I know some amps can sound loud soon as you touch the volume
OK, this is !opinion!, not so much based on personal experience. I only have experience with one bass amp, as mentioned above, the Carvin BX1600. This is two 800 watt channels operated with or without biamp @ 2 ohm per channel on up. I have not run it with a higher load than 4 ohm, by that I mean I've only run it at 4 ohm/channel on up in Z.
So the opinion is, if someone can't easily adjust their rig to lower volumes, they most likely either have a setup problem or operator error, with the system as a whole. Or least likely, poor amplifier design. Setup and operator error could range from too much cab, too many cabs, too low of Z (for the desired lower volumes) with a high powered amp, active bass cranked up all the way, knobology on the amp, and the list goes on...
I usually like to play pretty loud, but try not to extend the time periods of playing so loud it scares the dogs too much. They are learning. Last night I mic'd myself to test a new mixer, and the only thing I do worst than play bass is sing, so I toned it down a bit. After 8 bottles of liquid courage, I muted and shut everything down. This morning I find the following settings:
Amp - drive 8/10 (3:00), compression half (noon), eq. all flat (Parametrics at noon and freq settings noon, graphic eq sliders centered), Master 5/10 (noon), using one channel, rocksmith through the effects loop
Cab 1 4ohm 15" (essentially detunes the amp to about 500 W)
Bass - One PUP half, other PUP off, bass boost half, tone full CCW
Rocksmith also piped to the stereo via mixer, 100 W/ch, volume less than half (amp -5db, mixer gain full CW/+20db with channel fader just under mid way), bass reduced at the amp, mixer high/mid/low eq 12:00.
Volume is very smooth and easily controlled down to 0. I can easily dial it in where I can hear the strings themselves on the bass, up to jail time levels. This is just from reading up a bit and some experimentation with speaker setup and adjusting the controls. The Carvin does have a hell of a lot of control, and I haven't tried others, so I wouldn't venture to say other amps would or would not be as easily controlled for volume.
Edit: added clock references, all times EST unless noted otherwise. After initial post I noticed computer output was about 1/2, which I didn't check last night (Rocksmith normally cranks it full go when the program is launched).
your CLEAN gigging volume dial position
I missed the keyword gigging... I don't gig. I am my own audience
As you were, smoke if you got 'em.