Zakowsky

So I still haven’t had time to post a review of my new Android head unit; I got the HIRIOT Android 8.0, 4GB with the PX5 Octa Core processor and I am very pleased with it. But before I get around to that, I figured out a fairly simple strategy to get the fade working and the sound up to par without totally replacing the Bose amp.

When I ordered the HU I got one of the $100 MOST adaptors, figuring I would change out the Bose amp eventually, but wanted to use the HU right away to test it out. How you rate the sound quality with the adaptor is obviously subjective; I know many people say Bose sucks, but I would say the stock PCM was reasonable - with all the speakers and how they have it balanced I was OK with how it sounded. With the adaptor however I would call it a significant drop in quality, mainly because it pushes all the sound to the front, relying on those 3 meh speakers, poorly driven off the amp. Sounds a bit like a radio with one speaker in the dash, to me anyways

So I started looking for a 6 or 8 channel amp on Kijiji, which was hard to find, and I was hesitant about dropping $1200 on a new JL 8 channel amp if the speakers wound up being not up for it. The stock amp has 6 channels plus the front center and satellite speakers (mono), plus an output for the sub. Some people cut out the center/satellite units and just use 4 channels for the doors, but I didn’t want to lose the basic zones that were designed into the car, they seem to work OK. So basically with the MOST adaptor the only weakness is the rear door speakers (well, plus the sub sucks, but that isn't the adaptors fault).

So I thought what if I just add a 2 channel amp to boost the power to the rear door speakers, and leave the Bose amp powering everything else. And if I drive the new amp off the head unit rear pre-amp out lines (the front out drives the MOST adaptor), I would get my fade control back. Fortunately I had a couple of 2 channel amps lying around in the garage so I gave it a try.

I took pictures but don't have the time right now to process and post them; if people are interested I can do so later. But basically the procedure is like this.

1) Get to the amp. I just took off enough of the rear trim to put back the side liner and unplug the connector to the amp. So head liner like you are doing the hatch shocks and then pull the side panel back.
2) I originally thought I would have to cut the wires to the speakers (blue/brown, blue and red/brown, red) but I managed to take the connector apart and extract the leads right from the connector, so no cutting! I took pictures of how to do this, quite easy once you know the tricks.
3) Attach speaker wires to the door speaker lines, shrink wrap them and run them into the spare tire area.
4) At this point I actually looked at the cheap &%$ sub and figured I would replace it with a 10" Alpine sub that also had lying around the garage. So the sub comes out.
5) Now run a 20' RCA line from the rear speaker output on your HU to the back, with the fronts still powering the MOST adaptor. Easy, just go from the deck to the passenger side dash, and tuck it under the side trim all the way back.
6) Grab your 2 channel amp (I used an old Pioneer 200 watt, with 0.08% THD), use the input from the HU rears, and output to the rear door speakers.
7) Mounted in the spare tire well gives you access to the connector for the sub. You can get power and trigger lines from there.
8) I had 2 of the Pioneer amps, so I also took the sub audio out of the connector and put it into the second amp. The connector has enough power for both the amps. The second amp was bridged, LPF, and into the sub box.

Powered it up and the difference was amazing! With the rear pre-amps from the HU driving the accessory amp to the rear doors your fade obviously works, and the extra power to the back means you can balance the front/rear doors really nicely. Plus with the second (third?) amp driving the sub, it sounds significantly better than the original setup. And I know most people get rid of the front center speaker and the satellites, but having everything working like stock is nice, it fills out the sound in the whole car. So for a $100 dollar 2 channel amp you can get fade and more power to the rear and balance the sound out. And you don't need to cut any wires. It would obviously make more sense to get a 4 channel amp and bridge 2 of them if you want to upgrade the sub as well, I just happen to have 2 x 2 channel ones already.

So now the question is can you bridge the outputs on the Bose amp - since I have significantly more power available to the rear speakers than the fronts, it would be nice to add the rear channels on the Bose to the fronts, just to pick them up a bit.

Brainz

That's a clever solution. Thanks for posting.

I still don't think I've read a report from anyone that's tried the 4-channel MOST bridge that's available from Russia. It'd be interesting to know how well that works too.

Zakowsky

Thanks Brainz - reading it over I guess it sounds a bit involved, but if you skip the sub upgrade, its just running an RCA cable from the HU back to a 100$ 2 channel amp and unplugging the two rear speaker lines from the Bose and wiring them to the amp out. Using it for a few days now it does sound really good and the extra watts help too.

