I had my H/K AVR 1710 hooked up to my RF 83s and experienced the same thing you describe here. I ended up replacing it with a Denon X4000. Same thing happened when I hooked up my AVR 1565 to my RB 75s. Replaced that with a Yamaha R S700. Now the H/K sounds fine with my WF 35s. I don't know what it is about these H/K avrs and Reference series speakers, but they are not a good combo to my ears at all. I'm sure others will disagree, but that's just my opinion.
My advice, try another brand and see if it isn't better to your ears also.