Retro Reviews: EV-643 Dynamic Unidirectional Microphone

Last week I tested the Deity short shotgun microphone from Aputure against the Sennheiser MKH 416. This week I found some cool YouTube videos that review the EV-643 Dynamic Shotgun microphone.

This microphone was produced in the mid 60’s by Electro Voice and in the manual references a patent for some of the other dynamic unidirectional microphones Electro Voice produced at the time.


Here is that patent.


Here you can see uniform sized holes going down the inside shaft of the shotgun. A dynamic microphone capsule would sit inside this and sound waves coming from the side would cancel each other as they try to move the coil of wires. The more directional you wanted your microphone, the longer the tube needed to be. This size to directional pickup ratio would end up creating the 7ft monster The EV-643.

The pickup pattern and frequency response for the EV-643 really leaves a lot wanting compared to modern standards.

Unidirectional really is the only polite way to  characterize that pickup pattern. Who wants a flat frequency response when you can have an adventure on a scenic mountain range. If you are reading this review and thinking about buying a EV-643 for your next project you should seriously stop now. If you have to ask why, you also should stop reading this blog. Now for more history and fun!

My favorite microphone advertisement ever. I would have loved to actually have called and asked for the traveling salesmen to come to my house and preform a demo.

Oddly, the EV643 is actually an improvement over what was used before it. If you wanted a super unidirectional microphone before Electro Voice’s patent, you went with the a rifle microphone or a machine gun microphone. These were omni-directional capsules that used spiraling tubes of different lengths to delay off axis sounds, so they would get canceled when they reached the coil. Here are some examples of this type of microphone.

Really makes booming a MKH416 in a blimp look like a cake walk. I personally will never complain again.
As you can see, these aren’t much smaller then the EV-643, but they weigh so much more.

10 Years after the Electro Voice patent, a company out of Germany put forth their own directional microphone patent. That company went by the name Sennheiser Electronic. Here is their patent.

What’s very interesting is in this patent is that they make reference to the Western Electric 618A.

“In another known construction, a bundle of directional or acoustic tubes of different lengths is utilized.

This construction is, however, awkward and difficult to handle because of its ‘unwieldiness and is expensive and difficult to manufacture. Furthermore, the directional tubes cause considerable losses and high damping at high frequencies and considerably lessen the sensitivity of the unit as a whole.”

That is some Grade A Patent smack talk!!!! And they go on to smack talk the Electro Voice dynamic unidirectional microphones too.

“Another object of the present invention is to provide a directional microphone which avoids and overcomes the difficulties and disadvantages of known directional microphones.

Another object of the present invention is to provide a directional microphone which utilizes a single, short directional or acoustic tube which functions with the effects of a long tube.”


Here the “effects of a long tube” is referencing the Electro Voice series of dynamic unidirectional  “shotguns.” And if you did happen to click on the link to the patent you would have found this photo submitted by Sennheiser Electronics on Nov 8, 1967.



Does Fig. 5 remind you of something?

It should.

A photo that looks all too similar to the one Electro Voice put forth 10 years earlier, except this one now features varying size air holes and where a dynamic coil of wires once sat, now a mechanical transducer comprising of a diaphragm.


When you defeat a giant terrorizing a kingdom, stories and legends are created. When they defeated the 7ft long monster, a legend would be created that would last 40+ years.

Sennheiser was driven to defeat the monster that is unidirectional dynamic microphones and would create the legendary sound that we now know as the Senneheiser MKH 416.


profile-picAbout the Author

Andrew Jones is a location sound mixer based in Los Angeles. He started in the TV and Film industry in 2004. You can email him at


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