mystical, the only place I can think of would be the location that Professor Dave suggested. I know that the description kind of gives a narrow view of what can be discussed, but I don't think anyone would mind you discussing those things you mentioned in your post. If they do, they will move your post and then direct you where you should be posting. I'd love to see some conversation on those topics, cause many times that amp, those speakers, subs etc can make or break the way SIRIUS sounds in your vehicle. So, by all means...... post away.
