Newbie question.. Preamp and Sub

Jin,
To amplify (sorry :-) what Greg said, the sub is inserted between your pre and your speakers by either using line level (RCA) inputs/outputs on the sub (inserted between pre and amplifier) or speaker level inputs/outputs (inserted between amplifier and speakers). Most subs have more flexibility in adjusting the crossover frequency (what goes to your sub versus what goes to your speakers) using the line level I/O.

All these answers are good, but to get an exact answer we need to know the exact model number of the sub. I agree line level is the best way to go but different subs do different things to the line level pass through to the main amp. Some may use a crossover set at 80, 90 or 100Hz. Some may not even have a line level pass through. For integration it is best to consider what is happening to the signal all the way through.
Cheers,
MaxCast

thank you for the inputs guys :p

i just learned that the preamp i am looking for now the most
( bryston BP-25 or BP-20) has 2 sets of RCA outputs in the back...

the sub i will get are probably gonna be matching OM Mirage BPS-150 or BPS-400 wich have a crossover adjustment on them.. my speakers the OM-10 also have crossovers but they can't be adjusted ..

so could i use one of the RCA out of the preamp to the amp and one to the sub ?
would that be also a good way to do it ?

if not, i think that i can use the way you described..the line level thing, with the BPS speakers ..

thank you :)
Jin

Buy a REL Strata III or Storm III. One of the best brands for music listening. This sub connects directly to the amp speaker terminals (does not interfere with speaker connections). It "listens" to the amp output and just fills in the bottom frequencies below where your speakers cut out (you can dial this in on the back of the sub). Buy one, others here will agree.

I'd have to second argent. I listen only to 2 channel music, from chamber classical through to AC/DC, depending on mood. I bought a Rel strata 3 and it's wonderful. No boom, just depth, and impossible to hear where it takes over from the mains. I have to admit I didn't demo any other subs ... it wasn't necessary. RELs are a bit pricey, but have great resale, so I wouldn't worry about losing money. It probably would not serve well for HT, though, as its strength is speed, rather than SPL.