Monday, May 01, 2006

Comparison: 77DX vs Proscenium


Doesn't this look like an old Polacolor print? I used to enjoy doing Polacolor
transfer prints using Polaroid peelaway film onto cloth, rice paper, and wood.
See how close the Proscenium curve comes to Herb Singleton's Measurements.

Here is a comparison spectrogram of the 77DX vs the Proscenium ribbon mic. The Proscenium has only a figure 8 pattern, and the 77DX was set to figure 8 (open shutter) and with the reactor switched OUT.


The horizontal lines are at 10 dB intervals. The software used is Visual Analyser version 7.0 which can be downloaded for free, somewhere. I like it because it is well suited to R&D use.

The Blue curve is the Proscenium.

The Red curve is the 77DX.

Both microphones are excited by a single white noise source placed equidistant to each. No attempt is made to normalize the source transducer, which is a cheap RCA-branded two transducer affair that I got on sale. It has its own kinks that you can observe, as they tend to show up on each channel.

The frequency range shown is log, Zero Hz to 20,000 Hz. I know it is hard to see and I have to find a way to save these as a jpeg in the future. We are going to need them.

2 comments:

Elliott said...

Very interesting. So little information is available about this microphone (Proscenium). Thanks!

To make a jpeg in windows, take a screenshot (press "print screen" button on keyboard). Now paste the screenshot into paintbrush or photoshop, and save it as a jpeg.

Under Mac OS, press command-shift-3 and the file will be on the desktop in png or pict format, open it up with photoshop or preview, and convert.

Bob Crowley said...

Thanks
Since this post of over two years ago, there are some reviews and comments on this mic in the press. Most owners try them and if they work on their application, keep them.

I tried the print screen thing and for some reason it did not work for me. I will try again.