Using different gauge wire for biwiring

if your pigtailing the speakers bidding post? Then the distance from post to post is to short to be noticeable.

If you slightly reduce the amount of energy to the top by using a smaller ga cable you are disrupting the balance of the speaker the way it was designed.

Hifichic, I agree with the electrical theory but I question whether there would be an audible effect of the two different sizes because the current demand is typically lower to the high frequency drivers due to their higher sensitivity and lower resistance. I think the penalty could possibly be higher if the MF/HF and LF wires are the same gauge but the resistance of the LF wire prevented adequate current transfer to the generally lower sensitivity bass drivers, especially in the case of long runs. That said, most audiophile wire is likely oversized for the required current flow, and I am sure the 6awg of AZ's Double Barrel is probably not needed....except for welding.

I personally would not use different gauge wire on a 2 way because you are making the wire change in a critical area of the music. I have found some speakers that offer separate posts for bi-wiring actually sound more coherent with single wire.

If the speaker is a 3 way and the woofer is crossed very low I don't see any harm in a different gauge wire to the woofer.

The ideal is to use identical wire. Barring that, if you only have the two different sizes on hand, surely you an use them to bi-wire. For many years prior to buying entire sets of cables to compare I would swap around different cables on the Mid/Treb and Woofer terminals. It helped to teach me the importance of distinguishing between different cables and their effects.

If you have a good rig and good ears it will be likely that you will immediately notice a difference in the sound if you swap the two cables. You may be very surprised at it. The largest reason for this is the difference in total gauge.

There is no predicting which you will prefer; you may end up liking the sound of improved mid/treble with the larger cable on top, versus the cleaner, fuller bass with the larger cable on the bottom.

Your choice. But, immediately you'll realize that with both sets of terminals having the larger cable you'd have the better mids/highs AND the better bass. You would have just proven to yourself the importance of running the same cable to achieve superior results. :)

05-03-10: Douglas_schroeder
The ideal is to use identical wire.

Why would that be the case? Wiring in just about any application is sized to the current demand. My experience is with the DH Labs cable which is a 14g and 12g combination and it has worked admirably with two very different speaker and amp combinations.