Sennheiser LABOR W MD4 Noise-Cancelling Microphone.

Following on from my posts about the LABOR W MD7 and the MD21, here is another gem from the early years of Sennheiser.  Released in 1951, the MD4 is an unusual looking, handheld, noise-cancelling, dynamic microphone designed to suppress feedback and ambient noise.

Back view.

So How Does It Work?

The MD4 is side addressed. Sound can enter through the openings on either side of the capsule. When the user is speaking in close proximity to the front of the microphone their voice is strongly reproduced and very little sound is entering at the back of the diaphram. On the other hand, unwanted sound arriving at the microphone from further away, and in particular at the sides, will enter front and  back simultaneously. Bearing in mind that the back of the diaphragm is 180 degrees out of phase with the front, these sounds will be cancelled in varying degrees. This capsule design achieved a considerable degree of off-axis rejection, making it much less likely to pick up unwanted sound from PA loudspeakers or other sources.

Outside of the military and commercial aviation, the MD4 was the first purpose designed, dynamic, noise-cancelling microphone that I can think of, on sale for domestic use.

N.B. Sadly the original Grosse Tuchel connector has gone missing but at some point I will replace it. For now it works fine direct wired.

In a market previously dominated by feedback-prone omnis, the MD4 gained considerable popularity for use in public address and continued in production until 1973. Although initially intended for use with speech the MD4 also found favour as a vocal mic.

Here is the legendary Sonny Boy Williamson II pictured at a folk/blues festival in Germany in 1963. 

So what does it sound like? 

Here is a Voice Recording Demonstrating the Noise-Cancelling properties of the MD4

CLICK HERE to listen.

And now for something completely different ………….

Close-Mic’d Guitar Amp

CLICK HERE to listen.

N.B.   In the context of a live gig the noise-cancelling properties of the MD4 will provide considerable isolation from other performers.

Below is some technical information on the MD4 from the 1953 LABOR W catalogue.

English Translation 

Moving coil microphones

Moving coil microphones have two major advantages over other types of microphones:

• They are robust and insensitive to weather influences.
• Due to their low source resistance, they can be easily connected via lines of several 100 metres.

Moving coil microphone MD 2

Universally usable microphone for particularly rough operation. Well suited as a table microphone because of its elegant shape in combination with a table base. Frequency range 50-10,000 Hz. Sensitivity approx. 0.1 mV/ub at 200 . Dimensions: 54 Ø x 120mm. Table base available as an accessory.

Moving coil microphone MD 21

Thanks to a new design and modern production methods, we have succeeded in creating a high-quality universal microphone that, despite its low price, is top class. Frequency range 50-15,000 Hz. Sensitivity 0.20 mV. Dimensions: 120 x 46 x 46 mm. An elegant table base is available as an accessory.

Stand microphone MD 3   

Very popular as a stage microphone because of its barely visible input stage. The high-quality moving coil element housed in the base ensures high transmission quality. Frequency range 30-10,000 Hz. Sensitivity approx. 0.08 .V ub and 200 Ω. Spherical polar pattern. Dimensions: base 170 mm Ø, 60 mm high, tube 900-1 500 mm long.

Stand microphone MD 3 Studio

In a frequency range of 30 to 15,000 Hz, it has an effective treble boost from around 6,000 Hz. Externally, it can only be distinguished from the MD 3 by the form of the input stage.

MD 3 and MD 3 Studio are supplied with an attachable Plexiglass panel, which gives the microphones a slight directivity.

Probe measurement microphone MD 3 M

The extremely small sound absorption of only 8 mm Ø does not cause any distortions in the sound field. Therefore particularly suitable for many acoustic measurements. Frequency response 50-10,000 Hz + 2.5 db.

Moving coil microphones (page 2)

Table microphone MD 3 T

A particularly elegant table microphone for first-class transmission of speech and music. Base plate can be unscrewed and has a thread suitable for mounting on a photographic tripod. Balanced frequency range 50 -10,000 Hz. Sensitivity 0.08 mV/ub at 200 Ω. Omnidirectional polar pattern. Dimensions: ball 60 mm Ø, plate 70 mm Ø, projection 450 mm.

