My new system, designed to look as stock as possible and without loosing too much trunk space and with access to the spare tire etc. This system was designed for one purpose only and that was high sound quality on a medium scale budget.

Although the installer took a few attemps to eliminate any noise from the signal path it proved to be all worth it.

To anyone attempting the same thing in their car. If your keeping your stock Bose HU you must keep the Bose AMP as well, unless your using an amp with balanced inputs such as the JL 'slash' series (or so I've heard). But my amps and EQ were not balanced and thus I had to tie into the signal after the BOSE AMP and through an LOC, the model I chose was the Audiocontrol LC6 - a very nice unit !! I feared that the system could never sound good if the Bose AMP was still in the system but I was wrong (well at least after re-equalization). Comparing the sound tying the signal lines into before the Bose Amp and after it using an LOC and negating the noise and hiss of the first setup there was still a night and day difference in the sound regardless. Let me repeat, you need to keep the Bose Amp in the system and use a good LOC or like myself an Audiocontrol LC6 and you'll be very happy.
I cannot speak of those with JL type amps with balanced inputs but unfortunately these systems although may have the luxury of not needing the Bose Amp and an LOC, I fear that these system would be poorly EQ'd because of the tainted Bose headunit!

Here is a picture of my trunk with a custom fiberglass box which still allows the netting to be used.

 

Under the rear deck where the Bose Amp and the Bose Subwoofer used to reside, now is home to the Bose Amp, my 26 channel Eq, and an Audiocontrol LC6.

 

I had the original Bose door speakers removed and replaced with Focal 165K2P's, not the cheapest speakers on earth but they do sound nice
I also had the doors sealed with a Cascade VC2 vibration dampening product similar to Dynamat but this stuff has no smell ! Because of the massive magnet on these speakers a MDF spacer was required.

 

A lot of the car had to be dismantled to install the new speaker wires, I also had coaxial RCA wires run for the future in case I do a Double-Din convertion.

 

Because of the small opening in the plastic grills of the front door tweeters a new metal mesh needed to be installed to allow the tweeters to breath properly. Even though the grills are custom made they sure look stock !

 

I had the two amplifiers, an Audison LRx4.300 (4 x 65w) and an Audison SRx1 (1 x 350w) power the whole system. This is more than enough power as these amps are truely under rated in their capabilities. The SRx1 which drives the Boston Acoustics 10" sub (a G510 dual 4 ohm voice coil) has an internal fan thus the reason you see no external fins. The Subwoofer weighs in at hefty 27 lbs not including the fiberglass enclosure which in comparison is surprisingly light. The Amps are mounted in an amp rack which was designed more for function than for looks and is designed to handle a full trunk load of items on top of it. Although these amps reside underneath the carpet they barely heat up and since I don't listen to music too loud they should survive just fine.

 

Well the engineers at Bose really out did themselves trying to make their poor little speakers (and I mean little) sound as good as they did. But because of this any aftermarket system will suffer

After having the system tuned with an 1/3 octive RTA and adjusted flat with my EQ there were some frequency ranges that really needed some help.

To have a flat EQ curve from 250HZ to about 8000Hz I needed to apply these adjustments:

32 0
48 0
64 0
90 0
125 0
180 0
250 +1db
500 -3db
1000 -2db
2000 +12db
4000 +3db
8000 +6db
16000 -3db

As you can see without re-equalization I would have had a massive dip in response around 2000Hz (2500Hz on the RTA) at -12db !!! That is huge. Those Bose speakers must have been really sensative in that range.

 

Nice, looks real clean!

 

Looks like Infiniti changed it's speakers in 2005 on their Bose systems.
Perhaps to make them sound better or perhaps to cut down on weight, but either way these are the speakers that were installed. The front door speakers are identical to the rears, although the bass sounded so much better in the front than the rear this could probably be contributed to the fact that the front doors had a metal covering the access holes compared to the thin plastic sheet in the rear. You have to give it to Bose though the magnets used all these speakers must be neodymium due to there size and weight and neodymium is the best material to make magnets with. So although these magnets are tiny, they do outpreform standard magnets many times their size. The speakers don't have a foam or rubber surround but it seems more like a soft reinforced tape or fabric. The ridigity of the speaker is based soley on the spider of the speaker, this would give the speaker it's great midbase sound but poor midrange.

The tweater impedance is 4 ohms with a resistance of 3.5 ohms.
The 6.5 speaker isn't marked with it's impedance but measures only 2.3 ohms making me think it's an odd value of 3 ohms !!

 

Well the original Bose subwoofer is unique. It has an inverted magnet structure !! Normally you have a cone with a dust cap or phase plug, then a spider, and finally the magnet. But not so in this beauty. You first have the magnet pointing straight up, then the cone protected by a dust cover then the spider, and then a plastic cover filled with absolutely nothing.
The impedance isn't noted but it's resistance is only 1.3 ohms which is even on the low side for a 2 ohm impedance speaker.

 

Instead of using a fuse by the battery terminal we decided to go with a circuit breaker which makes disconnecting the stereo equipment from everything else if and when the car goes into service very simple. The circuit breaker is rated for 60 amps and is fed with 4 guage multistrand wire running into a distribution block in the trunk.

The subwoofer volume control is hidden in the ash tray, finally a good purpose for that space.

And a picture of the front door grills -- with the correct lighting you can see the fabulous yellow colour of the poly-kevlar cones.

 

Oops almost forgot to mention my Rear Door speakers the Focal 165CV, these come with an external 12db crossover which is located in the pilar between the front and rear doors. Oh and the front speaker's crossovers are located underneath the front dash.
I almost purchased Focal 165CA instead to save some money thinking that they would be similar to the 165 A component speakers of the same line but after hearing them in direct comparison the tweeter was far too metalic sounding and although these are primarily used as fill I felt that the brightness of these tweeter would ruin the soundstage.

During the tuning process I had to increase the brightness of the front speakers to raise the sound floor while keeping the midbass of the rears strong for a good fill sound.

 

That was a very informative post! I just wanted to confirm a few things. You tapped into the signal AFTER the BOSE amp correct? So you're signal at the LOC is already "pre-equalized" by the Bose amp? I tapped into BEFORE the Bose amp and I currently have an aftermarket amp powering my stock Bose front component speakers (crossovered at 3.9 kHz instead of ~7.9 kHz) for now until I can afford some K2Ps as well (been slowly saving). I plan on doing an RTA today. It'll be interesting to compare the freq response.

 

Yes I tapped into the signal AFTER the Bose amp. I don't think the Bose amp is doing the equalization, I'd put my money on the headunit as being the culprit. You're RTA may look flat even without an EQ because you are still using the Bose speakers which I believe the headunit is equalized for. If your response isn't very flat then you might be correct that the Bose amp is doing the equalization or that Bose engineers really screwed up in the first place.

 

nice......

doc