Brainz

Where is the factory amp? Is there room there for the extra amp?

Zakowsky

You could probably fit a small amp right below the factory amp, vertically in the slot behind the wheel well. Mine actually has straps for something I don't have that maybe could be used. Just pop off the right side panel and you can see the space:



To get to the amp you have to take the pillar cover off and unscrew the side panel. To take the pillar cover off you have to drop the ceiling trim down a bit, like you are replacing the hatch shocks. Once the side panel is free you just bend it back about a foot, which gives lots of room to get to the amp, which is right above the CD changer:



With the connector unplugged, ID the rear speaker lines, arrows. The part of the connector that has the speaker lines comes out of the main body of the connector, you just have to press two tabs in to get it out.



To get the wires out of the connector itself, take a 40 year old resistor (or similar) and push the wires in the two holes on either side of where the pin on the amp goes in:





Then pull the speaker wire plug out:



I used plain speaker wire and ran some solder onto the wire ends to stiffen them up and then pushed them into the plugs and shrink wrapped them:



I upgraded my sub too so I used 2 small amps and put them where the sub used to be, but one of these should fit in below the amp, if you want to keep your stock sub. Remember, this is just boosting the rears, you still have the 225 watt Bose amp powering the rest, so even if it is just a 100 watt 2 channel amp (some are really small and cost less than the MOST adaptor), that is all you need. The price with shipping of the Russian 4 channel adaptor is more than a 2 channel MOST and an amp, and the one report about it I read somewhere was it didn't work so great.

Brainz

Good info. Thanks for posting. I'd forgotten the amp was back there -- it's been a while since I was in that area of the Pig.

mrottjers

Excellent Idea! The loss of fade was keeping me from installing the Android unit. You just showed the way. I love the fact that it is such a simple solution to a problem that has been around for years. Why did we not think of this earlier. Kudo's!

Zakowsky

Thanks! I'm really pleased with the setup now. I made a few improvements today - so with the extra power available I was noticing I could more easily over-drive the rear speakers, and hear a bit of distortion at max volume. Although those Pioneer amps are rated at 100 dB SNR and 0.008% THD, I bought a pair of Nakamichi PA-202's off Kijiji today ($50 each, so what the heck), less power but that old school sound and 0.005% THD and 110 dB SNR. They have nicer sound and the distortion is less, but you have to really balance front/rear well and play with the gain to make it sound perfect. And they are smaller; Brainz, I did a test fit and it does look like one would fit in the side compartment, although you might have to flip it around once the cables are connected:

So if you want to keep your stock sub or maybe actually put a spare tire in there and not an amp, this would work fine. Although I have 2 of the Nakamichi's I am still driving my sub off the Pioneer - the PA-202 is only 40W continuous and the GM3000T is 100W, plus the Pioneer has a LP filter built in; the Nakamichi is designed more for the rears.

But I'm noticing with the Android HU instead of the old PCM there are several new issues to consider. As vandal pointed out in the main 9" Android thread, changing the head unit is mainly for a huge increase in functionality (which it is 100 fold), and sound quality is similar to stock. Since the stock PCM is playing wav files off a CD, you need to be playing good tracks to compare them. My goto test tracks are from a FLAC rip of an ASOT album; aside from a great bass test there are many electronically generated signals that can result in harmonics that really test for flaws. I was surprised that the player app you use makes a big difference. Apps like Neutron, that make use of the specific DSP chip your HU has and can do 32/64 bit processing, really make a difference. Also whether you use the apps EQ or the decks, and OpenSL or not, all these things make a difference too. I think though with the combination of the Bose and the Nakamichi amps you can get (barely) enough quality out of the Android HU chip to drive the speakers to their limit. But this will all be the fun of tuning. To note, this is all at volumes that with ASOT vibrate the mirrors on the car next to you in traffic. Normal listening levels and everything is all good.

Brainz

Thanks for the update! Looks great.

AJ88CAB

I did this work-around for my install of the Android HU. I am getting a buzz in the rear speakers. I installed a ground loop isolator.
I would like to figure out the source of the noise and try to correct it without the isolator if possible.
I was wondering where you got power & ground for your amp?
I picked up power at the passenger side fuse panel, and the ground is at a ground point in the cavity below the Multi-CD Unit.

