stereo amp to passive sub

B&W · 26 Mar 2006 at 23:50

hi, i have a nad c350 amp connected to my soundblaster x fi. i have 2 speakers connected to the amp. B&W dm110.

i have a passive subwoofer here and i wanted to connect the subwoofer to the amp but i dont have a clue how to do this.

on the bak of the sub there are 2 pair of speaker terminals.

one says input from amplifer.

other says output to speakers. but since theres no crossover freqeuency i can set i was thinking that mite mess up my sound quality.

the sub also has two rca inputs, right and left. left has mono written next to it.

can i somehow use these to connect to my amp? :confused:

james.miller · 26 Mar 2006 at 23:51

if there'sw no crossover then the sub would be run full range and yeah, it would sound crap lol.

actually since there is a second set of terminals for smaller speakers on the sub, maybe it has a passive crossover. i dont know im tired lol.yoyu only need to connect the sub to one channel of the amp, but dont expect it to sound brilliant. I use a seperate denon amp to drive my subs. nice and simple

clockworks · 27 Mar 2006 at 07:33

If it's got low level inputs (RCA), it'a an active sub (built-in amplifier), not a passive one. Presumably it plugs into the mains?

There are 2 ways of connecting these:

1)RCA from a dedicated sub output on an amplifier. Will also work if connected to the pre-outs on an amp, or to the tape-outs (no volume control with this method, though)
2)Speaker cables from L&R outputs on an amplifier, then the pekers connected to the sub.

The first method is easiest, if your amp has the correct output.
The second method will work fine. The sub shouldn't affect the sound quality from your existing speakers much, as most of the signal will go straight in and out again. The sub just uses a tiny bit of the signal, and amplifies it for it's own speaker.

Not having an adjustable crossover just means that you can't fine-tune the response from the sub, it'll still work OK.

james.miller · 27 Mar 2006 at 07:58

it doesnt have low levels, he said it was passive.

DRZ · 27 Mar 2006 at 18:12

james.miller said:
it doesnt have low levels, he said it was passive.

If it was passive, why would they give it RCA inputs?

Dont do it - leave the sub out of the equation. If you must, put the sub in series with the speakers but bleugh, putting such rubbish in your system should have even crossed your mind!