I have been using the RNS-E as my radio for a few weeks now and I must say I am disappointed with the sound quality. Its probably less the quality of the sound and more that fact there is less control over the way the radio sounds. They symphony 1 had bass MID and treble controls while the RNS-E only has Bass and Treble. Also the symphony 1 had a hidden EQ which allowed granular control over the sound system. This EQ along with the debose option on the symphony 1 enabled the user to transform the sound system to produce harder hitting bass and mids with very clean treble. I really liked the sound of the symphony 1 and never thought it necessary to add anything to it, but with the RNS-E, I am looking at adding a possible crossover and an Amp to improve the sound. The navigation fuction and the Display of the RNS-E is phenomenal and a worthwile upgrade, I just wished the same control over the sound could be acheived.
I tried debosing via code but did not make any improvement. It maybe something is not quite right with my install, but all the speakers work, and fader and balance tansfer sound correctly so I don't think so.
That is really bad news! I had the CD based Nav+ in my car and when I put it in I thought it had better sound quality than my Symphony, however once I removed it and put the Symphony back in my ears really started to enjoy the sound of the Symphony much more than the Nav+. Strange because to my knowledge the Nav+ was to put out more watts than the stock head unit. Good to know though.
Could it be that the RNS-E is designed to work with the B6 BOSE system, and not with the B5? I really think the sound is better, clearer after replacing my Symphony II with the EU RNS-E. On the other hand, it could be that it's just the FM tuner and converting the few CDs to MP3, which made me believe it sounds better.
You did say that you tried VAG-COM settings, I guess those:
STG 56 (Navigation System) -> Coding -> Function 07
0xx?xxx: Sound characteristics
0 - linear
1 - Audi A4 (> 2004)
2 - Audi A6 (< 2004)
3 - Audi A4 Cabriolet (> 2004)
4 - Audi TT (> 2004)
5 - Audi A3 (8P)
9 - Bose Soundsystem
Did you also try these:
STG 56 -> Adaptation -> Function 10 -> Channel 008 (GALA)
000 - GALA off
001 - Charakteristics 1
002 - Charakteristics 2
003 - Charakteristics 3
004 - Charakteristics 4
005 - Charakteristics 5
255 - GALA via microphone (Bose AudioPilot ?)
I tried with Bose off, but I think I chose the A4 setting. I will try bose off with A6 and see if it makes any difference. It is possible that the RNS-E does sound better as a replacement for the symphony II. But I really think the biggest difference lies in the hidden EQ which either the RNS-E does not have or the no one has found yet.
Here is a link that discusses in detail the hidden EQ and how to access it.
I don't have the RNS-E yet but it can't be any worse than the Bose Symphony II in my B6 S4. Even with the mid, bass and treble controls it still sounds like crap, especially with the XM radio. When you turn it up it just amplifies the crap and makes it louder. When I listened to my old B5 S4 with the Bose Symphony I it sounds much better - more defined highs and lows and clearer sound. You would think they make the newer Symphony better but I am very disappointed in the B6 S4 Bose.
I had a chance to listen to the RNS-E Bose in a B7 S4 and the Symphony II Bose in a B7 S4 and the RNS-E sounded much better than the Syphony II almost to the same quality as the B5 Bose Symphony I.
I also had the Nav+ (CD based) in my B5 S4 with bose and would say it sounds the same (good) with the Nav+ and with the Symphony I headunit.