Hand microphone MD 4

The MD4 has proven to be excellent for all voice transmissions where there is a risk of acoustic feedback. Through particularly effective compensation, any sound coming from a greater distance is very strongly suppressed. The MD4 is therefore just as suitable for transmissions from very noisy rooms. Frequency range 50-10,000 Hz. Internal resistance 200Ω. Voltage emitted during normal discussion 4mV. Dimensions: case 60 mm Ø, length 180 mm, weight 380 g. – The MD4 is available with a talk switch and also in a switchable high-impedance version.

Hand microphone MD 42

Field of application like MD4; but is end addressed. Frequency range 200-10,000 Hz. Internal resistance 200Ω. Voltage emitted during normal discussion 2.5 mV. Dimensions 47mm Ø. Length 120 mm, weight approx. 135 g.

Moving coil microphone MD 5

Universally usable microphone in a favourable price range. Can be used as a hand, table or tripod microphone. Excellent reproduction, especially for voice transmission. Available in low and high resistance, with and without a switch. Sensitivity approx. 0.25 mV/ub or 7mV/ub. Dimensions: 86 x 65 x 52 mm.

Speech microphone MD 7

Particularly good speech intelligibility due to emphasis on high frequencies. Therefore recommended for announcement and dictation systems. The soft rubber housing makes the MD7 insensitive to rough use. Available in low-impedance and high-impedance versions. Dimensions: 76 x 48 x 48 mm.

Microphone Accessories

Tripods, flexible necks, table bases, cables, couplings in various designs available.

---

Conclusion

Throughout the decade following the establishment of LABOR W in June 1945 Fritz Sennheiser and his colleagues at Laboratorium Wennebostal worked hard producing a range of innovative microphones for a variety of purposes, aimed at different sectors of the market. They offered microphones for the home, the office, the stage, journalism and TV and sound studios. As we can see from the catalogue above they demonstrated a remarkable degree of ingenuity, technical expertise and creativity. These are characteristics which distinguish the Sennheiser brand to this day.

Credits

Many thanks to my old school friend Alan Marchant for kindly donating this fascinating microphone. Alan is owner of The Vintage Wireless Co in Manchester at 174 Cross St, Sale M33 7AQ. His shop is an amazing Aladdin’s cave of ancient wirelesses, car radios, gramophones and phonographs. Well worth a visit!

Thanks also to Keith Thompson for sparing the time to record the tasty blues guitar clips.

And thanks to Hazel Hanson for the English translation of the LABOR W Catalogue.

MB – UNITRA TONSIL MDO 23 (Circa 1975-80s)

Between 1973 and ‘75 German microphone manufacturer MB Electronic (today known as MBHO) designed a range of quality microphones that were licensed to Polish state owned electronics company UNITRA TONSIL.

Back in May 2020 I wrote a post about the UNITRA Tonsil MCU-53, an excellent cardioid condenser. Now, (from the same stable) here is the MDO 23, a slender, omnidirectional, studio dynamic.

So What is it Good For ?

The thing I have always liked about omnidirectional dynamic microphones is the absence of proximity effect coupled with the ability to handle high SPLs. This makes them perfect for close-micing loud guitar amps without having to mess around EQing unwanted boominess caused by proximity effect. I have often used a Sennheiser MD21 on rock ’n’ roll theatre shows for this purpose.

Omni dynamics also make excellent speech mics and are very often used in TV and radio for interviews. Once again the absence of proximity effect is useful, allowing a good deal of freedom of movement without significantly affecting the frequency response.

Picking up sound from 360 degrees, Omnis are also just the job when it comes to capturing ‘atmosphere’.

CLICK HERE to hear a range of sound sources recorded with the MB UNITRA TONSIL MDO 23

Technical Specifications

Frequency Response graph

Standard 3 pin small Tuchel  connector

Conclusion

Having scoured the internet for information about this microphone I have come to the conclusion that it is somewhat rare! Apart from a couple of photographs, the tech spec and frequency response graph pictured above were pretty much all I could find. Sadly, it would appear that company records of this period have long since vanished in the mists of time.

In common with the MCU-53 I wrote about previously, this microphone has been generously sent to me by a friend in Poland, Adam Wilma. It is a serious quality professional microphone with a myriad of uses, and a very welcome addition to the Polish section of my collection. So thanks once again Adam!

