Critical Podcast Script — Microphones

Does music contain energy we cannot measure? Does it have a vibe and essence or some other unknown and/or esoteric quality, or rather quantity? Let’s be clear, we are not talking about individual preferences here. This is not about perceived quality or listener preference. It’s not about the reproduction equipment at all, nor the instruments making the music. It is also not about the listener’s response to the music — we will get to that later.

This is about scientific and measurable quantitative metrics for sound, the microphone or other transducers and the recording process. There is this saying: We cannot manage what we cannot measure. This is a fundamental law in that we cannot manage the unknown, an immutable fact. To get quantitative and qualitative information for a property, we have to somehow identify it first, then measure it. We must be able to explain that in some meaningful, rational and logical way. Otherwise it is bunk and bs, agree you must…. If not a rational and logical argument it is that you make, opinion is all that is left…. There is nothing wrong with having an opinion, and yours may well be correct. This is what this is about, finding out about the facts to support or disprove your opinion. You be the judge of that at the end. There is nothing wrong with a lack of understanding, it’s just that we do not yet understand something, but that something must be identified. Then the process of understanding starts.

Before we start answering anything, let’s be crystal clear here, every human has the right and ability to believe what they believe and have a strong conviction about that. This is akin to people’s response regarding spiritual, religious and political beliefs and convictions. Having an opinion or a belief, does not proof nor disprove anything, only facts can do so. We are also not trying to diminish the emotional response to music, nor its importance in the enjoyment of music. Simply put, we focus on what can be measured and understood, hence the original question.

An oversight correction first, and my bad. I did not define Critical listening and what I take that to mean in the first place. Air over at the local AVforums pointed me in the correct direction, so here it is: Simply put, critical listening is when we perform the listening with the focus and intent of excluding any and most external distractions, allowing us to enjoy the music, simple as that. There is the term called Flow. This is when we are so immersed in what we do that we lose track of time and are fully immersed in said activity, in this case, critical listening.

I started asking the above question, guess what? The response I got was overwhelming, the answer: Yes. But here is the thing, almost no scientific explanations, all of them were on the emotional side, some were mentioning cables, harmonics and ultrasonics…. Nothing wrong with the answers, all are valid, but not answering the original question. So the question was read, interpreted really, as one of asking about the response to music. That was not the question, but nonetheless the universal response was, “So what if you cannot measure it really?”. It is clear from the responses by those that replied, that the response to music is individual, no two people respond the same.

It is thus not an issue for those that responded to the question, to accept that there must be something in the music, eliciting an emotional response. How or why that happens is not important to them, only that it is an emotional feeling.

However, however that may be, we still do not know if the artists making the music, generate some form of vibe or essence at that time, apart from making the music. Let me say this, if no music is made, nothing is produced, no vibrations and no sound waves. So nothing can be recorded. Well, no music anyhow and only noise, as nothing else exists yet. When the music playing starts, there are the pressure waves that can be captured, recorded and stored.

Let’s unpack. What does a recording do? Even more importantly, what does a microphone do, and how does that work? Why is this important information? We want to try and figure out what gets recorded and how, and ultimately gets reproduced. On top of this, let us try and understand if anything else is produced besides.

Now microphones.

Just some basics here, we are not designing a new mic 🙂

Sound is produced by vibrations and that creates a wave of varying pressure that is a direct correlation to the source making the vibrations. That energy is transferred from the source vibration, like vocal cords or a piano string, to the air molecules and propagates everywhere until the energy is lost to friction. A microphone is a transducer for pressure wave energy differences, converted into electrical energy. It is a way to capture the pressure differences produced by sound.

Sound, voices, noises and music are all just vibrations mechanically disturbing air molecules by alternately compressing them (higher pressure than average) and then rarefying (lower pressure than average) the air molecules. That creates the pressure wave energy. There is nothing else, absolutely nothing else that gets emitted that we know of or can measure, just vibrating air molecules. In turn, there is nothing but pressure wave energy transferred to a microphone. Everything is encoded by vibration into pressure waves, and nothing else.

Let’s pause here for a moment…. All the energy of the artists and musicians are encoded into vibrations, via their actions of singing and playing. All the emotions are brought to bear on their own voices or via their instruments. This is encoded into pressure differences and emitted or radiated as pressure wave energy like we said. Think about that…. Now, Critical thinking is even more important to Critical listening, than Critical listening is to Critical listening….

There are people claiming that the music has a vibe and essence and that passes through amplifiers… well certain amplifiers anyhow. Those amps with the best circuits in the eyes of their design engineers and such. These designer people are seen by many as possessing some great skills, some knowledge only known to them. A very famous amplifier designer, Baskom H King believes Jeffery Cook and he said this is possible. And Bascom designed the PS Audio Signature amplifier for Paul. But here is the question, how is the essence or vibe of the music captured by the microphone? For this unknown essence to pass via the amplifier to the speakers, it must be captured in the source, no? We already established that no part of the reproduction chain should alter what it is fed in any way, only faithfully reproduce what is input.

Why is the answer to this question vital you may ask? We can only record and reproduce what was captured by the microphone in the first place. Electrical guitars, synthesisers and the like work a bit differently, as they directly create the electrical energy to be recorded, or use a different device to capture the vibrations of the string and not the air pressure wave energy.

