Any experience with MCA SP-1?

[arcanemethods]

Some folks on rec.audio.pro have had very kind words for the ultra-cheap MCA SP-1 available from Musician's friend for, I think, $39. I'm wondering if anyone here has given it a spin.

It isn't really a large diaphragm. I got one and immediately extracted the capsule and it's 18 mm, more in the SDC range.

It is an excellent example, IMHO, of the principles I've been espousing of high quality, low cost, repeatable capsules made possible by careful attention to manufactuability during design.

The design is novel and clever. Obviously thought through for solid construction yet ease of manufacture. One big screw instead of lots of little ones holding it together and the diaphragm tension looks to be determined at final assembly which means it could easily be tensioned while stimulated and producing output to give consistent results off the line.

The downside I see by inspection is that the diaphragm is recessed into the housing by 3 or 4 mm which could give some unevenness or drop off in off axis HF response.


Bob

 

[Marik]

<The design is novel and clever. Obviously thought through for solid construction yet ease of manufacture. One big screw instead of lots of little ones holding it together and the diaphragm tension looks to be determined at final assembly which means it could easily be tensioned while stimulated and producing output to give consistent results off the line.>



Bob, of course it is novel and clever
The capsule is a Nemann KM84 clone, and the circuit is a Schoeps clone.

<The downside I see by inspection is that the diaphragm is recessed into the housing by 3 or 4 mm which could give some unevenness or drop off in off axis HF response.>

Yep, right now I am modding MXL603 mic, which has exactly the same capsule and circuit (as also MXL990 has)--just different body. The very first thing I payed attention is this 4mm cavity, which creates resonator and HF reflections and other nasty things.
To get the most of output from the capsule they raised polarizing voltage by means of oscilator to 48V. The HF boost and LF cut can be changed by carefull adjustment of the polarazing voltage, and actually very nice and flat response can be achieved. Needless to say it uses very cheap caps, which mostly determine the sound.
For better bass response 0.22Mf coupling caps should be changed to at least 1Mf films.

 

[toorglick]

I have two I use for drum overheads. I generally mic drums with 4 mics (the MCAs on overhead, a SP B1 for the kick and a random condenser for the snare). The MCAs work really well in this application. The HF roll off is my friend here because it keeps the cymbals under control.

I've tried them on some rock vocals just to see and they aren't very good on the voices I've tried them with.

But, for the $35 a piece I bought them for, I love them as overheads.

 

[Marik]

<The HF roll off is my friend here because it keeps the cymbals under control.>

Hm, I was under impression it's there because of acoustical properties of brass ring around the capsule...

 

[toorglick]

<The HF roll off is my friend here because it keeps the cymbals under control.>

Hm, I was under impression it's there because of acoustical properties of brass ring around the capsule...

Does HR Mic Forum = instant dickhead responses?

 

[arcanemethods]

Bob, of course it is novel and clever
The capsule is a Nemann KM84 clone, and the circuit is a Schoeps clone.

I'll be damned! Never looked at the KM84. Good news about the circuit. Do you have a diagram anywhere?

Bob

 

[Brent Casey]

Does HR Mic Forum = instant dickhead responses?

toorglick, I think that Marik is speaking of the acoustical properties of a brass dress ring rather than vibing you.

Brent Casey
PMI Audio Group
877-563-6335

 

[Marik]

Toorglick,

I had no any intention to flame you, as I am not into this stuff--there are much more interesting things on this board--microphones, for example . I probably wasn't clear enough, and if you read it this way, I apologize.

 

[toorglick]

I read it several times over since and it still is an odd response to me. But I can accept that it wasn't a flame, so, my apologies to you as well!