UNITRA Tonsil MCU-53

Acel GM-17B

MB UNITRA Tonsil MDO-23

Electro-Voice RE20 Cardioid Dynamic 1968- present day.

Picking up the RE20 for the first time the expression ‘built like a tank’ immediately springs to mind. Weighing in at 1lb 10oz everything about this microphone is heavy and solid. Able to operate in conditions of extreme temperature and humidity the RE20 can also handle pretty much unlimited SPL. If I was commissioned to record an erupting volcano, or maybe a nuclear explosion from close quarters this is the microphone I would choose! In addition it also has a wide, flat frequency response, uniform cardioid polar pattern and excellent transient response all of which allows the RE20 to compete with the very best of studio condensers.    

Here below is the manufacturer’s Technical Data and Service Sheet for the RE20 

re20_engineering_data_sheetDownload

pl20-and-re20-serviceDownload

Short History Lesson.

At the tail end of the 1950’s Lou Burroughs, co-founder of Electro-Voice announced that the company was to move away from the manufacture of condensers and ribbons and concentrate on producing dynamic microphones. He believed that condensers and ribbons were too fragile and temperamental and that dynamic microphones were superior in every way. He declared ‘These are the microphones of the future’.

Throughout the 1960’s Electro-Voice developed a series of quality dynamic microphones based on their famous Variable-D design, starting with the EV664 ‘The Buchanan Hammer’ and culminating in 1968 in the now legendary RE20. The advertising clip below for the EV666 illustrates how the Variable-D design uses phase cancellation to reduce unwanted pickup from the rear of the microphone and thereby ‘create a uniform cardioid pattern at all frequencies.’ The most obvious practical advantage is that ‘proximity effect’ is pretty much eliminated. This allows the user to address the microphone from very close quarters without any unnatural rise in bass frequencies.

Right from the start the RE20 proved to be an enormous hit with radio stations, recording studios, PA companies and performers. The RE20 was used for lead vocal on two albums by Stevie Wonder, ‘Talking Book’ in 1972 and ‘Innervisions’ 1973. Producer Robert Margouleff said that the RE20 helped achieve a “close, intimate sound”.  Tracks such as ‘Superstition’ and ‘You Are the Sunshine of My Life’ are outstanding classics of popular music.

Impervious to Popping.

Another important feature of the RE20 worth mentioning here is the internal ‘pop’ filter. Every entrance to this mic is protected by a barrier of thick foam.  I can think of no other microphone like it! For singers, actors and broadcasters who are prone to ‘popping’ or sibilance the RE20 is the solution to the problem. Even from a distance of ½ an inch it is almost impossible to make it ‘pop’!

Here is me being silly just to illustrate the point. 

Soooo…. In Conclusion.

Apart from close up recordings of plosive tongue twisters what else is the RE20 good for? Over the years it has been used for many things. Apart from broadcasting and vocals it has gained a considerable reputation on kick drum, guitar (electric and acoustic) bass (electric and upright) and brass instruments of all shapes and sizes. To be honest it is one of those very rare microphones that will sound great on almost anything!

CLICK HERE for recording with Tenor and Baritone Sax and Kick

Sennheiser MD408 N Super-Cardioid Dynamic Gooseneck Microphone. 1960’s/70’s

Originally designed for speech and vocals the Sennheiser MD408 N is a solid, reliable, workhorse microphone which is useful for many tasks. It performs well on guitar cabs, delivering a rich beefy sound with plenty of midrange punch. The flexible gooseneck makes it particularly easy to position. It is also useful on snare and a variety of percussion. Once again the gooseneck is very handy for manoeuvring in awkward spaces. Being a super-cardioid it also has excellent feedback rejection.

Some microphones were destined to appear with the stars, glittering centre stage with Elvis or Tina Turner or David Bowie. Others however, never quite made it to the limelight. Back in the 60’s and 70’s the MD408 N was often used as a humble studio talkback mic. Even so, when it comes to dull publicity photos the shot below takes a lot of beating!

Sennheiser MD408N Klien Tuchel Connector and standard 3/8 inch stand adapter.

The MD408 also has a silent on/off switch which is very handy if it is used for talkback or as a lectern mic. The neat square plastic actuator has sadly gone missing on mine but you can see it in the publicity photo.

CLICK HERE to listen to the MD408 on rock’n’roll Guitar at a live show.

