What's wrong with classical music on vinyl?

As I go through my collection of classical music on vinyl, and get new ones from record stores and eBay, I notice that I am not impressed with the sound quality. Most of my pop music albums sound fine. The classical (even sealed), on the other hand, sounds full of static, noise, and pops that completely drown out the music. The rubber surrounds on my woofers ripple visibly, and the more intense passages become distorted (particulary the brass instruments). (And yes, I've tried it with minimal volume, to test the feedback theory, and with the same results.) I've tried extensive record cleaning with some of the most recommended products. On the other hand, my non-classical music sounds fine. Madonna, Yes, and Simon and Garfunkel play fine. So do Crosby Stills + Nash, REM, and Nickelback.

The only thing I can think of is that the classical music tends to be recorded at a much lower volume, thereby causing a low signal to noise ratio, whereas the pop music is inherently recorded at a higher volume, and this helps to drown out the noise.

I'm beginning to think that I should stick to CD's or brand-new 200g LP's for classical music from here on.

Any comments/suggestions?