Category Archives: Vintage Microphones

Shure 430 ‘Commando’ Controlled Magnetic / Controlled Reluctance Microphone (Circa 1957)

Shure Model 430 CommandoShure 430 Commando grill

The Controlled Reluctance microphone (aka Controlled Magnetic) was developed by Shure during World War 2 to fulfil the need for a battle announce microphone that could operate reliably at extremes of temperature and humidity. (Subsequently also perfect for Korea and Vietnam!)

Although the Controlled Reluctance design was in some respects similar to a conventional dynamic in other ways it was significantly different.

The 2 diagrams below illustrate the differences.

  • DYNAMIC MICROPHONEDynamic-moving-coil-diagram
  • CONTROLLED RELUCTANCE/MAGNETIC MICROPHONE (2 slightly different versions)Controlled Reluctance Microphone Sectional Diagram

Here, in response to an email enquiry, is an explanation from Shure of the working of this microphone

On 3 May 2017 15:06, “Shure Europe” <support@shure.eu> wrote:

Response By Email (Michael P) (05/03/2017 09:06 AM)

Controlled reluctance is a variation of a dynamic mic.  The controlled reluctance mic diaphragm connects to a small lever made from ferrous material.  The other end of this lever is positioned inside of a stationary coil of wire.  Surrounding the coil of wire is a stationary magnet.  As the ferrous lever is moved by the mic diaphragm, the lever disturbs the magnet field.  This induces an AC signal (the audio signal) in the coil of wire.

Answer Link: Difference between controlled reluctance and controlled magnetic

This type of mic was originally designed for military applications.

Michael Pettersen

Shure Historian

 


2 pin Ampenol Connector

If you buy a 430 make sure it comes with one of these as 2 pin Amphenol connectors are hard to find.

The CR/CM elements have a high output (making them suitable for transmission over large distances) and require no additional transformer. They are therefore cheaper to manufacture than a conventional dynamic.

After WW2 Shure introduced several models for the civilian market, including the famous Green Bullet (still popular with harmonica players to this day). These were mostly budget PA mics intended for speech applications such as paging and announcements. Whilst not being particularly noted for high quality audio, their main selling points were cheapness and reliability. It is therefore not hard to see why these sturdy, affordable mics soon found favour with musicians and singers.

Apart from being highly profitable, Shure’s military communications contracts had the additional spin-off of enhancing a lasting reputation for reliability. Indeed, the company have often boasted that all of their products are tested to military standards (MILSPEC).  Even though the Model 430 was made for the civilian, domestic market it nevertheless trades on its military heritage with the name ‘Commando’ and it’s distinctive, camouflage green head!

Shure 430 Commando head

Data Sheet for the Shure Commando series.:-     us_pro_415_ug

Shure Microphones  :-  1957 Catalogue

 430 Commando Original Box

So what does it sound like?  CLICK HERE for a short clip of spoken word and Blues Harmonica.

 

Sennheiser MD441-U Another Classic Dynamic Microphone! (1971 to the present)

Following on somewhat from the theme of the previous post.

Sennheiser MD441-U

Sennheiser MD441-U Grill

Launched in 1971 as Sennheiser’s flagship dynamic the MD441 has remained in production ever since. Famous users include David Bowie, Stevie Nicks and Elton John. It is a superb example of German design and engineering, and even today has few competitors. However, a microphone of this quality does not come cheap. A new MD441-U will set you back around £700.00 !

Cool Mic Dave!

When AKG produced the remarkable D224 (c1967) they went to great lengths with their twin capsule design to eliminate proximity effect, and create a wide, flat frequency response from 30Hz-20 kHz, regardless of distance from source. With the MD441 Sennheiser took a rather different approach. Whist the frequency response is similar to the AKG (30Hz-20kHz), Sennheiser allow the user of the MD441 to have creative control over proximity effect and also high end brilliance.Sennheiser MD441-U Frequency response graphs

This is achieved using a five position bass roll-off switch and a 2 position brilliance switch. This provides a choice of 10 different frequency curves to suit the needs of a wide range of applications!

