500Hz and 1kHz - most common frequency collision areas?

I've been using MMultiAnalyzer a lot to EQ my tracks for better separation, and what I've found is that the most common areas it's collision detection feature alerts me to are the areas around 500Hz and 1kHz. Give or take a hundred Hz or so, these are the regions which seem to require the most attention. Is there any particular reason why this should be? Has anyone else noticed this? Like I find I'm frequency cutting 500-600Hz in instruments to make the bass cut through a little more.

Yeah I find I have to cut a lot out with pianos. When detecting frequency collisions with bass there's always a very dense collision around the 500-600Hz mark and I always feel there's some good stuff in the bass there so I cut some out of the other instruments. I think it makes the bass "nose through" the mix a little more. 

batsbrew
only cut what sounds bad.
 
maybe those frequencies actually sound GOOD on certain parts,
and a blanket rule simply whimpifies some of your best tracks.
 
'collision' detection....
there's a real mind phuck of a term.......

I only use Collision Detection on tracks I feel could use some separation, and if it tells me that there are a lot of collisions around 500Hz I will make a cut around there on one of the tracks, and it definitely helps distinguish them both. I wouldn't make the cut in the same place on both tracks.

Thanks, Jeff, for another very enlightening post. I really enjoy your detailed to-the-point explanations.
 
Having the arrangement take care of the mix is a great, but unfortunately takes a lot of time/pre-production and also convincing people. Just last night I had a drummer eventually realizing (after the 3rd round of "downsizing" his groove) that if he completely leaves out the ghost notes on that verse, it doesn't get thinner but the opposite is happening as now the subtle rhythmic throbbing of the synths was no longer masked by his ghosts and snare rattle and the whole section developed different dynamics and feel ... so I reckon it applies across all instruments and not only to the studio as this was during a rehearsal session for a live show.

I think I recall a Ken Scott interview where he noted that 200 hz was the ugliest frequency on the spectrum. He said he never failed to cut 200 hz out of almost everything. I isolated a few tracks with a steep 200hz band pass - and I'll be damned -  it IS ugly.

Dang, so there is no one size fits all?
 
Who knew?

I often hear people citing an arrangement as the problem in a mix when in reality, I can't disagree more. I've heard  some busy mixes in my time where there were counter melodies, and technical riffs along with orchestra sections. Though I can see where this may be a concern to some, I highly doubt the majority of us are dealing with Trans Siberian Orchestra mixes.
 
Frequency masking is the biggest culprit along with not making the right calls simply because a person doesn't know when to tweak or when a sound needs to really be discarded. Proper compression as well as panning, control of panning of effects and eq-ing of effects is crucial. We all too often forget to mention this and right away blame an arrangement. An artist should be able to create and play what they want, even if it clashes with something. It is our job as the engineer to make it work, not just remove it as a clutter track.
 
I'll give you a tip to totally prove my point. Any time you think the arrangement is causing the problem, put a high pass to the extreme on each instrument in the mix to where all low end is removed. From there, mix and pan the instruments to where you can hear them all. Then, gradually release your high pass a little on each instrument. As soon as you notice masking or something disappearing to where you need to raise a fader on something, you have found a source of masking. Eliminate the masking, not the track or the arrangement.
 
The only time I have messed with an arrangement is when it was so cluttered and against the grain, that it sounded like 5 different songs were playing at the same time, and the track made no sense. OR....when a keyboard player is playing left hand on top of the bass guitar track. Other than that, I have never had to mess with an arrangement or tell someone to change something. It has to be really extreme for me to even try to persuade a client to change their song. So I always attack the mix and exhaust everything regarding it before I go after the arrangement. ;)
 
-Danny