Is this clipping?

Getting back to my particular system (300B, SET, high efficiency full-range driver), I believe that all the components are well-matched, and there is no clipping. My suspicion is that this combination of components (as good as they are for traditional types of music) cannot faithfully reproduce the type of dynamics that are encoded in some modern digital recordings. I'm talking about the types of recordings that go from loud to louder to ear-splitting.
One interesting thing about these drivers is that there is never a hint of visible cone movement regardless of the volume. This in contrast to the clearly visible excursion of multidriver designs.

SPL Calculator

Here's a tool you can use to determine how loud your system can go given 10w/ch if you know your speakers efficiency.

These things are usually just ballpark estimates to determine where you are on teh grand scale perhaps. Playing a system at a believed safe volume level still does not tell you how accurately transients are handled at various volumes for example, so the more subtle effects of clipping are still possible.

If you are way into the green zone based on how loud you like to listen given the factors considered, though, that probably means clipping is less likely than otherwise, at least.

It would not surprise me if some full range drivers are undersized overall and/or have limited driver excursion and are thus more of a challenge to produce high level volumes and realistic dynamics with than multi driver designs , especially with low power amps.

BTW the way, I think the OHM Walsh speakers I am fond of and use are perhaps one of teh best designs out there for maximizing what you can get out of a single driver. Everything up to 8000hz or so is produced by a single omnidirectional driver using Lincoln Walsh's principles that can be scaled up or down in size accordingly based on room size with minimal or any change to the resulting sound. Properly amplified and in room sizes typically found in residences (I use 500w/ch Icepower amps) these go as loud as you want with fantastic dynamics and essentially no sign of stress. They are true "muscle" speakers also capable of finesse and detail. Conventional box designs have to be much bigger and way more expensive to compete IMHO.

After many years of trying, I think my current combo of high power Icepower amps and the OHM Walsh speakers finally puts my system performance into the upper echelons of performance possible in regards to ability to go loud, clear, and dynamic yet for comparatively modest cost.

Psag,
If you would read the Simon Thacher of Spectron paper as I suggested above then you would see easy explanation why you can "drive" jazz but not heavy rock

EASY: your amplifier's power supply can reach headroom (peak) voltage and current required for jazz AND heavy rock (for your speakers, size of room and volume you set) but but but not for the duration (duty cycle) heavy rock requires.

If you want to listen heavy rock well - change your speakers to more efficient or amplifier with better headroom (do not confuse it with rms power as its not the same and power in rms is probably the most misleading specs in audio as it tells me nothing but some clue...).

Your dealer or manufacturer must be your consultant: they do not sell refrigirators and got to work for their money !

Dob,
I've read that paper and I agree. The 300B amp can reach the peaks, but can't sustain them.
Fortunately I have Spectron monoblocks in my other system!

"The 300B amp can reach the peaks, but can't sustain them. "

That sounds like clipping to me?