K 240 MKII Damaged?

[weldroid]

Hi Folks,

I use my K 240 MK II together with my HP laptop for music production and recently I accidentally generated a very loud (and clipped) noise burst due to an internal feedback within the software. I have managed to somewhat protect my ears by removing the headphones, but it was for an another 1-3 seconds until I could disconnect it from the sound card.

Since then I am a little unsure if I have damaged my headphones or not: there is no crackle nor any other evident sign, but who knows what migth have happened inside my beloved cans...

Is there any good way to test for damage?

Any help/suggestion would be highly appreciated.
cheers,
Tamas Zsiros

[CptKlotz]

Hi,

I have used the K 240 S, which is essentially the same headphone as the K240MKII and I think they're quite rugged.

While it is possible to make the capsules distort with very low bass frequencies at very high levels, I doubt that most notebook outputs will provide a level high enough to easily damage the headphones - especially with a signal that doesn't primarily consist of very low bass frequencies and after only a few seconds of exposure.

Usually, if you turn down the volume after noticing distortion, the headphone won't be damaged too easily (it should still be avoided, of course).

My guess is that you should be fine.

For a quick check you might want to listen to bass heavy music at higher levels on a stereo system that has a little more clean output power than a sound card. While a laptop might be able to drive the K240s to enjoyable listening levels, you will quite likely not be able to use the headphone's full dynamic range.


For a more thorough test, you could try to create a sine wave sweep that covers the low frequencies (for example 20 hz to 200 hz) with an audio editor such as CoolEdit, Audition or Audacity. You can then use this signal to listen for distortion.

Do keep in mind though, that any speaker or headphone *does* have its limitations, so raise the volume level carefully and try to make sure that distortion that you may hear is not caused by a hair or particle on the diaphragms (or by clipping the laptop's sound output again).

Some very slight distortion is probably normal (and typical for most kinds of speakers; They have to work pretty hard in the lowest registers). Just make sure there's no noticeable buzzing or crackling.

Also, in the bass range, your ear's sensitivity is much lower than it is in the midrange, so the sound levels may sound softer than they actually are and this may be a little hard to judge.

If you really *have* blown one or both capsules, spare parts should be available from the AKG distributor in your country, but again, I wouldn't assume that for now.

Kind regards,
Stephan

[weldroid]

Hi,

I have used the K 240 S, which is essentially the same headphone as the K240MKII and I think they're quite rugged.

While it is possible to make the capsules distort with very low bass frequencies at very high levels, I doubt that most notebook outputs will provide a level high enough to easily damage the headphones - especially with a signal that doesn't primarily consist of very low bass frequencies and after only a few seconds of exposure.

Usually, if you turn down the volume after noticing distortion, the headphone won't be damaged too easily (it should still be avoided, of course).

My guess is that you should be fine.

For a quick check you might want to listen to bass heavy music at higher levels on a stereo system that has a little more clean output power than a sound card. While a laptop might be able to drive the K240s to enjoyable listening levels, you will quite likely not be able to use the headphone's full dynamic range.


For a more thorough test, you could try to create a sine wave sweep that covers the low frequencies (for example 20 hz to 200 hz) with an audio editor such as CoolEdit, Audition or Audacity. You can then use this signal to listen for distortion.

Do keep in mind though, that any speaker or headphone *does* have its limitations, so raise the volume level carefully and try to make sure that distortion that you may hear is not caused by a hair or particle on the diaphragms (or by clipping the laptop's sound output again).

Some very slight distortion is probably normal (and typical for most kinds of speakers; They have to work pretty hard in the lowest registers). Just make sure there's no noticeable buzzing or crackling.

Also, in the bass range, your ear's sensitivity is much lower than it is in the midrange, so the sound levels may sound softer than they actually are and this may be a little hard to judge.

If you really *have* blown one or both capsules, spare parts should be available from the AKG distributor in your country, but again, I wouldn't assume that for now.

Kind regards,
Stephan

Hi Stephan,

Thank you very much for your detailed response! I will check my headphones with a proper amplifier as soon as I get the chance, but meanwhile I did the sin sweep test and everything seems to be fine. For a moment I thought I heard some distortion in the below 100 Hz range, but fortunately I could borrow a K 171 from a colleague (not the same, but at least in the same league) and it had very similar distortion with the sub-bass (the kind of distortion most people would probably not even notice).

After comparing/testing them for a day, I am pretty sure my K 240 has survived last nights ordeal.

Thanks again for the testing tips and all the information!

BR,
Tamas

[micdoctor]

Hi Tamas,
As the soundcards phones output has not really a high output the chance is really high that your phones survived the accident.
As Stephan mentioned a sweep test from 20 - 200 Hz can help identifying a damage on the capsules.

kind regards
micdoctor