MC402 vs FPB 300cx

J, both the MAC and Krell FPB amps are more transparent than your KAV amp was.
Probably the case is that now you are revealing, through your FBP amp into the B&Ws, some of the weakest points of your system.

I know you said you've been through some speaker cables before and it was a waste. IMO now, since you have upgraded the amplification, it is time to look it over.

I would start with the interconnects. Especially the set between the source and the preamp. I would do this before the speaker cable change.

I almost completely exclude your speakers as the weak link and the cause of the problem you are having. Yes, they are not up to task with regards to reproducing the bass that the Krell is capable of delivering. In any other area, the speakers are fine.

If you are about to audition the speaker cables, this may be a good test for the rest of the system and your existing interconnects. See how everything sounds with these cables. What have changed for the better, what got worst, what qualities remained.

If you can, buy some used ICs here and try them out. Just make sure you are dealing with the brands/models that are easy to re-sell.

Arthur, right on.

Jc51373, let the new source break in. Keep your system on and don't touch anything for several days. See if it gets better.
Sometimes when you move the wires the sound changes and the system needs time to settle again. I'm not kidding.

Sure thing!

I have two other audio buddies here in town and one way we can track down what we are actually hearing is to swap gear and hear it in each other's systems. This is a great way to figure out what is good and what isn't - and to double check our feelings about them. Knowing this information is about the only way to truly assess what you actually have. If you have some friends you could do that with, you would find it extremely enlightening.

With all do respect to your KAV, the 400cx and MC402 are quite a step up. Unless you know for a fact that the rest of your gear is on par with these amps, you will never hear what the amps actually sound like. Only when the rest of the system is "better" than those amps will you be able to judge them accurately. This makes setting up a great system (for the money) a challenging task to say the least! It never seems clear what you are listening to. This is also why Audiogon is so popular for buying and selling - it is easy to make mistakes and end up in a never-ending merry-go-round of equipment changes by trying to hit what is essentially a moving target.

My solution to all this is to make all my upgrades in little baby steps and for each one, I try a range of power cords and interconnects to rule cables out of the equation and be able to triangulate to a final judgement before moving on (in addition to testing in others' setups). I also try to upgrade a little of everything as I go to avoid showing up the rest of my system with one big upgrade.

Oh, and since I used to be an N804 owner, I can say that those speakers reveal EVERYTHING. The 803 will be less revealing because their meatier bass will mask some of the ultimate resolution the 804's have. Lean bass definately accentuates system issues. It could be that when you go to 803s, your problems will "disappear" and your new amp will be perfect. I have also witnessed this effect first hand.

But it is great that you are looking at the rest of your gear first. This is the next best step IMO. Good luck, have fun, and try to keep your sanity in the process. :)

Arthur

Aball, Cosecant resolved about 80% of the sibilance I was experiencing. I am at a loss for words with the sound of this thing.

I am thinking the small remaining glare I might get could easily be resolved by a tweak.

Jc51373, so have you tried what Krell suggested?