To Bi-wire or not?

Okeeteekid -- I looked into the Kappa 9's a bit. As you realize, but others may not, and assuming that you are using the "extended/normal" switch in the back in the "extended" position, at bass frequencies they are perhaps the most difficult speaker load ever devised by mankind.

In that mode, which seems to be the one most commonly preferred, they go down below 0.8 ohms at some bass frequencies, causing them to be widely known as amp killers.

Your 12 foot round-trip run of 12 gauge wire has a resistance of only about 0.02 ohms, which is negligible even in comparison to the 0.8 ohms. But I calculate that approximately 0.2 ohms of resistance anywhere in the path would result in a 2db bass loss. You shouldn't have that much resistance if all of the joints between cables, terminations, jacks, etc. are well-made and are not oxidized, but when we are dealing with such low levels of resistance being significant, who knows?

In any event, considering how uniquely difficult that speaker is in the bass region, I would not make any generalizations from your observations about bi-wiring that are applicable to anything other than your own setup.

Regards,
-- Al

hi al, just did the same test using the renaissance 90's that are not as difficult to run as the kappa 9's and i still get a 1db drop from 20hz to 100hz slightly less than the kappa 9's 2db, i still think it has something to do with current, i have all infinity speakers that are mostly hard to run, i have a pair of infinity towers that i use for ht i think they are 6 ohms i will try the test on them to see what happens.
greg

Okeeteekid,

Here's a theory I just thought of: You are not really losing bass in the bi-wire configuration; you are just getting better bass damping (meaning tighter, more well-controlled bass), for reasons I'll explain below. That would very conceivably produce the slight measured loss in bass response that you have found (I presume using test tones), and on musical material could very conceivably produce a subjective impression of less bass.

The reason that may be happening is as follows:

In the bi-wire configuration, back-emf from the low frequency drivers is conducted directly (and only) back to the amplifier, which in your case has an extremely good damping factor (i.e., an extremely low output impedance). So the back-emf is absorbed there very effectively.

In the single-wire configuration, some small fraction of the back-emf from the low frequency drivers is conducted through the jumpers into the mid-frequency drivers, where it will not be effectively damped (because the impedance is much higher than at the amplifier output), and, more significantly, WHERE IT WILL PRODUCE SOUND THROUGH THE MID-FREQUENCY DRIVERS, ADDING TO THE SOUND PRODUCED BY THE LOW FREQUENCY DRIVERS.

So you may indeed be getting measurably more bass in the single-wire configuration, but bass which is the result of back-emf effects and is therefore less accurate!

Regards,
-- Al

Al, you may be right, anyhow on my infinity's it just sounds better with a single wire and it may be because the infinity's are on the bright side and the bi wire makes them sound even brighter or slightly more detailed, i was gonna run the bass test on my infinity ht towers but there is no option to bi wire them.
greg

Don't quote me but on this but it maybe related to your question. I read back somewhere in a interview with Cardas that you want to run the smallest gauge possible( just above the min.) that is required by your speakers otherwise bass can be effected.

9 gauge is pretty big but not out of hand.

Your ears are the final truth, if single wire is the best way for your system, by all means stick to it.

Take all of this with a grain of salt but the only way to get a much better answer is try different Bi-wire cables and perhaps an amp but Right now it just apples & oranges.