It is more complicated. Modern violins can be louder, and audience generally think loud=better, but this may not what the player prefers or what is wanted in an orchestra. There is also the issue of playing an instrument only an hour vs playing an instrument for a tour or longer time.

https://www.violinist.com/blog/laurie/20121/13039/

This is a description by one contestant who participated in the 2010 test. She generally likes that new violins can sound really good, but she criticizes:

> As for the old violins: one was a Guarneri del Gesù (circa 1740) and two were Antonio Stradivari (circa 1700 and 1715) "These violins were loaned with the stipulation that they remain in the condition in which we received them -- precluding any tonal adjustments or even changing the strings." That means that, whatever happened to the old violins during their trip -- if they got jostled on the airplane, etc. -- there was no soundpost adjustment, no bridge adjustment, no check for open seams. If the strings were a little older, they were a little older. … My concern is this: it sounds to me like the older instruments were not optimized -- by either selection or by luthier adjustments -- while the new moderns were.

There are also differences between Stradivarius. In the formal test one old Stradivarius was universally disliked and in an informal test a modern violin beat an old strad. She wonders if that was the same model:

> […] During the same event when this study took place, another more informal "study" was done by those who did this one. While jurors were deliberating over the outcome of the Indianapolis violin competition, the audience that was gathered was asked to evaluate some moderns vs. old Italians. Indianapolis Symphony Concertmaster Zach De Pue played four pairs of violins, allowing the audience to decide which they liked best of each pair, based on playing excerpts from "Scheherazade" and Strauss's 'Don Juan.' Each pair included one old and one modern violin. The votes were very close each time, but ultimately the audience chose one modern violin and three Strads, from the years 1699, 1714 and 1715. Several more tests and votes narrowed the fiddles to the one the audience liked best: Jimmy Lin's 1715 Strad. (Was that non-preferred Strad from the study in the mix? I'm guessing it was, and it was the one not-preferred).

It should be mentioned that "old" violins that are still used today have all been substantially rebuilt to accommodate later repertories. There is a lot of difference between an early Baroque violin and a late 19th century violin including the fingerboard and the type of strings, and only a few museum strads that have not been played have retained their original configuration. One benefit of the early music movement that took off in the second half of the 20th century was realising that the "old" and "original" instruments weren't actually that old or original after all, and new baroque violins had to be made from scratch to attempt to reproduce what they would have sounded back like in the 17th and 18th centuries.

It's more than that - the bass bar on modern instruments is substantially heavier, because string tension with modern wire wound strings is higher than baroque era gut strings; the older instruments are more lightly built.

The tone you get with gut strings is completely different than with modern strings - more complex, more resonances, but a modern style instrument will deaden that somewhat, you really want a period instrument to take advantage of gut strings.

https://www.youtube.com/watch?v=7y4lcQ7BTLw

The neck is also different, but that affects reaching the high end of the fingerboard more than accoustics.

It may be that the old violins are preferred as tools because they somehow help the player achieve the same (optimal for their skill level?) sound, more easily and consistently.

Think of a car that is less effortful to drive. From external appearances, the same driving is happening either way. But inside, the “worse” car has a lot of compensating on the part of the driver, while the “better” car does not.

It’s a good hypothesis. Anecdotally though, I know a bunch of people who have experience playing both, and say that the old instruments can be difficult to play, though sound amazing when played well.

It might be purely due to how expensive they are.

MRI studies proven that people really do draw more pleasure from tasting wine when they know it's expensive.

I imagine some people would also derive more pleasure from knowing they're eating the last of a particular species, or walking on a floor made from the last of a particular irreplaceable forest, or racing a car that is the car that was raced in historical race of ages past, or even winning a rai stone in a game of backgammon. All exclusive experiences.

>>> There have been double-blind tests that show that Stradivarius violins are acoustically nothing special: experts cannot pick them out by sound alone, or may actually prefer other violins.

This is widely acknowledged among violinists. In fact there is a growing concern that the Strads are deteriorating. The vast majority of working musicians have never handled a Strad.