Can you get realistic bass sounds playing your guitar through an octave pedal (i.e., the BOSS OC-3)? I would like to add some bass lines to my guitar recordings but don't own a bass.
Without buying a bass, I think you might get better results using a sampler with bass samples or a soundfont player (some are available as free downloads), or using a soft synth that excels at bass sounds (again, available as free download if you want to keep your expense to a minimum).
Either of these options would sound better and more like a bass IMO than trying to use your six-string.
You can buy a cheap used bass for about the same price as a good octave pedal, and a real bass, even a very cheap one, will sound much better than a guitar through an octave pedal. Buy a bass.
I have an OC-3 and I bought it for exactly that reason: to play bass lines on my guitar while recording. I can say from personal experience that this approach sucks.
With this pedal, you have individual control of the levels of the input signal, the signal 1 octave below, and the signal 2 octaves below. As soon as you turn down the original signal, all of the attack and harmonics go away, leaving you with basically a sine wave with no attack or definition.
Plus, you have to put it on the neck pickup with the tone knob turned all the way down in order for it to track the notes properly, and even then it'll lose track every once in a while and sneak an 8va note in on ya. with this setup, you've essentially sucked all of the tone out of your instrument.
In some situations, this might work, but it's certainly no replacement for a bass guitar. But it sounds sweet if you ever cover "Fool In the Rain"
But what does sound pretty convincing as a bass is recording either a clean electric guitar or an acoustic guitar and pitch-shifting it down an octave in Cool Edit or other software. The attack and general sound of it is pretty close to a clean bass guitar, but I haven't really experimented with it too much. Cool Edit makes this a bit difficult because it has presets for pitch shifting down all the way to 11 half-steps, but not a full octave. You have to know the multiplier to type in for it to go that last 1/2 step, and I'm not quite that mathmatically inclined. I just ended up borrowing a bass from a friend.