Bridge adjusters - how high?

[George700DL]

Last night, after re-shaping my bridge curve to accommodate easier bowing, I ended up having to raise my adjusters by 2 turns to keep the previous string height of my 2 outside strings. So now the adjusters are exactly 3 full turns up from the dead bottom. This being summer time, I suspect I might raise them up even more in the winter due to wood movement.

What would be the realistic maximum height for these? Meaning, before possible loss of volume or bridge instability.

If I remember correctly, the threaded part is a bit under an inch or so, and right now the exposed part (between the leg and the wheel) is about 3mm - or just slightly less than the thickness of the wheel itself. Is it pretty common to see these adjusters set much higher than, say, 3 mm?

(The adjusters I have are 1 piece, aluminum, threads down).

If this is a stupid question, then well, it is what it is .

George

[Jake deVilliers]

I've seen adjusters extended to half their threaded length with no problems. It probably depends on the density of the wood in your bridge and the depth of your threads.

In your case with only three gut strings, I don't think you need to worry.

[MIKMAN]

IMHO in the winter time you'll have to adjust the strings lower, not higher.

[George700DL]

Originally Posted by MIKMAN

IMHO in the winter time you'll have to adjust the strings lower, not higher.

Based on what I've read here, it seemed like the opposite would happen - on a fully carved instrument, as humidity goes up, the back swells, pushing the scroll toward tail piece, thus increasing string height. The reverse happening in low humidity.

But then again - my back and ribs (on the bass ) are plywood, so there may not be too much of movement in any case. So far this is all theory on my instrument, since it was only born this January. I'll deal with it when it's time to deal with it I guess, and ignore any OCD symptoms.

Thanks for the reply.
George

[George700DL]

Originally Posted by Jake deVilliers

I've seen adjusters extended to half their threaded length with no problems. It probably depends on the density of the wood in your bridge and the depth of your threads.

In your case with only three gut strings, I don't think you need to worry.

Thanks Jake.

I just did a more detailed search/reading across this forum and did find posts by a few pros suggesting the 1/2 of the thread thing. So my question has been addressed in the past.

I guess my question has more to do with volume and less with structural issues - I don't think I'll ever need to get anywhere close to even half of the threads exposed.

It seems that a few millimeters of exposed threads is good for the volume in my case. My friend played my bass the other day and noticed the new volume and sustain right away.

Thanks for the quick reply.

George

[tornadobass]

Originally Posted by George700DL

Based on what I've read here, it seemed like the opposite would happen - on a fully carved instrument, as humidity goes up, the back swells, pushing the scroll toward tail piece, thus increasing string height. The reverse happening in low humidity.

The bass I bought this spring (4 yr old carved Romanian) had fairly high action (E = 13mm) with the adjusters fully lowered. I asked the luthier who worked with the shop I bought it from to lower the bridge height a bit so I could have some adjustability.

The bass came back with a good string height but the adjusters were up about 1/4". The luthier told me I would be glad for that because I would want to lower the strings in the summer. So far, things have remained the same though (E = 8mm, G = 5mm), even though the room humidity has gone from the low 30% range to the current 50% or so.

BTW, the bridge is a Kolstein with the wooden adjusters.

[George700DL]

Originally Posted by tornadobass

The bass I bought this spring (4 yr old carved Romanian) had fairly high action (E = 13mm) with the adjusters fully lowered. I asked the luthier who worked with the shop I bought it from to lower the bridge height a bit so I could have some adjustability.

The bass came back with a good string height but the adjusters were up about 1/4". The luthier told me I would be glad for that because I would want to lower the strings in the summer. So far, things have remained the same though (E = 8mm, G = 5mm), even though the room humidity has gone from the low 30% range to the current 50% or so.

BTW, the bridge is a Kolstein with the wooden adjusters.

That seems consistent with what I've read. My concern was that I might have cut the bridge too much, but it sounds like the adjusters will be able to accommodate nicely.

Thanks.

George

[Mark Perna]

My string height goes down in the winter and up in the summer so I have to raise the strings in the winter and lower them in the summer.

mark

[MIKMAN]

In my country the winter months are characterized by increased humidity levels (between 78% and 92%). If the heating system consists of radiators the humidity level remains above 50% indoors. From the other hand if the heating system implies forced air circulation the humidity drops quickly indoors and a humidifier is more than necessary.
Summers are generally dry in Greece, so the humidity indoors, combined with the air conditioning systems, drops below 30%. The humidifying devices have to work on a 24 hour basis in order to compensate.
This situation explains my adjustments (lower in the winter, higher in the summer). These are typical situations in the European South.
My fellow Europeans rarely use adjusters and particularly the double bassists of many known Symphony Orchestras detest them. I never managed to explain the reason why.
BTW i do use them in my gig bass and i found them more than
necessary in many cases. When the threaded part is exposed up to half length the sound becomes magnificent. Exposing more leads to a "nasal" sound and in my case is not recommended.
My $0.02
Mike

[Mark Perna]

That certainly explains your results. In Pittsburgh, the humidity drops to 20-30% in the winter (sometimes lower) requiring a humidifier. In the summer it is usually between 50-60%.

mark

[George700DL]

Originally Posted by MIKMAN

In my country the winter months are characterized by increased humidity levels (between 78% and 92%). If the heating system consists of radiators the humidity level remains above 50% indoors. From the other hand if the heating system implies forced air circulation the humidity drops quickly indoors and a humidifier is more than necessary.
Summers are generally dry in Greece, so the humidity indoors, combined with the air conditioning systems, drops below 30%. The humidifying devices have to work on a 24 hour basis in order to compensate.
This situation explains my adjustments (lower in the winter, higher in the summer). These are typical situations in the European South.
My fellow Europeans rarely use adjusters and particularly the double bassists of many known Symphony Orchestras detest them. I never managed to explain the reason why.
BTW i do use them in my gig bass and i found them more than
necessary in many cases. When the threaded part is exposed up to half length the sound becomes magnificent. Exposing more leads to a "nasal" sound and in my case is not recommended.
My $0.02
Mike

That makes total sense, thanks for explaining.

The adjusters made my bass louder, without a doubt. Good to know I hav e plenty of room for adjustment.

George

[Eric Hochberg]

Originally Posted by George700DL

Based on what I've read here, it seemed like the opposite would happen - on a fully carved instrument, as humidity goes up, the back swells, pushing the scroll toward tail piece, thus increasing string height. The reverse happening in low humidity.

I've been told that the top swells the most, raising the bridge and maybe requiring a longer sound post.