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Re: Going for a full Bosectomy (renamed)

Posted: Sun Jul 16, 2017 8:14 pm
by kikbuti
I assume that you considered a front center channel. Did you come up with any solutions?

Re: Going for a full Bosectomy (renamed)

Posted: Mon Jul 17, 2017 1:21 pm
by DeudeMann
For now I am only going to run five channels:
LR bass in doors
LR midrange/tweeters in a-pillars
Subwoofer in hatch
With good time alignment, the imaging will be as good or better than it would be with a center channel, albeit only for one person at a time. Since 99% of the time I am the only person in the car when commuting, and am the audiophile of the family, that is OK with me.

Re: Going for a full Bosectomy (renamed)

Posted: Sun Jul 23, 2017 11:23 am
by DeudeMann
Here is the 4-channel amplifier and the C-DSP 6x8 installed on the mounting plate. This will be placed in a hidden spot in the car.

Re: Going for a full Bosectomy (renamed)

Posted: Mon Jul 24, 2017 7:16 pm
by DeudeMann
More progress today... So I had heard about how cheaply made the Bose drivers were, and after seeing them for myself, yeah, they are pretty cheap. Plastic baskets (not always bad, but not impressed with these), really thin paper cone, very thin rubber surround, small voice coil, puny magnets.... I am happy to see them go.

They are good for one thing however, The basket can be gutted, and used to mount the Tang Bands, or I imagine most any other 6.5" speaker. With only a pair of wire cutters (a.k.a. dikes) one can remove most of the basket, the cone, and magnet assembly, leaving only the circular portion of the basket that bolts to the door panel. Epoxy the basket to the back of the new speaker's mounting flange, and viola, you have a nice, clean mount for your new speakers. In the case of the Tang Bands, they needed to be spaced away from the door since they have a much greater mounting depth than the Bose drivers.

Here is the Bose basket after removal of the cone, surround, magnet, spider, wire leads, and connector. It has been placed onto the back of the Tang Band's mounting flange.

Here is a close up of the epoxy used to glue the Bose basket to the Tang Band's mounting flange. I taped the Tang Band screw holes to hold in the epoxy, roughed both surfaces with 200 grit sandpaper, pre-coated both mating surfaces with epoxy, assembled them, then ran another bead around the outside perimeter of the joint. The plate is used to support the Tang Band by the flange. I suppose you could set it down on its surround, but I do not recommend that.

Re: Going for a full Bosectomy (renamed)

Posted: Mon Jul 31, 2017 11:18 am
by DeudeMann
More progress over the weekend. I have removed the Bose door speakers from both front doors, salvaged their frames for reuse (as noted previously), epoxied them to the Tang Bands, added sound damping material to both doors, and installed the new drivers. Everything went smoothly. Here is the passenger door with the new speaker in place.

Even though the back of the Tang Band is much larger and deeper than the Bose speaker, the forward offset from reusing the Bose mount lets the speaker drop right in. Also, it still matches up with the 'tunnel' protrusion on the back of the door panel.

Re: Going for a full Bosectomy (renamed)

Posted: Mon Jul 31, 2017 11:30 am
by DeudeMann
Note that I have cut out the plastic vapor barrier and covered all of the holes in the door panel with the soundproofing material. This isolates the back wave of the speaker from the cab and provides some significant sound damping. In the areas where the holes in the door panel are large, I doubled up the thickness of the soundproofing material. The material is the typical peel-and-stick stuff consisting of a rubberized mat bonded with a layer of aluminum. It is Noico 80mm available from Amazon. I'm happy with it, and the price is reasonable compared to the name-brand stuff. It does not have an odor at all from what I can tell, is clean to work with (no mess), and cuts easily with a utility knife.

A quick tip... Notice in the pictures that I trimmed out the clear plastic vapor barrier up to where the black goo is used to hold it to the door, rather than removing the plastic completely. That goo is very, very messy stuff, so I chose to just leave it there, covered up by the left-over plastic, rather than remove it. This is a big time saver.

Another quick tip... Some of the youtube Leaf door removal videos show that the door handle section can be unscrewed from the door panel. That works, but it is a lot easier IMO to just disconnect the actuator cables. They are easy to remove and reattach. Overall the door panel assembly is a breeze to remove, much easier than others I have messed with.

So the stereo still works, but the door speakers are way down on output as expected due to their higher impedance (4 Ohms). For now I'm using the rear doors to fill in the sound until I wire in the new DSP, amp, and dash pods.

