DJ,
Just to throw this out there, i hope your tone testing hasn't been too taxing on either your speaker or your amp. Test tones can be useful in discerning frequency drop outs and frequency ranges but at even moderate volumes they can stress a driver quite hard.
Read the end paragraphs of
this post where i briefly mentioned some testing we did in house. What i never mentioned was that one of the Tannoy Saturn speakers we tested with was brought back to the dealer because of some anomalies in sound the lower driver and upper tweeter (inside the concentric driver) was producing for 2 test tones. On the dealer's system, the test tones did NOT reveal any driver anomalies like those we heard at the same volumes and with the same test tones at home. It came down to 2 things, the receiver we used or the source player (a one year old Toshiba dvdp).
The dealer's system of course had all separate components with a dedicated and extremely beefy amp (200W, big Class AA/B thing). He was positive that it had something to do with the feeble power put out by the receiver but i know it had to be more than just that since some of the tests were done at low volumes. The tweeter anomaly was measured at 60dB (less than 50% volume level) on the home system, in stereo only mode, but as i said, it was not apparent at all even at higher volumes on the dealer's system.
We tried the same 'tests' on my home system. We heard somewhat different anomalies from different drivers (i also have Axiom M60s so that might make sense) but nonetheless concluded that power is a possible issue. Mind you these odd sounds (like the driver was broken somehow) were different for each system and were not evident with music. I certainly had never heard any of those noises before except with raised volumes and the odd very low bass note. The only music that elicited the 'broken driver' noises consistenly was a song from the Point Blank movie soundtrack and it make an odd noise with both the Saturns and the Axioms but only on the home systems and not the dealer system.
I do believe that although power plays a role here, there could also be other factors like some drivers sitting a touch closer to the tight edge of manufacturers specs than others, certain resonance points being hit rattling one driver closer to that spec line, who knows.
Maybe Alan would have some more thoughts here.
The moral of my story especially newbies,
Be wary!
Test tone dics can seriously damage your speakers even at moderate volume levels!!
Stick to the Avia calibration type discs and be happy.
. That far north at this time of year leaves little else to do except solve problems (and make really good speakers).