Oye, I own an Ibanez SRX 700 and a Behringer BXL1800A(with eq) amp.
Thing is, I cant keep a good tone to it, I have an active eq in my bass and Ive set it to maximum on bass around half way on middle and either really low on treble or really high(depends if i slap and pop).
Ive tried setting the eq on the amp but Im not familliar with it and tried setting it various ways.

Any tips on how to set and keep a good warm bass tone?
Dont turn the low up so much on the bass itself. Try to figure out what about 75% is. You dont really want to turn anything all the way up or all the way down on the bass itself. If you want to boost the lows a little, then go ahead, but boosting it all the way will make it sound horrible. Same with highs. Rely more on your amp for a good tone.
i have that same amp, and i use a squier jazz bass and it gets a really nice round, warm tone. i would first try flatwound strings, then:

boost the lowest band on the EQ about 25%

second lowest band about 50% and scoop the mids about 25%.

add a small bit of compression (around 9 o'clock)

and modify the eq on your bass to suit the needs of the music/your taste.

if you need to cut through a bit more, try boosting 2k and biasing toward the bridge pickup a bit.
i thought i had magic fingers once, and had uncovered the fountain of love.

turns out my girlfriend was just peeing on me.