Double Bass Full circle killing my acoustic tone?

[B String]

I won't say that there isn't a difference in tone between some adjusters and the full circle however I think this conversation has the possibility of internet overthink and I want to caution that if there are differences between them they are subtle, not profound. If you play regularly with the pickup they are irrelevant.

I have personally noticed more of a change in tone when using wing pickups like the Bassmax, the Rev Solo, and the Underwood than I have with the Full Circle.

I remember finding somewhere on the internet, an in depth
study on the tonal differences in adjusters. The difference
between Aluminium and brass, wood, etc. They had tons of
audio clips too.
There were (I think) very audible differences in sound between
wood and brass and aluminium, but not much difference
between different aluminium adjusters.
I had a set of brass adjusters on a bass. Just choked all the
sound out of the bass. We put aluminium adjusters on and the
bass was much more open and loud.

 

[John Goldsby]

Well, the distance between the nut and bridge is about 1041.5mm on the G string and 1041mm on the E string if that helps.

Is this a matter of fine tuning too?

I think if your G string is .5 mm longer than your E string, that would affect the sound somewhat. Maybe some of the luthiers here could chime in, but I think the string length should be the same on all strings and the bottom side of the bridge should be perpendicular to the top of the bass (90o angle).

I just got a bass made by Jean Auray, and he includes a little measuring stick to check that distance every time the bridge is repositioned. You can see the Upton guys here demonstrating their version of the tool.

I think when you repositioned your bridge, the sound might have changed somehow, but not necessarily because of the adjusters. I don't think the Fishman adjusters kill the sound any more than other aluminum adjusters, and I've found that sometimes basses sound better with adjusters than with just a wood bridge.

 

[B String]

I don't think the Fishman adjusters kill the sound any more than other aluminum adjusters, and I've found that sometimes basses sound better with adjusters than with just a wood bridge.

In the study (with sound clips) I found, The wood and
especially the brass adjusters had the most detrimental effect
on the tone of the bass. The aluminium adjusters let the most
amount of sound come out. I don't think the brand of aluminium adjusters makes too much of a difference.
I must say, I was taken back at how much some of the
adjusters effected the sound. No more brass for me....ever!