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Topic: Adjustable intonation |
Dave Hepworth
From:
West Yorkshire, UK
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Posted 18 Aug 2023 7:26 am |
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Hi All,
On a regular 6 string guitar the bridge saddles are adjustable to accommodate strings intonation going sharp or flat as you fret .
This makes me wonder if the industry standard of a fixed axle and finger / roller system is flawed.
Would a system using an actuating lever on the string which would then allow the string to go over a rolling bridge saddle which in turn could be adjustable forwards and backwards.
If this system was deployed would it negate the use of sweetened tuning charts as you could do sweetened intonation at the " bridge roller ".Are any steels made using this ?.If so how effective are they.One advantage would be increased string to body contact and therefore possible increase in resonance and tone.
Any comments guys ? |
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Ross Shafer
From:
Petaluma, California
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Posted 18 Aug 2023 8:20 am
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Intonation adjustment at the saddles assumes a fixed amount of deflection in the string as the string contacts the fret. Using a slide, this fixed point does not exist, therefore any intonation adjustments at the bridge would not assist in fine tuning a string's intonation unless you're able to somehow use precisely the same pressure with your bar at each fret....pretty much impossible.
Furthering the difficulty of maintaining the exact bar pressure from which to set your intonation is the fact that each fret would require its own exact bar pressure to achieve the deflection needed to match intonation set at the saddle.
I feel that bar pressure has much more to do with intonation than is generally thought of or discussed. |
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Ian Rae
From:
Redditch, England
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Posted 18 Aug 2023 8:21 am
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Dave - I'll stop you right at the first paragraph. A steel guitar doesn't fret, so it doesn't need adjustable string anchors. On a 6-string guitar, the strings go sharp by varying amounts as you fret (never flat!) but the strings on a steel are all the same length all the time. Just imagine for a moment what would happen if they weren't!
[Ha - Ross beat me to it, as usual...]
_________________
Make sleeping dogs tell the truth!
Homebuilt keyless U12 7x5, Excel keyless U12 8x8, Williams keyless U12 7x8, Telonics rack and 15" cabs |
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Georg Sørtun
From:
Mandal, Agder, Norway
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Posted 18 Aug 2023 3:12 pm
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Adding to what Ross and Ian have mentioned…
While redesigning my Dekley, I tested out the simplest form for bridge-adjustment: slight angling of the entire bridge / changer.
With the thickest wound string 3mm longer than the thinnest plain string, there was/is an audible improvement in how the PSG strings sound individually and together – very improved clarity. Thus, I kept this angling as part of the modifications.
The about 3mm "offset" I now have on that PSG, makes the thick wound strings exact over-the-bridge vibration points closer to that of the thinnest, which explains the audible improvement. So while the bridge / changer axle does not allow for individual vibration point adjustment, it most definitely sounds like a good compromise without causing any problems with the changer's raise/lower functionality.
Intonation as such (apart for in open) depends entirely on how the bar is positioned and pressed down; i.e. how well the PSG is played. So while minor improvements can be introduces to improve the instrument itself, I do not think a fully adjustable bridge (with adjustable rollers separate from the changer) will do much good intonation-wise. May even harm sustain characteristics if not built well.
If anything; individually adjustable nut-rollers, might be useful. |
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Doug Earnest
From:
Branson, MO USA
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Posted 18 Aug 2023 6:05 pm
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| You have to be able to actually play the thing before worrying about any of this. I never did watch Hal Rugg play and wonder how he got along without bridge adjustments. |
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Tommy Mc
From:
Middlesex VT
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Posted 20 Aug 2023 6:06 am Re: Adjustable intonation
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| Dave Hepworth wrote: |
If this system was deployed would it negate the use of sweetened tuning charts as you could do sweetened intonation at the " bridge roller " |
Dave, I'm pretty sure the reasoning behind sweetened tunings has little or nothing to do with compensated bridges.
_________________
1980 MSA Vintage XL S-10, 1975 Session 400
1972 Dobro model 66s
Derby SD-10
Tom McDonough |
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Ian Rae
From:
Redditch, England
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Posted 20 Aug 2023 11:28 pm
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Agreed. And while Georg's angled bridge is convincing, it's surely less trouble to angle the bar if your ears tell you to, and the effects of uneven bar pressure are greater than any of this.
_________________
Make sleeping dogs tell the truth!
Homebuilt keyless U12 7x5, Excel keyless U12 8x8, Williams keyless U12 7x8, Telonics rack and 15" cabs |
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Georg Sørtun
From:
Mandal, Agder, Norway
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Posted 21 Aug 2023 8:48 am
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| Ian Rae wrote: |
| Agreed. And while Georg's angled bridge is convincing, it's surely less trouble to angle the bar if your ears tell you to[…] |
As I (think) I wrote: an angled bridge has nothing to do with intonation. Any and all PSGs resonates with the body via the bridge – not the bar, which is how/why the angled bridge has an effect on "clarity".
| Ian Rae wrote: |
| […] and the effects of uneven bar pressure are greater than any of this. |
For intonation; yes. And we have to keep in mind that no two strings react the same – pitchwise – on varying pressure-depth. |
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