Conclusion

Whilst it may not have the kudos and charisma of the more famous Sennheiser Models such as the MD421 and MD441 it is nevertheless a recommended addition to any collection.

Omnidirectional Dynamic Vocal Microphones

Up until the late 1960’s, cardioid, omnidirectional and figure of eight dynamic microphones were all commonly found in use on public address systems. Singers were able to choose whichever pattern suited their particular style of delivery. Figure of eight ribbon mics, for instance, were enormously popular with the jazz singers and ‘crooners’ of the 40’s and 50’s because of their smooth response and rich proximity effect which enhanced the low end of the voice. Omni was preferred by singers who required a more ‘open’ sound and the ability to move around without altering tone. Unfortunately, with the development of high power PA systems and the introduction of wedge monitoring in the late 60’s, only cardioid microphones had the required rejection characteristics to deliver a suitable amount of gain before feedback. Consequently, within a few years figure of eight and omni all but vanished from the stage and were pretty much banished to the studio!

I recently acquired a number of vintage omnidirectional dynamic mics from the tail end of the last century. Although the primary purpose of these mics was originally news gathering, my attention was drawn to the following excerpt from the AKG Engineering Data sheet for the D130. It perfectly describes the numerous benefits that an omnidirectional microphone offers the vocal performer.

AKG D130 Data Sheet.

A wide-range instrument, the D-130E offers “open”, natural reproduction of speech and music -without harshness, popping or bass emphasis. Moreover, the D-130E ‘s omnidirectional pattern and consequent absence of proximity effect enable the microphone to retain this natural quality -regardless of the relative position or distance of performers working into it. Together with its handling comfort and attractive styling, these same characteristics also lend the D-130E to a variety of hand-held on-camera applications in the studio -especially to pop-free coverage of vocalists who do not desire proximity effect.

Many singers (especially male vocalists) have an uncomfortable relationship with cardioid microphones because of their inclination towards ‘boomy’ bass and unpleasant popping plosives. I have also worked with performers who are in the habit of pulling away from the mic when delivering the loud bits leaving their voices sounding suddenly thin and weedy (N.B. Proximity effect works in both directions i.e. moving away reduces bass). With omni the bass remains constant with the desired reduction in volume.

And another thing………

For performers whose vocal style involves ‘cupping’ the back of a cardioid dynamic, maybe an omni would be a better choice? It comes ready ‘cupped’!

 

 

 

 

 

 

 

So…….. Here’s a thought…….

With the rise of in-ear monitoring many performers and bands are dispensing with their cumbersome (and feedback prone) on-stage wedges. So it would seem to me that for cardioid averse vocalists, perhaps now would be a good time to consider bringing back the considerable benefits of the

Omnidirectional Dynamic Vocal Microphone.

UNITRA Tonsil MCU-53 Cardioid Condenser (1970’s/80’s)

History

In the early 1970’s MB Electronic (now known as MBHO) produced the MB C540. This was a high quality battery powered condenser microphone. It boasted an almost flat frequency response from 20Hz to 20kHz with a slight dip at the low end. The MB C540 was modular in construction and had the option of 2 capsules (omni or cardioid).

In the UK it appeared as the PEERLESS MBC-540.

Reviewed here in Studio Sound May 1977.

Meanwhile in Communist Era Eastern Europe.

This German design was also manufactured under licence by the Polish state owned electronics company UNITRA Tonsil and marketed as the MCO-30 (omni) and the MCU-31 (cardioid). According to Polish sources, the only difference between the German and Polish versions appears to have been variation in quality control at the Tonsil factory. This lead to some Polish mics reputedly sounding rather better than others.

Around 1980 the design was modified and updated. Whether this was done by MB Electronic or by Tonsil’s own engineers is not clear. (MB licenced a number of different designs to Tonsil but sadly MBHO now have no records relating to this microphone !)…….. Anyhow, the resulting microphone was somewhat shorter in length, the battery powering was changed from 2 x 15v to 1 x 6v and the previously unbalanced output was upgraded to balanced. The WCU-31 and WCO-30 capsules were retained and the frequency response appears pretty much the same. The new model was the UNITRA Tonsil MCU-53 (cardioid) / MCO-52 (omni).  The Tonsil 50 series continued in production through the 1980’s. In the late 80’s a further modification was carried out to provide 48v phantom power. This model was the MC-265.

