Blog Quiz


The Sennheiser MD21, the Aston Origin and the Electro-Voice EV664.

What do these 3 microphones have in common? 

Post guesses in Comments below.

Answers Next Week…………………………………………….

One Week Later 

In addition to the correct answer given by Chris Dando, here is the other one I had in mind.

Answer.     The manufacturers of each of these microphones have made extravagant claims about their product’s durability, and in order to demonstrate this each mic has been subjected to somewhat ‘rigorous’ testing!

Sennheiser MD-21

From Sennheiser’s website:

“The indestructible design of the new microphone was impressively demonstrated at the Industrial Fair in Hanover in 1954. “We set up a round wooden board, about 5 feet in diameter, on which we had fitted ramps at regular intervals. An MD 21 suspended on a short cable was placed on the board, which was then rotated quite fast. The microphone was dragged up each ramp and could be seen crashing down onto the board again and again,” said Fritz Sennheiser describing the unusual demonstration. “It was sensational – at that time, microphones were delicate objects and had to be handled carefully.” And even today, the extremely low percentage of repairs for the MD 21 – 0.4% – speaks for itself.”

 Electro-Voice EV664 

John Woram, 1986

(Reminiscing about Lou Burrows, one of the founders of Electro-Voice)

Lou’s lectures were often hard to forget, as anyone who attended a demonstration of the E-V 664, the Buchanan Hammer, can testify. Lou would show up with a few mics, a piece of wood, and a nail. When the talk got around to the matter of durability, he’d unplug the 664, use it to pound the nail home, and then get on with the talk, having more than made his point.

Aston Origin

Following in this illustrious tradition of abuse here is James Young MD of Aston carrying out his very own ‘Microphone Destruction Test’ .  Enjoy!

FUN WITH FIGURE-OF-EIGHT! Episode 1 Radio and Film.


Back in the 1950s the iconic Marconi AX ribbon microphone was the main tool for BBC drama production.  Actors were familiar with its figure of eight characteristics, and would utilise the dead zones at the sides of the mic to great effect. Noisy page turns could be avoided by holding the script to the side of the mic. The impression of going off into the distance could be achieved by simply delivering the lines whilst slowly moving to the side of the microphone. Shouting from a distance could be managed in the same way. Actors were also very conscious users of proximity effect, moving closer or further from the microphone as the script required.


Figure of Eight Marconi AX                                                             BBC Training Manual 1942

Bearing this in mind an elderly ex-BBC producer told me the following delightful tale about a well- known actor of the day.

Whenever a trainee or inexperienced engineer was spotted entering the control booth he would go through the same entertaining routine. On being asked to deliver some lines to test the mic, he would start speaking in a fairly quiet voice whilst very gradually moving his head round the side of the mic. All the while the hapless young knob- twiddler in the control booth would be increasing the gain on the input. When our actor judged that the gain was almost certainly up full he would deftly swing his head back to the front of the mic and inquire in rich, thespian tones, (as if addressing the back row of the gallery)                            ‘HOW’S THAT FOR LEVEL?!!’



In the early days of talking pictures, years before the invention of the shotgun microphone, considerable use was made of the directional characteristics of figure-of-eight ribbon microphones to minimise the pick- up of unwanted noise on the set.  Cameras and other noisy equipment could be positioned in the dead zones. This greatly improved the quality and intelligibility of the end product. It also made it possible (using more than one microphone) to balance the levels of different performer’s voices. This had not previously been possible using Omni-directional models.

Filming in locations with high levels of surrounding ambient noise, a figure-of-eight could be suspended horizontally above the actors’ heads. The back of the mic faced upwards (away from the sound sources) and the front faced downwards towards the actors. In this position the dead zone effectively attenuated 360 degrees of surrounding noise!

These days, when recording studios seem to be generally stuck in Cardioid mode, I thought it might make a pleasant change to revive some of these vintage figure-of-eight techniques. In the following episodes I shall take a look at more uses for this versatile but somewhat neglected polar pattern.


