A sub output is a purely Home Theater feature. It has a fixed bandwith (the LFE channel of 5.1) of app. 20-120, and has no care of integration with your speakers.
In the two channel world, however, sub integration is a HUGE part of putting together a musical system. There are two schools of thought on how this should be done.
Number one is called line level. Your sub is equipped with RCA inputs, RCA "high pass" outputs, and usually a "link" output. The link outputs are either full bandwidth or just low effects, for adding another sub. To hook up your setup line level, you run a pair of interconnects from your pre-amp outputs into the inputs of the sub. Then, you run another pair of interconnects out of the "high pass" output into your amplifer. If the sub has an adjustible crossover, you need to adjust it to where the sub takes over just as your speakers lose most bass response (most easily done with an SPL meter from RaT Shack). This is also a nice feature of line level, as the low frequency info is not sent to your amp, causing it to not have to work as hard amplifying information that can't be output by your speakers. An SPL is also very useful for setting the sub's level from the listening postion.
The other way is called speaker level. Run cables to your speakers as usual from your amps, but also run ANOTHER set of cables into the speaker inputs on the back of your sub (not all subs have this capability...but most do). This way is really only feasible if your sub has an adjustible crossover.
In my experience, line level is FAR superior to speaker level, but you'll have to make your own judgements. Cheers!
In the two channel world, however, sub integration is a HUGE part of putting together a musical system. There are two schools of thought on how this should be done.
Number one is called line level. Your sub is equipped with RCA inputs, RCA "high pass" outputs, and usually a "link" output. The link outputs are either full bandwidth or just low effects, for adding another sub. To hook up your setup line level, you run a pair of interconnects from your pre-amp outputs into the inputs of the sub. Then, you run another pair of interconnects out of the "high pass" output into your amplifer. If the sub has an adjustible crossover, you need to adjust it to where the sub takes over just as your speakers lose most bass response (most easily done with an SPL meter from RaT Shack). This is also a nice feature of line level, as the low frequency info is not sent to your amp, causing it to not have to work as hard amplifying information that can't be output by your speakers. An SPL is also very useful for setting the sub's level from the listening postion.
The other way is called speaker level. Run cables to your speakers as usual from your amps, but also run ANOTHER set of cables into the speaker inputs on the back of your sub (not all subs have this capability...but most do). This way is really only feasible if your sub has an adjustible crossover.
In my experience, line level is FAR superior to speaker level, but you'll have to make your own judgements. Cheers!