Lower bridge to improve action - good or bad idea?

[Peter Michael]

Hello,

Please can I draw on the knowledge and experience of you all.

My Stentor Student (laminate all round) sounds great but the action feels high. Above say C on G string my left hand fingers need to move off the fingerboard what feels an exaggerated amount when changing strings. It is my first bass so I'm not sure if that is normalish.

The G string is 14mm off the end of the fingerboard and 11mm above the fingerboard at octave harmonic (1/2 way). The corresponding measurements for E string are 9mm and 6mm (all measurements from bottom of the string). The scale length is 1020mm. I think I recall somewhere standard heights should be 10mm for E and 8mm for G at the end of the fingerboard. The bridge makes a 90degree angle to the top of the bass on the forward edge (upwards), so I think it is on the correct way round.

 

I think I can lower the bridge by the correct amount at the G (and corresponding at D and A) , but this would come at a price of reducing the break angle over the bridge from 30degree to about 26 degree I think. In the acoustic guitar world reducing the break angle is a bad thing as it reduces volume loads. I guess, but don't know, basses might work the same way. Current volume is OK, but I do not want to lose a noticeable amount of volume.

 

So my question, assuming my assumptions are OK, is;

Should I reduce action or will the loss in volume be too high a price to pay and so should I just get a better technique?

 

Thanks in advance for your wise advice

 

 

[jrixn1]

I can't answer your question quantitatively, but can share my experience.  I recently had adjusters installed (https://www.mjbl.co.uk/double-bass-bridge-adjusters-for-sale) for a similar reason - wanted to try a lower string height.
I didn't go down much at all, but I was surprised how noticeably it negatively affected the tone and volume. The tone had less attack, and I think the lower volume caused some amplification feedback issues as I had to add correspondingly more gain to be the same volume as previously.  It's the only time I've had any feedback issues in many years.  However I'm always playing in lots of different venues so I could not say for sure that the string height was the problem.  Anyway I soon raised the adjusters back up to the original height.

If I wanted to pursue this, I think I'd take it to a luthier as I'm not versed in upright setup and I wonder if there are other factors which can be adjusted.

[Rabbie]

Hi. As a disclaimer, I am not a luthier, just a long time player. The only sure thing is that no solution can be even approximately reached without seeing the bass. In saying that, what you have at the moment sounds quite a bit wrong. It may well be that your bridge is mounted the other way around. The straight edge of the bridge, if there is one, should be facing the tailpiece, and the centre of the feet at either side should be approximately lined with the little points in the middle of the f holes at either side. 
A modern string action with a well set up bass is around 6mm-10mm (or even lower) G to E that’s measured at the end of the fingerboard. String height is very subjective and optimal varies from bass to bass and player to player. Don’t be worried about the loss of sound, as a bass that is a joy to play and has low action can still sound huge with good technique and the optimal setup. All the great jazz players have a lower-than-you-might-think action and can be heard very clearly even in the context of a relatively loud band.
A 9mm-14mm action G to E is a tolerably high action for the fit & macho gut string player (I was once one of them, well…never macho, but young and fit). However a string action that goes in the opposite direction 14mm to 9mm G to E like yours, is never correct.

I’m sure you already know, but please read loads of resources before trying anything yourself. Any bridge work will also mean resetting a fallen sound post, which is a whole headache of its own. 
It really sounds like a trip to your closest luthier would do your bass a world of good.

Hope this helps a bit and so sorry if it’s not so clear. 

Edited February 6, 2023 by Rabbie
Typos and clarification

[SubsonicSimpleton]

@Rabbie is spot on - the flat side of the bridge should be towards the tailpiece.

 

It is pretty easy to turn the bridge round to the correct orientation - the first time you do it however take some time over the process, if you are ever in a situation where your bridge has been knocked out of alignment or knocked over and you need to sort it out at the gig what you learn about the process now will be invaluable. You might want to let people know whereabouts you are based, as there might be an experienced DBer locally who could help you with this if it seems a bit overwhelming.

 

Before you start, check that the soundpost is still in position (you should be able to see it through the G side f-hole), if it isn't there and you can hear something rattling round inside the bass, you'll need to detune the bass and get to a luthier.

 

 

 

First you need to lay the bass on its back - don't use the floor, the bass needs to be resting on it's back, not the neck, a bed is ideal as you can let the neck over hang the edge.

 

Second you need to apply some weight to the top of the bass to avoid the soundpost falling - big heavy books are ideal.

 

Third slacken off the tension on the strings (not all the way, but enough that you can easily remove them from the string grooves), remove the E and A to the E side and the G and D to the D side.

 

Swap the bridge round so the flat side is facing the tailpiece, take this opportunity to lubricate the bridge and nut slots with a 2B pencil.

 

Replace the strings back onto the bridge A,D then E,G.

 

While the strings are still at low tension line the bridge up carefully (inner f-hole notches should line up with centerline of bridge feet, string position should be centered on fingerboard looking down the neck, bridge should be perpendicular to bass top, strings seated correctly in their grooves at nut).

 

Slowly bring the strings back up to tension, checking that the bridge is staying in position and not being pulled towards the fingerboard - the following video is a pretty good guide to adjusting the bridge, but as you can see from the way Herve-Jean places the bass on the floor, you couldn't weight the top of the bass to prevent the soundpost falling.

 

 

[NickA]

Quick answer to your question.  Yes you can make the action easier by filing down the top of the bridge.  It will change the sound too, quieter and buzzier.

 

I did it to my ( fully carved ) bass but later had the bridge converted to adjustable.  Now back to the old high action for bowed / classical ( best tone and fastest response to the bow) and low as poss for jazz / pizz ( easiest action, more "mwah", lower volume .. but I'm using a pickup, so no issue).

 

Bass playing needs a strong left hand though, so good to get used to it.  I often practice jazz with the high bridge as training.

 

Having said which, I just got a ruler to my bass and found my "high" action is 9mm on G, 10mm on A (hard to measure the E as I have one of those "Romberg bevels" on the fingerboard.

 

Edited February 5, 2023 by NickA
added actual action numbers

[Peter Michael]

Thank you everyone for your useful and well informed replies.

@SubsonicSimpleton and @Rabbie - Thank you, This is what I shall try first - after much research I think, clearly a fallen soundpost is to be avoided. I'll update when I have done it/lost the sound post.

 

And @jrixn1 and @NickA you have confirmed some fears I had about loss of volume, mistake averted so thank you

 

The plan then is to turn around the bridge and see what we have got actionwise, if workable I will stick with it and work at technique.

 

Great advice from all

[Marty Forrer]

My string heights are 5mm under the G and 8mm under the E, measured at the end of the fingerboard. 

[javasound]

I have a Stentor Student bass, which I bought as a beginner. After a year or so I got a buzzing on the neck, so took it to a luthier. That was easily remedied, but at the same time I said 'do what ever you think it needs'. He moved the bridge and also the sound post - and its like a different instrument. I also had adjusters put in the bridge so that i could experiment with the action.

Taking it to a luthier is the best thing i ever did, and i cant stress what a difference it made - I constantly get remarks about how good the bass sounds (and its the instrument, not the player !)

[Peter Michael]

Thank you, I think that might be a more prudent way forward, Excited though I am about taking the bass apart, the perils are clear and obvious. 

There are some good recommendations on other threads on here for luthiers, I'll make some phone calls first before DIY

 

Peter

[bassace]

This is what I do if I need to slacken strings or take the bridge off. You can see the spacer I made to go between the end of the fingerboard and the top of the bass. It keeps the pressure on the soundpost. Blue towel optional (!).