls*.
Took about 2 hours to install; that required cutting a strip of plastic from the inner-top of the opening and removing the rectangular bracket within the cavity**.
Initial impressions of sound quality are positive--the bass and treble spectrums were MUCH better balanced and no longer shrill. So far, I have the bass and treble cut a couple notches. The lowbass from the SW sounds quite good--probably good enough to leave being driven by the original amp. I believe this new frontend will prove to be a fine unit.
Further plans will be to install the same Polk home-system satellite speakers, model TL1 SAT, atop the instrumentpanel and in the corners, same as I had in my Ford Escape. Here the right-channel unit is pictured without its grill.
These handle the 8 octaves of upper-bass thru treble very well, driven thru a 50Hz hi-pass filter. I plan to continue to drive the rear-door, D-pillar, and subwoofer with the original digital amp.
I'll replace the front-door speakers with the very same 8" bass drivers I installed in the Escape, SB Acoustic SB23NRXS45-8s from Madisound. These are high-excursion, fairly shallow bass drivers that sounded excellent in the Escape driven thru a 100Hz low-pass filter. I used and will use again an old, classic Alpine V12-series 4-channel amp, model MRV-F307...
...in which I've improved some parts, mostly coupling and powersupply-bypass caps.
I'll use Audioquest Type 2 4-solid-conductors speakercable for the Polks and AQ's G2 stranded cable for the frontdoor drivers.
More later. So far so good.
1. The back-up camera, because there apparently is no adapter from the European connector Mercedes chose to the video-RCA connector the rest of the world uses.
2. The front-back fader, but left-right works.
* I've had several cars over the years with steeringwheel controls and NEVER used them.
** The 2 blue-with-white-stripe wires must be connected or the original poweramp won't turn on.