Repairing a Rycote Windshield and Panamic Shock Mount for Sennheiser MKH815T

On the day I chose to record the voice-over for this video the wind was lashing the trees and bushes in my garden and the branches were swaying backwards and forwards. So I thought it would be a great idea to demonstrate the effectiveness of this vintage Rycote windshield by recording the voice-over sitting on a bench at the bottom of the garden!

Sennheiser MKH 815T Manual

How to take apart an AKG D2000 or a D170

Recently I noticed a thread on a well known web forum which specialises in disseminating misinformation on a range of gear. In this erudite discourse it was suggested that these ‘inexpensive’ old AKG dynamics were not made to last and that they couldn’t be taken apart or repaired by the user. This is of course complete bollocks!

Simply peel off the name strip from around the grill ( taking care to save it to put back on afterwards.)  The top half of the grill can then be easily unscrewed. If necessary the element can be gently pulled out from it’s rubber mounting. At the other end a single screw holds the XLR in place.

The AKG D170E  pictured below has been taken apart to clean and replace the disintegrated old foam inside the grill.

AKG D170E Dismantle 1AKG D170E Dismantle 2


It is also worth noting that when they were new these ‘inexpensive’ old microphones cost more than a week’s wages for the average musician!

AKG dynamics from the 1970’s were well designed, solidly engineered and intended to last. This one is nearly 40 years old and still sounds as good as the day it left the factory!

AKG Catalogue 1978



AKGD170 Bass Drum Application

Apart from being mainly designed for heavy rock vocals I was interested to note that the AKGD170 is also recommended for Bass Drum ‘ (where other microphones sound too ‘bassy’ and muddy)’……………… So with that in mind I recently took it out on some live rock’n’roll gigs and was very pleased with the tight, punchy sound it produces. If more low end is required it also responds very well to additional EQ.

CLICK HERE for AKGD170 Bass Drum Clip

Electro-Voice Rags To Riches. T45 Noise-Cancelling Microphone (1944)

In 1942 after America entered World War 2, the US military estimated that only 20% of radio communications in combat were successful. Failure in the other 80% was mainly due to the voice of the radio operator being drowned out by the surrounding cacophony of war. Like no other conflict before, success on the battlefield relied on communications. Spotting a gap in the market Al Khan and Ed Burrows, the owners of Electro-Voice, came up with a brilliantly simple, ingenious and cost effective solution to this problem. Electro-Voice T45 Box

Electro-Voice T45 Instructions 1944

Electro-Voice T45 Instructions P2Even in 1942 the single button carbon microphone was a piece of old fashioned tried and tested technology, having been in use in telephones since the tail end of the previous century. Although the audio quality of the T45 is little better than it’s telephonic predecessors it is extremely reliable and very robust. It also has a high output making it ideal for long distance communication. Even if the microphone gets wet you can simply dry it out (as per the instructions above) and it will carry on working! However, the really clever part of this design utilises 2 small holes of equal size on the front and back of the mic.Electro-Voice T45 Back hole.Electro-Voice T45 Front Hole

These allow the surrounding noise to enter the microphone on both sides of the diaphragm. The sound striking the back of the diaphragm is 180 degrees out of phase with the sound at the front. This causes a very impressive cancellation of the unwanted noise whilst the speaker’s voice, which is less than a 1/4 of an inch from the front opening, dominates the transmission.

In terms of manufacturing costs it would be hard to produce a cheaper microphone.  A carbon button is a very small tin of glorified coal dust (carbon granules) with a simple diaphragm attached.  A bit of wire and some lightweight plastic fittings and that is it! Pure genius !Electro-Voice T45 Noise-cancelling Microphone

After some initial military skepticism the product was thoroughly tested and a first order came through to Khan and Burrows  for 100,000 units! The T45 was soon taken up by all branches of America’s armed forces and  the success rate of combat communications rose to 90%.

