jwm841 posts05-13-2017 9:21pmGeorge I would put the Rockport’s along with your Wilson and B & W speakers.
Depends which model and if it had a test/s done so we can see the impedance vs -phase angle graph then I could answer that for you.
This old model " Antares" had a 3ohm load at 200hz and 4-5khz which isn’t bad seeing there is no nasty -phase angle at those frequencies as well. So both amps should work well with these speakers, the Ago having slightly the better drive/punch though at 200hz.
The Ago will definitely sound better at 20hz with pipe organ. because at 20hz there is 4ohm and -50 degrees which is a current sucker from an amp.
Also Sprach Zarathustra (2001 Space Odyssey) has a 20hz organ at the begining.
http://www.stereophile.com/images/archivesart/rokantfig1.jpg
Cheers George