UNITRA Tonsil MCU-53

A clever modular design. Well constructed and finished in shining nickel plate.

WCU-31 Cardioid capsule.

Unusual 5 pin DIN connection.  (below)

Pins 4&5 in the plug are shorted together to provide a ‘switch’ for the battery. When the cable is plugged in the power is thereby switched on. N.B. This also means that if you accidently leave it connected when not in use you end up with a flat battery!! Arrrgh!

Technical Specifications.

Pages from MCO-52/ MCU 53 Owner’s Manual

In Conclusion.

Being battery powered made the MCU-52 /53 suitable for use with cameras and tape machines which in the 70’s and 80’s often did not provide phantom power. This made it a popular choice for wildlife and location recording.

When there is once again an opportunity to record music I will be interested to see how the MCU-53 compares to the AKG C451E as their frequency responses appear to be somewhat similar. I suspect the Tonsil may have a bit more self-noise but tonally may give the AKG a run for its money. Let’s wait and see…………

Credits.

Many thanks to Adam Wilma for sending me this pristine example of the UNITRA Tonsil MCU-53. Very generous. And thanks to my old mate blues guitarist Keith Thompson for bringing it back from Poland. His March tour was sadly cancelled after only 2 shows as Poland went into COVID-19 lockdown. Luckily for me the second gig was in Adam’s home town of Torun and he kindly dropped the mic off for Keith to bring back before the borders closed!

Update Dec 2021

CLICK HERE to hear the MCU-53 on Acoustic Guitar.

AKG C451E (Circa 1970) A Classic from The Golden Age of AKG

Today AKG is little more than a brand name owned by a multi-national corporation. Like a tired old rock star it rests on the laurels of its former glory whilst still churning out a few old favourites.

However, if we go back to the late 1960’s and into the 70’s AKG was a powerhouse of innovative design and high-tech engineering. Major achievements include the D200 series which took dynamic microphone design to a peak which even today sees few competitors. This period also saw the legendary C12 condenser evolve into the C414 which continues to be a favourite in studios across the world.

In 1969 AKG launched its newly developed Condenser Microphone System (CMS) using audio frequency circuitry with Field Effect Transistors. This was a fully modular microphone system based around the C451E, the inherent features of which were claimed to be;

• Low noise level,
• Extremely high reliability and
• Life-long sta­bility.                                                                                                    

A selection of interchangeable capsules and extension tubes could be purchased along with a variety of accessories covering a wide range of recording and live sound applications. The CMS proved to be enormously popular with broadcasters, TV companies and studios throughout the 1970’s and beyond, and can be seen on many BBC music programmes of the period.

These contemporary AKG brochures/guides explain the features of the CMS in detail.

AKG C451 CMS Technical Specifications

Technical Info AKG CMS microphones.

My C451E

Judging from the old style of logo and the lack of an externally stamped serial number on my newly purchased C451E (see top 2 pics), I think that it must be a fairly early example. It is in perfect condition and even the case is hardly marked. As always it was a bargain!

So What Does it Sound Like?    

Sadly, like many, many other people I am stuck at home at the moment practicing social distancing, and so recording music with my beautiful new C451E will have to wait until the current COVID-19 pandemic dies down and we can all get back to work!

Meanwhile Stay safe!

P.S.   Went for a walk today and recorded this:-    https://www.youtube.com/watch?v=k5MHEL6ZPHI

 

Philips LBB9050/05 Dual Capsule Dynamic Microphone 1970

Launched in 1970 the LBB9050/05 was Philips flagship dynamic microphone, and was heralded in Philips literature as being a ‘revolutionary new design incorporating high and low frequency systems’. However, a small amount of research reveals more than a passing similarity in technical specifications between the LBB9050/05 and the popular D200 series of microphones by AKG, which had been around for several years.

The mystery unravels further, and the true origins of this microphone become clear when we observe the words ‘Made in Austria’ on the packaging, the storage case, and on the microphone itself. Michael Amon, top technician at AKG for 30 years, has confirmed to me that the LBB9050/05 was indeed made by AKG for Philips in 1969.

Picture above shows Tuchel socket, and ports for the LF capsule.

The Dual Capsule Design.

