How to tell if bass speaker is worn out?

I have a boogie walkabout scout (about 1 year old, don't know exact hours of use since I bought it used) and it has a 12" Neodymium 300 Watt (4 Ohm) speaker in it. When pushing the speaker medium to hard it moves quite a bit and when I put too much bass into the EQ it start flapping (or farting) on very low notes, moving a whole lot. On more modest volume, or when the very low frequencies are flat at high volume, all is fine. Optically the speaker looks just fine.

Being a guitar player who just got his first bass rig I am not used to this. How do I know if the speaker is worn out, or if this is just normal? I have never seen a guitar speaker wear out, but when I see how hard these bass speakers have to work I wonder if there are only so many hours until the membrane gets so soft or worn that the speaker cone moves too much, thus the low frequency farting.

If this is a stupid question, remember I am just a guitar player ;-)

thanks

-- Axel

I am also a guitar player who happens to have a good bass rig and I actually practice on the dang thing. I run a Markbass head with an ashdown 210 and there haven't been farting problems. I'd say even though it is a bass guitar, don't turn the bass up too high. You'll just end up with mud when you play live. I'm guessing if it is farting out, then you are pushing the speaker too hard (unless that is what you want. You can always put an extension cab under it and that should tighten things up.

Put a compressor infront. Makes everything stick out more and sound better. It will also help with the movement alot.