I guess I'm not being clear. Yes, with the tone controls flat, active and passive sound identical.
I experience the same thing with my Warwick, and really all of my other active basses with a switch.
I'm comparing the tone of the Dingwall - flat - to my other basses, and noticing that there's a lack of bottom end by comparison. Since these basses are often used in metal, is the thinner tonal character something that is desirable for metal? Maybe because of the effects used? I'm just trying to learn more about the design of the instrument and why it sounds the way it does.
BTW - I have NEVER heard a low B sound this good before.....
I see now, yeah it's apples to oranges. Different strings, woods, pickups (including pickup position), right hand position etc. are all gonna have an effect on how something sounds.
In short, all basses sound different, some more trebly, some more bassy, some more mid focused, if you're getting the sounds you're looking for by turning a few knobs then you're golden.
I do sort of see where you're coming from with them sounding a little less bassy when flat, I wouldn't call it thin though. I find the AB's and Combsution series with the FD3s leans more toward a modern sound with a lot of clarity, that can sound brighter than most other basses.
Keep in mind they also react very differently to where you play, if I play over the pickups closer to the bridge it's more trebly, nearer the neck (I often play right over the end of the neck) a lot more rounded and full sounding.
These basses aren't 'designed for metal' but they certainly have been taken up by a lot of metal players I suspect due to the downtuneability (yep, a word I just made up) and clear modern sound which probably helps a bit in dense mixes and distorted tones.