Trouble with intonation on resonators

[mando]

Hi there,

I have been having the same issue with every resonator I could get my hands on so far: the intonation is off when going up the fretboard.
The issue is most noticeable on the lowest string, where the fifth fret sounds already very sharp to my ears (which are NOT very sensitive). 7th fret is about 20% sharp.
I never had this issue on other types of guitars, banjos, mandolins (at least, I could not hear it), and have it on every resonator that passes through my hands, so it seems they are pretty fiddly when it comes to intonation... But lots of players sound great with them, so I must be missing something!

I've realised I can't keep playing that way, as everything sounds horrible up the neck. But I have no luthier who knows resonators anywhere close to home (Clermont-Ferrand, France), nor do I know much about resonators' setup either.

Here's a little video of my MM Blues 28 (by far the resonator with which the issue is less noticeable. I've played a NRP tricone which sounded great but had horrible intonation, and a busker which was pretty much the same).


I think the setup is alright, but here's a little video of the neck angle and the bridge, in case something seems of to you:



I suppose I should :
- give the strings some slack
- push the bridge towards the saddle a bit
- hope the intonation gets better once tuned up

But I'm pretty scared to mess around with this resonator, which appart from the intonation problem, sounds absolutely great!!! So I prefer to ask before doing anything wrong: does the process described above seem like the right one ? Anything I should be cautious about/aware of ?



A link to a couple of pictures of the saddle, bridge and neck angle: ibb.co/album/Hp2BHq


Thanks in advance

[alexkirtley]

Someone correct me if I'm mis-speaking, I work mainly on flat top acoustics, but I believe the intonation can be adjusted slightly by the rotation of the cone, it is sounding a bit sharp, so the bass side of the saddle wants to be moved nearer to the tailpiece than the neck, try rotating the cone very slightly counter clockwise

[bonzo]

Good point Alex. I have done this and it worked. I followed a procedure that was posted on the forum about this subject.
What I did was loosen the strings slightly, enough to allow the cone to move while still keeping pressure on it. Then using a pencil rotate the cone by pushing against the bridge as Alex has described. Be gentle of course and don't press down on the biscuit, just enough pressure to rotate it and push it back slightly.
Retune and hopefully you'll be good to go!

Best wishes to you all, John

[pete1951]

The first thing to do is put on new strings ( which you may already have done) as strings age they stretch unevenly and this can cause intonation changes.

More from me later if nobody else adds more .
Pete

[lonelyjelly]

What is the action like? If it is a smidge higher than normal to enable slightly easier slide playing then you’ll likely always have to compromise a bit with intonation up the neck - especially on the two lowest strings. I have the same situation on my reso and it’s a bit annoying but I live with it. I play in standard tuning a lot but don’t tend to fret high up on the 6th string for the action is around 3+ a bit mm at the 12th and it starts to fret sharp from around the 7th.
What the others have said is sound advice. Also consider the string gauge ~ lighter strings with a higher “slide” action will struggle a little more with intonation than heavier strings with the same action.

Best regards
Lew

[Michael Messer]

Hello Mando,

There is no reason why that guitar should have a problem with intonation. MMB28s are usually bang on and hardly need any adjustments.

I think you should follow the advice given to you by Bonzo and Pete. Rotate the cone so the intonation is correct. To do this, use two pencils or sticks. Use one on each side of the cone - for example...neck side by the low E string and tailpiece side by the high E string. Have the strings slackened down and very slightly twist the whole thing by pushing the two pencils.

I do have one question about your guitar. Is it a very early MMB28 because it does not have the MM coverplate? The only MMB28s without MM coverplates were the first 25 ever made.

Shine On
Michael

[bonzo]

Lonelyjelly has said exactly what I was about to post!
The fact that you have this problem with reso's and not 'regular' guitars is probably down to the fact that the reso's are set up with a higher action to help with slide playing. The higher action doesn't help with fretting, either physically or intonation wise. Looking at the pictures of your guitar the action does look quite high, but measuring string height at the 12th fret will tell you more accurately. Generally 3mm or slightly higher seems to be the general consensus. But it will depend on your style of playing. I also noticed from your pictures quite a bit of play wear on the upper fretboard indicating you do a lot of fretting up there. If so maybe you could set the guitar up in a more standard guitar manner, favouring fretting over slide. It is something you can overcome, it might just take some time and adjustments. I've got a few reso's and have managed to get them sounding okay intonation wise. With more practice I hope oneday I'll sound okay music wise! Good luck.

Best wishes to you all, John

[bonzo]

Was posting at the same time as Michael.
As he says and I and others will confirm MM guitars are always setup very well. I have never had any problems with intonation with them and actually use them as a benchmark when adjustments have to be made on my other reso's!

