Orchestral brass and fanfare - analysis of system

Judit, I'm a tad confused & much intrigued. Let's assume for a moment that the recording is not at fault (i.e. it suffers from the usual d*nm compression!). If I'm not mistaken, the fact is that you detect a compression in the fundamental upper-mids that you happened to notice with passages of brass.

Then, if "mids and lows are good, however the highs become compressed at LOUD volumes. On low volume (...) the system relaxes into my comfort zone...", the prime suspect seems to be, electronics. I just can't tell if it's the pre, the amp or a combination of the above. I'm really tempted to join Stehno's suggestion -- but that me, not Judit (although I, too, judge by classical). Let's go further.

Brass is impolite in that its harmonics can go over 50kHz it seems, & well into subwoofer areas. So, as you note, the sub has helped a lot & a super-tweet (as per Mara, above) may help some more...

This said, the above still don't address the compression issue IMO, because this comes from the main speaker, not the peripherals.
Speaker: if they're incapable to take the drive from the amp, you'd be hearing driver distortion/blowing it -- which you aren't & it isn't. Remember, we're not discussing whether it sounds "correct" - just the compression.
Likewise with the cables: if they don't like the loads on either side, you'd be complaining about more than the specified instruments and, again, the issue is not how "nice" it sounds: just the compression. The wire would make a mess of it -- but wouldn't compress (unless badly connected -- and you'd hear that across most of the the spectrum).

So, there MUST be something off with the "engine" driving the speakers; if it were the pre, I think you'd be complaining about the lower register too. That leaves us with impedance & power capability in the amp-speaker combo. If the impedance were, say, to drop inconveniently at the fundamental of the brass, & the amp were tired, it would (& will) compress. OTO, I haven't lived with a KAV250 nor with 805's (but have w/801's), and don't know WHY it would find it appropriate to compress...

But, I put forth OUR answer to your question: can you borrow an amplification power-house, ANY, and try it out? Brass is difficult but, if it's anything BUT the amp you'll know just by trying another one.
THEN we can put forth intelligent propositions.

A long way of returning to Sten's idea -- sorry. Clink!

Judit,

I'm sorry I gave such a brief reply to your post. The other members have addressed your concern more fully than I have. My statement was made from listener experience since I have yet to hear a full orchestra classical recording that is reproduced to my satisfaction. My system is modest by comparrison to many here and simply may be incapable of ever satisfying that type of demanding music. I do have non-classical music that encorporates full orchestra and uses lots of brass. On a few of these recordings the effect is staggering it's so real. I have found in very general terms that a great recording is similar to spending several thousand dollars on equipment upgrades. Average pop recordings are more listenable than average classical recordings so I may have made an incorrect analogy but my experience supports my earlier post. It's my humble belief that great classical recordings are the most difficult to make of all music. The same holds true on the hardware end. Any system that can pull off classical reproduction that is satisfying is approaching the pinnacle of our hobby.

Lugnut, allow me to second your proposition.

I like Stenho's comments. Look to the amp. The impedence curve of many speakers have funky phase angles and dips in the lower midrange and so on. I've replaced several amps that otherwise sounded fine but were unmasked by symphonic brass. It was the amp and not other components that was the culprit. Of course, the speaker designer could have redesigned the crossover to make it an easier load but this was not in the cards...

I hear some very strong arguments here suggesting a link of this problem to amplifier performance. I do not know what the performance curves of the Krell look like, so I am not sure what happens at the high end. It is the weak link in my system, without doubt-it is a hometheater product.

Krell is supposed to be a good match for B&W, but perhaps the unit I own is a notch too low in the performance chain. I own a pair of Vandersteen model 3s upstairs that I will swap in, for diagnostic purposes. I am thinking I would like to try an amp like the Pass X-350, a class A design like the Krell [if I have my facts straight], but in another league entirely.

By the way, I appreciate the thought that went into many of these responses.