Re: how to record bass?
Depending on your situation, it may vary.
Live:
Most venues use a direct box. One output goes to the amp for stage volume, and the other goes to the sound engineer's desk. The same can be done with a Sans Amp, if you're using one.
Recording:
Here's where it gets tricky. Getting a good bass sound is tough, because there is so much going on, frequency-wise. You want to get low end, of course, but you don't want to miss out on a great bass tones midrange growl and you need the high frequencies for finger noise, otherwise the sound is over-damped and lifeless.
The simplest way to record bass is with a Sans Amp and compressor. This will get you a fairly good tone, just going straight into the desk, but you will need to do some tweaking. Expect to set the compression ratio to about 4:1 with a pretty low threshold. That is a generalization, of course.
For my upcoming album, we went with a different approach. My bass player uses an Ampeg stack, and this is what we did -->
After dialing in a good tone in the room, we blocked off the area around the amp with studio baffles. This keeps room reflections from coming back into the mic's at oblique, out of phase angles. A blanket thrown over the amp will have the same basic effect. You want as much direct sound from the amp as possible. We turned it up to live playing volume in order to get the amp really cooking. (It's an Ampeg SVT 350H head)
I split the signal using a BBE 411 (from 1985, I think), with the process off, but I did use the gain. A direct box will do the same thing. One output went direct into the amp head, and the other went direct into the HDR (hard disk recorder).
For the top 4x10 cab, I placed a BLUE The Ball mic on it, centered on one of the drivers, close to the cab. This mic ran to an ART tube mic pre, phantom on, and then balanced into one channel of the HDR (hard disk recoreder).
For the bottom 1x15 cab, I placed a Shure SM57, slightly off axis, also close to the cab. This ran balanced into another channel on the HDR.
We then tracked each input to its own seperate track. That gives you total flexability to dial in any tone you want, and then you can correct/mix it with EQ. When recording this way, we use compression at the mixing stage, not the recording stage.
** NOTE: This was done at my own studio, not at a commercial facility. It doesn't take a lot of $$ to get a great bass sound, just time + patience. **
Hope you found this helpful!