[Michael Messer]

Sept 7, 2020 8:06:30 GMT lonelyjelly said:

What is the action like? If it is a smidge higher than normal to enable slightly easier slide playing then you’ll likely always have to compromise a bit with intonation up the neck - especially on the two lowest strings. I have the same situation on my reso and it’s a bit annoying but I live with it. I play in standard tuning a lot but don’t tend to fret high up on the 6th string for the action is around 3+ a bit mm at the 12th and it starts to fret sharp from around the 7th.
What the others have said is sound advice. Also consider the string gauge ~ lighter strings with a higher “slide” action will struggle a little more with intonation than heavier strings with the same action.

Best regards
Lew

A 3mm string height is perfect for slide playing and for some open tuned fretting, but if you play mostly in standard it should probably come down to 2 to 2.5mm. It won't go lower than that.

I have a high action on my guitars and sometimes I tune the bass string down a fraction so it is in tune when fretted.

There are always ways around these things and no guitar can ever be perfect, it is always a compromise.

Shine On
Michael

[Stevie]

It is true that with even temperament, no guitar will exhibit perfect intonation- even with the rarely encountered nut compensation. In addition, the simplistic nature of the biscuit style of bridge severely limits attempts to reconcile intonation with the angry discordance you are hearing. Put succinctly- you need to take a little of these compromises "on the chin". That said, I have "been inside" my biscuit bridge MM many times and intonation after re-assembly has never been an issue at my level of listening. This I attribute to Robin's masterful set up. I have a very expensive acoustic guitar that had to go back to have the nut re-worked because due to the applied nut compensation, it simply wasn't happy in open tuning.

The way I see it is that folks tend to use slide vibrato freely with the slide, and with plain vanilla brain / listening coordination, they subliminally filter out what they want to hear from the chaff? I believe this is done subconsciously. If you are hearing angry notes that you cannot minimise by rotating the biscuit, addressing the "action" and / or chamfering the leading or trailing edges of the bridge slots, then you should congratulate yourself on having above average pitch recognition because the drunkards in your audience will probably not notice, or will likely be too busy analysing the provenance of guitar you are playing.

e&oe ...

[lonelyjelly]

Tbf I have only played a handful of resos (set up for slide and non-slide) that had excellent intonation all the way up the neck and they were all in the £2K - £4K price bracket!!!

Another possibility is to tune down a step and capo at the 2nd ~ this reduces the action a bit and therefore should improve the intonation a little. Also makes bending those heavy strings a little more pleasant on the tips!!!

Lew

[Michael Messer]

Lew, Actually we are finding these days that all MM Guitars are playing really well in tune up the neck. It has nothing to do with price, it is to do with geometry and cutting bits of wood to the correct dimensions.

Shine On
Michael

[mando]

Thanks to all for your kind answers!

To clarify one thing: I DO NOT have above average pitch recognition, quite the opposite. I often realise I have been playing a very out of tune guitar for half an hour when I check with a tuner. I'm not talking about high precision here, but rather a 7th fret which is nearly a quarter tone off, which anybody (except drunkards, maybe!) notices as quite unpleasant . 

I will be back home on wednesday and will try to rotate the cone as suggested. However, every string goes sharp when going up the neck... So I suppose this will help with the lowest string (which is the most problematic), but it will make the highest string worse.
It seems to me as if the whole bridge needs to move back towards the saddle, but I'm not sure this is possible.


to Michael: I bought this guitar from Simon Ambridge. It is number 18, so it seems to be one from the first batch indeed!
Appart from this intonation issue, I was actually pretty impressed by the setup: this guitar is very easy to play and is by far the best sounding and loudest reso I have had the luck to play! And because the other resos I played had the same issue, I thought it was maybe just a resonator thing... but it rather seems like I have some kind of curse as I seem to be the only one in that case


to Lonelyjelly and Bonzo: I don't think the action is the issue, as the note is just as off if I place the side right above the fret. Above the 7th fret, I have to go about halfway between to frets to be in tune. Plus I have played acoustics with action just as high, and the intonation was alright (probably not dead on, but good enough for me).

[lonelyjelly]

Sept 7, 2020 18:44:43 GMT Michael Messer said:

Lew, Actually we are finding these days that all MM Guitars are playing really well in tune up the neck. It has nothing to do with price, it is to do with geometry and cutting bits of wood to the correct dimensions.

Shine On
Michael

Cool cool 😎 I’m away at the moment but I now have an obvious itch to check my guitars!
For the record I wasn’t talking specifically about your guitars 😊

Mando ~ as far as I’m aware it is feasible to move the whole biscuit / cone back towards the tailpiece 👍

[richclough]

A couple of questions from me....

Is it just the 6th string that is going out of tune, the others being okay? If so, you may simply have a dud string. I had one once where the windings were noticeably thinner towards the bridge. It took me a while to work out what was going on...

Do you get less of an intonation issue depending on the tuning? I find that intonation tends to worse the lighter the strings get and the lower the tuning i.e. the lower the string tension. Might be worth experimenting a bit here.

Just a couple of thoughts.

Cheers,
Rich