probably very easy, speakers?

[batman]

i have two speakers, a left channel and a right channel, and each speaker has two jacks on the back, a - and a +.

what i want to do is place a subwoofer in between them that responds to both channels. how can i combine the speaker's outputs and feed them to the subwoofer without interfering with the left and right speakers' outputs?

also, do i need to build a low pass filter for the sub?

thanks!

 

[Nigel Goodwin]

i have two speakers, a left channel and a right channel, and each speaker has two jacks on the back, a - and a +.

what i want to do is place a subwoofer in between them that responds to both channels. how can i combine the speaker's outputs and feed them to the subwoofer without interfering with the left and right speakers' outputs?

also, do i need to build a low pass filter for the sub?

Yes, a sub-woofer needs a low pass filter, you should also probably filter out the bass to your existing speakers and rely on the sub-woofer, which is what most sub-woofer systems do.

There are basically two methods, active and passive.

Active: Each speaker is fed from a seperate amplifier, the cross-over is done at a low level using opamp filters - this is by far the preferred way, and it gives you easy control of level and crossover frequency. As you already have a stereo amp feeding the existing speaker, you will only need an extra mono one for the sub-woofer.

Passive: This requires a special speaker, with two voice coils, it's fed from both existing speaker outputs with passive filters. You can't easily alter the crossover frequency, nor can you easily alter the respective levels, you really need to have matched speakers and sub-woofer.

 

[Styx]

i have two speakers, a left channel and a right channel, and each speaker has two jacks on the back, a - and a +.

what i want to do is place a subwoofer in between them that responds to both channels. how can i combine the speaker's outputs and feed them to the subwoofer without interfering with the left and right speakers' outputs?

also, do i need to build a low pass filter for the sub?

thanks!

whats yr sub-woufer make?
most have LP filter in them
Also most have a phone jack input.

I have a tape phono output that I feed to my sub with no probs