In my opinion, Zoom has got this category cornered. The B1X Four (and the B1 Four for that matter) will give you possibilities for modeling your bass sound that'll keep you busy for months if you don't watch out. ;)
It is capable of doing a lot of things. For starters, it will give you a *lot* more control over the tone of your bass -- you don't need an active bass anymore to get the same kind of tone control.
It also comes with a load of dynamic, modeling, and overdrive effects. I don't really care for the distortion-type effects, but the modeling effects (phasers, flangers, choruses, that kind of stuff) are great, and the dynamic effects (compression, slow attack) can be indispensible.
The effects can be ordered in patches; each patch will hold up to five effects, and you can store up to 50 patches. It already comes with a lot of patches preconfigured... which are usable as examples, but not much more than that. The best idea is to create your own patches (you can start from scratch or use an existing patch as a starting point), and, after having made a backup, get rid of the example patches you don't like (I'm looking at you, #39!) to free up space.
Or if you want to keep it simple, just line up your effects in a patch and then use it as a stomp box, taking effects out of and back into the patch while playing.
The best way to figure out how this device suits you best is by just trying out what works best for you. Zoom has freely downloadable software (for PC or Mac) on their web site to help you create and edit patches.
This device also contains an excellent tuner (which is mutable), a 30-second loop facility if you want to go Jaco (Pastorius) or even Jacob (Collier), and a drum computer (essentially a glorified metronome) that will help you practicing.
I love that it will take power from the USB port, because that meant that I could use one of the USB mains plugs that I had lying around. I love how the output can also be used to drive a headphone. The only thing I don't like is that, while internally, it has the capability to be used as a DAI, it won't use the USB port to output anything. I suspect that Zoom did that to not eat into their own DAI products...
I agree with those who say it's not something you'd take into a professional studio, but I disagree with anyone who says they won't take it on stage. If it's good enough for Marcus Miller on stage, it's good enough for you and me. :)
Build quality and finish is better than I had expected, especially at this price point.
For me, it's a keeper. I love this thing. It's brilliant. It's not gonna lose its place between my bass and my amp ever.
And at this price... seriously? That's a no-brainer.
