You mean
<------------- this, used on a regular bass with headstock, just for the transposing feature alone? Might fail for the lack of calibrated (defined) string lengths… what actual Steinberger basses suffer from as well today. Not enough trems made to justify production of said strings.
Yes. Exactly! That one! Transposing trem for bass. Now, I know about their inherent issues. I play headless basses myself. But they could revive it in some other way. Today you have that Drop B-tuner in those bridges, DB tuner I think they're called, which are made to function as a headless HipShot drop d tuner, of some sort. You could re-design it, and since it is no problem to drop one single string back and forth between E and D you could do the same for three strings. I think even...was it Zion hyperbass used by Michael Manring? Full of switching machine heads that alters tuning on each string? Can't be that hard imho to produce strings that would be easy to set up like that.
Mind you, and everyobody else reading this thread. That even Dingwall 5 and 6 strings DOES HAVE DROP D Tuners at the E-string. Playing in the key of D on a big 5er isn't the same as having OPEN STRING D, or Eb or C sharp. So there's really something to it that Bucephylus said, that he's in contrary view to most around here. I e that the detuned 4 string sounds better than the same notes on any b-string. I tend to agree with that. There's always a weakness among all of us for playing OPEN STRINGS and especially if they're in the tonic of the key the song or part is in.
But by and large, I think if you change the drop tunings too much on a four string, the necks relief come into play and, playing too low tuned, the oscillation of the lowest string will be buzzing against the frets. Then the neck should be made so flexible that it immediately get's more relief as you tune down, in order for strings to vibrate in more space, but then again, then will action rise, and intonation is thrown off. So at a maximum of two halfsteps down, like Eb and D would suit me fine. In the key of C, I think that's the upper limit on a four string bass. I can play tunes in C on four strings, standard tuning, without complaining about low end missing. I think it'll only be c-sharp that you can't play open strings to and in that key. But how many top 40 songs are written in C sharp?

Maybe the old blues standard "Born Under a Bad sign" perhaps....
I do think some of this will be remedied SOMEWHAT (the slacking of the strings while tuning down too much) with a four string that is fanned fret too. Then you can buck that large difference in oscillation to a certain degree, and the relief won't bother you as much. Something for Dingwall to take on? A four string Fanned Fret, but with ingenious NEW transposing whammy bar system?
- - - -
Blowinblue, no offense, next time, it's me that's gonna goof it up over something. But keep up the good posts!
-----
So there, why going from 5 to 4? Why is that rationalisation enough? Is there anyone bought Tony Levins signature MM bass with three strings and even went down to three?
Just out of laziness?