The microphones for voice tracking

Voice recording has always been a challenge for the sound engineers since there are several aspects to be taken into account to achieve a valuable vocal track.

A skilled singer is the main thing for sure but, right after, we have the microphone that is responsible for translating the air vibration into electrical signals.

The right choice depends by the specific voice and by the context implied by the song. It is not given for granted that the more expensive mic is the best choice even if high budgets often drive to high level performances.

Sometimes unusual approaches may exactly lead to the results pursued by the producer.

The market offers a whole lot of possibilities. Here we shall consider some of them without claiming to be complete. .

Top notch microphones

Belong to this set all the devices not prone to any trade off from the component selection to the manufacturing process. Every detail is thought to provide top performances.

Very often here we find tube microphones thanks to their ability to be warm and detailed in the same time. Let's look closer to some examples.

Telefunken U 47

The original version of the U47 was introduced by Neumann in 1946. The Telefunken version, actually available at the stores, follows the original specs in every detail starting from the main components (the capsule, the tube and the output transformer).

From the sonic point of view the U47 has a good presence on the upper mid frequencies complemented by a solid bass response. Those features are often associated with the “crooner’s” voices but the mic is capable of providing astonishing results with any kind of singer.

The large metallic grid houses the capsule (M7). The rest of the components can be found inside a nickel cylinder including the VF14k valve (recreation of the now unavailable original tube) and the BV8 transformer (still in its modern version).

The following video shows the recording of a soul voice.

Telefunken ELA 251

This microphone uses a 2213 alloy (instead of the most common Mylar) as substrate where the gold film is sputtered on the capsule.

The higher rigidity of the alloy yields a higher damping factor which leads to an airy upper range that still remains smooth.

This fact makes the ELA 251 one of the first choices for female voices.

The high level of the rest of the device allows for high quality recordings in the whole audio band so, the results are wonderful even with male voices.

Here the tube is the ECC801S while the output transformer is a Haufe T14/1.

AKG C 12

The first version of the AKG C 12 was introduced in 1953. The capsule is the CK12. The tube is a 6072 while the transformer is the U66.

As for the other mics, the C12 works well also with other instruments. With the voice it provides a good top end capable of giving the right presence to the track.

THe mid band is clear and articulate while the bass range is solid and focused to guarantee the proper balance of the recording.

Neumann M 49 V

Introduced in 1951, the M49 mic revolutionized the studio technology thanks to its continuously variable polar pattern.

During the years, the M 49 has been continuously improved: the original Hiller MSC2 valve has been replaced by the Telefunken AC701 and, later on, by the AC701k.

Thos mods (plus others) improved the signal/noise ratio, the dynamic band and the immunity to the interferences.

The actual version (M 49 V) uses the same circuit layout as the M 49 c but with a new valve further optimized with less noise.

In the following video the M 49 V and the vintage M49 c are compared (in the test there is also a TLM 103 that we shall discuss later on in this post).

Mid level microphones

In the late ‘50s of the last century the transistors got their main role in the audio amplifier circuits. The valve got used less and less and, inevitably, transistor based microphones hit the market.

Some advantages were the less power required, smaller sizes and much higher reliability.

As of the sound, the differences were due to the capacity of the transistors to push out odd order harmonics.

Field effect transistors (aka FET) behave closer to the valves and for this reason is often preferred in audio solutions.

Just to name a couple, the Neumann U47 FET and the U87 use FET based designs.

Another advantage of size reduction (which kept improving over time) was the sensible price reduction.

Considering all of these facts it becomes possible to realize high performance mics with reduced prices points still capable of delivering professional results.

Let’s see some of these again without claiming to be complete.

Neumann U87

It is very likely that every professional studio owns one or more U87. It has three polar diagrams (omni, cardioid and figure of 8 ) and a high pass filter plus a 10dB attenuator to allow it to track with SPL as high as 127 dB.

Great flexibility as a single or in stereo matched couple. Warm and body with strings and horns. Excellent with piano and percussion.

Very much used for vocal recordings and voice over is the standard in dubbing studios.

Neumann TLM49

Valves and transformers are the most expensive components in a mic.Having replaced tubes with transistors, the next step was to take care about the transformers. Those are used in the output stager for impedance matching and to balance the signals.

They also have an important effect on tone due to the non linearity of the magnetic parts.

Neumann spent part of its effort to design electronic circuits capable to mimic the sound of the transformers without the required price tag.

The result is the TLM series(in fact TLM stands for Transformer Less Microphone).

The TLM49 is the voice specific model inspired by the M49 (we have been talking about earlier) at a fraction of the price.

The TLM 49 is then a large diaphragm studio mic with a cardioid polar pattern and a warm sound especially suited for voice tracking.

The mechanical design refers to the legendary M 49 and M 50 from the ’50s with the typical Neumann nickel finish.

The sound is close to the inspirer thanks to the use of the K47 capsule known for a flat frequency response up to the upper mid range with a slight boost over 2KHz to guarantee the required presence.

The capsule is protected by a large metal grid that is wide enough to not influence the sonic performance of the whole assembly.

Neumann TLM103

The TLM 103 is a large diaphragm mic suited for pro and semi-pro applications where the highest possible quality has to be paired with the lowest possible price.

It is part of the TLM series and has low noise floor and high SPL handling capability.

The cardioid capsule, derived by the U87, is acoustically well balanced with a slight tendency to enhance the high band.

Used with a proper preamp can give a lot of satisfaction to the user.

Telefunken TF29

The Far East production of some parts allows for the realization of good but affordable Valve mics.

The Alkemy series by Telefunken is aimed at this goal. While the TF47 and TF51 models are inspired by the top range mics (namely U 47 and ELA 251), the TF29 is somehow original.

The Telefunken TF29 Copperhead is a tube cardioid microphone derived from the older CU-29.

It is a successful Telefunken design that has got thousands of fans thanks to its natural sound and a very good quality/price ratio.

The TF29 Copperhead includes a 5654W made in America NOS tube, a brass capsule K67 and a premium transformer Lundahl made in Svezia.

The sound is natural on the mid-range with a wide bass response. The copper finish of the grid and the connector are responsible for the Copperhead nickname.

In the following video a Copperhead mic is used for vocal tracking.

The unusual mics

Sometimes happens that devices thought for certain applications find their own way in a completely different path.

This is what happened for the dynamic mics Shure SM7B and Electro Voice RE20. Those were designed for broadcasting but had found their way in vocal tracks recording.

The SM7B has been used to track the album Thriller by Michael Jackson and this fact alone makes the mic become a legend.

The RE20 owes its success to the very well controlled proximity effect (courtesy of the Variable D system).

Check the next video to better understand how the RE20 behaves.

Conclusion

A lot more things could be written about this interesting subject but the allowed space and time advice us to stop here. The vocal recording is such a wide field…

The proposed solutions are anyway capable of providing a more than adequate array to reach any result for various budgets and technical capabilities. Have fun!