Mutes and high positions on the G string.

I have a couple of violins that had upper G string problems until I either changed strings (to a set of Larsen Tzigane) or replaced the E string with a Peter Infeld-platinum E string when using other string sets on those fiddles. Since those times I found they both do well with Warchal Timbre strings, and right now one of them is "happily" strung with Pirastro Perpetual-Cadenza strings. Both of these are quite low-tension string sets.

For solo playing I like to use a leather mute that allows me to vary the amount of damping the mute does. (Actually I don't like to use a mute at all and find bowing "over/near the fingerboard" can has a similar effect for short passages.)

I keep Spector mutes on the afterlengths of all my violins in case a surprise muted passage appears in front of my eyes. The Spector has all the advantages of the old "wire mutes" and none of the string-damaging disadvantages. However if I know in advance I will be playing muted I will have other mutes handy to match the situation (I keep a little bag of mutes in the small side compartment of my Musafia case).

1. Do you have similar G-string problems without a mute?
Not particularly, although my technique is still developing.

2. What strings are you using?
Zyexes. I hate them!

3. Which mutes are good for this and which are bad?
Shield mute bad - all others good (ultraheavy, single-slot Tourte, double-slot Tourte)

4. Have you tried the "one dollar mute" (i.e., a folded or rolled up currency bill held by the string afterlengths and touching and damping the bridge)? This gives a mild muting effect.
Not yet.

You know what will happen now. Everyone will pipe up "I don't like shield mutes, that's your problem"
They may be right. But shield mutes are very convenient for orchestral work.
I'll check out Spectors too, though, although the reviews indicate that they don't work for everyone. They look as though you have to fit them while stringing your violin. Is that right? And sometimes different coloured rubbers have different properties - here we get spectors in bronze and black rubber. Have you tried both?

Correction - one-hole tourtes seem better than two-hole tourtes. I've just ordered a Spector, but if it's the same as the shield and the two-hole tourte, then it won't have any effect. Never mind - next time I change my strings, I will have a different set of problems.

A tonal problem on the G, sometimes called a “wolf”, is in my view a multifactorial problem that depends on what is affecting the vibration modes of the top table. I think the factors involved include: the design and build of the violin, position of the bridge, position of the sound post (leave this to a luthier to sort out), position and weight of the chinrest and/or shoulder rest, the tailpiece, the strings (both in their type and the ways they can be mixed), the mute, the bow, and, certainly not least, bowing technique (see teacher for a solution).

The string choice is among the most important factors that can easily be addressed by the player. It is worth remembering that up to the beginning of the post-WW2 era strings were plain gut or had a gut core, with the exception of the steel E which appeared early in the 20th c. Gut strings generally have a lower tension than their synthetic equivalents, and I have noticed that a wound gut G can be easier to play in the high positions than its higher tension synthetic equivalent.

My violin, an 18th c family heirloom, has suffered from a G string wolf in the past, but recently it seems to have disappeared. This old violin has always been a bit tricky to set up for tone, and I put it down to the fact that it is slightly oversize with a 14.25” back length, and proportionally larger bouts and rib height. Btw, before anyone raises the point, violists in my orchestras who have examined the instrument say it isn't a small viola, so I have no intention of purchasing a set of viola strings (end of that story line!).

One thing I did a couple of months ago was to move the bridge 3mm towards the fingerboard so as to get the correct locations of my hand on the neck in the higher positions. This worked well, but then I also found to my delight that the wolf had disappeared from my gut Chorda G. It had always shown some sort of presence on that string, but had been much worse if I used a synthetic G and so avoided playing anything above the harmonic G. Now, the even better news is that when I installed a set of Warchal Ambers a few weeks ago the wolf has still remained absent. I am limited in my use of the higher positions on the G not by the sound but solely by the larger ribs and bouts and my short pinky which is unusable above the 7th position on the G. This “difficulty” with the pinky isn't a problem on the E and A strings because the other fingers do an efficient job of reaching notes in the highest positions as necessary, but far less easily on the G.

There are bad copy cats of that mute kicking around though, that buzz and tend to fall off

Mutes shift this resonance downwards, depending on their weight (pressing dowards) and their mass (inertia) restraining faster vibration.