[Steve Karl]

Greetings all,
I have 2 sets of AKG K702 and they sound different from each other.

The set that I wonder about has a bit of a scoop in the upper bass,
my rough guess being that it's between 250 and 400 Hz.
The 'good' set - the one without the scoop - sound more accurate to me - more linear - on a well recorded sound track.

I purchased both sets used, so I have no idea how many hours are on each set, so I'm wondering about burn in time,
and also wondering which set 'might have' been burnt in fully,
and if possibly the set that has the missing warmth would be the set to suspect needs more burn in time?

Hopefully the warmest set - the set without the scoop - is the one that is fully burnt in?
The above is the important question. I'd hate for them to eventually deteriorate.

The upper mids, highs and ultra lows seem to be the same on both sets.

I'm just hoping that someone with more experience with the 'burn-in' idea will talk with me a bit about this?

Edit -
Solved - See the last post. It was the ear cushions causing the sound difference.

Thank you!
Steve

 

[PurpleAngel]

Could one of the K702s been built in Austria and the other K702 built in China?

 

[dunring]

Grab a decibel meter app for the phone and use an online test tone generator. Try different frequencies on just left or right to see if each side is playing the same volume. I've had pairs I returned because they were 4db off at different frequencies on each ear cup. It's really hard to tell unless you measure them that way.

 

[HipHopScribe]

Have you tried swapping ear pads?

 

[Steve Karl]

Could one of the K702s been built in Germany and the other K702 built in China?

Ahhh! Quite possibly -
The questionable set with the scoop - definitely China - it has a sticker on the headband,
and appears to be newer by the SN: 170288

However, there is no sticker on the ones that sound correct - to my ears and I'd guess they're older by the
SN: 145327

I'll guess that the folks in the basement of Harmon / AKG might be able to tell me the country of manufacture by the Serial Number.
I'll make a note to give them a ring come Monday.

Thank you!

 

[Steve Karl]

Grab a decibel meter app for the phone and use an online test tone generator. Try different frequencies on just left or right to see if each side is playing the same volume. I've had pairs I returned because they were 4db off at different frequencies on each ear cup. It's really hard to tell unless you measure them that way.

I have a tone generator in SoundForge that I could use if I wanted to get more accurate on what the difference is, but my mission isn't to exactly define the difference,
just try to discover why there is a difference.

 

[Steve Karl]

Have you tried swapping ear pads?

Ahhh - very good idea! - and no I haven't tried that as of yet, but I will ASAP.

 

[Steve Karl]

Could one of the K702s been built in Germany and the other K702 built in China?

I did some looking around and it appears that the ones made in Austria have that written on the bottom part of the outer shell.
See attached Image ...
So, both of mine are made in China - no photos of mine included.

 

[Steve Karl]

Have you tried swapping ear pads?

Yes!
I swapped the ear cushions and that is what the difference in sound is.
The scooped sound seems to be because of non OEM cushions.

The scooped sounding cushions are slightly harder feeling when squeezing them, and the material they're made from is slightly rougher feeling with a slightly different weave.

I'll be calling the parts dept. at Harmon / AKG ( 844-776-4899 ) on Monday to order a set of OEM cushions.

Thank you HipHopScribe - good call!

 

[Steve Karl]

OEM Cushions for the K702 are $16.08 each - $32.16 for the pair from AKG. They're back ordered now but will ship in December.