Just What Is Tone, In A Microphone?

As long-time Hackaday readers will know, there is much rubbish spouted in the world of audio about perceived tone and performance of different hi-fi components. Usually this comes from audiophiles with, we’d dare to suggest, more money than sense. But oddly there’s an arena in which the elusive tone has less of the rubbish about it and it in fact, quite important. [Jim Lill] is a musician, and like all musicians he knows that different combinations of microphones impart a different sound to the recording. But as it’s such a difficult property to quantify, he’s set out to learn all he can about where the tone comes from in a microphone.

He’s coming to this from the viewpoint of a musician rather than an engineer, but his methodology is not diminished by this. He’s putting each mic on test in front of the same speaker at the same position, and playing a standard piece of music and a tone sweep through each. He doesn’t have an audio analyser, reference speaker and microphone, or anechoic chamber, so he’s come up with a real-world standard instead. He’s comparing every mic he can find with a Shure SM57, the go-to general purpose standard in the world of microphones for as long as anyone can remember, being a 1960s development of their earlier Unidyne series. His reasoning is that while its response is not flat the sound of the SM57 is what most people are used to hearing from a microphone, so it makes sense to measure the others against its performance.

Along the way he tests a huge number of microphones including famous and expensive ones from exclusive studios and finally one he made himself by mounting a cartridge atop a soda can. You’ll have to watch the video below the break for his conclusions, we can promise it’s worth it.

Thanks [Michael Field] for the tip.

23 thoughts on “Just What Is Tone, In A Microphone?

  1. Definitely worth watching, even if you aren’t a music lover. What I am amazed about is how he got through the entire video without saying “snake oil” or “fraud” or “con artists”. But yeah, the placebo effect is strong in audio.

      1. The thing with FET vs. tube is that both should be linear amplifiers up to a point unless there’s something wrong with the circuit or components. The differences start when you approach sound levels where they start to distort.

        1. Though I doubt the condenser capsule can ever produce a signal hard enough to distort either. It’s the capsule itself that starts to distort first when you hit it with a big pressure wave.

  2. I admire his dedication. And it really was eye opening (ear opening?) to hear the differences. Apart from the deliberately fat, thin, bright, and dark mics, most were subtle enough that any of the mics he tested just weren’t that different.

    Spending extra money on them might make for a pretty photo for an album cover or a bit of flash on stage for a live performance, but if you’re a starving artist it’s good to have the knowledge that a $99 guitar center mic is as capable of catapulting you to stardom as any thousand dollar mic.

  3. I’m part of a few diy electronics forums including some that diy microphones. Yeah, you don’t have to be super critical most of the time. In regards to grills, they’re there for protection of the capsule, the foam is mostly to keep dirt from getting into the microphone though it can affect the response if it’s not porous enough. The mic capsule will change over time as it ages but that can be a detriment if there’s rust or dirt buildup so that same mic could sound noticeably different years later even with proper maintenance. The housing body is just a personal choice though you need one big enough to fit the pcb and components. There’s something to be said about choosing some parts with longevity in mind with the individual components however.

    A common trend is to buy a cheap metal knockoff mic with the body and grill desired and build around it. I’ve made clone mics with entirely different bodies and grills from the originals though I had to make custom pcbs.

    1. Right. This is a start, though. Nobody else (that I know of) has compiled a comparison of so many different microphones. This might not be the most comprehensive comparison possible but it may well be the most comprehensive comparison in existence.

    1. Whether live or through a computer, the signal goes through an enormous amount of processing that affects the response curve and the sound produced.

      Adjusting the tiny potentiometers on the back of concert speakers has infinitely more importance for the sound than the microphone ever will, provided it’s big enough, functional and not heavily resonant.

      These are filters that can compensate for the frequency curve and even my computer has a software equaliser that radically changes the sound.

      And as far as perception is concerned, it’s not a question of hearing the differences when the microphones are tried next to each other, it’s whether listeners are able to perceive it in a real situation. This is not the case.

      The real concern for sound engineers is noise and distortion (and the resulting mix). Any audiophile who isn’t just trying to lower the noise level of their equipment under ambient noise is deluding themselves.

  4. The video was incredible, both technically and cinematographically, although it’s a shame that he only looked at the frequency curve. The other important aspect is the Total Harmonic Distortion, but this is hardly ever mentioned. There is a standardised process for taking these measurements, but I can’t find it.

    However, in view of the process he went through and the efforts he made: he really tried everything, but in the end, there’s no difference between a can and the ‘best mic’…

    Yet he never said why? The value of this “vintage microphone” is historical and sentimental, and does not come from its technical quality. The best mics are above all the most reliable and the most versatile (even if there is an element of aesthetics and marketing, don’t get me wrong), as with any basic tool.

    If this study has never been done, it’s perhaps because the conclusion only confirms the limited influence of the microphone beyond a certain point of quality.

    He himself says that he’s trying to reproduce the sound of his favourite musicians, but it’s pointless: You shouldn’t try to reproduce or remake a sound, because there are a thousand ways of achieving a good result (and millions for a bad one), but imitating doesn’t allow you to create your own style (I didn’t come up with this idea).

  5. This made me think of the ultimate diy mic. Which pops into my head often because of the horrible audio replays overheard when my wife is watching her ghost hunting shows.

    https://youtu.be/quuHV9pTyoo?si=AKzEJM_axGTD1xyS

    You can hear his heart beat at one point. If you screamed into, I’m sure it’d just turn into clipped garbage. So… right tool for the right job? Or for more fun hack the wrong tool into the right one for a job.

  6. So, within the first minute of your video, I thought this was a quick upfront joke and that the real apparatus and configuration is coming up in the video. Dude, you need to learn a little bit about acoustics and electronics. As a (studied) engineer and musician who had lived in Nashville for 25 years, I can say something very positive about this: your video, or rather the content therein, is consistent with the Nashville music industry in general. That is to say, you can and do arrive at some measure of market success completely unencumbered by knowledge and content sophistication. You’re approach to mic analysis is like a song about losing your dog Bo over a 1-4-5 progression. If the music industry doesn’t work out for you, you might consider pivoting into video production. You do have talent, in my opinion.

  7. As I have no wish to veer “off topic” from this excellent discussion, I hope someone might inform me when there will be-or presently is-a discussion on the alleged realities and causes of differing tonalities among audio amplifiers. Many in the audio technology community would take issue with Jenny List’s premise that such claims of perceived tonal differences among amplifiers are so much rubbish. Most of those I’ve encountered at this forum tend to share Jenny’s views on this. https://www.audiosciencereview.com/forum/index.php?forums/amplifiers-phono-preamp-and-analog-audio-review.13/ OTOH, most at this section
    https://www.diyaudio.com/community/forums/pass-labs.8/ and at this thread https://www.diyaudio.com/community/threads/beyond-the-ariel.100392/page-722 , would claim to offer loads of proof to the contrary.

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