The bi-wiring confuses me even more...I think at this stage you are best off to snarf up an SPL meter and go back to square one.

However, now that I think about it, doesn't your receiver have HK's EzSet/Auto calibration/eq feature? These I've traditionally found to every bit as accurate as a Radio Shack SPL meter (though I've never used HK's). I would think running that should at least get you close to a proper volume setting, close to the right delay settings...enough that dialogue wouldn't be an issue as you describe.
Unfortunately, you won't know until you find out...but it might be worth your while to give the EzSet one last go before dropping cash on an SPL meter (which, by the way I feel every one should have even with auto-setup features)