Also you mentioned in another thread that you picked up ACC power for the MOST adapter from the CAN-Bus decoder. Where did you get the "Battery" (red wire) power & ground. Is it possible the buzz is a ground loop issue from the MOST adapter which I powered from empty ACC & Always Hot locations on the passenger side fuse panel. The MOST ground was bolted to a spot on the steel dash support frame.

The amp is an inexpensive SSL SoundStorm 200W unit, so that might be the issue.

It is all working quite well other than the need for the ground loop isolator, so maybe I should just fugataboutit...and enjoy the Android head unit and all its features...

Zakowsky

So I got the power for the amps from the connector to the sub-woofer that was already there in the back. It's perfect, because it has power, ACC, and the trigger to turn the amp on. I run a total of 400W of amps off it no problems. I didn't post my photo of it, but how to connect to the sub connector is explained well here. This is a photo with the connector (top left) from that thread (from 6speed).



As far as a humming noise, I did have that happen at one point, but I swapped the amp out for a different one and it went away. Of the 3 amps I tried, only one would hum, so I figured it was the amp. Btw the hum would go away if I touched the screen of the HU, so yeah, some kind of grounding issue with some amps maybe. But using the ground, power and ACC in the subwoofer connector I have it hum free now.

For power to the MOST adaptor, I just took power and ground from the main connector to the Android HU, which plugs into the car connector that used to be plugged into the PCM. On my head unit the CAN Bus is a brown rectangular box that connects to a plug with like 10 wires from the HU. One of those is ACC, and I spliced into it. I took pictures of all this but don't have access to them right now, but from the generic unit picture, box 2 is the CAN Bus, so I took ACC by splicing into the bundle out of the plug at the arrow, and power and ground comes in from the car connector through plug 1 in the picture, and I spliced in to those at the other arrow.




BTW I tested every fuse on the passenger side, and couldn't find a power source that turned off with the key...where did you find it?

AJ88CAB

Thanks for the detailed info.

I still have the Bose sub under the spare, so I am not sure if I can tap power from that location with the speaker still there...any thoughts on that.

In retrospect the MOST adapter can't draw much power, so tapping power from the HU & CAN-Buss makes sense.
When I started I thought a dedicated fused source made sense...for sure probably didn't need that, and may have introduced a ground loop in the process.

As for the fuses that turned off with the key. I checked several fuses and blank spaces and found that the bottom row had key switched fuses or spaces (at least the 3 or 4 that I checked did). My CS is a 2006, maybe yours is different.
FYI...I used these devices to tap the power from unused spaces on the fuse panel.


I will get back into this at some point and try to sort out the buzzing, but it is OK with the ground loop filter for now.
With your experience with one buzzing amp, it might point to that cheap amp I have.
For now I am really enjoying the install...

Thanks Again
Andrew

Zakowsky

I don't see a problem tapping off the sub connector with the sub still intact. I removed mine and replaced it with a 200W amp and a sub in a box, so I run that plus the 200W amp for the rear speakers. The stock sub is only about 100W I think so you should be able to also run the rear amp no problem.

Thanks for the fuse tip, I will check it out. Mine is a 2004 CTT so maybe slightly different.

hirinhu

hi zakowsky, thanks for posting! how do you identify the rear speakers wiring? and sub? ill try this workaround but i also want to use SUB output from the unit (DSP included) keeping the oem bose sub
what do you think?

Zakowsky

Here is the wiring code for the amp out pins, although you might be able to find a better copy out there...



For the sub, yeah, just run an additional RCA from the head unit back for the stock sub, pull the wires out of the amp connector that go to the sub and patch in the RCA in instead and then you can use amp sub controls. I was totally going to do that, but I found that when I keep the stock amp output to the sub (so it is tied to the front speakers) it actually works out really well. If you fade the sound forward you also get more bass coming form the rear, which just seems to work really well in the sound space. And if you shift the fade to the rear door speakers, which have some bass, the sub is cut back so again it works. So I guess what I am saying is by just setting up the rear door speakers off the independent amp you get the fade and the stock sub wiring still sounds really good as it is tied to the fronts; worth tying anyways. $50 for a used amp and an hour to wire it and I have been happy with it for over a year. And been busted by 5-0 for volume! If I was to do any more work on the system it would be to put some Focals into the rear doors...having an independent amp lets you drive those as hard as you want...