The Sennheiser MD441 User Manual below explains very thoroughly the operation and characteristics this extraordinary dynamic microphone.

Sennheiser MD441 Manual.

Sennheiser MD441-U

So What Does It Sound Like?  CLICK HERE for a drum clip illustrating the wide frequency response, dynamic range and highly detailed transient response.

CLICK HERE for Tenor sax and clarinet.

In Conclusion
Whether you choose heavy metal guitar at full volume, or a solo violin, a baroque recorder, or a baritone sax, the MD441 delivers! There is little to distinguish between what goes in and what comes out! It sounds remarkably natural on a wide range of acoustic instruments and the human voice. The Sennheiser MD441-U has all the subtlety normally associated with a high quality condenser combined with the smoothness and punch of a great dynamic. If I was only allowed one microphone in my ‘desert island’ studio this would probably be it!

Electro-Voice EV642, 643, & 644 Cardiline Microphones , (circa)1960

Ever since the advent of the ‘Talkies’ sound technicians have struggled to pick up speech in motion pictures with sufficient clarity. For many years the problem of getting the microphone close enough to the performers without it being in the camera shot was a constant challenge!  On the other hand if the mic was too far away the sound was often ruined by the pickup of unwanted surrounding noise.

Seeking to address this problem, in October 1959 Wayne A. Beaverson of Electro-Voice filed for a patent on a new type of directional microphone which could be successfully operated at a distance from the sound source.  At low frequencies this microphone exhibits the directional characteristics of a cardioid mic, with excellent rear rejection. As the frequency response rises it becomes a line mic with considerable attenuation of unwanted sound from the sides. Thus the new ‘Cardiline’ design provides excellent directivity right across its operating frequency range.

Electro-Voice Patent for Unidirectional Microphone 1963

The success of the new microphone was such that in 1963 Electro-Voice received an Academy Awards “Oscar” for the development of the model 642 Cardiline, The award, in part, read “To Electro-Voice for a highly directional dynamic line microphone… capable of picking up sound in situations where a microphone cannot be placed close to the sound source and where unwanted sounds are to be discriminated against.”

Although the Academy Award went to the 642, the microphone drawn and described in the original patent application was in fact its close cousin the EV644. At this point you might be wondering about the 643?  Well ……… The 643 was pretty much the same as the 642 except in one significant detail ……… it was just over 7 feet long!  All three of these mics were of the Cardiline pattern but they were aimed (excuse the pun) at different areas of the market. As we know, the 642 was tailored very much for the film and TV industry and came with an elastic mount for attaching to a boom.

EV642 Advert 1963

EV643  Advert

Electro-Voice_643 Advert

electrovoice_643_2

Although extravagant claims are made for the mighty 643 in the advert above, I suspect that this mic was in fact quite awkward and unwieldy to use (even sighting along the barrel!!) It is certainly hard to find any fond recollections of it. I came across one report from some poor sod who once spent an afternoon standing on the roof of a football stadium trying to follow the ball round the field!! Anyone who has ever operated a theatre follow spot will appreciate just how ludicrous that must have been!

Which leaves the 644. (My latest eBay bargain!)

electro-voice-ev644

Designed for use on stage, in theatres, auditoriums and churches,  the EV644 Sound Spot came with a microphone stand mounting and was finished in classic Electro-Voice chrome. You could also buy it with a dull matt paint finish,(non-reflective under lighting), but why do that when the chrome version just looks so rock’n’roll cool !

Allied Catalogue 1960

List Price $110. A bargain at $64.68 ! (Not cheap in 1960!)

ev644-back-end ev644-body-and-stand-mountev644-end-grillev644-original-box-insideev644-original-box

CLICK HERE for Voice recording at a distance of 12ft

CLICK HERE for Glockenspiel Recording

In Conclusion

The 1963 patent shown above acknowledges a number of earlier inventions relating to directional microphones. In particular the patents of Harry Olson dating back to 1939. However, the earlier inventions, (mostly involving complex arrangements of multiple tubes of differing lengths), were awkward and cumbersome. In contrast, Beaverson’s Cardiline microphone, using a single multi-path tube feeding a single cardioid capsule, was an uncomplicated work of genius. It was both effective and easy to use.

