Head-Fi.org › Forums › Equipment Forums › Sound Science › Headphone Burn-in
New Posts  All Forums:Forum Nav:

Headphone Burn-in - Page 6

post #76 of 82

 

Quote:
Originally Posted by rohan575 View Post

it can be the dried out ear pads recovering


Good point.

 

 

Quote:
Originally Posted by rohan575 View Post

the increased weight explains the base response changing too you know

 

confused_face%281%29.gif

 

post #77 of 82

After finally having a pair that benefitted, heavily, from burn-in, I can say I know it's real now.

post #78 of 82
Quote:
Originally Posted by NA Blur View Post

Tyll and I are going to do some double blind testing to see if we can identify which 701 is "burned it" and which is not.  I am also going to suggest we try to make one headphone look like the other sonically by moving the ear cups around the dummy head, adjusting clamping tension, etc.  If we can make one graph look like the other this would suggest that we did not measure burn in.  If no matter what we do we cannot replicate the result other than using the burned in headphone, then this would suggest the possibility we measured the process.


At a past meet, we had a pretty new pair of 702 and a 701 that was several years old. Using the same rig, we could hear a difference between the two. We then swapped the pads and the differences reversed. The difference wasn't the drivers but the pads.
post #79 of 82

exactly, the drivers as from my past experiments do not change in characteristics. None, of the electrical properties apart from weakening of the magnetic field strength (which takes a LOT of time to be significant) everything remains same. Especially when modern drivers are sealed  with corrosion resistant coils there is probably no electrical property (in my knowledge) which actually changes with time. 

 

The pads on the other hands do change,

 

Grokit:

 

the increased density of the pads (from moisture) actually do affect the lower end of the spectrum (longer wavelengths) more than they do for the higher end. 

 

 

Until and unless we have the technology to actually map quantitatively rather than qualitatively burn-in will remain an unsolved myth. 

 

 

 

post #80 of 82
Quote:
Originally Posted by rohan575 View Post

exactly, the drivers as from my past experiments do not change in characteristics. None, of the electrical properties apart from weakening of the magnetic field strength (which takes a LOT of time to be significant) everything remains same. Especially when modern drivers are sealed  with corrosion resistant coils there is probably no electrical property (in my knowledge) which actually changes with time. 

 

The pads on the other hands do change,

 

Grokit:

 

the increased density of the pads (from moisture) actually do affect the lower end of the spectrum (longer wavelengths) more than they do for the higher end. 

 

 

Until and unless we have the technology to actually map quantitatively rather than qualitatively burn-in will remain an unsolved myth. 


Gotcha, thanks. Perhaps this is due to less absorption and more reflection.

 

post #81 of 82
Quote:
Originally Posted by grokit View Post




Gotcha, thanks. Perhaps this is due to less absorption and more reflection.

 


Case in point is the tape mod on Grados. I also noticed an increase in bass impact and soundstage when I washed and dried my 701 pads with some weight on them. It made the cushion denser and put the driver closer to the ear.
post #82 of 82

Burn in effects are real. Small in magnitude, but real. After all, everything is mechanical - even semiconductor materia(s) undego tiny deformations due to voltage/current forces acting on them .

 

I can confirm burn in in capacitors used in audio equipment. It varies in magnitude and time required to undergo changes to ceretain level, but it is real. 

If I do a recap on any given piece of audio equipment I am familiar with and confident enough to listen to it inserted in my sistem without first checking it on test bench ( DON'T do that unless you know perfectly what are you doing) there is some crackling for about five to ten seconds that dissapears after said few seconds. That might be initial burn in that will allow the equipment to function and measure as per spec. Such a piece of audio equipment will not sound good yet, it takes diffderent amount of operation for various type of capacitors with music to settle down to final SQ. I call that secondary burn in - and that can take up to 300+ hours to complete. It is not a placebo - i tried it with the same "box" that looks externally exactly the same, has exactly the same components built in, yet one was burnt in and another with maybe couple ( under 10 ) hours of operation. People consistently differentiated between the two. 

 

I do not therefore ever release any component to the end user that has not been subjected to at least 100 hours of operation - saving me from the chore of answering phone/mails regarding changes in first hours of operation. Customers "get it" after that in a natural way; I certainly agree there is also psyhological aspect to the burn in issue, with people getting used to any piece of gear and listening through it - but that comes into play towards the end of the burn in period where changes get ever smaller. That "initial" burn in is real an verifiable either by listening ( in headphones of course) or hooking up your gear to some scope/analizer - BUT you have to have everything up and going before switching device under test on - it really lasts for about 10 seconds at most. 

 

Burning in of loudspeakers and headphones is another matter. It is true if you do not like the headphone/speaker initially, burn in is not likely to change it enough for you to fall in love with it. But if it is close to your liking - give it a good and well controlled burn in. Suspension in drivers is likely to loosen up when subjected to relatively large amplitudes of low frequencies - yielding looser suspension that should result in lowering of the resonant frequency for that driver. Preferably well below audible range, below 16 Hz.

 

http://en.wikipedia.org/wiki/Resonance

 

Any resonance is audible due to phase shifts it creates, even if it is of relatively low amplitude. High Q resonances of as little as 0.2 dB in midband where our hearing is most sensitive have been reported to be objectionable in the long run.

 

Resonance(s) in bass colour the sound well into the midrange ( via mentioned phase shift(s) ) and whatever it can be done to eliminate resonance or at least push it towards the lower frequency is a step in the right direction. Please note that analizers to be used should cover bandwidth greater than the officially generally accepted hearing range for humans, from 16 to 20000 Hz, in case of bass resonance preferably going to at least 5 Hz if not DC for the results to be meaningful and accurate. It is easy to hear the (d)effects of resonance pleagued reproduction once you hear it right. Particularly the correct representation of acoustics of the venue preserved in well done recordings will markedly improve - even when it means pushing low frequency resonance of headphone/speaker from say 25 to 16 Hz. If resonance frequency is higher up than say 25 Hz, as in majority of cases, effects are more pronounced and colour further into midrange.

New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Sound Science
Head-Fi.org › Forums › Equipment Forums › Sound Science › Headphone Burn-in