looking at upgrading my car audio processor .... please help

[Bruno]

I have a car audio processor. Its called the Pioneer ODR Carrozzeria RS-P70x and I'm looking to make it better.

Here is some info I've gathered:

The processor has a 31-band graphic equalizer. Frequencies are on 1/3 octave center frequencies form 20 Hz to 20 KHz, with an available gain of +/- 12 dB, on 0.5 dB steps

Crossover topology:
Subwoofer:
Highpass frequencies: 20-100 Hz, selectable at 1/3 octave
Lowpass frequencies: 25-250 Hz, selectable at 1/3 octave
Gain: +10 dB to -24 dB (0.5 dB steps)
Low (Midbass):
Highpass frequencies: 25- 250 Hz, selectable at 1/3 octave
Lowpass frequencies: 250 Hz - 10 kHz, selectable at 1/3 octave (this frequency causes heartache with a bunch of people, by the way, as a minimum of 250 Hz is, in most cases, too high to cross low frequency speakers over at).
Gain: 0 dB - -24 dB (0.5 dB steps)
Midrange:

Highpass frequencies: 200 Hz - 10 kHz

Lowpass frequencies: 2 kHz - 20 kHz

Gain: 0 dB - -24 dB (0.5 dB steps)

Treble:

Highpass frequencies: 1.6 kHz - 20 kHz

Lowpass frequencies: 8 kHz - 20 kHz

Gain: 0 dB - -24 dB (0.5 dB steps)

Slope on all crossovers: 0, -6, -12, -18, -24, -30, -36 dB per octave

Both units have a tone control:

Bass: Shelving at 63 Hz, 100 Hz, 160 Hz, 250 Hz Treble: Shelving at 4 kHz, 6.3 kHz, 10 kHz, 16 kHz

Gain: +/-12 dB (1 dB steps)

The processor have a digital gain structure, known as “SLA.” This can be adjusted up or down to get more gain out of the system.

The processor has a time alignment feature.

The processor has a copper chassis.

The RS-P70x has a digital output



Now, I'm looking to upgrade the internals, relatively cheap upgrades that would sonically make a difference ... so please not $400 part upgrades

Here is the parts list for the RS-P70x:

High, mid, low DACs - BB PCM1704 (not K grade, maybe E if I can dechipher my notes correctly)
Sub DAC - BB PCM1716 stereo 24bit/96kHz
Oversampling IC - BB DF1704
DSPs - Toshiba TC9331F, TC9271F, and TC551001CFI
Digital Input Receiver - Sanyo LC89055W
Op-Amps on DAC board - JRC 3403A
Op-Amps in analog output section - BB OPA2314


Thanx in advance

[Bruno]

any help? anywhere else i can go for help?