...but there is more energy in the low frequencies, so you'll get the clipping first in the low frequencies. You can probably get clipping without low notes if you play it loud enough. But the other choice is possible, too, you may have a problem with your woofers -- is the buzzing coming from the woofers or from the tweeters? If the woofers, bad, they might be "blown".
Is this the sound of clipping?
I recently switched to some old Signet 260s, hooking them up to my Arcam Alpha 3. The 260s are about 87db in efficiency, the Arcam puts out about 40 wpc. In the large room that I'm playing it in, I get a course buzz from the speakers at higher volumes. But the sound is only bad on low-frequency notes. The highs and mids don't deteriorate. I never had this sound with my more efficient Spendors that I had used previously. I always assumed that clipping meant an overall deterioration of the sound, not just on the low end. Is it clipping or something with the woofers? I know that I could solve the mystery with the substitution of a more powerful amp, but won't have an opportunity to do that for a little while.