[Akathisia]

So I recently received my first K240M 600Ω, purchased on ebay, seems to be in great condition (needs adjustment bands replace, slight cracking on pleather pads, sonme worn paint) and has has had a ton of use (very comfy, broken in feel).

Here is my problem. I haven't heard K240M's in quite a while, and the last time was in a studio where I didn't really have time to 'analyze' the sound. This pair seems really really muffled, to the point where they are almost unlistenable. Soundstage and volume are fine (no blown drivers, no volume difference between L & R). I am curious if maybe it is my amplification, I currently have a CMOY, a Technics home theater receiver and my plain jane headphone out on my PC.

I normally use my receiver, which has been fine for all of my other headphones, with great results. With the K240M I have to turn the treble way up to get decent 'neutral' sound, but I don't have to turn the volume way up???

Same with my PC, I don't have to turn the volume to max (quite loud), but I have to CRANK the high side of the EQ, and then the SQ goes to crap.

The CMOY, the volume doesn't have to be high at all, but they still seem muffled.

Does this sound like poor amplification? Or are the headphones bad? I figured an insufficient amp would suffer in volume first, but everything I have will get much louder than my standard listening volumes... And I know the K240M is supposed to be silky smooth, but the last pair I heard didn't sound bad!

I hope that wasn't too convoluted... any thoughts?

 

[Fitz]

Check the flat foam discs that cover the drivers. If this pair has seen that much use it may be deteriorating and literally caking up and blocking the sound. When you pull them out, you should be able to run your fingers across the surface without there being any tears or crumbling of the foam.

 

[Akathisia]

No tears of crumbling on the little foam driver covers. With them removed the sound is a little brighter, but still muffled.

 

[Fitz]

Which material does yours have for the vent damping around the driver?

 

[Akathisia]

It seems like a white cotton paper... sort of like camera lens cleaning wipes if that helps.

 

[ericj]

here's a thought - cracking on the earpads? They go flat long before they crack. Got any other AKG vinyl pads?

 

[Akathisia]

They are a little flat, I was planning on ordering a new set soon though. Could this cause such a huge sound quality issue? I mean, they sound HORRID! They make my K240S sound crystal clear by comparison.

I haven't heard anyone suggest amp issues. So I am guessing that is out of the question

 

[ericj]

Well, probably not that much mud.

If you have a K240-S you could put the pads from that on 'em and see if that makes a difference.

 

[facelvega]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif Well, probably not that much mud. If you have a K240-S you could put the pads from that on 'em and see if that makes a difference.

x2, good idea. If that doesn't make a difference, it might just be that you've got a bum pair. These are old headphones often used in harsh studio settings, and it's possible the pair you got was used six hours a day for twenty years. Do heavily used old pairs sound different from their NOS brethren? Fitzie?

Even at their best, the 240M are only alright, pretty good. They should be noticeably flatter-sounding than and at least as detailed as a K240S.

(wondering whether Fitz will spit out his coffee to see himself refered to as "Fitzie")

 

[ericj]

Quote:

Originally Posted by facelvega /img/forum/go_quote.gif Even at their best, the 240M are only alright, pretty good. They should be noticeably flatter-sounding than and at least as detailed as a K240S.

Probably depends on which version of the 240-M you have, and i imagine there are several.

The version i have is visually indistinguishable from a K241. The baffle is identical to a late-production sextett, the only difference being the filter discs rather than full blown passive diaphragms. That and there's no nonwoven fabric over the face of the driver.

 

[facelvega]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif Probably depends on which version of the 240-M you have, and i imagine there are several. The version i have is visually indistinguishable from a K241. The baffle is identical to a late-production sextett, the only difference being the filter discs rather than full blown passive diaphragms. That and there's no nonwoven fabric over the face of the driver.

Well, I've had a Sextett, a K241, and a late production 240M and they were all flatter than and at least as detailed as a K240S. However, the Sextett and 241 were both clearly better than the M.

 

[ericj]

Just found this picture of a K240-M:

That looks like mine, except there seems to be fabric over the driver itself. On mine, the foam discs had decomposed and a lot of greasy foam-flotsam had gone through the grille over the driver -- no fabric.

Regardless, there are three white filter patches and three black filter patches on each baffle - the black ones are just harder to see for obvious reasons.

So, yet another permutation. But you can see where the Sextett-style grille attaches, and the four pinholes usually seen in a late production Sextett.

How does this compare to the K241?

 

[facelvega]

very similar to K241.

 

[Akathisia]

Quote:

Originally Posted by ericj /img/forum/go_quote.gif Just found this picture of a K240-M:

mine has one solid piece of cotton paper around all of the baffle holes and no screen over the driver.

 

[The Other Allen]

Quote:

Originally Posted by Akathisia /img/forum/go_quote.gif So I recently received my first K240M 600Ω, purchased on ebay, seems to be in great condition (needs adjustment bands replace, slight cracking on pleather pads, sonme worn paint) and has has had a ton of use (very comfy, broken in feel). Here is my problem. I haven't heard K240M's in quite a while, and the last time was in a studio where I didn't really have time to 'analyze' the sound. This pair seems really really muffled, to the point where they are almost unlistenable. Soundstage and volume are fine (no blown drivers, no volume difference between L & R). I am curious if maybe it is my amplification, I currently have a CMOY, a Technics home theater receiver and my plain jane headphone out on my PC. I normally use my receiver, which has been fine for all of my other headphones, with great results. With the K240M I have to turn the treble way up to get decent 'neutral' sound, but I don't have to turn the volume way up??? Same with my PC, I don't have to turn the volume to max (quite loud), but I have to CRANK the high side of the EQ, and then the SQ goes to crap. The CMOY, the volume doesn't have to be high at all, but they still seem muffled. Does this sound like poor amplification? Or are the headphones bad? I figured an insufficient amp would suffer in volume first, but everything I have will get much louder than my standard listening volumes... And I know the K240M is supposed to be silky smooth, but the last pair I heard didn't sound bad! I hope that wasn't too convoluted... any thoughts?

I've found my 240Ms to only work well with the headphone jack of my 80s era Yamaha receiver, with the volume at about 9 o'clock. Anything less than that and they are lifeless and anything more is just too loud. But at the volume sweet spot on that one receiver they come alive and keep me wondering about the 340s and the Sextett. The volume knob on my Presonus has to be cranked all the way up to get comparable sound on most music. My Go Vibe 5 portable can't handle 120 ohm 501s (IMHO), let alone the 600 ohm 240Ms. Might be several factors at play here, but I'm guessing that the volume level is one of the culprits. BTW, I'm not EQing my pair at all (neither treble or bass.)