Help -- my system is too bright

The ringing is somewhat inherent in the design of their tweeter. I remember seeing evidence of it in an old Stereophile review of the Studio 20s. They showed a waterfall graph with a severe resonant mode in the 22KHz-25KHz area. It was reported as being the first breakup mode of the metal dome tweeter. When I had the 50s I had them in a system with either Rowland or Pass electronics and Discovery and Sumiko OCOS cables. With the toe-in adjusted so that I could still see a substantial portion of the inner speaker panel and a listening height several inches below the tweeter level I never noticed the resonance "problem". I've read that it's relatively easy to design a crossover that traps out the offending frequencies, but I believe Monitor Audio purposely has not taken this approach because they think it does more harm than good.

Assuming that the 60s are even better than the 50s, you've got a very fine speaker. I hope you can work out this issue.

Having an ultrasonic peak is not unique to the MA tweeter - most metal-dome tweeters have such a measureable ultrasonic resonance point, of differing magnitudes and frequencies depending on the design. It is assumed that the higher this peak can be pushed up in frequency and the lower it can be pushed down in magnitude, the better. It is also assumed that any deleterious effect this peak may have on the sound would be more caused by possible interference artifacts, reflected lower down the spectrum, than by the peak frequency itself (which is, let us remember, above the range of normal hearing). The perceived 'brightness' range actually occurs below the top octave (below 10KHz), well away from a 22KHz peak even for those few listeners who do hear up that high. With typical CD sources, the steep HF filtration usually employed by that format would tend to make tweeter resonances at or above 22KHz a less suspect issue.

Z-Man -- interesting stuff.

Right now, I am going on the assumption that my amps
need a little more break-in time, my AC needs to be
cleaned up, my room needs a little treatment, and that
it is possible that some of the fatigue is being caused
by room resonances mixed with a little AC distortion
and low level noise from the Universal player amplified
and passed on by the extra sensitive amps, and possibly
even by simply hearing more detail accross a wider spectrum
than that to which I have become accustomed.

If more break-in time, a high end AC isolator and filter,
some room treatment and a new CD player don't solve the
problem, which -- remember -- is slight to begin with --
I will have to consider other alternatives.

I appreciate all the interesting information y'all have offered -- I have learned a few things from this discussion.

Thanks!

Rsbeck,

I am not sure of your budget, but the new Ayre CD deck is outstanding! If you are considering new, add this to your list.

Rsbeck, I have been through exactly what you are experiencing. Krell amps are neutral, accurate, powerful, and painfully revealing. This is great when the source and the rest of the system are up to the task, but otherwise they can drive you crazy. I have the MC version of the FPB 350's and love them. However, it has taken some time and money to get the rest of the system up to par and I still need a first class cdp. I once had B&W N802's connected with junk speaker wire and it sounded horrible at medium to high listening levels. There was no bass and the highs would peirce your ears. I added Cardas GR speaker cables and that made a huge difference in bass extention and mellowed out the highs significantly. But I was still not satisfied. At the time, I was using the Krell HTS 7.1 as the pre with a old Denon cdp connected with a digital coax. I began to realize that the AV preamp was not going to give me the first class 2 channel performance that I was seeking. So, I sold that and the N802's. The N802's were purchased as a temp until I could find the speakers that I really wanted. I recently added a Krell KCT preamp and Wilson WP 7 speakers and now things are starting to gel. The resolution is unreal and the sound is smooth, powerful, full and sweet but I can hear the old Denon cdp in the chain. I am currently shopping for a cdp but have not made a decision yet.

I am not suggesting that you need to go through the changes and expense that I have. Your goals may be totally different than mine. But, if you are ever to be happy with Krell amps in your system, the rest of the system must be on par. They will definately let you know if something else in the chain is noisy. They are extremely revealing.