Well, back in the day when I was in a very popular Northern California new wave band we would always
impress the sound people wherever we went because we would spend five minutes at the start of each sound check by having the bass played and I just play eighth notes in unison
until we could figure out how to eq the bass and the kick drum
(with both equalization and tuning of the kick and equalization on the instrument and at the board for the bass).

I remember that (and this was the days before wireless technology became prevalent or affordable) the bassist had a special sound check 50 foot bass chord so that he could walk around in the room and check for nodal spots and spots with subsonic mulitplication (a huge problem the deeper the tones get).

We definitely fine tuned our sound EVERY NIGHT for each individual hall. Amazing, because in this day and age of relatively cheap digital parametric equalizers, you could just play a hall once, figure out your equalization and program it for future shows.

In those days we would also use a technique called 'zipper eq' in recording studios whenever there were troubles with timbral masking of the low end between kick and bass guitar.

you put the bass through one side of a 31 band graphic and the kick through another......then you go to the lowest frequency and you boost one instrument by 3 db and cut the other one by the same amount............move on to the next frequency and do the opposite. When you are done, the graphic looks like a zipper..........

fascinatingly, if you soloed either instrument, they sounded a little strange with such a radical equalization but play them together and both sounds are extremely distinct and the brain fills in the gaps and hears both instruments as sounding full yet distinct.

Another thing for drummers (and bassist to realize) is that in larger halls with reflective surfaces (Santa Cruz' premier showcase club, the Catalyst used to be a bowling alley for god's sake) one frequently has to tune the drums up to a higher pitch in order for it to be percieved as a lower pitch in the hall.........same thing with the equalization of the bass.

I once did a gig with a wonderful bass player named Jeffrey Wash. We played this podunk club in the middle of nowhere
and Jeffrey took about fifteen minutes with a beautiful fretless Music Man bass and a very sophisticated multi band parametric to play EVERY SINGLE note on his bass: dialing in each one so that the instruments' notes all sounded the same volume all the way up the neck.

I've never heard a better bass sound in my life. It was full, with rich bottom but you could hear every single articulation in it..........just amazing.

Mostly, it's just listening to what the room tells you.
Every time I walk into a new performance space, I quickly walk around the room and clap my hands and listen to the ambience of the room and the subtle natural equalization that the rooms' reflectiveness gives to the percussive clapping sound.

I've finally gotten to where I can usually hear how to alter my tuning (or how busy I can play in a room; the boomier the room and the greater the slap back echo in a big room the less I play, just because it's harder to hear for the audience with all that reflection going on.

Every now and then you get into a room that you just can't do anything at all about (with the exception that the worse a room is, the quieter you should attempt to make your onstage sound to have it sound good). I hear a lot of bands try to drown out a room with volume..........it's just the wrong thing to do and usually has to do with the emotion of the musician rather than their ability to sound good.

Okay, I'll shut up!