Why hardware is still relevant in a software world
• What software cannot do
• Hardware audio workstations
• Other outboard equipment
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Even at today’s advanced stage of software development there is no such thing as a software microphone, preamplifier, audio interface, power amplifier or monitor loudspeaker, and there probably never will be.
So there will be at least some hardware items in your studio
alongside your computer, digital audio workstation software and plug-ins.
But you might want more hardware. For example you might not want to use a computer at all. If so, then you might find a hardware digital audio workstation to your liking, and indeed they have a number of interesting features.
And although there is no shortage of plug-in emulations of analog equipment, there is something very satisfying about operating real knobs and switched. Often you will find that hardware can produce sound textures that software cannot somehow cannot achieve.
Microphones
• Dynamic microphones
• Capacitor microphones
• Ribbon microphones
• Polar patterns
• Vacuum tube microphones
• Stands and supports
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If you record purely instrumental music then you may not need a microphone. Of course if you want to record vocals, a microphone will be essential. Also if you want to record acoustic instruments, a microphone will be required. Some acoustic instruments can be fitted with a pick-up but this changes the sound and it won’t produce as natural a sound as a microphone can.
Even if you use only electronic and digital instruments that could be connected directly to your audio interface, you can benefit from having a microphone. Connecting these instruments directly can result in a rather dry and uninteresting sound. By connecting these instruments to an amplifier - a guitar amplifier and speaker often works quite well - you can achieve a sound which is more natural, more alive and more in keeping with sounds of vocals and acoustic instruments.
In any case, if you don’t have experience of recording using a
microphone then you could, over a period of time, become expert in all aspects of sound engineering, music production and recording,
but this one blank area where you haven’t experience of using a microphone prevents you from being a complete sound engineer or producer capable of taking on any studio task.
How many microphones are necessary in the studio? In theory if all you need the microphone for are vocals then you only need one microphone. Even if you intend to record background vocals then you can layer them one at a time so more than one microphone isn’t absolutely essential.
But there are reasons why having more than one microphone is better. Firstly, if you have two identical microphones then you can record in stereo. It would be unusual to record a lead vocal in stereo, in fact very unusual, but if you record an acoustic guitar in stereo it can sound much better than the same instrument recorded in mono.
This applies to just about every acoustic instrument. When you mic up an instrument in stereo with two identical microphones, you can afford to capture some of the natural ambience of the room, which makes the recording more realistic. If you have two microphones but they are not identical then, surprisingly, you can still make stereo recordings. The left and the right sides of the stereo image may sound a little different but if you try this for yourself you will be surprised how well it can work and, with a little equalization, you can make it so that few people would realize that dissimilar
microphones were used.
Another reason for having more than one microphone is so that you can record more than one musician at the same time. You may, for instance, have a singer and an acoustic guitarist. It is likely that you will get a much better performance if you record them both at the same time, rather than recording the guitar track first and then overdubbing the vocal. You could record the vocal and guitar with
just one microphone if you placed it in exactly the right position to capture the correct balance of the two instruments. However, it is difficult and time consuming to find the right spot so it is much better to use one microphone for the singer and one microphone for the guitar, or if you have three microphones you can use one
microphone for the singer and two microphones for the guitar in stereo. But probably the main reason for having more than one microphone is that different microphones have different sound qualities.
There is, even now, no such thing as the perfect microphone that will capture a sound with perfect accuracy. All microphones are flawed to some extent, and in different directions. So one
microphone might be good at capturing the fine detail of a sound in crystal clarity while another might be good at capturing the body and the fullness of the sound with warmth and depth.
In a sense, microphones to the sound engineer are like all the different tools an artist might draw or paint with. An artist might use charcoal, pencil, water color, acrylic, oil paint, all the different brushes and all the different tools available to add texture to their work and to contrast one area of a painting with another. It is similar with microphones.
A certain microphone will suit a certain instrument. Another
instrument might be best served by a different microphone, and an experienced sound engineer can build up a complete sound image using each microphone to its best advantage and blending the result together into a satisfying whole.
When you have just one microphone you won’t be aware of how different different microphones can be because you have nothing to compare your one microphone with. When you have another
microphone that is a different model or make to the first one, you will hear straightaway that they have different sound qualifies. On some instruments they might sound very similar; other instruments will point out the differences. Soon you will develop a preference as you will use one microphone for certain purposes and the other microphone for other purposes. And then you will start to wonder what it will be like to have a third microphone, so you have another sonic texture to play with. Once you have arrived at this point,
there’s no limit to the number of microphones you could aspire to have. You never have to ask a sound engineer what they want for their birthday. Another microphone will do nicely, thank you.
There are two types of microphones in common professional use.
