The Liberty came with the standard McIntosh headunit and integrated climate control. This - in turn - connects to the McIntosh Amp. I am not sure of my exact model, but it is similar to the McIntosh
EF12591-A. It is NOT the
EF-1080I. The Amp then powers FR, FL, RR, RL, Sub and CENTRE speakers (i.e. 5.1).
Interestingly, I cannot find any information on the wiring of this specific unit. Most info says that the Centre output is produced within the unit, via a crossover. This is NOT correct. This amp HAS a centre input. The cable has a proprietary plug (referred to as J101 in the photo) - which is a round 20-pin plug - hard to find!
Note, in the following photos, the orientation has changed. In the top photo, the "key" (pin 21) is at the top, in the second photo, pin 21 is on the bottom, in the schematic, 21 is on the RHS. Sorry
- Male Plug, Pin Side (actually upside down!)
- DSCF0111.JPG (98.99 KiB) Viewed 25182 times
- Male Plug, Wire Side (right side up)
- DSCF0110.JPG (178.04 KiB) Viewed 25182 times
- 20 Pin Plug - Schematic (for pin numbering only! refer below for actual pin supply)
- mcintoshampschematicpg2hk5.jpg (17.6 KiB) Viewed 25182 times
Looking from the WIRE side of the MALE plug, here are the pinouts.
Top row
1 = Woofer (-) = Dk Green
2 = Woofer (+) = Dk Blue
3 = Shield/Gnd = Open (covered in black heatshrink in my photo)
2nd Row
4 = Front Right (-) = Lt Green
5 = Front Right (+) = Orange
6 = Shield/Gnd = Open (covered in black heatshrink in my photo)
7 = Rear Left (-) = Red
8 = Rear Left (+) = Yellow
3rd Row
9 = Not used
10 = Not used
11 = Shield/Gnd = Open (covered in black heatshrink in my photo)
12 = Centre (-) = Brown
13 = Centre (+) = Grey
4th Row
14 = Front Left (-) = Black
15 = Front Left (+) = White
16 = Amp Remote Turn On = Lt Blue
17 = Rear Right (-) = Purple/Violet
18 = Rear Right (+) = Pink
5th row
19 = Not used
20 = Not used
21 (Casing) = Shield
The Sony XNV-770BT has 2 options for audio output. (1) Standard FL, FR, RL, RR speakers (4 channels only) or (2) Female RCA pre-amp outputs - FL, FR, RL, RR and Sub (i.e. 4.1).
So, I had 3 choices.
(1) Remove the McIntosh amp from the circuit, and wire the speakers directly into the stereo - This would involve me re-routing the Speaker cable from the AMP under the passenger seat to the Headunit. I wasn't too sure how long the cable was, so I wasn't too keen to do that, although, I'm sure it would reach. But that would also mean I would have to get a separate amp just for the Subwoofer, AND I would have to figure out how to wire the centre/front speaker!
(2) Or I could buy a McIntosh J101 plug (don't know where to start! Jaycar just laughed at me!) and wire RCA male plugs to each of the McIntosh J101 terminals. Not ideal, as it would be fiddly and would involve 2 more connections in the circuit. And I wanted to do it all in a day!
(3) The third option - the one I chose (for now) - was to cut the 20 pin cable and wire RCA plugs to the appropriate leads. This gave me 5 RCA male plugs - FR, FL, RR, RL and Sub. However, I had to figure out what to do with the AMP Remote and Ground leads, and these two spare wires (which, as it turned out, served the Centre speaker!). The Amp Remote and Ground - I combined into One Male RCA cable - simple!
So the trick was finding a Centre output (5.1) from a non-centre output (4.1) stereo. So I used a technique that my dad taught me when I was about 8 years old. I connected the CENTRE speaker leads to the RR (+) and RL (+)! This gives you the DIFFERENCE between the two stereo channels - basically it is all mid and treble (bass is usually mono). I chose Rear instead of Front for no particular reason... (have since changed this to front - to make sure that the balance is better)
Anyway - it all sounds great. There is no hiss, crackle or static and the sound is fab!