Truly awesome System.
You have enough power to drive half the city.
I have never heard your speakers, my ’imagined’ take:
1. I am not a fan of ports, if so, Front Only.
2. Lots of description relative to Violins, however I have never seen/heard a Violin with a hole in the back.
Sooo, can you
a. close the ports, live with change for a while, differences beneficial?
b. audition different ’portless’ speakers, find something that sound fantastic to you?
Listen, particularly to imaging, and, despite apparently less bass, is ’stereo bass’ improved, i.e. very low bass mono, but the bass overtones become directional thus bass player’s location more readily identified. Port Sound Waves are detrimental to Bass Overtones IME.
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IF you have a lot of open space behind the rear port, as I once had, the rear port can be beneficial, barely if at all detrimental, I would still try them blocked, ascertain the differences.
My speakers, in their current location, have their rear ports blocked. Open when I moved in, but definite improvements, HERE, closing them.
Prior Location, open space, they had a full room behind them, the rear port gave extra extension to the 15" woofer, i.e. like in a larger enclosure than the 6.8 cu ft enclosure without reflections of sound waves out of the rear port.