"Burning in?"

[Lisa]

Hey there. ^^

I'm more of a SMing techie, but I heard the term "burning in" recently, and it caught my interest. Someone noted that sometimes, when you've got new equiptment, you should let it run something [music, whatever] for 50 hours. According to him, it improves the sound quality tremendously. He called it "burning in."

So, here's the question. Is that completely made up, or is there some legit reasoning behind it? If so, what's the mechanical part?

Lisa

[JahJahwarrior]

i don't know if it applies to all things, but to guitar amps and drum heads it does. The speakers in guitar amps do seem to sound better, or atleast different, after several hours of playing. I do not know if anyone has documented a change in frequencies and db during the life of a speaker, but they do seem to change sound just a little bit after a while. And with drumheads, they sound best after they've been stretched a little by playing and retightened. Come to think of it, guitar strings sound better after a little bit--they don't go out of tune as fast after thy've been played for a little bit. So with somet things, it does appear to help. I think if it applies to theatre, then it applies mainly to speakers. I do not think a cd player will play a cd better after a few hours, or a cable carry a signal better after a few hours

[Mayhem]

Well guitar strings stretch with use, which is why they should be stretched when first put on. As stated, this is why the guitar goes out of tune more easily when new strings are applied.

Valve amps always sound better when hot and the valves give more “life” as they age. Essentially, the valves become microphonic, meaning that they introduce noise as the filaments and plates resonate. It is this that further “adds” to the sound and why overdriving a valve amp produces such a distinctive sound. However, at some stage this noise becomes too much, and the valve(s) require changing.

I cannot think of any "non instrument" application though.

[JahJahwarrior]

guitar strings and drumheads both stretch, yes. But what about the guitar speaker? I have just heard from some people on other forums for guitar amps that they seem to notice that, I never thought about it when i got my amp so i didn't really listen to notice. but, have you noticed that effect with speakers? I think the sound difference is in the lower mids spectrum. I've never had new pa speakers to listen to either

[Peter]

Not to push this thread in a completely different direction... but the instructions that came with our new follow spot did instruct us to "burn it in" by running it with (or without... i cant remember) the iris closed then give it time to cool off and repeat until it stopped smoking. I think this was the temper the metal iris so it didnt warp and bind up during the first use. It was very hard to tell what the smoke was commming from, but it might have been oil or paint burning off the surfaces too close to the bulb.... I am by no means an expert as to what this was all about, I just followed the instructions and did it!

[falcon]

we hae 3 sets of speakers each set of varying age, and they all sound the same, I can't seem to hear a difference bewteen our new speakers and our old ones.

I have heard of "burning in" for lighting equipment due to the heat the lamp produces it will smoke until hte metal has "adapted" to the heat. It just make sence to do this before you use the fixture in a show due to the smoking, the audience might get a little scared of it

[EPAC_Matt]

Originally Posted by Peter

Not to push this thread in a completely different direction... but the instructions that came with our new follow spot did instruct us to "burn it in" by running it with (or without... i cant remember) the iris closed then give it time to cool off and repeat until it stopped smoking. I think this was the temper the metal iris so it didnt warp and bind up during the first use. It was very hard to tell what the smoke was commming from, but it might have been oil or paint burning off the surfaces too close to the bulb.... I am by no means an expert as to what this was all about, I just followed the instructions and did it!

What type of followspot was it? Some types of followspots use high intensity discharge lamps that operate by passing current at a high voltage through an inert gas and sometimes a vaporised metal halide. These types of lamps do need to be 'burned in' to help distribute the metal halide evenly. I'm not sure if this is required for xenon HID lamps however.

As others have mentioned here, the burning in process for lighting instruments is also required to adapt the fixture to the heat produced by the lamp.

As far as audio equipment goes however, I couldn't imagine anything else other than an amp head (Or anything else with tubes) needing to be broken in.

[avkid]

the oils on a bulb(that has been handled improperly)will usually "burn off" in less than 5 minutes.

[Peter]

I am not sure what kind of spot it is, I'll have to try to remember to take a look on Monday when I go back into school.

I figured it was something to do with the metal b/c of how specific they were about the setting the iris had to be at.

[len]

Lamps tend to need a burn in period, so the field is more even. Carbon arc spots need adjustment, and stuff, and sometimes if you don't trim the rods correctly (going on memories from 20 years ago) they look a little off so you have to burn them down to an even point or whatever.

I've never seen any issues with new par lamps, or with the S4 lamps when they get replaced.

As far as opening the iris/shutter, I do that on dmx lights when not in use. I don't know if it helps keep the lamps cooler, but it can't hurt.