Playing around LED Christmas lights

[Tom Holtz]

So this bar in Baltimore (Bertha's) where I play on Wednesdays put up a whole gob of red lights inside, and they aren't the little incandescent bulbs we're used to seeing. These lights are little LED lights on a long cord. No big deal, until I started warming up. Playing low CC's and BBb's (not pedal tones) made my head vibrate on a frequency very close to the operating frequency of these lights. I'm not sure if they're working at 120 Hz, or at 60 Hz and I'm doubling up on them. In any case, the net effect was that the lights appeared to be weaving up and down while the room stood still. Of course they only appeared to be moving to myself. Very, very disturbing. Playing low B and Bb created a very slow bobbing effect, while low C made the lights look like the roof was coming down. What could be causing this? Please, don't tell me to avoid the shrimp salad.

[windshieldbug]

Please, don't tell me to avoid the shrimp salad.

OK, avoid bad Chinese food

[trseaman]

This also happens when you look at the old style LED clocks. The ones with red numbers (not sure about other colors)... It makes the numbers dance around a bit!!! All that and no drugs!!!

Regards, Tim

[sc_curtis]

I've seen this as well while looking at computer monitors, and on the same notes that you described.

[ken k]

Its not the lights moving, its your skull. The same thing happens when you play and you look at a TV or computer screen. The vibrations of the skull move your eyes. As you mentioned the frequency of the ocillating skull must aline with the frequency of the lights somehow and it looks like the lights (or TV/computer screen) bounce around.

You are not going crazy. Close your eyes!

A similar thing happens in my practice room. There is something in my room that I have not been able to find (It might be the flourescent light fixture) that vibrates quite loudly whenever I play an Ab. Drives me nuts.
(So I just don't play Ab!)
ken k

[Tubaryan12]

More can be found here viewtopic.php?t=6224&highlight=eyes

[TubaRay]

You are not going crazy. Close your eyes!
ken k

I'm not sure how Ken is able to say this with certainly. It's quite possible that you MAY BE going crazy. You're playing in a bar in Baltimore, aren't you?

Just kidding around.

[tubatooter1940]

Try to sit where the lights are not in your line of sight. It's inevitable that your head rattles when you play tuba. Try sunglasses. I focus on my guitar player's right hand because he taps his foot out of time. These are illusions that happen often when you emanate those low vibrations.

[iiipopes]

And just think -- some people take hallucinogens to get this!

OK, USA alternating current is 60 cycles/hertz.
In an equally tempered scale A=440, low BBb is @ 58.3, low BB is @ 61.7 and low C is @ 65.4. So you're going to get the full effect of the heterodyning whatever you do and phase right on out. Try to get the lights out of your line of sight. Your body will react, probably not with an epileptic seizure as can happen (Apple many years ago started putting controllable repetition rates on their mouse, menus, key strokes, etc. for exactly this reason), but it can give you a real headache!