To this day the elements of Beaverson’s patent can to be seen in shotgun microphones all over the world.

Below are the Techincal Specification Sheets for all 3 microphones.

Electro-Voice 642 Spec Sheet

Electro-Voice 643 Tech Spec.

Electro-Voice 644 Tech Spec

Grampian DP4 (circa 1963) A trip down memory lane!

It was the mid 1960’s and I was a teenager at school in Manchester. Only 30 miles from Liverpool. Before the age of discos. It was a fantastic time for live music. The Mersey boom was at its height and the pubs and clubs were rocking to the latest beat groups. (It is worth noting that none of the music clubs such as The Cavern in Liverpool, or The Twisted Wheel in Manchester, were licensed to sell alcohol. Nevertheless on a Saturday night their subterranean vaults were crammed with teenagers who had often queued for hours to see their favourite bands!)

In the 5th form some of my school mates formed a group. I used to lig along to their rehearsals in the school music room. They had a couple of Vox AC30 guitar amps and an old Selmer which was used for PA. I can remember the singer turning up one day with a very shiny new microphone. All black enamel and chrome, like the headlamp on a classic British motorcycle.Grampian DP4  Removed from it’s bright blue box the mic was duly plugged into the Selmer amp. The lads then launched into their version of Buddy Holly’s ‘Peggy Sue’. The assembled hangers-on (including myself) thought it sounded amazing!

I was therefore overjoyed a few weeks ago when a friend kindly gave me this bright blue box. I recognised it straight away!Grampian DP4 Box

Grampian DP4 with clip

Just below the chrome bezel there is a ribbed rubber ring designed to prevent the mic rolling off flat surfaces. Brilliant feature!

If you buy a DP4 make sure it comes with the 2 pin mic connector as these are as rare as hen's teeth!

If you buy a DP4 make sure it comes with the 2 pin mic connector as these are as rare as hen’s teeth!

Grampian DP4 Label

Here in the UK although the Grampian DP4 enjoyed a good deal of popularity as a PA microphone, and also with amateur tape recording enthusiasts, it was never really thought of as a top quality professional instrument. Sennheiser had launched it’s superb MD21 in 1953 and followed it in 1960 with the MD421.  Around the same time AKG gave us the D19 and the D24. The poor old Grampian was not quite in the same league. However, for a while the DP4 was used by the BBC for outside broadcasts and by their Wildlife Department in conjunction with the Grampian Parabolic Reflector. (As seen on the front cover of this issue of Tape Recording Magazine from 1969 )

tape-recording-uk-1969-04

A few weeks ago on TV I saw an old film clip featuring an impossibly young David Attenborough in the middle of the jungle somewhere clutching a Grampian Parabolic reflector with a DP4 mounted on it.

In the end Grampian Microphones were no match for the German. Austrian and American competition. As the 1960’s rolled on bands got louder, PAs got bigger, stage monitors were introduced and the omni-directional dynamic microphone fell out of use. Cardioids simply had more gain before feed back! By the mid-1970s the Grampian DP4 had disappeared from the stage and eventually the company went out of business.

So what does it sound like? 

 CLICK HERE for a short vocal trip down memory lane!

 

Grampian Brochures and Technical Information (These came in the box with my DP4.)

grampian-dp4-page-1grampian-dp4-page-2grampian-dp4-page-3grampian-dp4-page-4

grampian-dp4-instruction-sheet-page-1028grampian-dp4-instruction-sheet-page-2030

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

RADIO

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.

CLICK FOR SHORT VOICE DEMO.

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?!!’

 

FILM

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

N.B.

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

AKG_Mics_1978_part1

AKG_Mics_1978_Part_2

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