does anyone know what size of 2 channel amp to use for 2 10''subs there 50 - 200rms 400 max 4ohms thanks

I think that subs should normally be amp'd at the same level as their capacity - they are much stronger speakers than smaller mids and tweeters. In your case, I would look for a 2 x 200w RMS amp. I've always tended to amp my subs at half to three-quarters of the rating of the subs (e.g. 2 x 240w power into 2 x 400w subs) - but that's only because I have my subs right behind my front seats in my Mini and any more power would take my head off, lol.

Different people will give you slightly different advice about amps and how much power to use. Someone with more experience of subs than me will undoubtedly give you a slightly more sophisticated calculation later on!

DJNafey.

Why not use a monoblock amp designed for subs.?

Wire your subs in series, this will give you 2 ohm if there single voice coils and get a GOOD quality mono amp, i'm sure you'll not regret it. Try car audio direct ,if they have any Viper audio amps left, then have a sniff at these.

"Wire your subs in series"

ITYM parallel, series will present a total load of eight ohms :p

Steve.

Give us a hint at budget - are we talking 100 quid, or 2 grand here :D ?