Connecting a Sub-Woofer for BOTH Channels

Having its own separate amp channel is the best bet. If you're determined t o use it without, it can be run via a large air cored inductor to each outp ut channel. But you really won't get as good a result, being unable to cont rol the low end amplitude separately.

NT

You could do that just use one of the channels since bass is mono, but it will load down that channel impedance even with inductor.

Greg

Regards,

Boris Mohar

Got Knock? - see: Viatrack Printed Circuit Designs (among other things)

void _-void-_ in the obvious place

Thats a very bizarre way of connecting speakers. I question whether there will still be stereo sound, or just some sort of mono????

I actually think I am going to go about this in a different manner. The plan is to use a separate amplifier for the sub-woofer. Those small amp modules can be gotten on ebay for $5 or less. That way I will get full wattage on the main speakers and can power the sub-woofer separately.

But this brings another issue. Is there any way to get half or each channel at the input to the main amp? Can I just put a capacitor from each input line to make a center channel, or will the two caps cause the channels to combine into one? Or maybe I also need a resistor, but of what ohms?

-OR- is there some sort of transformer that will work? (Two windings on the primary, one on the secondary) ???

Just use 2 resistors of apx the sub amp's input impedance.

NT

The capacitor or transformer will still connect the two signals. The easy way to do this is to buy a stereo amp and use both inputs. Then push the MONO button and use one output for your subwoofer.

Mad. Sorry, it is.

NT

If anything this will ephasise the difference between left and right. maybe stick 100uF parallel with the sub-woofer

yeah, and put the "sound card" into a mode that provides a sub-bass output.

I had my speakers hooked up this way. There will be full stereo. Just try it with what you have. It is an elegant solution.

Regards,

Boris Mohar

Got Knock? - see: Viatrack Printed Circuit Designs (among other things)

void _-void-_ in the obvious place

If you are going to use a separate amp for the woofer then it is an easy so lution. Or at least I think so. Have not tried this.

I would connect a 1 kohm resister to each of the stereo amp outputs. Conne ct the other end of the resistors together. and another 1 k ohm to that j unction to signal ground. So the signal from stereo amp a would go thru on e 1 k resistor and thru another 1 k resistor to ground. So half the signal would be fed into the woofer amp. THis signal would back feed to the ster eo amp B , but be seriously attenuated by the divider of the 1 k ohm and t he output impedance of the stereo amp B. So the signal from amp A would ha rdly appear at the output of amp B. The woofer amp would just need a gain of about 2.

Clear in my mind, but probably not clear to anyone else.

Dan

I'll give it a try wiring it in that manner...

What is the 100uf cap for? Is that a simple form of crossover? I did want to obtain a crossover of sorts, so only the bass goes to the subwoofer. But I dont really need to buy a complete crossover unit, since I am not needing the mids and high freqs. The MAIN speakers will cover the FULL freq range. So, I just need one or two passive components to separate the low freqs.

"Sound card"???? You lost me.....

I'd assume that if I use a separate amp, I can filter out the mids and highs at the INPUT of the subwoofer amp, but how???

Thanks

So then the separate woofer amp would connect to that junction between the resistors, right?

Your speaker + sub system will sound like dogshit if you don't have any way to adjust the crossover of the combined 2.1 system.

Get one of these and feed one main output to your small amp for the bookshelf speakers, and then feed the "mono" output to your sub amp.

Makes L&R speakers see the whole frequency, woofer only sees LF

RC filter.

NT

Yes, but 1k is rather low. Some things will feed that fine, some won't. 10k would be better. If using historic equipment, 47k.

NT

madness.

NT

Maybe you should get a new amp with provision for a subwoofer. Then it will have the filter and the amps for all channels. I see some one eBay for under $30.

Right

Dan