The original Austrian patent dates from 1960. The full specification appears in the English patent registered by AKG in 1965, and shown below. This makes an interesting read if you want to understand how this clever piece of technology works.

Original AKG Patent for Dual Capsule Microphones

Philips Advertising Leaflets Courtesy of Philips Company Archives.

LBB9050 microphone,

leafletLBB9050 microphone, leaflet, 1971

So What Does It Sound Like CLICK HERE for a short clip of Blues Guitar

In Conclusion

Just like its AKG cousins the D200, D202, D222 and the D224, the Philips LBB9050/05 is a serious quality professional microphone, exhibiting a wide frequency response, tight cardioid polar pattern, and no proximity effect.  Sadly, these days it is much less well known than the AKG models.  But maybe Philips is to blame? If you were to choose a completely unmemorable name for a product you really couldn’t do better than to call it the LBB9050/05!  Two minutes from now you will probably have forgotten it!

 

Sennheiser ”Telemike” (Circa 1976) with ME20, ME40 & ME80 capsules.

My eBay bargain with K2-U powering module and MZF 802-U 100Hz filter.

Below, page from ‘Telemike’ manual.

Sennheiser’s ‘Telemike’ is an extremely versatile, high quality, modular, electret microphone system originally designed for reporters and film makers. It consists of a powering module K1, K2 or K3, a metre long telescopic boom arm MZS 802, (how cool is that?) and a choice of 3 interchangeable microphone modules (ME-20 Omni, ME-40 Super-Cardioid or ME-80 Shotgun) There were  also a number of accessories such as the 100Hz filter, windscreens and various clip mounts and table stands.

Unlike all of the other Sennheiser microphones in my collection ‘Telemike’ is extremely light. Even with the ME80 attached to the telescopic boom it adds very little weight to a camera or portable tape machine, making it an attractive tool for location recording. Back in the 70’s an additional benefit of the telescopic boom was that it kept the microphone at a distance from the motor noise of the camera or tape machine.

Apart from professional users ‘Telemike’ also attracted an army of amateur video camera owners and tape recording enthusiasts. It was easy to use and came with a handy booklet of instructions on how to connect Sennheiser mics to a huge range of tape recorders from 51 different manufacturers!! (No that isn’t a typo!) My Dad was a tape enthusiast with an interest in local history, and so when I was a child we always had at least 2 tape recorders in the house! The microphones that were supplied with domestic machines were usually of poor quality. These Sennheiser mics offered the keen amateur a huge improvement in sound quality. They also produced excellent results with more professional machines such as the Revox A77 and B77 which did not provide on board phantom power.

CLICK HERE  for a short voice demo of ”Telemike” featuring all 3 capsules.

Original Users guide and Technical Specifications

Sennheiser MKE 202. (with K2pre-amp)Sennheiser MKE803 (K3 pre-amp with 3 position bass roll-off)

These versatile modules can also be simply used either hand held or stand mounted. All in all, a very useful set of microphones!

 

 

Mélodium 76A 1960’s / 70’s

Looking like a cross between a Van Gogh Sunflower and a pepper pot, the Mélodium 76a is a shining gem of chrome and aluminium. A classic of French design!

In the 1960’s Mélodium developed a variety of modular parts and accessories to give their range of microphones greater versatility and customers more options.

The basic 76A microphone (head) came with a choice of 10 ohms or 200 ohms impedance.

The mic could be used plugged straight into the cable. (Great for harmonica players!)

If required this handy plug-in transformer converts the 76A from 200 ohms to Hi-Z.

There was also a choice of handles.

In this 1970’s Mélodium Catalogue (below) the technical details of the microphones are presented along with a full range of parts and accessories, including goosenecks, tall stands, short stands, table stands and a large selection of adapters, switches and transformers. It is a very comprehensive selection, to cover every possible application.

CLICK Here for MelodiumCatalog

Sadly these days it is hard to find much information about Mélodium. Even in its heyday the company was little known outside of the French speaking world. By the end of the 1970’s Mélodium were no longer in business. Probably wiped out by the superior German and American competition.

Finally

Having finished re-soldering all of the joints in my eBay ‘bargain’, I just need to plug it in and find out what it sounds like!

CLICK HERE for Sound clip of Voice and Blackbird in the garden.