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Is it okay to stress your IEM?

post #1 of 9
Thread Starter 

Hi, I have a few questions...

 I have Earsonics SM3 version 1 (I reviewed it in >> here <<), and I accidentaly played 15khz frequency (using SineGen, you can google this) through my FiiO E5 amp at max volume!

From what I know, FiiO E5 max output is 100mW at 32 Ohm... Considering SM3 is 34 Ohm, it may got a power slightly below this...

Question 1: Is my SM3 okay and not damaged? I heard no difference in sound though...

Question 2: How much input in mW can be handled by SM3 before the drivers starting to broke?

Then according to official websites, SM3 frequency response: 20 Hz -18 kHz

It plays 18khz fine and sound nothing around 18.5khz, but at 19khz and above, I am surprised to heard that SM3 still emits a sound above that... But this time I know it's not the real sounds because it's obviously sounds lower than 18khz...


And at 18khz the volume is very quiet but i started to heard a louder lower notes at 19khz - 30khz, and obviously human ears can't hear until 30khz...

Question 3: Is my SM3 okay and not damaged because of playing this extreme frequency? I heard no difference in sound though...

Question 4: Why I can hear this? Is that because of harmonics? Because it started low again (around 6khz) at 19khz and becomes higher toward 30khz...


Question 5: I dropped my SM3 from around 1.5 feet (around 40 cm) height to a solid floor once... Is my SM3 okay and not damaged because of this dropping? I heard no difference in sound though...


Well I'm sorry if it sounds traumatic when I asks this question... It's because I'm only an university student and it costs me arm, leg, lung and kidneys to buy this (kidding :D)... And my HD-555 started to sound muddy, maybe because I dropped it already hundred times from around 1.5 feet (around 40 cm) height to a solid floor (or maybe my brain becomes burned-in because of SM3 clarity)... :p

Thanks for your attention. Really appreciate it... Sorry if my posts sounds funny to you...:)




I also do this frequency test using my HD-555 (it has a freq response from 15hz to 28000 Hz) and I also heard the same strange harmonics although this time it started to becomes louder / sounds unreal (I heard lower notes) at above 20khz instead of 18khz (SM3)...


So I also have new question... Normal human ears only hears 20hz - 20khz... Is it supposed to have the same loudness? Because I notice the volume becomes quieter past 15khz, and at 19.5kHz I must crank up the volume a lot to heard the sounds (using FiiO E5 + HD-555)...


Am I starting to get hearing loss? But I'm not 70 yet (only 24)... Maybe I listen too loud with headphones?


Or is it actually because of the natural jaggy frequency response of headphones like below?


Edited by MusicHolic - 5/24/11 at 3:46am
post #2 of 9

The human hearing frequency response is definitely not flat.  I'm pretty sure that it's focused mostly on the midrange, where our voices are, and rolls of significantly towards the upper and lower ends.  And most headphones tend to roll off at those ranges anyway, so there's nothing weird about that.


As far as your headphones go...they should be fine, there's no way that the E5 would be able to destroy them, especially if you only played the tone for a short period of time.  Maybe if it played for long enough and the wires inside the driver overheated, but if it was only for a few seconds there shouldn't be a problem.  Frequency response has nothing to do with how much current/voltage they can take before blowing a driver.


Anyway, if you can't hear any difference at all it's probably fine.  Even if you feel you can hear a small difference it's probably just your mind playing tricks on you.  Only if there's a significant difference somewhere that's quite obvious should you be worried.

post #3 of 9

Sounds like they're fine but the type of signal that you used could break them if played too long. On multi way units, the tweeter driver will be more delicate as it's not designed to actually see as much energy as the lower units. There's a lot less high frequency energy overall in the music spectrum. If played even just a little too long which a few seconds can be, a high amplitude sine wave doesn't give the driver a chance to rest, can over heat it and melt some insulation off the coils. Sweeps are less a problem but should still be at moderate volume. Every driver manufacturer warns against sine waves. At 'full volume', you were most likely clipping the amp which gives even more high frequency content with harmonic distortion products. Clipping and the resulting high amplitude harmonic distortion products is what can break a tweeter even with a sine wave that's outside the tweeter band and is wh a smaller amp can actually be more dangerous for tweeeters than a bigger one. It still has plenty of energy to do damage and is more likely to clip.


