[fred]

The GK-1R has LEFT and RIGHT output for subwoofer.  I would like to sum this into a single mono subwoofer output so I can connect it to the one available input on my subwoofer.  Can someone tell me if that can be done, and (if so) how?

Although my subwoofer has two inputs, one of them is used for the LFE channel from my home theater processor.  I tried using a Y-adapter connecting one GK-1 channel and LFE on 2 legs of the Y, but this terribly degraded the GK-1 output for that channel.

[AKSA]

Fred,

This can be done, and the simplest way is to resistively join the two 'hot' leads via a couple of 47K resistors.  This point is then the summed node, which can be fed to the subwoofer, but this configuration necessarily reduces the signal output so you might need to turn up your sub a fair way to compensate.

The other way is to sum the two channels into an IC opamp buffer, using a standard summing configuration like the one above, with a gainset on the IC to compensate the loss.

Choose a good IC and you won't notice the additional chain of amplification.

Cheers,

Hugh

[fred]

This can be done, and the simplest way is to resistively join the two 'hot' leads via a couple of 47K resistors.  

My sub has a lot of room to increase gain (currently set to 3, on a scale of 1-10), so I'll try this first.  

But I have a question: Are the 2 resistors to be connected in series or in parallel?  If series, why not just use one 100K resistor?

Thanks!

[AKSA]

Fred,

A 47K resistor to the summing node from the left channel, and another from the right channel.  The node is then L+R (hot).  Earth is ground, just as before, all connected.

This will sum, but with minimal crosstalk between channels.  I guess you'd say the resistors are connected from L hot to R hot, in series.

Ain't words grand??

Cheers,

Hugh.