I'm not going to put my Headphones on for a day or two, because I want to give me ears and headphones alittle break from that really bad audio feedback ( I'm guessing since the Grado's are open backed, when I was too close to my condenser microphone it picked up the sound and created a endless feedback loop causing that really high pitched sound)
I'd say your ears need more time to rest than the drivers do. They'll cool down pretty quickly.
So basically what your telling me is that my HP should be fine? unless it was physically hurt mishandling it, the headphones can deal with loud and high pitch feedbacks, and still work good?
Yes and no. Yes it sounds like your cans here are fine, but in general extremely large input signals are a bad idea. Most headphones, however, can sink a lot more power than your ears can tolerate (Grado as an example rates most all of their headphones right around 100 dB/mW, so 1-2 mW of input power is enough to split your head open, but they can take a few orders of magnitude greater input power before they are actually damaged).
I guess my new question is
can momentarily overpowering headphones cause damage to the drivers for specific frequency responses without noticeably affecting all of them? And if they still sound alright do you think I can assume they didn't get damaged? I was useing a
ISA One pre-amp
Yes and no. It has to do with excursion and heat - if the input is large enough, it can destroy them instantaneously, but we're talking VERY large inputs. The longer they're made to run with a (relatively) smaller large input, it can rack up to damage if you get into over-excursion (tears in the diaphragm and the like) and cooking the voice coil off (if it can't cool it will eventually fuse). I think you're probably alright here, but I don't want to give an "open range" kind of message - you can kill your gear doing this kind of thing.
Regarding frequency - in a music signal, LF makes up most of your power requirements, but if you're feeding a big sine wave (or whatever) into your cans, power requirements can be high no matter what. So feeding some HF signal in at insane amplitude will kill them too. Since they're single driver, anything that damages the driver will damage it across the board. With speakers this is different (usually you'll blow tweeters up before the woofers go, and usually you'll destroy the surround or cone on a woofer before you destroy the motor, so it's possible to damage the speaker's ability to run full range, without killing it entirely (this assumes the crossover doesn't give out or that there's no sacrificial fuses/relays/etc inside of the thing)).
