Q: Nakamichi cut out at 2/3rds volume problem...

Hi,

I have a question

I recently upgraded the car component around my audio system, and
consequently had to replace a few things they, being speakers.

the unit is a Nakamichi indash CD unit running only 4 relatively small
speakers, problem is it cuts out at about 2/3rds of the maximum volume,
which in an Alfa with a 3" exhaust is not adequate really.

Nakamichi CD35Z - 4 x 43W [4 Ohm]
2 x VDO HSP 1321's - MAX 110W, NOM 30wW
2 x Eurovox 6420 - - [I think 20W nom. ]

possible problem:  is as Italian cars frequently have no 'accessory' power
setting and CD units need two supply's, one always on, and one that works
only when the engine is on. I had to wire up the Unit's standby system power
supply to the old systems power source and connect the units internal AMP to
the rear window power supply. although if i operate the windows during play
nothing happens.

any suggestions?

/carmoda