so subs is 400w rms 200 ea
they are wired to 2 terminal cups on the enclosure, then tied in together at the amp so both positives from both subs are on same amp terminal , negatives are tied together I think this makes them 2 ohms?

Amp puts out 500w rms @ 2 ohms and is a single channel amp
preamp voltage on headunit is 6v

I have 4x 30w rms speakers that I just need to hook up. could I hook these up to same amp?