Pro Audio Myths- True or False….. Part1

Over the years the Pro Audio Industry has developed many elaborate Myths. Please keep an eye out for our two part blog dishing out the truth and reasoning behind some of the folk tale stories.

Myth #1- Some microphones have more reach than others

False: The reality is that microphones do not reach out and grab the sound from a distance. They merely measure pressure variations right at the diaphragm itself. The microphone doesn’t “know” anything about what is happening at any distance from itself.  ”The reach” of the microphone, if you can even call it that, is mostly dependent on the ability of the microphone to pick up sound in the middle of  noise. No microphone has a “reach” that is defined independent of ambient noise.

Myth #2: Microphones always sound better in the store

It depends: An in-store demo of a microphone or any other acoustic product is greatly affected by the acoustic environment of a store. (That’s why there are listening rooms.) If the store is noisy or quiet, if you’re listening to the microphone through loudspeakers or headphones, all of those factors change the perceived sound of the microphone. In-store demos are not really indicative of how the microphone will perform in real life. Ideally, if you to take a mic to a gig or record your voice speaking or singing a phrase and then listen to it in playback. We suggest you evaluate it that way.

Myth #3: A wide range flat response microphone is better than a shaped response microphone

Depends: For a sound source that has a very wide frequency range, you want a microphone that can reproduce it in a high fidelity manner. That’s what a flat response should do. The assumption is that whatever the destination of that sound, either a playback system or a live sound system, the mic will reproduce the range that you’ve gone to so much trouble to get.
The average rock and roll sound system is not a wide range flat response thing itself. So putting wide range flat response mics on the front end doesn’t get you much. You can’t hear the performance difference.
But with a very high quality sound system or a recording environment, yes.

Myth#4-The SM58® hasn’t changed in over 40 years

False: When the SM58 was introduced in 1967, it was aimed at broadcast applications for which it was not ultimately embraced. But it was discovered by the fledgling live sound industry where it quickly gained a reputation as a reliable, good-sounding and affordable mic for a huge range of applications.

Dynamic microphone technology hasn’t changed. Take the internal combustion gasoline engine. A 327 small-block Chevy engine is old technology. It was designed in the early 1960s and is highly regarded and widely used today because it is a proven design that offers great performance. There have numerous improvements in reliability and manufacturability. There was a secondary tap on the transformer that was eliminated about 15 or 20 years ago related to a 50-ohm output impedance condition that was no longer a factor. The voice coil wire was changed to a copper clad aluminium to improve the solderability of the voice coil leads into the cartridge structure. The grounding mechanism for the output connector was changed. The paint formulations have been improved. The grille plating has been improved – the things that relate to long-term reliability have been changed incrementally throughout its history.

Myth #5:Condenser mics are not as rugged as dynamics

False: Today, all of our condenser microphones are engineered to hold up to exactly the same abuse as an SM58 – they go through the same exact environmental testing. Drop testing. Temperature testing. Humidity testing. Salt spray testing. Vibration testing. Electromagnetic testing. They have to pass the same battery of tests – and they do.

In the days when this myth came into existence, the average condenser microphones were very expensive, studio-grade models. The microphone they were compared to might have been a dynamic like the SM58. So if I take the ultra-expensive, circa 1930s vacuum tube Telefunken microphone and I dunk it into a glass of beer or drop it on the stage ten times – or even one time – it will probably stop working. It’ll become a paperweight while the SM58 will survive all that.

Myth #6: You have to match impedances to get the best result when you’re hooking up parts of a sound system

False. This isn’t true and it hasn’t been true since the late 1950s. In a sound system of modern design, the load impedance or the impedance of the device that you’re plugging into has to be significantly higher than the source impedance, which is the device that you’re plugging in. For example, a microphone has a source impedance of about 150 ohms.  The device that you’re plugging the mic into needs to have an input impedance five to ten times greater.  If it were a mixer, for instance, it would have to have an impedance of at least 1000 to 1500 ohms.

If you look at the actual specifications of mixing consoles, you’ll see that the actual input impedance of a so-called low impedance mic input is typically about 1500 ohms. If you match the impedance, you get less level and less headroom – the systems are not designed to work that way any longer. Matching, generally, is not an issue.

Watch out for Pro Audio Myths- True or False…. Part 2