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.
how old is old? sounds like you might have some problems with the woofers. If an amp clips it clips the entire signal not just the lows, you will usually notice when your tweeter and mid no longer work.
...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".
Speakers are probably 10 years old. It really is just the woofers, not the tweeter. I'll try to turn the bass down completely and see. Wouldn't I notice buzzing at virtually all volume levels if the woofers were blown?
Something worth considering - if the speakers have been sat unused for a long time (or are old) then the cone surround may have deteriorated causing the cones to "slump" down and the coil winding to come into contact with the magnet pole pieces. This can cause a horrible "buzz" when you try to play a signal thru the speakers. Try and check this out, it may help you. Richard
Thanks all for your advice. I did check back with the person who sold them to me, who seemed quite trustworthy. He says the speakers weren't blown. I do know that I have to turn up my amp quite a bit higher to get the same sound level as with my earlier speakers, so I'm thinking indeed it is the sound of clipping. I'll try to verify it by using the speakers with a different, more powerful amp whenever I get the chance.