As per many suggestions on this forum regarding the C6 Bose system, and how to improve the sound, I disconnected the dash speaker. Most have stated that it does help, but I really didn't see a substantial improvement. My hearing isn't 100%, so that could be an issue as well
Since my car is in hibernation for a few more weeks, I decided to remove the dash speaker, and use the connector to hook up one speaker between the 2 rear speakers to see if that would help the sound quality. I installed a 5" - 2 way 4 ohm speaker (non Bose) just in front of my hatch divider. The speaker enclosure that I made uses the same carpet that I used for the divider and top partition. The speaker enclosure is not permanently attached, so it can be removed if this experiment is a total bust. I won't know that until I get the car back on the road to see how it sounds.
Here is a pic of my experiment. If nothing else, that speaker is closer to my deaf right ear The top pic is what is hiding behind the speaker enclosure

 

Interesting idea. I would just check to see what the impedance of the stock Bose speaker was (8ohms ?) and try to find one that matches.

 

The dash speaker is 4 ohms stamped in the underside, and the one I am using is also 4 ohms.
It's a crap shoot whether it will be worth it or not. Worse case is to put in a new system.

 

Perfect, then you are good to go. I like your idea, please let us know what difference (if any) it makes.

 

The Bose system only has two speakers that are stereo, and it's the small speakers in the doors.

The front speaker, the back speakers, and the large door speakers are all mono channel, and used for fill.
Also, since none of the speakers has tweeters in them, and so much mono fill, you end up with "Got no high's, Got no lows, must be Bose.

Lastly, since the amp is really not pushing much power to start with, have to be very careful on the speaker that you put in play with the Bose amp (need to use ones with high sensitivity, isntead of speakers with lower sensitivity/ but can handle more power that the Bose amp can put out.

So on that note, about the best you can do with the Bose amp is change the speaker out so to say Kicker CS series speakers. The front speakers and the rear CS speakers do have tweeters, so you pull up some highs, and on the rear speakers, pick up some lower mid base as well.
On the front speaker, disconnect its since a mono filler speaker to get better separation out of the door speakers that are stereo, or you can leave it in play using a CS speaker there, to give more filler with higher highs up front instead.

As for the factory radio, they do not have RCA outs, but instead the Bose amp uses the standard Radio wires out into the amp, which the amp cuts the voltage down to use as Pre amp signals. The problem with this, is the signal out of the radio is not as clean if it was RCA outputs, so even with a great amp, still getting more distortion into it than desired instead.

The last one, is If you really want deep rolling base, would require something like a 12" sub woofers, which would require a closed box of 1.75 cubic feet each to resonant frequency Q correctly, and short of taking up the entire back areas, just don't have the room in the car isntead. You can go with more smaller woofers to gain some punch, but going to roll off way before you get down the the 20htz mark. As from here, then we get into either ribbon/ dome silk or polypropylene tweeters, and just depends how smooth you want the highs to be in the first place.

My take, maybe the CS speakers if the ones in the car are aged, but since I use the car for mostly road course days with the radio off, the Bose system that came in the car is fine for my use. If I really want to listen to music, then have the sound room in the house with Checkpoint electrostatics, being driving by Conrad Johnson tube amps and pre-amps, and your not going to get kind of Clarity/Roll/Depth out of any car system in the first place.

 

Dano, Thanks for your explanation of the system. I'm not expecting opera house type sound, but hoping for a bit better.
We shall see.

 

I'm hoping to get the car back on the road and out of hibernation shortly, so I will give it a test at highway speed. I'm wishing it to make some difference, then I'll redo the partition and speaker box into one piece, and not make the box as deep.

 

Initially I disconnected my centre speaker on the Non Nav Bose Head unit, and swapped out the OEM Bose 3.5" door speakers for Boston Accoustics S35. That gave me better highs and more of a left right thing.

Later I went to a Kenwood system (DNX990HD) with an Arc Audio amp and Focal door speakers. The Arc Audio amp took the place of the Bose amp by the passenger footwell.

I also separated the OEM rear speakers by running left and right wires to the internal left and right amps of the Kenwood. The rears are only for fill, so the Kenwood has ample power to drive the rears.

Overall very stealth and a BIG improvement.

I passed on a sub.

And the Garmin nav and rear camera make a wonderful addition.

M....

 

Thanks for your input. That will be an option to go to an aftermarket unit if all else fails. I'm expecting a world changing difference, but I'm hoodgul that there will be an improvement. We shall see.