So I spent some time tweaking things this weekend and re-ran Audyssey, looked at other sub placement options, ect.
After running Audyssey I used the real traps test tones and ran a frequency sweep and noticed that there was a pretty bad dip at 150 hz. If I move my SPL meter a foot forward or backward it reads much higher so I assume I must be sitting a dead zone for this frequency...?
Anyway, so the problem: I re-ran the real traps 150-159 hz test tone today to compare the volume at the 150hz mark with and without audyssey. At louder volumes (about 80db) there is a buzzing noise coming from both tweeters on the right m80. I haven't noticed this before but I don't think that I had the test tones as loud the time before.
I swapped tweeters between speakers and confirmed that the problem is not with the tweeters themselves. I called axiom and spoke with JC and he suggested that the crossover is bad. The noise is pretty loud, and always occurs when I hit about -27.5 on the denon volume control at the 150 hz test tone. turn the volume down a notch and it stops, back up and it starts again. This is in the right speaker only. It did not appear to happen at the 160hz mark, at least not at the same volume.
Apparently there have been some minor changes in the crossover design in the m80's since I purchased them 2 years ago. As a result JC said I would have to send in my m80 for repair since they don't want to send me a new one (then my two m80's would have slightly different crossover designs). What I have to do is pay for return shipping to Axiom's US depot. This will cost me about $70 ($40 for axiom to send me a box/packaging stuff that is appropriate for holding the m80's) and $30 for the shipping label itself.
JC also cautioned against using test tones that play the same frequency for a period of time because it could damage the drivers.
I popped in my DVE disk and did a buzz and rattle test on the right speaker from 15hz to 300 hz. Even with the volume cranked way up I don't hear any buzzing.
So, I guess my dilemma is that it appears that one of my speakers makes a loud noise at about the 150hz mark. This noise stops when both tweeters are removed and unplugged. It doesn't appear to be noticeable when listening to music or movies, or even running a frequency sweep test such as the one found on DVE. I am not sure if the dip at 150hz and the buzzing noise are in anyway related because as mentioned when I move my SPL meter forward or backward a small amount the DB level jumps up considerably. Perhaps it is just a null spot at that frequecny and Audyssey tried to bump up the db level at the 150hz mark so much to compensate and then when running the test tone at this frequency it damaged the crossover or something. However, JC said that the test tones could be harmful for a driver, but shouldn't pose a threat to the crossover itself. Perhaps the crossover has been bad all along or perhaps there is no problem at all.
Any thoughts, comments, suggestions? What would you do?
OH yeah, if I send it in it will cost me $70 as mentioned, and I will be without an m80 for about 3 weeks