What should I use to send the right signals to a passive subwoofer

[stonesman2764]

I am running a Sansui QRX 6001 with a preamp circuit added. I'm using a Carver M600 to power the front Pioneer HPM 100's and I have a rebuilt Dynaco QSA 300 amp for the rear which I'm running Cerwin Vega D-5's. I am very happy with the setup and love the OPPO sending those great quad flac files thru the discrete CD 4 input. I have 2 channels on the Dynaco that aren't being used, and after the rebuild it tested at 90+ WPS x 4. I have a 12' JBL that the plate amp died and a 10 Cerwin Vega that also has no indication of life when it is plugged in. I have a Velodyne 10" running off the Sansui A speakers. My question is I want to output from the B speakers to a line level output to plug into the 2 unused channels on the Dynaco. I just want the 80 hz and below to run right to the passive subs. Do I need a full DSP, or can I get a speaker level to line level converter that will only pass thru the low frequencies? I'm thinking this shouldn't be so difficult. I don't really care about streaming as 95% of the time I'm paying from the OPPO. I know I can hook up the amp to the subwoofer out on the oppo, but that hinders my playback while watching TV and Movies, as it only works when the oppo is being used, and I don't think the volume control on the oppo does much. Sorry if I'm asking in the wrong forum, and if I ramble on. I really just don't know enough about DSP's to know if that's what I need or will the simple converter work for me? Thanks in Advance. Alan

 

[jimfisheye]

If you have to do actual speaker/bass management - ie. pulling the bass out of mains channels and redirecting to the Lfe, that gets into cross-over eq and summing. Not just a simple converter.

If you already have the Lfe channel content ready to deliver 1:1, then you don't need anything. Simple as it gets.

If it's the former and you need to move the bass around, using DSP in an AVR or computer media setup is easier now than an old school analog cross-over and mixer.