AKG D-224 Question

Hi folks:

Long time no see, and I'm back with a question.

The AKG D-224 dynamic microphone, with separate capsules for low and high frequencies, was a formidably good sounding microphone in years past, but it had one Achilles' Heel: it was incredibly fragile, and you had to handle it with the equivalent of kid gloves. (I recall the D-224's siblings, the D-202 and D-222, as similarly fragile.)

My question is this: What made the D-224 so ##$&^ fragile? And would it be possible to cure that fragility without destroying the remarkable sound of the mic?

Peace,
Paul

I've heard of them and I've always considered it an interesting thought to have a two way moving coil mic. Should take some mass off for the higher frequencies.
At the same time I've worried about the cross over and inevitable phase issues.
Don't know why they are so fragile. My guess is that it's the smaller diaphragm/coil part and its attachment to the rest.

micaddict said:

I've heard of them and I've always considered it an interesting thought to have a two way moving coil mic. Should take some mass off for the higher frequencies.
At the same time I've worried about the cross over and inevitable phase issues.

Click to expand...

Well-designed cross-overs do not necessarily have "phase issues". The x-over in the D2xx is 1st-order, so has perfect voltage, phase and energy recombination, as testifies the ultra-flat midrange frequency response .
Dual-capsule microphones do have inevitable phase issues, though. How audible/annoying they are is debatable. Indeed, all gradient microphones have phase issues; that hasn't stopped anyone using them so far.
The D224 has always been considered an excellent sounding mic, and I don't remember anyone being annoyed by "phase issues".

Don't know why they are so fragile. My guess is that it's the smaller diaphragm/coil part and its attachment to the rest.

Click to expand...

Yes, and the fact that the rather long capsule assembly, with its increased moment of inertia, created fatigue of the inner suspension and the flimsy wires. The 202 was less fragile, as testified by the number of working survivors.
The idea behind the 224 was to be an alternative to condenser mics, with about the same extended frequency response.
The 202 and 222 were of a different philisophy; they were designed to have a more frequency-consistent directivity with slightly less HF extension. And they were designed for stage use.

I had hoped someone would use my remarks as a platform for elaborating.
So thanks for that. 

Not to hijack, but would a two way moving coil mic be a feasible DIY project?
From the ground up I mean.

Hi,

abbey road d enfer already provided the essential infos.
Here are some photos to complement it.

D202 and D224 basically shared the same high-frequency system, just implemented a bit differently. On the D202 it was attached with a rubber shock mount to the low-frequenzy system. In the D224 there ´s no rubber shock isolation but a stiff attachment to a plastic part.




The D222 has a different construction but also an elastic mount of the small capsule (the black stuff is rubber).


If money and time is no issue it´s probably possible to DIY. To reach a similar sound quality quite some R&D work and experience would be necessary. Given the very low prices of those mics it´s not economical.

micaddict said:

Not to hijack, but would a two way moving coil mic be a feasible DIY project?
From the ground up I mean.

Click to expand...

Dynamic mics are typically products that need to be industrialized. The assembly of the voice-coil to the diaphragm requires extreme precision that can only be achieved with jigs; same for assembling the moving system (diaphragm + voice-coil) with the magnet and pole pieces, similar to loudspeakers but 10x smaller. Producing the diaphragm is another challenge, it needs to be thermoformed.
It is probably possible for a DIYer to do all this using different techniques, but I think that will be a time travel to the origins, with performance to match.

Yeah, I had a hunch this would be the case. And it shows on this forum, too. The bulk of DIY mics is condenser, with the odd ribbon thrown in. Some may argue condensers sound better anyway, but dynamic mics, including moving coils, certainly have their strong points, as well.

BTW "from the ground up" was a stretch from my part. E.g. most members here who build their own condenser mic don't build the capsule. But a couple do.

In short, I hear what you're saying. And to bring it back to the mic at hand, I can see why a two way version would be trickier still. Even for AKG this was not a piece of cake, obviously.

I do have another, related, question, but I''ll refrain. 

Oh, and @ MS Vienna; thanks for the splendid pictures again!

It seems the AKG dual capsule microphones are rather fragile.
I heard from a lot of people that the low frequency capsule had failed in those microphones.
Although I am not sure if it was the capsule itself, or a failure in the LF attenuator of the microphone.
I remember that in the radiostation I worked for, they had a lot of D224 microphones in the studios.
(Later they were replaced with Neumann U47 Fet microphones.)
The only disadvantage of the D224 was that they produced a very low outputl.
(Some female presenters even produced not enough 'modulation' to reach 0 dB output on the meter with all faders full open!)
My own experiences with the D202 are good, I used to have a D202 for over 40 years, and it still works like new! (I just sold it...)

No one mention other dual capsule mikes from AKG - D200, M539 (Uher), M611 (Telefunken).
From all of these i really like d224 (wooden snare) and M611 for different sources.
Not really like D202 and hate to service them all, especially D224

ln76d said:

No one mention other dual capsule mikes from AKG - D200, M539 (Uher), M611 (Telefunken).
From all of these i really like d224 (wooden snare) and M611 for different sources.
Not really like D202 and hate to service them all, especially D224

Click to expand...

The D200 was the "recording enthousiast" version, with a frequency response not as flat as the others, and lacking the humbucking coil.
As for the UHER M539 and TFK M611, they appear to be OEM versions of the D200. To my knowledge, neither Uher nor TFK ever actually made the microphones bearing their name.

abbey road d enfer said:

As for the UHER M539 and TFK M611, they appear to be OEM versions of the D200. To my knowledge, neither Uher nor TFK ever actually made the microphones bearing their name.

Click to expand...

ln76d said:

No one mention other dual capsule mikes from AKG - D200, M539 (Uher), M611 (Telefunken).

Click to expand...

Each is little bit different, even using same capsules (not sure about D200), specs are also minimal different.
Most difference in sound is probably  due to different headbasket design.
D200 have different mounting system.

I know this post is ancient history, but does anyone know how to remove the capsule from the head basket? I have 2 mics, one working but physically in poor shape, the other, dead but physically pristine. I've gotten the mic to the point that the head/capsule assembly is free from the body, but cant seem to work out how to get the capsule out with out breaking it to pieces. (already had a little chip of plastic break off trying to wedge it out).