Big breakthrough! I posted this issue I'm having with boomy bass on audiogon and a fellow named Al had a great idea. Lots of others gave me solid ideas too. But the one Al gave was out of (my) box, intelligent and resourceful.
He suggested I feed the low frequency terminals on my usher be-718's 4ohms my Primaluna Dialogue One and use the 8ohms for the high frequency.
This has helped a great deal with my bass issues. I am now enjoying what sounds like a new rig.
It took me a few efforts to get what he was talking about. For those who may not understand I'll explain what I did.
I wired two speaker cables to each speaker. One speaker cable (which of course includes 2 ends, - & +) would be wired from the 4ohm terminal to the low frequency terminals on the ushers and the other cable from the 8ohm to the high frequency.
Where I got confused is how I can do this given that there is one ground terminal on my primaluna (there is a 0ohm, 4ohm and 8ohm terminal for each channel). Does this mean I can share a 0ohm terminal (ground) for two separate speaker ends? Yes it does. I had to do some work with the wires but it all worked out.
The reason why, as Al explained, is because of the way that the ushers handle bass. Here is a link to some data on the Ushers. See figure 1.http://www.stereophile.com/content/usher-audio-technology-be-718-loudspeaker-measurements
Here is how Al explained it...
"A major reason that the bass heaviness is evident with the Prima Luna to a much greater extent than with your former Harmon Kardon amp, which I presume was solid state, is the interaction of the tube-based Prima Luna's relatively high output impedance with the speaker's impedance variation as a function of frequency (see Figure 1 here), the speaker impedance being generally high in the deep bass region, and also including a very large peak in the 50 to 90 Hz area, while reaching much lower values in parts of the upper midrange and treble regions. Using the lower output impedance of the amp's 4 ohm tap for the low frequency driver, while using the 8 ohm tap for the high frequency driver, will significantly alter that interaction in the direction you seek."
Here is a link to the whole thread.http://forum.audiogon.com/cgi-bin/fr.pl?fcabl&1383669863&openflup&48&4#48
I thought there would be many people who could benefit from this so I posted to share.