audiomasterclass.com visitor, Donh Casi, has some fascinating comments about recording bass guitar. Read on...
I realize that the recording-bass article may have been published a bit ago, but I recently had a similar problem and wanted to share my experiences, which may help some people, and that also reinforces some of your previous lessons/articles.
My recorded bass was sounding very mushy, out of time, and flabby. I also had some problems with different sorts of hum, and with phasing of the recorded tracks. Here's what I did and what fixed it.
To start with, I'm using Pro Tools (at different times an HD2 and an LE) system, an SM57 and an AKGD112, and a Behringer Composer-Pro Compressor.
As far as musical equipment, I tried variations of the following: a Digitech XP100 pedal, a Fender Squire PBass, a 69 Fender Bassman through an old Fender/JBL 15", and a Traynor through a 15" Carvin ported bass enclosure. Lastly, my favorite instrument was (honestly) my hallway!
I used guitar-amps because I like the sound of old Cream records (JB used to use Marshall guitar amps). So, Both Traynor and Bassman amps use tubes in a very similar sort of circuit, the ported enclosure giving more lows, the open-back JBL a more ambient 2.5k-type mid, and I like the resonant character of the long-scale Precision-Bass.
Good starting sounds.
When I first started recording, the acoustics and hum were so bad that I couldn't properly hear the bass (single-coil pickups, small rooms and bass-buildup, you know). So I put a couple of Carvin Humbucker pickups in the bass and got rid of most of the hum.
Then I accidentally discovered that putting the Traynor/Carvin at one end of the hallway and micing the doorway at other end sounded GREAT!
Apparently the hallway was long enough to allow the long bass waves to develop (like a long bass-horn).
Micing with an SM57 gave me great midrange and presence (I ended up putting this in front of the edge of the cone), and the D112 at the end of the hallway near the floor emphasized the low frequencies, along with a little ambience (check out david's 'vocal microphone shootout').
But the bass still didn't have quite the definition I was looking for. I had heard about the Guitar-rig and tried it, but it seemed to 'clip' too easily -- not enough headroom. I had also tried using the compressor as a limiter, but it sounded pretty muddy and noisy (compressors, of course, add noise).
So I tried one of my guitar-pedals in 'bypass-mode' (essentially using it as a preamp-splitter). The main 'out' went to the bass-amp, the 'dry-out' went directly in to my PT system, and the variable-output knob of the XP allowed me to 'dial in' the right bass volume. Finally!
Using only three track-inputs, I was suddenly getting a clear, ambient, full bass sound, that I could finally hear and play in-time with. There are also three other 'caveats' that I noticed.
Firstly, I was getting a lot of 'rumble' between bass-notes (using the two-finger 'walking' technique to pluck the notes). I appreciated David's technique of using a pick to clean up the bass, but that didn't work as well for me. What DID work was a modification of the slap-bass 'claw' technique, wherein I was muting the other strings with my thumb and palm, and alternately picking with curved index and middle fingers. This gave me a very precise control over which strings were 'ringing'.
Secondly, when I visually compared the recorded waveforms of the compressed and uncompressed bass, I noticed that the compressed (limited) bass signals were squashed into a smaller-space and were a more consistent volume, but they lost so many of the dynamics that they just sounded like a noisy 'wash' of bass-buzz. It was also harder to 'edit' the track, because I couldn't discern the individual notes.
Once I took the compressor out of the recording-loop, I got a much better signal which I could later compress 'just a tad' so it would better fit in the mix.
Finally, if you use both close and distant mics (and especially if you mix them with a direct signal), you'll probably get phase-problems (nasty clicking, thin sounding, and 'phasey' sounds). This is because of the difference in time that a direct signal takes to get into the computer, versus that same signal traveling through an amplifier, into a speaker, into the air, across 5 or 6 meters of space, through another microphone, and into the same computer recording system. The second signal is delayed, and listening to them played back together makes one partially cancel out the other. Worse yet, some frequencies are affected more than others.
To correct this, use the direct signal as a comparison, zoom into the tracks with the magnifier tool, and 'line up' (slide backward in time) the other two waveforms so each set of notes has a 'zero-crossing' at the same point in time (You may have to use something like the 'separate region at transient' command to chop up the bass-line and then align the smaller pieces). Suddenly, the bass is big, full, resonant, ambient, and as loud as you need it. THEN, you can compress it. Voila!
So, it took me awhile, but I finally got a bass sound that I like. Another choice for a cheap 'splitter' is a headphone-amp like a Behringer HA-400(US ~$40) between the bass and the amp/DAW input.
BTW, I have nothing against Guitar-Rig's RigKontrol once I get my signal into the computer, I just don't think it's got enough headroom for me. Also, I recently got a DigiPRE and noticed that the sound I get on my bass-DI is 1000% better (better preamp headroom). I think that with Bass and Percussion sounds, 'it's all about bandwidth and transient response'.
Donh Casi, Thermionic Sound and Media