Hi Pat (and others),

>> I don't remember who said that, was it me?

Yes!

Just wanted to let you know where I'm headed. I appreciate the good advice...many thanks to you, Jan, Erick, and Stoney. I've made some compromises to keep the cost/size down. Here's what I've decided to buy to upgrade my '99 V70 SC813 headunit:

Alpine 6-Disc CD Changer CHM-S620 with Blitz-Safe digital adapter, $399.00. (www.alpine1.com)

MTX Thunder 4200x 25Wx4 Amplifier, $350.00. (www.mtxaudio.com)

Polk EX Series II 6.5" Component Speakers EX2560, $180.00.

Polk EX Series II 6.5" Coaxial Speakers EX602a, $85.00.

(www.polkaudio.com)

BTW, PIE currently does not support the SC813. The Blitz-Safe adapter is digital and supports "all" units. It is also recognized by Autosound 2000.

The pricing is bundled...I found one shop nearby to source everything I wanted with pricing that beat mail order except for the changer, where I didn't want to press my luck to save a few bucks and have to deal with uncertain mail order.

The changer will sit in the glovebox. I don't know where I'll put the amp yet...probably against a rear panel. The coax speakers will go in the rear doors. The component speakers will go in the front doors with the tweeter units placed/angled under the dash grills. The component crossover units will go behind the head unit and also serve as speaker wiring terminal blocks.

I may purchase the Crutchfield wiring harness ($10.00) to solve half of the problem of interfacing with the factory harness. If I can source individual female stack terminals with sleeving to attach to the headunit connector male stacks, then the problem is solved. And, I will be making a 6-pin DIN male-to-RCA to connect the amp.

Here are the results of my wiring investigation...the DIN pin numbers and amp channel numbers are thus far arbitrarily assigned:

(So which channel *is* which speaker? )

1999 Volvo V70 Audio Upgrade

SC813 AM/FM/Cassette/CD Changer Ready head unit (Malaysian made)

Connector AMP (from external amplifier), DIN, 6-pin, male:

Note: Channel connection disables head unit internal amplifier and/or speaker outputs.

Pin Description

Keyhole at 12:00

1 at 11:00 CH 1, front left speaker (+)

2 CH 2, front right speaker (+)

3 CH 4, rear right speaker (+)

4 CH common, speaker (-)

5 at 1:00 CH 3, rear left speaker (+)

6 center remote amplifier turn-on lead (use to turn on amp)

SHD/CHS ground

Connector CD (from external CD changer mini-bus), mini-DIN, 8-pin, male.

Connector A (power), Yasaki, 14-pin, female, [top 1-3, 4-6, bottom 7-14]:

Pin Wire Description

A1* R-W CH 1, front left dash speaker (+), int Y from pin B4

A2* Y-W CH 1, front left dash speaker (-), int Y from pin B3

A3 BL-W power antenna (+) (not present...use for CD changer adapter power)

A4 GN-BN battery (+)

A5 - not used

A6 B ground

A7* Y-GR CH 2, front right dash speaker (+), int Y from pin B10 ?

A8* GR CH 2, front right dash speaker (-), int Y from pin B9 ?

A9 - not used

A10 P 0.75 rheostat (+)

A11 - not used

A12 GN-BN battery (+)

A13 Y-VO accessory (key-ignition +12v)

A14 B ground

*Head unit pins not used after external amp upgrade.

Connector B (signal), Yasaki, 10-pin, female, [top 1-2, 3-4, bottom 5-10]:

Pin Wire Description

B1* BN-B CH 3, rear left speaker(s) (-), Ys to door & deck/column

B2* BN-W CH 3, rear left speaker(s) (+), Ys to door & deck/column

B3* GN-BN CH 1, front left door speaker (-)

B4* GN-W CH 1, front left door speaker (+)

B5* P-W CH 4, rear right speaker(s) (-), Ys to door & deck/column

B6* P-B CH 4, rear right speaker(s) (+), Ys to door & deck/column

B7 Y-B 0.75 speed sensor

B8* - not used

B9* R-W CH 2, front right door speaker (-)

B10* R-B CH 2, front right door speaker (+)

*Head unit pins not used after external amp upgrade.

The MTX amps are reputed to be under-rated powerwise, so I feel 25Wx4 will do me. I like its feature set and no-nonsense exterior...and interior. I may yet be able to slip it under the glovebox, although heating and noise concern me here. It has all the features I need to insure a solid installation:

o slim (11x9x2"), clean package with typical wiring on one side,

o high-power, low-noise, flat response, and NO turn-on/off thump,

o high (not to be used) and low-level inputs,

o dual adjustable low-level input gain sensitivity to match headunit pre-amp output,

o HP or LP selectable crossover per channel with summed pre-amp output for future sub amp,

o adjustable bass boost EQ.

I welcome suggestions on how to tweak the amp input gain and advice on setting the HP/LP/crossover circuits. Given the passive crossover in the front component speakers, I'm guessing I disable the amp's front channel crossover and tweak the rear channel crossover to limit high frequencies to the rear speakers so as not to detract from the wonderous imaging and sound stage that will be created to the front...where I sit!

Amp power and speaker cable recommendations? Thanks!

So, how do I look!