No personal experience with double bass here. But I would think it makes sense similar to use with acoustic guitars. You can use a great basis sound and add the incredible effects. In my studio I also use the Kemper to re-amp all kinds of tracks with very different instruments and vocals on it.
By the way: Saw a live video with Apocalyptica playing their Cellos through Kempers on a festival. Look here... no Jazz indeed but interesting use case as well 
I was wondering about how 2cellos use to Amplify their instruments and You showed Apocalyptica using kemper.. Perfect! no need to add anything
The Fishman Piezo pickup on my Kydd Bass works well with Kemper. It's was designed for double bass.
Thanks everyone for your input.
My impression is that the overall possibilities of the Kemper would indeed offer something valuable to double bass players. I guess, the key difference is that for the electric guitar and bass the amp is part of the characteristic sound of the instrument, whereas double bass players normally expect an amp to reproduce the natural acoustic sound of the instrument. Then again, Apocalyptica...
By the way: Saw a live video with Apocalyptica playing their Cellos through Kempers on a festival. Look here... no Jazz indeed but interesting use case as well
... is different, and interesting indeed. In that video, Apocalyptica also seem to be using microphones (dpa?) rather than pickups. I wonder, do they use them as input to the Kemper? Hard to tell...
my idea of a setup would be the KPA together with a rather neutral sounding amp (such as an acoustic amp)
Not sure what you want to achieve with the redundancy. The KPA can be a very neutral sounding amp or even mimic an acoustic amp. It is just depending on the profile and actually there is good stuff out there for acoustic instruments (and for my case also for vocal and other instrument re-ampings) as well, e.g. profiles of Consoles or Channel Strips.
Does that make sense?
yes, it makes sense.
You have to use a pickup for your acoustic instument.. double bass or whatever.
I ve seen intersting review of this contact PU https://www.schertler.com/it_US/musical-…tarra/dyn-g-p48
I ve never tested by myself but it seems to be a good one for any acoustic instument.. viola..banjo..classic guitars.. anything that vibes.
Yes I would expect it to work very well.
There are some great bass amp profiles for your electric. For the stand up you might wabt to just bypass the Stack section or load a profile of a good mic preamp/mixer channel strip to give it some extra character.
Do you have Logic? You can use Match EQ and their Impulse Response Utility to make a custom IR for your bass, which can then be loaded into the Kemper (or any other IR player) as a cab. Also something like a ToneDexter would work - generate a preset with it, then profile that preset with the Kemper.
In both cases, you'd mic up the bass and plug in the pickup, then generate a custom EQ curve/Wavemap (ToneDexter terminology) to make the pickup sound like the mic.