  All that said, if it sounds like it did before, don't worry about it. You didn't overdo it and caught it in time. I just thought the info good for the board.

Edited by goodvibes - 5/24/11 at 5:39am
post #4 of 9
Thread Starter 

Thanks for all your answer, really appreaciate it :)


I'm glad hearing that E5 with 100mw output would not break it, especially for only some seconds...


I was thinking this initially because I think 15khz on E5 is considered loud... I can hear it even if I dont wear this IEM...


Think it like this... Maybe a headphone emits the same SPL at 1khz and 15khz (or it's -20dB as stated in graph in first post)... And I know the fact that I'm hearing 1000hz much louder... I can't imagine such a sound from that tiny 1mm holes if 1khz, or even full music, is being played...


I just happen to know that headphones can becomes overheated... To makes it melt, it might be hotter than water boiling point... Is it only happened in BA or it's also becomes a problem in full-size dynamics like my HD-555? I remember sometimes my ear becomes hot if I wear HD-555 for too long (could also because of hot temperature in my tropics country :p )


Then I also remember an electrostats headphone... It has insane impedance... Does it translates to much heat, or am I wrong here? :p

post #5 of 9

That your ears get hot when you wear the HD555 for a long time is normal, that's just like how you can get too hot when you wear clothing that's too thick.  It would be getting a lot hotter than the boiling point of water to melt!  But only for a fraction of a second before it short circuits and fries itself completely, then it'll cool down again pretty quickly.


Also, high impedance won't translate to heat, a lower impedance actually would...that is, if you have a high enough current.  Electrostats shouldn't get hot at all, nor should any other headphones under normal conditions (other than just natural environmental heating/insulation).

post #6 of 9

The E5 could break it, easily, if you did the wrong thing.

post #7 of 9
Thread Starter 



Yes you're right... I forgot basic physics when I was in a senior high schools :p


Less impedance = More voltages = Less current = Less heats = Less energy loss... That's why people use high voltage when transmissing an electricity through a far distance to minimize energy loss :p

Originally Posted by goodvibes View Post

The E5 could break it, easily, if you did the wrong thing.


Err... How? confused_face(1).gif


And I also wondering, if I plugs it to speaker amplifier (set to max) and blows it... If broken, is it covered in warranty? blink.gif


post #8 of 9
Originally Posted by MusicHolic View Post


And I also wondering, if I plugs it to speaker amplifier (set to max) and blows it... If broken, is it covered in warranty? blink.gif


Not if you tell them that you blew it by plugging it into a speaker amp.  I doubt that's covered...that's no better than plugging them into a wall outlet, which I doubt is covered either. :P

post #9 of 9


Originally Posted by goodvibes View Post

The E5 could break it, easily, if you did the wrong thing.


Originally Posted by MusicHolic View Post


Err... How? confused_face(1).gif


When maxed out and clipping, 2 bad things happen. You lose the space between the notes and can overheat a coil on any IEM with enough time but the more common issue with multi way units would be that clipping. Tweeters generally are more delicate and designed to see a lot less energy than lower range units to allow them to better respond to more quickly fluctuating high frequencies. This is fine as they don't normally see even 10% of the wattage in the range they cover. When you clip an amp at the lower frequencies that would occur at, it can throw near full amplitude harmonic distortion products which will then be in the tweeter range where it can't accomidate that much signal. Amps also tend to ring when clipped and can do same. Small amps tend to blow tweeters and big ones woofers. Folks that like to play loud and try to protect themselves with amps below the speakers rating blow tweeters. They'd be better off with too much power and not clip.


Current draw is from the source. I'd really worry more about the general effeciency than the impedance though optimum would always be high impedance and efficiency. Stats are more voltage devices.

Edited by goodvibes - 5/28/11 at 5:46am
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