I'm still loving my 2.3 TLs, but even when I first hooked them up, I noticed that the SDA effect in the left channel didn't seem as strong as in the right. After a few days of close listening, and judicious use of the channel inverter switch on my pre, I'm certain that it isn't. I've verified the following:
Alignment - speakers were aligned to the same plane using a laser sight, and to the same distance from the back wall and side walls.
Mono signal - balance to left results in right dimensional drivers on, left stereo drivers muted.
Mono signal - balance to right results in left dimensional drivers on, left stereo drivers muted.
Battery test - all drivers move in unison on both speakers.
Verified amp - used my backup common ground amp, same issue.
Verified pre to amp ICs - tried a spare set, same issue.
Verified source to pre ICs - tried a spare set, same issue.
What's interesting is that if I flip the phase (by reversing the speaker cable) at the amp on the left channel, I get a strong SDA effect, the same as the right channel, but the image is pulled hard to the left. Flipping both channels just results in the original issue.
The rest of the set up is: CJ pre, tube mono blocks, AI-1 SDA IC.
From reading the SDA trouble shooting guide, it seems like most SDA issues are related to phase. And the fact that if I flip the phase on the speaker cable to the left channel gets a strong SDA effect, I think it is a phase problem. But I can't figure out where to look next. Or does the fact that even though all the drivers in the left channel move together when testing with a battery still allow for the possibility that the SDA drivers in one or both channelse are out of phase?