Home theater system with ProAc Response 1s?

budget is much to low. A good sub alone will be 800. With a need to match the timbre of the ProAc's, you need $1500 for the speakers. A good receiver/processor is $1200.

Start with the sub, which should be the compact Infinity Cascade™ Model Twelve powered subwoofer features a 300-watt amplifier to deliver deep, powerful bass with dramatically reduced distortion for an incredibly lifelike sound. The Cascade Model Twelve also includes Infinity's proprietary Room Adaptive Bass Optimization System (R.A.B.O.S.) and test measurement kit, which allows you to optimize low-frequency performance to match your unique living environment. Refurb units cost about $800.

Speakers, look for used 1's, assuming you are happy with their sound. I have three pairs of ProAc's, all original Tablettes, including a EBT unit which I use for center. They sound great. I use dual NHT subs which are equalized using the RABOS system informaiton with a Technics 9060 equalizer. I don't have a receiver/processor, only a processor which I feed all the mono block amps.

I strongly suggest an initial Infinity Cascade™ Model Twelve sub. I have friends that have this unit and all are please and I think it sounds great in the different room's they have. After you get one sub, think about moving up to dual subs. Two reasonable priced subs beat one anyday. The latter fact has been proven in many double blind tests.