Ribbon Mic Scouring Pad Modification

[chris319]

We all know that economy ribbon mics such as the Nady RSM-2 and others sound better when you remove layer upon layer of internal wire mesh and silk. Unfortunately, removing these layers leaves the fragile ribbon exposed and vulnerable to damage from blasts of air. Here is my bright idea for protecting the ribbon of a modified mic and it only costs a dollar or two.

Go down to the supermarket and get yourself some Scotch-Brite® scouring pads or the generic equivalent thereof. One pad is about 1/4" thick and measures about 4" x 6". The pads are porous, stiff, and seem to be fairly transparent acoustically. Cut them to the size of the erstwhile perforated metal plates and mount them on the threaded posts that used to hold the plates by poking holes in the pads with an ice pick or awl.

With your mic open and the ribbon exposed, a handy way of working on it without risking damage to the ribbon from breathing on it, is to take a hoop-and-nylon-stocking pop filter that you've got lying around, attach it to a desk stand and position it between the mic and your breath stream. Now you can work on your ribbon mic and breathe at the same time.

The pictures below show the scouring pad modification. I imagine you could accomplish much the same thing with open-cell foam as well.

 

[bitman]

Nice, how does it change the sound as opposed to no "foam" at all?

:Ron

 

[chris319]

I have tested the scouring pad material as a pop filter in a quick-and-dirty test and if there was any effect on the sound, it was too subtle for me to hear. You could do the test yourself -- the generic-brand scouring pads cost a buck and change. Just place it between the mic and your sound source.

Once you remove the plates, meshes, silks, etc. from one of these mics, there isn't much between the ribbon and the outside world. It seems to me there should be something between the ribbon and harm.

 

[Rossi]

Hmm, personally, I prefer to leave the metal waffles in front of the ribbon. Those reflectors are actually quite well designed, IMO, and enhance the hi end in exactly the right places, i.e. flatten out the response up until about 15k. And the nylon fabric on those reflectors also protects the ribbon from blasts.

 

[rodabod]

Have you tried cleaning any dishes with the mic yet?

Good idea - try the suggestion of using it as a pop filter for testing. People should remember that the filtering also damps the low-end acoustically which is important.

 

[chris319]

[quote author="Rossi"]Hmm, personally, I prefer to leave the metal waffles in front of the ribbon. Those reflectors are actually quite well designed, IMO, and enhance the hi end in exactly the right places, i.e. flatten out the response up until about 15k. And the nylon fabric on those reflectors also protects the ribbon from blasts.[/quote]
I found that the most dramatic improvement in sound came from removing the outer metal meshes and silk/nylon layers. There was a noticeable improvement in transient response and reproduction of sibilants. Now that I've got the mic apart I could easily compare the plates and the scouring pads (but not until about a week from now).

I prefer to wash dishes with an AKG C414.

 

[bitman]

I'm pretty sure Pantyclaus (my wife) is going to be getting me an Apex 205 which I think is the same mic as the Nady. At least the pictures I've seen of naked 205s look like the motor assembly is the same.

I'm going to do this before night falls on Christmas night.

 

[chris319]

Rossi had it right. The perforated metal plates add a bit of brightness to the sound of the RSM-2. The scouring pads alone leave it sounding slightly more dull, but they do tame down the plosives. Both are an improvement over stock. Hear for yourself:

Scouring pads

Stock perforated metal plates

Both

 

[chris319]

I have added a recording of the naked ribbon - no metal, no silk, nothing between my mouth and the ribbon. The proximity effect is pronounced. It sounds a lot better with the metal plates left in.

Scouring pads

Stock perforated metal plates

Both

Naked ribbon