Which AV system or power ams ..

[webboy]

Hi all , just seen some quick advice here .

I have a friend who has a system with the following equipment .
6 x 140 - 450 4 hms W Sub-Zero Ice SS3328 Wired in Series
1 X subwoofer Yamaha NS-SW050

50 W (100 Hz, 5 ohms, 10% THD)

Denon AVR-1603 Receiver

• 80 Watt - 8 Ohm - 20 - 20000 Hz - THD 0.08% - 1 channels (center)
  80 Watt - 8 Ohm - 20 - 20000 Hz - THD 0.08% - 2 channels (front)
  80 Watt - 8 Ohm - 20 - 20000 Hz - THD 0.08% - 2 channels (rear)
  110 Watt - 6 Ohm - at 1 kHz - THD 0.7% - 1 channels (center)
  110 Watt - 6 Ohm - at 1 kHz - THD 0.7% - 2 channels (front)
  110 Watt - 6 Ohm - at 1 kHz - THD 0.7% - 2 channels (rear)
• Response Bandwidth
  10 - 100000 Hz
• Signal-To-Noise Ratio
  98 dB

The av system has become faulty and now looking for another system and my question is
he has 6 speakers on one channel could this had been problem or the subwoofer?

he is not using the system for video but just for music/what should be a ideal uint for this type of setting