High pitched noise coming from speaker that raises in pitch with raising rpm.

[spokey9 5,000+ posts]

Most of us here are just in it for the "hobby"

I would never consider my work on my system a job...if it was a job, I'd find something more enjoyable to do with my spare time

 

[spokey9 5,000+ posts]

First midranges won't play the full spectrum cleanly...20-20000hz

 

[spokey9 5,000+ posts]

Decibels are a measurement how loud something is...it's not the frequency of hearing...