K340 KT88 mod guide :) - Page 15

Hi,

my apologies for ressurecting this old thread,

My dad and I are recabling the AKG k340 and do not completely understand how to route the cables (connect them) . We got some cardas 4x24 cable (bulk) .

If you look at the pic. underneath (stolen from KT88) . This is the way we connected it. after first removing the input wires from the crossover. To our dismay however , a very faint signal was present when playing near full volume (on a 12wpc amp) . It did seem to work when we reconnected it in the original way.
So our question is, Which connections go from the crossover to the driver , the input or the output of the crossover? Our crossover looks slightly different, the coils are positioned at the electret side of the crossover geographically speaking.

If this is not clear enough, a picture of our k340 could be posted tonight .

As always, thank you for your kind help !

http://img64.imageshack.us/img64/3960/img2388gr1.jpg

Treble shrillness problem

Hi, I'm wondering anyone might be able to offer some advice regarding the AKG K340. I recently bought a pair from the for-sale section here.

They are in overall good condition and have had some mods done: original cable replaced with a HD650 cable and the headphones rewired to be dual-entry; cross-over mod done; plastic grill completely removed; cotton removed; cable-mod that bypasses the circuit-board (I think); velour pads.

I do need to get an amp, and I have plans to get a Darkvoice 336i, but in the meantime I am running the phones from an older Technics receiver hooked up to a pretty nice Denon 970 cd player.The receiver powers the phones easily with the volume turned about 1/4 the way, though I know the sound quality will be much greater with the amp. Just for sound comparison sake...I tested this setup with my reliable Bang & Olufsen Form 2 phones to see if the receiver was screwing up the sound - it's not, the B&O phones sound full, detailed and dynamic as they do when I run them out of the cd player.

Anyway...my question is about how to reduce shrillness in the treble of the K340 without muffling the overall sound. I tried taping the back of the phones with black electrical tape which did reduce the sharpness/sibilance of the highs, but the overall sound appeared blocked or muted. What is interesting is that the highs without any tape sound a tad rolled-off or muted at the very top, but also sharp. Listening to Karen Carpenter for instance made me clench my jar sometimes, and there is just about no one who is less shrill then her. I also tried the phones with no tape but with cotton inside, and the sound seemed to change very little. I would like to get the sound to remain detailed and a little bright without fearing the whole brass family of instruments. Oh, and the electret has the green back.

Thanks for any ideas you can provide. I think I will love the K340 once I get these details sorted out. The only phones I have heard at Head-fi meets that even had my interest a little were the $1500+ Grado PS-1 and HP-1, so the K340 for the money seem fantastic in comparison.

Thanks! -Joe

Things to try:
A) cover the back openings only partially (like half)
B) put only a small amount of cotton back in.
C) get 2 or 3 cotton balls and tuck them in under the earpads in the spot that will go behind the ears, this will angle the drivers a bit and create a larger space between the drivers and your ears.
D) amplification is everything when it comes to the K340s.

K340 cable mod

Hi!

I have to recable my K340 but I need your help to choose the right cable . I am using a M^3 amp and I like clear sound.
Could you help me??

Hey joe, I was fooling around with my K340 some more and applied standard mods done by ortho owners, which seem to have good effect. I damped the backs with felt instead of electrical tape (I'm not sure how good electrical tape is at damping... they seem to also be a fairly reflective surface) and then tried a reflex dot on the back of the dynamic driver. The size of the reflex dot determines how much more treble you want.

Edit: This mod tames resonances, increases treble extension, and makes the treble truely fast and clean, comparable to the speed and clarity of a full-blown electrostat. And I have not even removed the grille or replaced the cable, not that I feel a need to, and I hate ruining stock vintage headphones.

Reflex dot? Did you try it before adding this, with just the felt damping?

Yes, I did. The effect of the felt was to decrease backwave reflections off the housing, to cause less resonance and wonkiness in the highs, as well as increase bass. I then added the reflex dot (actually just some tape...) to the backs of the dynamic drivers to increase the treble. I just realized I'm probably just shifting the frequency response so that the treble can be better heard. I think I'll try using some wool felt for further taming of resonances. I could also try damping the passive diaphragms in some way, but it is sounding fairly good already. I will give it a try soon, just to see what the effects are.

Hi,
I'am planning a K340 mod.
What kind of inner cable do you recommend?
22 AWG Solid Silver wire with clear Teflon insulation is good or something else?
Outside I will use Mogami Quad 2534 or 4x 24 AWG Silver Teflon Wire (19 strand).
Thank you.

Too stiff and bulky. Not recommended.

Much better option. The latter with multi-filament nylon sleeving will be best in term of weight and flexibility.

Cheers!

the solid silver I want only use internal, between the cross-over and dynamic driver
meanwhile I found this: 99.999% (5n) Pure Silver Rectangular Solid Core Wire - eBay (item 140310395803 end time Apr-05-09 16:17:22 PDT)

That will be perfectly fine then.

This thread has not been posted in in over a year. Time for the Rasta man to come and bring it back to life........

 

 

Has anybody else treated these like orthos, with the felt and reflex dot. Is that the way to go, or is messing around with the cotton better. Thanks.

 

Chris

I managed to remove all honkiness and get very good lf applying felt all over the back of the cup and suing a lot of blue tack behind the felt and on the baffle.

However nothing could tame hf harshness.

 

Hi people,

 

I have recently picked up a pair of these, the green-drivered bass-light version, and am wondering whether there are any tried and tested methods of improving bass quantity and response? I'm pro with screwdrivers, soldeing irons and any hand tools, so am not averse to cutting and sticking things.

 

There's a lot of info in this thread, it all seems a bit all over the place though, and therefore hard to find any answers.

 

Any info will be most excellent. Cheers!

Edited by danzal - 11/27/11 at 8:28am