Re: Going for a full Bosectomy (renamed)

Posted: Mon Jul 31, 2017 3:02 pm
by kikbuti
Thank you again for your detailed posts. I was wondering whether you were going to use the head unit outputs (Front L+R and Rear L+R.) The Nissan Leaf AV docs show that the AV unit for the non-Bose with Navigation is part number JSNIA3618ZZ and has a 45 watt x 4 amp built in. Curiously, the AV unit for the Bose with Navigation is identical. This would mean that the pre-amp inputs on the Bose amp are actually speaker level outputs.

Have you tested them yet?

I am still in the planning stages for upgrading my Leaf. I'm leaning toward using the Bose amp to power the rear speakers. I would take the front pre-amp signals from the head unit and route to a Focal DSA500RT Powered Subwoofer with a built-in 2 x 65 watt amp for front speakers. The unit includes a DSP with an EQ and time alignment functions. I like this idea because I would be adding only one piece of equipment other than replacing the front speakers.

Re: Going for a full Bosectomy (renamed)

Posted: Mon Jul 31, 2017 8:07 pm
by DeudeMann
No I have not tested the outputs yet, but if they are speaker level outputs AND differential signals that is good for noise immunity.

That integrated Focal setup is nice. I had not seen that one before. You won't be able to independently time align the front speakers (door versus a-pillar) but you will be able to time align the sub which will help bring it forward. I like your idea of using the Bose amp, or even the head unit for that matter, to power the rear door speakers.

The next big step is to tear into the trunk panels to get to the Bose amp. I also need to finish installing the dash speaker pods.

Re: Going for a full Bosectomy (renamed)

Posted: Sat Aug 19, 2017 1:35 pm
by DeudeMann
Another update - SUCCESS!!! The Bose amp is out of the car completely and everything is running from the head unit and the DSP/amps I added.

Some details:
- The output from the STOCK head unit (originally connected to the Bose amp) works great as the input into the DSP. I am using the two front channels (front-left, front-right) as the signal to the DSP, which I am sure could also be used as high-level inputs straight into an aftermarket amplifier.
- I ran the rear outputs from the STOCK head unit directly to the rear door speakers for backfill. It works, but the output is very weak. If I decide to do anything more with them, I'll probably add another two-channel amp for those.
- I tapped into the stock wiring at the Bose amplifier by cutting off the Bose connectors and splicing in my own wiring harnesses with Molex connectors. I used two 16-pin Molex sets, which sounds like a lot, but a lot are required. Just for the audio, at the Bose amp, there are four pairs of input wires, and six pairs of output wires for a total of 20 connections.
- In the factory service manual I found that there is a remote amp turn-on wire for the Bose amplifier. So I tapped into that and am using it to power on the DSP and the two amplifiers. Works great. So there is no need to run a separate remote amp wire.
- I have not installed my dash pods yet so for now I am using the Bose a-pillar tweeters in the front. I believe I have them crossed over at 5 KHz. They are working well enough for now. The plan is to disconnect the tweeters and use those wires to power the dash pods.
- The Tang Band front door speakers are TREMENDOUSLY better than the Bose speakers. No comparison. Very natural sounding output on vocals, bass guitar, toms, whatever. I am very happy with these little guys.

So all I have done so far is set the crossover points on the DSP and the whole thing sounds much, much better than the Bose system. Once I add the time alignment and euqalization (Room EQ Wizard, reference mic, etc.) it is going to sound really, really good. I'm very pleased with how it is going so far.

FYI - You do NOT have to remove the rear seat or completely remove the right hatch trim panel to get to the Bose amp and the connectors. The panel is flexible enough to bend out of the way and get to everything. This ended up being easier than I expected.

Tapping into the stock harness is just a matter of cutting off the existing connectors, and splicing your wiring into the cut ends. It is time consuming, and took about 3 hours to complete. This included double-checking that I had the right input and output wires. There are a lot of connections to make, so it is best to write out a wiring list in advance, and use color coded wires whenever possible. The stock wire colors as indexed by the service manual are a little weird, like several different shades of blue that can easily be confused, so be sure to check colors against the pin outs on the stock Bose amp connectors (the ones that are cut off). Also, use a small speaker to check the output wires from the HU, and use a small AAA battery to check the connections to the speakers; if you tap the two wires you are connecting to each terminal of the battery (just tap, don't hold the connection), you will hear a small pop from the door speaker you are wiring. This does not work well with the a-pillar tweeters, so check those with an audio signal.

Here are some pictures of the Bose amp removal, the wiring harness splicing, and the finished harness with the panels back in place:

Here is a picture of the subwoofer box with the amplifiers, the DSP unit, capacitor, and the mating Molex connectors: