Hoo boy. DD drama again!
I use dial indicators at my day job also to measure many things in an automotive shop.
Ah, but when your dial indicator tells you something is .010", it's .010". The DD can tell you this tension rod is at 72 and another is at 72, yet one
sounds higher than the other. The DD gives you a false sense of precision. Enough of a sense that young or inexperienced drummers take it as you take your calipers, not taking account of the fact that variability in heads, shells, bearing edges, etc. make the DD far less precise than it looks.
I tuned for 38 years by ear and I know how to tune.
The dial is a handy tool for getting the heads close before fine tuning by ear.
As you suggest, the DD only gets you close. I've never heard a head tuned to "perfection" with a DD that didn't need lug-to-lug fine-tuning. And I've applied my DD to a head that was demonstrably perfectly tuned only to see varied readings. A gadget that imprecise is not terribly useful to me.
However anyone wants to tune, it's all good. But whenever I hear this I can't help but think: if you end up tuning by ear anyway, why not start by ear?
I don't see why its necessary for drummers to "learn how to tune" while every other instrument uses a tuning device.
I'm afraid this is simply untrue. Fretted instruments--yes, they can use a device. Others, not so much.
I play trombone professionally, mostly in the classical world (symphony orchestras and various chamber music groups), but also in shows and the occasional big band gig. In these worlds (and with these instruments--strings, winds, and brass) tuning is done by ear.
More importantly, even if we did all tune our tuning note to, say, a chromatic tuner, that only applies
for that one note. Acoustic instruments all work according to the harmonic series in one way or another. Alas, the harmonic series is out of tune with the equal-tempered scale. When playing any non-keyboard or non-fretted instrument, in any type of music, constant adjustments must be made, in real time, while playing music, to move our instruments from where they
want to play--according to the harmonic series--to where equal temperament says we should be playing. There's no such thing as tuning up and good to go.
It's a skill set that all of us who play non-keyboard and non-fretted instruments
must acquire to sound good.
[I won't get into how most instrumentalists actually veer intentionally away from equal temperament (toward something resembling "just" intonation) the minute we get away from those damn keyboards, because it will make people's heads explode. ;-) ]
But see, that's the issue with drummers who have never played an instrument that requires constant "tuning" on the fly--they've never acquired the skill set that allows you to perceive, and correct,
very minute deviations in pitch. The tiny variations in pitch you hear when doing lug-to-lug tuning are exactly the same thing as the vast majority of instrumentalists face every single day, every single note, as a matter of course. But if you've never been taught how to do it, and haven't put in the time to master the skill, you're at sea with a drum.
Drum Dials work but like anything else they need to be used properly. You can't say "75" and then allow a +/- on every lug. Its a precise measuring tool.
It is not. Or rather, I should say, given the realities of drums, heads, and bearing edges, it's
not precise enough given what we're trying to tune with it.
Why are drummers so terrified on this tool?
I don't know any drummers who are terrified of this tool, nor do I suspect anyone who has contributed to this thread is terrified of it.
But there are problems with it. One, it's not precise enough in actual use with real drums, heads, and bearing edges. As I said, DD-tuned drums need touch-up. Perfectly tuned drums show various readings. And anyone who has used one has run into the phenomenon of a very high reading on a tension rod that's falling-out loose. Two, the
appearance of precision leads drummers who can't tune by ear into believing that it's not necessary to learn how.
Look, if guys like bobdadruma want to use it to get close and then touch-up by ear, it's all good, although I find that the DD slows me way down compared to tuning by ear. But bobdadruma can tune by ear; he's made a choice, and it works for him.
But I'm with audiotech--drummers, like
all musicians other than keyboardists and fretted-instrument players, need to learn to tune their instruments and, in most cases, learn to play in tune on a constant basis. So I believe that drummers who can't tune yet would be far better off spending the $60 they'd spend on a DD and get a lesson or two from a drummer who can tune, and then put a little time in. Once learned, you'll remember it for life.