Electronic Music: How do EDM producers determine which key to put their track in if there aren't any acapella in the track?

Re psychology with perfect pitch: It has been said that for people with perfect pitch hearing "see" notes in different colors, and attach certain feelings to keys. A past bandmate had perfect pitch (I was so envious).  He psychologically coupled Eb to melancholy, he said C was light-hearted, and C# m was serious.  This was all while the guitarists tuned to E. Then we moved to Eb guitar tuning (-1 semitone for all notes), and for those few years his perception was shifted -- when his mind told him "that's in E, C# and Dm," he was actually listening to the world's Eb(supposedly melancholy) C(supposedly light) and C#m(supposedly serious). But he did not experience the same emotional "colors" linked to those equal temperament notes.  Now, the world's D was melancholy, B was light, C was serious (once light). It became apparent to us that his attachment of those feelings were JUST his own mutable perceptions, built over time, and subject to change. Re psychology with relative pitch: Me, I could never be sure what key a song was in, and keys did not have any psychological effect on me.  No emotions are invoked in the sense of absolute pitch, but they are however invoked by relative pitch.  Meaning I happen to hear striking differences in mood with obvious Major vs minor, Major 7th chords, Major Suspended 4th, but didn't matter what absolute note/key our songs were in.  C sus4 sounded exactly like F# sus4. Conclusion: According to surveys, only .1% of the US/Europe have perfect pitch (1 in 1000).  I don't think it's worth the effort to look for the "right" key to use.  I *completely* agree with Ethan Hein's response above, it doesn't really matter as long as the timbre of each note for each instrument stays within its range of intended frequencies.  Meaning your trumpets should not sound 2 registers lower (unless you're going for a French Horn brass sound), your kick drum should still maintain it's "bass" frequencies, it should not be tuned such that when playing on sound systems, the subwoofer will not play any audio for example.  Drum tuning is super important, as to not have perpetual song-wide dissonance. To make tuning drums simple, double the frequency of the drum (pitch will be much more apparent), tune it to root/5th/min7/3rd, whatever, then halve the frequency to bring it back down to the original register. When key matters is relative to preceding track and next: the only other thing I would keep in mind is that if your song is to be released on an album/compilation, where order matters, you may want to try to have each following song +/- a 5th from the previous song (a la circle of 5ths) to maximize the number of scale notes with the previous song to sound pleasant.  Also you don't want to "fatigue" the user's ears by forever keeping your entire 12 song album in the same, say C, key. Congrats on producing your track when you're done!

If you have a sub bass in your song i would suggest take in to account what what key is easier to hear it.