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R/E/P => Klaus Heyne's Mic Lab => Topic started by: hugovanmeijeren on December 27, 2014, 08:25:26 PM

Title: AKG CK5 Capsule Problem
Post by: hugovanmeijeren on December 27, 2014, 08:25:26 PM
Hi!

I'm having problems with the capsule inside an AKG CK5 (it's basically a CK1 in a rubber suspension and windshield).
A red plastic piece came loose from behind the backplate of the capsule. (See attached pictures, the piece used to sit within the centre of the gold coloured spring, at the back of the capsule).

Apparently there's no further damage, everything works, except sound wise. When I had the capsule mounted on my C451EB it sounded extremely mid rangy.

I have the feeling the plastic piece can be glued back into place, relatively easy. Can anyone provide any tips on how to proceed?

Some pictures:
https://www.dropbox.com/s/3lh1t3is82txxds/IMAG1598.jpg?dl=0
https://www.dropbox.com/s/bm9odoy6xi5ez6a/IMAG1597.jpg?dl=0
Title: Re: AKG CK5 problem
Post by: klaus on December 27, 2014, 10:00:56 PM
Hello Hugo,
While the CK5 looks identical to the CK1, it is actually a low-end attenuated version of the CK1.
The red plug can be glued back into the backplate space that is cut out for it. I would either use three small drops of crazy glue centered all around the red plastic barrel of the plug, or use something less permanent, in case you need to reposition the plug after the first fitting. In that case, I would use a thin film of E6000
Title: Re: AKG CK5 problem
Post by: hugovanmeijeren on December 28, 2014, 01:33:33 PM
Hi Klaus,

thanks for your timely reply! Another question: should the plastic be physically touching the backplate when it is put together?

Also, you mention the CK5 is a low-end attenuated version of the CK1. I have always been under the impression that the CK5 houses an actual CK1. The old AKG manuals state for the CK5 "see CK1 for specifications". From what do you conclude it attenuates the low frequencies? I haven't looked at the screw-in connector at the bottom of the CK5, could it be it houses a small HPF network?

I must say I have never noticed this low frequency roll-off. I have 4 CK5 capsules (for both C451 and C460 bodies), but no other capsules to compare them with.
Title: Re: AKG CK5 problem
Post by: klaus on December 28, 2014, 06:05:19 PM
Compare the curves of the two capsules here:

http://www.akg.com/pro/p/ck5
http://www.akg.com/pro/p/ck1

and you will see a 4dB greater attenuation at the lower limit, compared to the CK1, and a much earlier start of attenuation in the frequency range that is still completely linear for the CK1.

I also have technical literature of the CK5 in German, which clearly states that this capsule is the low-end attenuated version of the CK1, and specifically designed to attenuate the handling noise associated with hand-held condenser mics. Most likely, the attenuation is accomplished by higher tensioning of the CK1 diaphragm
Title: Re: AKG CK5 Capsule Problem
Post by: hugovanmeijeren on December 28, 2014, 07:58:16 PM
Hi Klaus,

Interesting! Any chance you can share this technical document? I'd be nice to read more about the ck5, no problem that it's in German.
Title: Re: AKG CK5 problem
Post by: Kai on January 04, 2015, 07:02:18 AM
... Most likely, the attenuation is accomplished by higher tensioning of the CK1 diaphragm
Comparing both I always felt the CK5 has a bit more directivity then CK1.
This might be partly due to it's mounting inside the basket is quite large, but not only.
Screwing a CK1 into the CK5's housing gives a quite different sound.
Obviously the CK5's sound is tailored to close up vocal pickup:
bass rolloff and presence boost.

The main problem I have with the CK1, CK1s and CK5 capsules are diaphrags that come loose, making the capsule useless.
Seems the glue gets old and detoriates over the time.

Regards
Kai
Title: Re: AKG CK5 Capsule Problem
Post by: hugovanmeijeren on January 12, 2015, 09:33:53 AM
I've managed to put the plastic part back into the backside of the capsule and everything sounds fine again.  ;)
I've only got some issues with RF interference when the capsule is inside the CK5 housing. I suspect the grounding is a bit iffy, there's a wire going to a metal part that is also holding the rubber suspension which is a bit corroded. Haven't had the time to clean this up, but I'm sure this issue can be solved.

When I attach the capsule directly to the C451 body there are no issues at all.
Title: Re: AKG CK5 Capsule Problem
Post by: ohhteriiii on January 21, 2015, 12:09:24 AM
I also have technical literature of the CK5 in German, which clearly states that this capsule is the low-end attenuated version of the CK1, and specifically designed to attenuate the handling noise associated with hand-held condenser mics.???
Title: Re: AKG CK5 Capsule Problem
Post by: klaus on January 21, 2015, 01:36:27 AM
Thanks for your contribution. Please identify yourself with your real, full name. It is a requirement for posting here.
Thanks,
KH