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
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