the bass is very boomy and muddy, so you're on the right track about realizing that you need to fix it. It also feels very separated from the guitar. There's a big gap in frequencies that either the guitar or bass should take over. Guitar sounds great, as always.
I play bass in a band and am very critical of my sound. Unfortunately I've never had the chance to sit next to the engineer when he mixes. However, I have a good idea of frequencies to mess around with. Hopefully these can help you out some. If it helps, my ideal tone is anything on the Incubus records Science, Make Yourself, and Morning View.
20-40hz: ultra deep lows. These should most often get cut slightly in my opinion to give more definition to the bass. They can eat up every other frequency the bass is projecting. If you boost them, do so because for whatever reason they enhance the mix.
80hz: good punch/smooth lows
100hz: can be very boomy, so be careful. May want to dial this back some, but can also provide some warmth is boosted.
165hz: i seem to like this one better for overall punch and cut
250hz: extreme punch and low mids growl. Boost this, but realize this frequency is the one every instrument wants to dominate their sound. Snare, guitar, etc. all want to hog this frequency.
300-500hz: these are some magic frequencies for bass. They produce a great low mids growl that can make a mix feel thick and heavy.
650hz: smooth mids for bass
700-800hz: honky, nasal tone. Use wisely. This is what gives Carlos Santana his sound.
850-1.5: upper mids...I hate these on bass. They usually come out when you play with a pick. The bass loses all of its deepness.
2.5khz: described as "snarl." This is typically a guitar frequency, so mix to taste.
4-4.5khz: great aggressive growl. Bass should have no problem taking this one as few instruments need it.
6khz: bordering on the edge of getting plinky. fret noise
8khz: sounds like an ice pick in the north pole
If you are able to get a smooth bass tone, you may want to start adding aggressiveness and crunch to it (if it's your thing). These frequencies lie elusively around the mids and lower highs.
P.S. What frequencies were you working with?
