Fantastic, inexpensive, quiet, versatile, and very easy-to-use pedal compressor is the Seymour Duncan Studio Bass. Good luck finding anything that meets or beats it in many, much less all, of those metrics. And it also has some very easy-to-use EQ options at the flick of a toggle if you want that someday.
The spectra comp actually compresses each string differently.
Some of the "toneprints" may be multi-band. I'm unsure. But no compressor can possibly compress each string differently as it can't possibly have any idea which string is being played, or even what type of instrument. That may be a bit semantical and I'd have not responded except...
But in general, compressors add low end,
No. Some have a baked-in EQ that may sound like there's more low end, but compressing doesn't add low end. Many compressors lose low end, or squash it too much vs. lower-amplitude high end and that's why some prefer multi-band or the ability to blend the dry uncompressed tone which is a typical feature of "bass compressors", and many more muddy the highs which can sound like more low end but isn't the case.
Yes, but that's why all of them have make-up gain so you can put the output at unity gain or make the output far louder than the input signal. It's quite difficult, perhaps impossible, to find a compressor - especially a pedal compressor - without user-controlled make-up gain.
and keep everything on an even keel. As in, remove dynamics from your playing.
Again, not so. The higher amplitudes are tamed, or more accurately compressed closer to the lower-amplitude dynamics. However while your louder playing is compressed, your softer playing is at the same time made effectively easier to hear (or apparently louder). So some dynamics are lowered while others are comparatively boosted. This point may not matter to someone who has no subtlety in their playing, but the boosting of signal or technique and string noise via compression should still be considered.