One is the dynamic microphone, the other is the capacitor microphone, which is sometimes known as the condenser
microphone. ‘Capacitor’ and ‘condenser’ mean exactly the same in this context. The dynamic microphone works like a miniature electricity generator. There is a diaphragm which is a small thin membrane which vibrates in response to sound traveling through the air. Attached to the diaphragm is a coil of wire. When the diaphragm vibrates, that coil of wire also vibrates, and it vibrates with the field of a magnet. When a coil of wire vibrates or moves at all within the field of a magnet, an electrical current is generated within the coil, which is the signal that forms the output from the microphone. It is a very simple technique but very effective.
Shure SM57 dynamic microphone
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The capacitor microphone is more complex. We don’t need to go too deeply into how it works here but the main difference is that there is no coil of wire. The the diaphragm is not weighed down by the
burden of the coil therefore it can be very much more responsive to the sound vibrations that strike it. So whereas the diaphragm of the dynamic microphone is sluggish due to the weight of the coil, the diaphragm of the capacitor microphone is light and quick to move.
This means that the capacitor microphone can capture a much more detailed sound. Where you will hear the difference most of all is in metallic percussion instruments.
AKG C414B XLS capacitor microphone
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A dynamic microphone used on metallic percussion instruments such as cymbals will sound dull. In fact it might sound so dull that it is completely unrealistic and therefore unusable. The capacitor
microphone on the other hand will capture cymbals with perfect clarity. This is not to say, however, that the capacitor microphone is always better than the dynamic microphone. Sometimes the
dynamic microphone just sounds nice on a particular instrument.
Dynamic microphones tend to sound good on drums, that is on the individual drums of the drum set. A capacitor microphone placed close
to a drum in normal modern drum recording technique will capture the sound of that drum from close up very accurately. If you think about it though, you would never put your ear that close to a drum so although the capacitor microphone is capturing an accurate sound, it is capturing an accurate sound that you would never
actually hear in real life. A dynamic microphone placed in the same position will capture a sound that, to the ear, is much more like we expect the sound of a drum to be.
The same applies to electric guitar loudspeakers. The capacitor microphone will capture an accurate sound, but the dynamic microphone may well capture a sound that is subjectively more pleasing. Dynamic microphones can be quite inexpensive and we are talking around $100 for a model that is entirely professional in quality. In fact there are two models which are so classic that they are found in all applications of sound engineering. They are both made by the Shure company. One is the Shure SM57, the other is the Shure SM58. These are very similar designs and the sound quality is very, very similar. The SM58 has the advantage of an integral pop shield which makes it more useful for live vocals on stage.
There are plenty of other dynamic microphones in common use.
One is the Beyerdynamic M201 which, for a dynamic microphone, has a very good sound quality. There are the Sennheiser MD421 and MD441, both of which have been in the catalogue for years. Like the SM58, SM57 and M201, the MD421 and MD441 both exhibit a good, strong sound quality.
One other model that is worthy of mention here is the ElectroVoice RE20 which is commonly used in radio. The reason this model is popular in radio is that subjectively it sounds good on speech. Often the choice of microphone is not so much a question of accuracy, it’s
whether it just sounds good for your particular application, and for speech the ElectroVoice RE20 has that quality.
Shure SM58
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Beyerdynamic M201
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Sennheiser MD421
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Sennheiser MD441
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Electrovoice RE20
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Capacitor microphones tend to be more expensive because they are more complex. In recent years budget capacitor microphones have come onto the market, many of them made in China. For some reason many of these budget capacitor microphones strive to
emulate high class and expensive capacitor microphones. But they often have irritating defects in their sound quality and they are definitely not the same thing.
There are other moderately priced capacitor microphones from established microphone manufacturers that don’t pretend to be
high class microphones, but they do a good solid job at a reasonable price. One example of this, although not the only example, is the AKG C3000B. There’s nothing fancy about this microphone, it doesn’t have an exotic sound, it won’t flatter any instrument or
voice you use it on but it will turn in a pleasing performance without defects every time you use it.
AKG C3000B capacitor microphone
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The diaphragm of a capacitor microphone produces a signal that is extremely weak and it can only travel a very short distance through a cable. Therefore, every capacitor microphone has an internal amplifier to boost up that signal so it can travel down the cable successfully.
Of course that amplifier needs to be powered; in fact the diaphragm needs to be powered too because of the way the capacitor
microphone works. So the microphone input of the microphone preamplifier, or the audio interface or the mixing console, will have what is known as phantom power.
Phantom power travels along the ordinary audio cable to the microphone. All you have to do is switch it on when necessary.
Some capacitor microphones are of a special type known as electret microphones that can be powered from an internal battery. In
general their sound quality is not quite as good as a normal capacitor microphone.
So, if you don’t have much money to spend on microphones, a reasonable compromise would be to buy a dynamic microphone of professional quality and a moderately priced capacitor microphone from an established microphone manufacturer, and you would get the benefits of the differences in sound quality between these two mics.
