I just changed my setup this weekend. Did a thing last week where I hauled the upright, along with a Hartke HA3500 and a 4x10, to play with an ensemble. Sounded fine.
Note: I use an Audix F90 on the bass, the way a DPA4099 might be used, under the strings between the bridge and tailpiece. The mic is powered via a Behringer mini mixer. The settings for that: bass is slightly higher than zero center, mids at zero, treble slightly lower. It’s the way the mixer itself works best for this instrument when gain is optimized.
So this weekend I used a different amp: a Crate BX100 combo. And it sounded great! At levels compatible with an un-mic’ed drum set and a mic’ed piano, it worked better than I imagined it would. Settings are shown in the attached image. Contour is switched off, so all you have is the input gain, the EQ, and the power out level. It was clean, and sounded like the bass only louder.
As you can see from the image, the EQ section is flat in the highs and drops off as frequencies get lower. (Good for headroom.) After the slight bass increase in the mixer, this levels things off so that my signal chain has what might be considered nearly a “summed to flat” frequency output. If anything, the bass frequencies are lower overall. My hypothesis is that it has something to do with the 15” speaker. It more closely resembles in size the top plate of the bass itself, so it more closely mirrors that in output. It does not need to be driven as hard to get those frequencies. And conveniently, the amp even has a balanced out should more volume be needed in a bigger amplified situation.
So the next time I need to haul gear, it will be the Crate. It’s not a small or light item, but it’s quite smaller and lighter than the 30 pound Hartke and the 4x10.