I just hooked up a pair of 1980s ADS L1590/2 towers as the main speakers in my HT. They sound awsome in stereo mode and also really good in HT but when I use the test tone (pink noise?) from my Onkyo TS DX595 to try and calibrate the system the left speaker sounds different from the right one. The volume is about the same but the tone on one is higher than the other. I've deternined that all four speakers (two 10" woofers, a mid and a tweeter) in each speaker are working and that the extended high switch is in the same position on each speaker. Is this a common phenomanon? Is speaker placement a possiable cause of the different tone? Each speaker is the same distance from the TV and each is also level with the front of the TV and the center channel. However, one is in a corner while the other is on a side wall with an open room behind it, I.E. it's not in a corner. Can this be a cause? I know this post is long but I wanted to give as much info as possible so that some of you knowledgable folks could offer up some possible answers. Thanks.