Ultimately, though, you should aspire to a capacitor microphone of real quality, particularly for lead vocals. Having a really great vocal microphone in your studio is important. If you can’t afford it right at the start, there is no reason why you can’t make recordings of a
good professional quality, but having that really good vocal mic makes your recordings just that little bit better.
So what makes a good vocal mic? Firstly, let’s look at what makes an accurate microphone. If a manufacturer wants to make a
microphone as accurate as possible and faithful to the original
sound source then that microphone will be a capacitor microphone.
It will have a fairly small diaphragm about 10 or 12 mm across.
The internal amplifier of this accurate microphone would need to boost up the signal without changing or distorting it in any way, and to do this the principal amplifying device would be a field effect
transistor (FET), which will give an extremely transparent
performance. With this accurate microphone we could record the lead vocal of a song and the recording would sound almost perfect.
So why would there be a problem with that? The answer is that we want the vocal to sound more than perfect. We want the sound not just to be as it is, we want it to be better than it is, and curiously that involves using a microphone that is less than perfect.
This microphone will have a large diaphragm, maybe 25-30 mm across. A large diaphragm is less accurate than a small diaphragm.
The reasons for this have to do with the additional mass and also cancellation effects for any sound which doesn’t arrive exactly head on at the diaphragm. But subjectively, for vocals in particular, the large diaphragm simply sounds nicer. There’s no way to measure this, it just does sound nicer and we accept that.
Also, for a vocal microphone, ideally the internal amplifier should use a vacuum tube as its principal amplifying device, rather than an FET. The vacuum tube has a tendency to produce a mild distortion, which does change the signal so it is not accurate any more, but subjectively the ear interprets that as ‘warmth’. So the
large-diaphragm vacuum tube microphone will add warmth, presence and fullness to the vocal sound, which is preferable to it being merely accurate.
There are large diaphragm microphones that have FET amplifiers.
One good example is the Neumann U87. This is a classic
microphone which, for many years, was considered to be the best microphone to chose for vocals. It also has many instrumental applications. Its rival was the AKG C414 which was rated almost as
highly for vocals and could be used very effectively on almost any sound source.
The AKG C414 also worked very well in a stereo pair and, though this microphone has been around literally for decades, you will still see it widely used for drum overheads. Both the Neumann U87 and the AKG C414 are still available new, the C414 in updated versions.
They are quite expensive, fortunately not as expensive as they used to be.
Neumann U87 large-diaphragm FET capacitor microphone
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A good example of a large-diaphragm vacuum tube microphone is the Neumann M147. In general, vacuum tube microphones can’t be operated from phantom power so they require their own special
power supplies, which are supplied with the microphone. So you connect the microphone to the power supply, connect the power supply to the mains and also connect an output from the power supply to your preamplifier, audio interface or mixing console. The Neumann M147 is a lovely warm-sounding microphone - but at a price, and you can pay even more for yet better microphones if you want to.
Neumann M147 vacuum tube microphone
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There is another type of microphone called the ribbon microphone.
This works in a way which is very similar to the dynamic microphone. The difference is that it doesn’t have a coil. The diaphragm is made from a corrugated material which is made
conductive and is called the ribbon. This is suspended in the field of a magnet so effectively the ribbon is its own coil. It is a coil of only one turn but a coil nonetheless.
Because there is no coil as such, the diaphragm (the ribbon) can be light and responsive. The dawback, historically speaking, is that it is difficult to suspend the ribbon well and ribbon microphones have tended to be fragile. There are exceptions. The Beyerdynamic M130 and M160 are ribbon microphones that are quite robust.
Ribbon microphones were perhaps not developed as much as they could have been because of the rise to dominance of the capacitor microphone. However, the ribbon microphone has its own
characteristic sound which in some contexts can be very desirable.
The ribbon microphone’s sound has a subtle fullness. It captures detail but without over-emphasising it. It is a sound that needs to be experienced. It would not be reasonable to suggest that your first microphone should be a ribbon microphone nor even your second or third, but somewhere down the line there will be a place in your microphone collection for a ribbon microphone, perhaps more than one.
Beyerdynamic M160 ribbon microphone
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Directional characteristics of microphones
Different microphones have different directional characteristics.
Some microphones are almost equally sensitive all the way round.
They are called omnidirectional microphones. Some microphones are sensitive at the front and at the sides but they are not sensitive at the back. They are called cardioid microphones. Some
microphones are sensitive at the front and equally sensitive at the back but not at all sensitive at the sides. They are called figure-of-eight microphones. In between the cardioid and the figure-of-figure-of-eight
pattern there is the hypercardioid microphone which is very
directional towards the front and has a slight sensitivity towards the rear.
When you become deeply involved in sound engineering, and
When you become deeply involved in sound engineering, and