One last thought, if money is tight then what you are doing is OK.
But if you can spare between 350 to 400 pounds, you can buy a full 5.1 system. You dont need to spend loads to get the benefits of a DVD player, but you will be missing out if you stick to 2 channel sound, it does make a big difference to the overall effect.
Something like a Yamaha HIB 40 system comes complete with all speakers ( tiny ), brackets, cable, powered sub woofer and dolby digital ( remote control ) amp. Stressing the remote control, cos wandering around in a darkened room turning amp up and down is a pain.
Happy viewing.