Rags to Riches.

Prior to World War 2 Electro-Voice was a small struggling company, with 20 employees, manufacturing a handful of dynamic and velocity microphones per week. By the latter part of the war Electro-Voice had 500 employees working in 3 shifts  producing more than 2,000 T45 microphones a day! After WW2 it was also adopted by commercial aviation and remained in service for several decades.  The T45 was also used on the Mercury, Gemini and Skylab space missions.

Over the entire production run more than a million were produced placing the T45  among the highest selling microphones ever made.

During the war many small firms went out of business due to a shortage of manpower and materials, but for those involved in the war effort fortunes were to be made. In 1946 Electro-Voice moved into an impressive new factory at Buchanan Michigan where they continued to manufacture  innovative and exciting audio products  for the next 60 years.



Circuit for powering a carbon microphone.  Circuit for powering Carbon Microphones.


The Shure SM58 (1966-2016). 50 Years at the top!

The Shure SM58 is a microphone I have never owned, and it is not a model that I would particularly recommend. I can always think of a better alternative. Nevertheless, if I arrive to engineer a show and find that the theatre or the PA company have supplied SM58s for all the vocals I am not unhappy with the choice! It is unlikely that any of the vocals are going to sound amazing. At best they will probably sound good and at worst they will be ok. Part of the ‘magic’ of the Shure SM58 is that whilst accuracy is not one of it’s hallmarks, it does a reasonably good job of flattering most singers. The SM58 is like Dave the rhythm guitarist in your band………… He is never going to be an inspired soloist but he turns up at all the rehearsals and can be relied upon at the gigs to play the right chords. Not fantastic but utterly dependable. A safe pair of hands!

With the 58 it is not just vocals. If you run out of quality mics at a gig and a stray conga player turns up who is not listed on the technical rider you will inevitably stick a couple of 58s on them. [NB. It is a matter of scientific observation that no matter how many microphones are used at a concert there will always be 2 x SM58s left in the case!??]  Not the best choice but they will do the trick! I once had a ‘guest’ fiddle player suddenly appear on stage during a live recording. He grabbed the nearest 58 on a stand and pointed it at his instrument. I hastily adjusted the gain and the impromptu fiddle track ended up on the album. (In fact quite a few people commented afterwards on how good it sounded!)

Shure SM58Another clue to the enduring popularity of the Shure SM58 lies in this photograph. They will put up with almost any amount of abuse!! On tour it is very hard to find one without a dented grill. In fact there is a brisk trade on eBay for replacement grills. (see pic above) You can drop a 58 regularly for 30 years and it will probably still be working  (that may not quite be true but I have certainly seen examples that look like that is what has happened!) and after the gig you can store them in a damp, unventilated van. Don’t worry; just chuck them loose in the glove compartment or in an old cardboard box under the front seat. (These appear to be popular storage solutions preferred by SM58 owners!)  Even when the paint is all corroded and chipped they will still be working just fine! A friend of mine was engineering at a festival a few years ago when an ‘overexcited’ singer vomited all over his 58. After a bit of a wipe and a rinse, unlike the singer, it was back in action! No problem!

The legendary rock’n’roll credentials of the SM58, I think, can be traced all the way back to the film of the Woodstock pop festival in 1969. The only mics used at Woodstock were in fact modified Shure 565s which are very similar to the 58 (just more shiny?!) They were used on everything from bass drum to vocals. Martin Scorsese’s film was seen by millions worldwide and in every camera close-up of the stars on stage there appeared the same Shure microphone! Woodstock was the first big festival PA system, setting a benchmark for years to come and cementing the place of the Shure SM58 in the forefront of popular music.

So Happy 50th Birthday SM58!

P.S.       If you want to listen to sound clips of this mic there are several million on the internet!



Happy New Year from Martin Mitchell 2.jpg