Please think about how this vibe and essence could be created and then transmitted and ultimately captured by the microphones, and then recorded. We will get to the rest after this is rationally and logically explained. Either there is a way that artists, mastering and recording engineers can create and capture that, and some others cannot, or there is no such thing. How do you know whose source materials contain this unmeasurable entity?

Compare this capture by the microphone to be like taking a picture. A picture is a snapshot of a visual scene in time, a single moment. A movie or Flick is a number of snapshots taken over a period of time. A microphone is recording a snapshot of pressure waves, both at a specific place in 3D space, and at a certain time. With the microphone in a different place, a different resultant wave is recorded. For speech as an example, the pressure waves move the capsule over time, as the waves change in magnitude and frequency, and we record these waves (encoded) as an electrical signal, somewhat resembling the pressure waves. A microphone transducer can only capture air pressure change energy. There is nothing else a microphone can transduce.

That being a scientific fact, for what a microphone can capture, there is nothing else known to reach the microphone besides pressure waves. Therefore there is nothing else converted into electrical energy to be recorded, no essence or vibe of the music.

Let’s unpack a little. All the directly received sound have their pressure waves and all the thousands of reflections from the walls and other objects are also received as pressure waves impinging on the microphone capsule. The reflections, diffractions, comb filtering, phase differences, peaks and valleys from all these waves have an influence on the sound as the pressure waves are blended together, creating all sorts of artefacts of their own, a unique sound.

This creates a specific and unique set of pressure waves at the point where the mic capsule is. These pressure waves are what contains the volume and timing information, both from the direct and reflected waves that is recorded as well as all those artefacts. The mic capsule responded to all of this information. The capsule element or diaphragm, the bit that flexes and vibrates, have a mass and inertia. This dictates what the mic will actually transform from physical movement into electrons, as a voltage and/or current to be recorded. We can see that right where we record the pressure waves, the information in the pressure waves are not converted perfectly. No mic is perfect, they all loose information at every step.

For the purposes of reproduction at home, or anywhere else, no part of the system should add , or add as little as possible, to what was captured, mastered and recorded if it is for a High Fidelity system. It is in the words HiFi, ie. do not add or remove anything from the source, be as faithful as possible. For reproduction equipment, in reality, we add noise, distortion and non linearities to varying degrees at every component. Then we have losses in fall-off of frequency response at every component and that is cumulative, just like noise and distortion effects are too. What use would an amplifier be with ruler flat response out to 50 or 100 Khz if the CD source only reproduce to at best 21 or 22 kHz? This is where SACD, DVD audio and HDCD comes into play, they have much higher frequency responses, up to 100 kHz and can contain energy above 20 kHz.

Therefore, we are constantly adding undesirable artefacts to the source before the energy gets converted to vibrations again. We also lose energy at the low and high end of the reproduction due to component response losses.

The crux of this matter.

Recording studios should care about the essence and vibe of the music, but do they? Do mastering and recording engineers care? And remember this is a multi billion dollar industry. Over the last about 100 years, electronic engineers and researchers have learned most of what there is to be had in audio systems. They can explain how systems work, and design and make them work according to the design specifications. All of this can be measured as well and proves the design. The proof is in the systems we use to record, master and play back music to High Fidelity standards — what you can buy and have.

There is no known or measured quantity outside of pressure wave energy, to transfer the emotions in a singer’s voice or the notes of a musical instrument. Let’s use a purely digital instrument like a synthesiser as an example. Any sound created is done electrically, either by analogue or digital means, using sine waves, sawtooth waves and the like. This is directly recorded, no vibrations or anything but electrical signals in between the synth and the recording. So here must be a lack of vibe and essence then, agreed? What about the countless piano, grand piano, organ and guitar samplings of individual notes, reproduced by keyboards and other digital instruments as music?

We all have emotions, convictions and the like. We all respond differently to music like opera, chamber music, live rock concerts, jazz, trance and so forth. That is accepted. Our emotional response will vary with the music type, and our moods for example. That is the first clear indicator that the music is music, only our responses vary.

You never know what was used by the artist: the real deal or a digital copy. Nobody tells you this either and the digital file or record or CD or DVD does not tell you either. Music videos are even worse in that regard. Most of what you see are for show, and not what was recorded, nor mastered. It is make believe. Nothing wrong with that, that is just the pretend world they offer. You may see a piano for real, but a digital copy was used in studio to do the actual recording, as an example.

Where does this leave us then? You tell me…. In my humble opinion, backed up by the arguments made above, there is no ability to record the vibe and essence of music in the first place as we do not have a transducer capable of picking that up. And that is based on the premise this essence is produced in the first place, and we do not have evidence for that at this time. Secondly, there is no such essence or vibe known to be created by singers nor instruments and no way for this to be transmitted or recorded either. There is just our emotional response to music.

Where does this leave us then? We can still have differing opinions about the essence and vibe of music. My own point of view? There is no such property. Therefore we need not worry to reproduce that. We all have an emotional response to music, and my view does not diminish my enjoyment of music, and should not reduce yours. However, it also crystallises what equipment can and cannot do. In some way, it shows what decent equipment (your definition of decent to be applied here) can and cannot do or reproduce. I thank you. Now Think about that…. Critical thinking is even more important to Critical listening, than Critical listening is to Critical listening….

Sarel Wagner