Topic: subwoofer for stereo preamp

[accastil]

mates, since most stereo preamps do not have subwoofer pre-outs, how do you connect your subs to them aside from the speaker level configuration?

i was thinking of buying another stereo preamp but im having second thoughts since i still want to make use of a subwoofer. my current stereo preamp is a BnK PT3 and this one has a sub pre-out.

hope to hear from you soon. thanks!

[ProtegeManiac]

as av-phile suggested to me before, I used the tape outputs on the preamp. works fine, any bass issues I get have more to do with sub positioning, I think, than with the signal chain. Just need to deal with two volume knobs though.

[accastil]

as av-phile suggested to me before, I used the tape outputs on the preamp. works fine, any bass issues I get have more to do with sub positioning, I think, than with the signal chain. Just need to deal with two volume knobs though.

alright! thanks protege...ill check if this would be possible.

[qguy]

if the pre-amp has headphone outputs, you can use this.....

[D75C]

Technically I agree on the possibility of hooking up your sub via the tape loops and the headphone out. They will work guaranteed.

However, how will you resolve the crossover since your preamp does not have a low-pass filter for your sub.

I foresee the answer of setting the crossover of the sub at 80hz but what about the stereo channels that are fed a full-range signal. To avoid a bass lump, you'd be probably be setting the crossover to its lowest, probably around 50Hz. But I still see an overlap in the 35-50hz region specially if your stereo speakers are a size above bookshelves. I'm just saying this because I ran into a situation like this before in my own system. Where I was attempting to recreate a B&W Matrix 801 with my B&W Matrix HTM and 800ASW.

If your both your subs do have speaker-level inputs why not hook one sub to left speaker and the another sub to the right? Set identical crossover points and set the phase to 0 degrees.

This way both satellite and sub would function as a single unit and have no bass lump issues.

Just a thought.

[av_phile1]

Technically I agree on the possibility of hooking up your sub via the tape loops and the headphone out. They will work guaranteed.

However, how will you resolve the crossover since your preamp does not have a low-pass filter for your sub.

This is already being done for so long by stereophiles, for 2.1 long before HT came into the picture.  An external active electronic crossover circuit is used to sit after the tape out and before another amp, integrated or power feeding a passive subwoofer.  The active crossover of the powered sub does the same job.  It does the job of actively low-passing the bass and blocking the rest.  You only need one such device when filtering. 

But you're righjt, you have to set the sub's crossover at the -3db point of your main speakers, typically in the 40hz to 50hz range so that it augments the main speaker's low freq roll-off from that point, with less dovetailing.  Some would set it even lower so as to preclude some possible overlaps if the rolloff on the sub is not steep enough. Or you can do a less elegant solution of turning down the bass control of your preamp if it has one, since the tape out signals do not pass thru the volume/tone circuits of the preamp.  Your ears will have to do the balancing, or use an SPL meter.