Harshness in tweeters: the price of transparency?

I know of no cheap tweeters that dont exibit the problems you list. But I do know of one that doesnt have any of these problems and its a fostex t500amk2. Crossovers can also be a source of harshness in trebile. I have to use very hi-quality parts and tweeters if I want no grain and harshness free trebile with lots of air and detail.

Ia gree that issues in the system are contributing. Herbies Audio makes some of the best isolation and resonance control devices for shelves and components.

A lot of interconnects and speaker cables are hyper-detailed. The lack of warmth magnifies the high freq issues. I very much like PS Audio Transcendent Silver interconncts (havn't tird their silver speaker cables) and Clear Day solid core silver shotgun speaker cables (he advertises here)

Having owned my fair share of monkey coffin speakers over the years, several years ago I made the switch to Magnepan 3.5Rs. The ribbon tweeters are amazing, but will reveal issues mentioned above.

when you get to a certain level of quality in your system, many new factors come into play. what didn't sound harsh and smeary at one time may ultimately display those characteristics. from years of constant trials and upgrades, i have learned a few things.
you may want to try power conditioning, especially on your digital front end and on your pre-amp. different interconnects and speaker cables affect harshness. as mentioned earlier, upgrading crossover components also have an affect. you may want to start there with bypass caps on the tweeter. see northcreek's website for more info, it's not very expensive to do.
i have found that removing static from cd's and lp's makes a huge improvement. i found the furutech d-stat to be far superior to the zerostat, it's also 6 times the price.
good luck with your endeavours

This is quite normal. You are hearing either tweeter compression or tweeter ringing or IMD distortion from the amp driving your speakers or compressed pop music. It is all too common - things sound great at modest levels (as almost all consumer designs do and then fall apart at high levels). Compressed pop music is all too common - so you need to eliminate a large percentage of popular music if you expect to be able to crank it without any harshness at all -see this.

Bear in mind, most consumer designs are not particularly intended to play dynamically and loud - they are mostly designed to sound best at modest levels while looking really great (costly cabinetry and finishes) - consider a pro speaker for you next upgrade -ugly but may get you what you desire.

Light weight materials will ring like a bell (for example metal or ceramic) - the ringing has nothing to do with the music so it is rather intrusive and gives you an etched sound. It can be misinterpreted as detail at low levels much in the way a hypercompressed modern pop CD sounds good at low levels and harsh when you crank it. Like a bell - ringing is worse when you drive the tweeter harder - at high levels it is constantly ringing. The diamond tweeter is perhaps the only exception - it has a resonance well outside the audible band. If you select a pro speaker then chances are much higher that they have chosen a tweeter that performs better at higher levels.

As you crank it your speaker amplifier is being asked to send AMPS of current to the woofers - at the same time it is sending milli-amps (thousandths of an amp) signals to the tweeter. Hardly surprising that this results in loads of audible IMD distortion coming out the tweeter. The amp is trying to feed 'niagara falls' for the kick drum and at the same time provide syringe-like accurate volumes to the tiny tweeter. Active amplification of each speaker driver with a separate amplifier will solve this issue. Funnily enough, most pro speakers are actively amplified...

When you get into this territory, every element can potentially add harshness. The highest potential offender is your CDP, then your amp, then your speaker cables, ICs and PCs. Of course, as mentioned earlier, some CDs are horrible, no matter how excellent your system.

Often overlooked is speaker placement. Intermodulation Distorion between the speakers adds a harshness and "shouty" nature to female vocals and horns. (I play trumpet, so I'm particularly sensitive to this). Sumiko's Master Set speaker placement method is the only thing I've discovered that addresses this. (Look for my review in the review section. Guidocorona also mentions it). In most systems, this is so effective it's like doubling your investment in equipment.

EQ will not fix this, it can only cover it up. Most EQ processors add their own IMD and negative elements. The very best processors can have a place in systems with room nodes that can't be cured with placement or traps and other acoustic devices; however, this is an expensive route that will not get you all the way to where you seem to be headed.

Some people move to tubes to take some edge off. I think this is a false god, that gives into the issue, but doesn't correct it. Anyway, the very best reference-level tube systems will reveal every flaw also.

Dave