Silly physics question about temperature, metal, and pitch

scrubs

scrubs

Not of sound mind
So, I have a glockenspiel/bell set. According to my strobe tuner, most of the bars are about 10 cents sharp. I'm wondering if this has much to do with the temperature of my room - i.e., would I be able to get them closer to in-tune if I changed the temperature of the room/bars? I'm guessing that heating them up would cause the metal to expand and drop the pitch - is that sensible? Anybody want to venture a guess as to how much I'd have to change the temperature to make an appreciable difference?

I guess I could always pitch-shift them, but I don't particularly like what that does to the sound.

Thanks.
 
2.7 degrees celcius per cent






















































psych. i don't know man. :p

i wouldn't think that the variation of a room's temperature would have an effect on the sharpness of your glock and bells. :D seriously, they're all 10 cents sharp? is that the attack or decay? is the attack slightly sharp? if your glockenspiel is consistently 10 cents sharp from bottom to top, i would imagine that it's designed that way. there's absolutely no way that all the bars will be consistently sharp being that they're different sizes. it takes a big temperature change to expand steel, which i assume the glockenspiel bars are made of.

your question sounds reasonable so you might want to wait and hear from someone else that's reasonable. :p
 
It's more likely that your tuner is not calibrated exactly the same as the tuner at the factory.
 
i'd say that either your tuner's off..........or that the QC at the factory that made your glock isn't all that great.

the real question is.......does it sound bad when you use it?


cheers,
wade
 
I don't have a clue but now I'm really curious.


..hmm. What about flat singers?
Just kidding on that part.:D
 
scrubs said:
Anybody want to venture a guess as to how much I'd have to change the temperature to make an appreciable difference?
Click to expand...
i suppose one of those crack pipe.....errrrr......creme brulee butane blowtorches would get you in the neighborhood. :D :p :D


cheers,
wade
 
Thanks for your responses. I'm using a Peterson VS-II tuner, which I think is pretty accurate. The bars are not all exactly 10cnts off, but that's about the average. It's a cheap Rogers bell kit that I bought used back when the Brooks Mays' stores were going out of business. I wouldn't say that the sharpness is very noticeable in the context of the recording, as the hits are pretty transient, I just found it odd. I tried the Cubase pitch shift and took them down 10cnts, which sounded more "right" but the tone was affected, so I'll probably just leave it.

I may experiment with a heater just to see if it makes a difference. :cool:
 
Yep, .. heating will expand... but you'll need lots of heat...

Put one bar in the oven at 200 centigrade, and see what's happened to the pitch?....
 
scrubs said:
Thanks for your responses. I'm using a Peterson VS-II tuner, which I think is pretty accurate.
Click to expand...
It isn't about how accurate your tuner is, it's about whether your tuner is calibrated to the tuner at the factory.

Thost things are tuned with a grinder, so it isn't an exact science. If you grind the end, the bar goes sharp. If you grind the middle, it goes flat.
 
maybe not so strange, i heard that most of the bigger symphonys were beginning to tune higher then 440, some as high as 447.
so possibly the bell maker is in tune with that trend?

possibly just a rumor though.
 
Rogers is old stuff, the earth was denser in the 60's. As it lightened up over time, the pitch of all instruments made back then naturally rose. You can hear the earth gettin less dense on concert recordings from back then, musicians were always retuning between songs because the earth would thin out a little while they were playing and throw their instruments off.
 
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