(I did not read all the posts, so if someone else mentioned a tip I have thought of, I apologize for redundancy)
Before you spend more time on it, read my article "Audiophile Law: Thou Shalt Not Overemphasize Burn In" at Dagogo.com
When you have been through that many speakers and have an issue with treble, then imo the odds are that either you are highly sensitive to upper frequency and strongly prefer a softer upper end, and/or you have a fundamental problem with your rig in terms of components/cables.
Another thought: Is that correct, 6.5' ceiling? If so and the speakers are elevated fairly close to the ceiling, then it would not surprise me why so many are overly bright. You may have to lower the speakers beneath ear level and tilt the baffle back. It may help. If the speakers are directed toward your ears, splay them, that is, move them to be parallel to the head/front wall.
I strongly suggest you try a different set of cables before plowing ahead with more speakers. No aftermarket power cords? That's a problem.
Before you spend more time on it, read my article "Audiophile Law: Thou Shalt Not Overemphasize Burn In" at Dagogo.com
When you have been through that many speakers and have an issue with treble, then imo the odds are that either you are highly sensitive to upper frequency and strongly prefer a softer upper end, and/or you have a fundamental problem with your rig in terms of components/cables.
Another thought: Is that correct, 6.5' ceiling? If so and the speakers are elevated fairly close to the ceiling, then it would not surprise me why so many are overly bright. You may have to lower the speakers beneath ear level and tilt the baffle back. It may help. If the speakers are directed toward your ears, splay them, that is, move them to be parallel to the head/front wall.
I strongly suggest you try a different set of cables before plowing ahead with more speakers. No aftermarket power cords? That's a problem.