response amp problem

Hey guys and girls
dont no if this is the propper place to put put this but...

i am having a few problems wif my Response amp. I'm not sure if i have wired it up wrong or if it has a problem wif the amp itself

hears wat i am running
1x Response amp
AA0429
Power @ 4ohm 14.4V: 800WRMS
Power @ 2ohm 14.4V: 1000WRMS
Power @ 1ohm 14.4V: 1500WRMS

4x 12' PIONEER TS-W308D4 subs
dual voice coil
power handling (watt) 1400w
power handling (rms) 400w
Impedance (ohm) 4ohm dvc

i wired them up in series i think ?
+ from the amp went to + on all 4 subs same wif the -
and i bridged the 2 terminals in the middle of the subs

now my problem
its really quiet (not bassy) even wif everthing like bass and gain ect turned up it still pretty quiet..
i hooked up a cheap amp i had lying around and it did make things abit better..
then i tried linking the 2 together but it just made everything worse.
have i done something wired it up wrong or is my amp just not powerful enough or is there a problem wif my response amp.

any help woud be excellent and much appreciated

cheers

p.s sorry for typing so much :-)