Well, it seems Sadowsky's talking about a pretty specific low-mid here. Most of the time when others discuss "mid-scoop" we're talking about the "Smiley Face" EQ that is a much broader band of cutting. And that'll kill a bass's place in the mix. Specifying that 300 Hz area makes a lot of difference.
jte
Exactly. A Smiley-face metal scoop won't work in anyone's favor (it makes basses disappear and it makes guitars painful to listen to at concert levels). A slight cut at a specific frequency can really clear things up, though. Roger says 300 Hz; I like to cut just a bit of the low mids on my amp, and I usually boost at 800 Hz a bit on my bass. It gives me a good, clear, punchy sound to work with... I change my tone with my left hand placement (I'm a lefty, so right hand placement for most of y'all), so I don't have to fiddle with any knobs between songs.
