System too bassy - Primaluna & Usher

Biwiring does sound better in some situations, really depends on the amp and the crossovers in the spkrs, might be worth a try since the amp would be driving the bass and the high loads separately. Sorry, don't know about prices; Google some Kimber retailers?

A double-run would require 2 cables hooked up to same tap at the amp, then one cable runs to the tweeter, 2nd cable runs to the lower bass terminal. IMO, this probably would sound better than a single cable. But, you would need to buy 4 cables and be able to wire them both to the amp terminal, meaning using bare wire or spades.
I think this is what mattmiller meant.

PS...In both cases, you would be removing the stock jumpers on the speaker terminals which would be beneficial.

Biwire to resolve bass issues in this case seems like a total potshot and a bandaid at best.

"Biwire to resolve bass issues.."
Agree, Mapman. This is not the root of the problem; spkr placement and room acoustics are the most plausible cause.
But since the OP is looking for an upgrade in cables as well, some used Kimbers would improve definition in his spkrs.

Ya I totally agree with all of this. Based on my reading, it seems that an upgrade on the right type of cables (ones that are tighter and leaner) should help the situation, plus the bewiring would help too. I don't know anything about removing stock jumpers on the speaker terminals of my amp and all of that.

I changed the tubes which I'll get to in a min...

I agree that speaker placement and room acoustic treatment are my best, closest to source of problem, options (other then changing my amp or speakers). I just got the amp and really love the speakers so I'm leaving that as a last case scenario, but will try to avoid spending too much with an inevitable case of having to replace the amp. The speakers are already out pretty far from the wall without it looking pretty weird being half way in the room. So room treatment seems to be the next best thing. Although there is a possibility of me moving within a year.

So last night I switched out my primaluna EL34 power tubes for some svetlana EL34 WC tubes that came with my used purchase. I've only listened for a couple of hours. It seems that these are making the issue a bit worse, but that's not conclusive just yet. I need a bit more time to listen. Does this sound characteristic of these tubes?

PS. What are your collective thoughts on DNM resin and Coincident RCA's and how they're known for a more lean sound?

IMO neither changing speaker cables nor biwiring would in themselves be likely to result in significant improvement, given particularly the short lengths of your speaker cables (most relevant cable parameters and most cable effects are proportional to length), and given that cabling is clearly not among the major root causes of the problem. Nevertheless, I strongly urge you try biwiring, but in a certain way. Let me explain.

What I suggest that you try is as follows:

1)Remove the jumpers on the rear of the speakers that connect the terminals of the high frequency driver to the terminals of the low frequency driver.

2)Connect the "0 ohm" output terminal of the amp (which is referred to on many other amps as either the common, -, negative, or black terminal) to the - terminal of the speaker's low frequency driver, for the corresponding channel.

3)Using the other wire in that 2-wire speaker cable pair, connect the 4 ohm output terminal of the amp to the + terminal of the speaker's low frequency driver.

4)Using another 2-wire speaker cable, or the other 2-wire pair that may be included in a bi-wire cable, connect the "0 ohm" terminal of the amp to the - terminal of the speaker's high frequency driver.

5)Using the other wire in that 2-wire pair, connect the 8 ohm (not 4 ohm) output terminal of the amp to the + terminal of the speaker's high frequency driver.

In other words, you would be driving the high frequency part of the speaker from the 8 ohm tap, and the low frequency part of the speaker from the 4 ohm tap.

A major reason that the bass heaviness is evident with the Prima Luna to a much greater extent than with your former HK 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.

Regards,
-- Al