My brother gave me some old alpine amps

A little MRP-T10
# 50 watts RMS x 2 at 4 ohms
# 65 watts RMS x 2 at 2 ohms
# 130 watts RMS x 1 bridged output
# stereo or bridged mono output

and a mono amp MRD-M501
# 275 watts RMS x 1 at 4 ohms
# 550 watts RMS x 1 at 2 ohms
# 2-ohm stable

what is the best speaker config? one or two subs? Do I bridge? 2 or 4ohm?

 

Hey there. I'd love to give you some advice, but you're not giving a ton of information here.
What car is this going in? (Year, make, model?)
What is your objective with the system? (Better sound quality, plain old loud bass?)
What speakers do you currently have and are you looking to upgrade them first?

You'd get better responses if you tell us a little more.

 

when bridge genraly their only 4 ohm stable bridged. those MRP amps aint to shaby, decent amps. you can do it how ever you want, you can run 2 subs, 4 subs, 1 sub, it doesnt matter each one has dif benefits, more subs, the more air movment the more sound, but the lower SQ with so much in such a small area, i prefer a single 12" my self. that does enough for me, but as many as 2 12"s will still mentaing decent sq depending on the subs you pick and how you box them. remember its all about the box