9

Everywhere on the internet I would people stating the differentiating factor of "power" and how high impedance mics require an audio interface but nowhere I find anything regarding "sound quality".

Are high impedance microphones better in terms of quality than low impedance microphones (of course when pared with an audio interface)?

A detailed explanation would be much appreciated, in terms of how one out performs the other or is it just that they're basically the same other than the power requirements?

14

The simplest difference to grasp is 'intended use'.
In one sentence, professional vs consumer.

High impedance mics are cheap & cheerful, designed to plug straight into computer headset sockets. The computer's circuitry is equally cheap & cheerful. They go hand in hand. You can't plug a low impedance mic directly into a cheap computer headset/mic socket & expect it to work.

High impedance is much cheaper to manufacture, is lower quality & doesn't push signal so well. Signal loss soon becomes apparent.
Low impedance signals can be sent a long way, over balanced interference-free cabling.

There's a great beginner's article on MyNewMicrophone.com - Microphone Impedance: What Is It And Why Is It Important?

Extract…

Why Are There No Professional High-Impedance Microphones?

The only advantage of high-impedance microphones is the low cost of manufacturing. The disadvantages, however, are grave indeed! In fact, I’d argue that there’s never an application for high-impedance microphones in any professional recording or sound system.

A good example of a high-impedance microphone would be a typical consumer karaoke microphone.

These karaoke microphones have a very high output signal level and therefore need a high-impedance output. This high output means no gain staging or amplifier within the mic, which drastically decreases manufacturing costs. These microphones don’t need preamplifiers to bring their signals from mic to line level.

The big downside is that high-impedance microphones do not perform well over long cable runs. The longer the cable, the worse the result.

This is due to the inherent capacitance in a microphone cable. When a signal with high-impedance is sent through a microphone cable, a low-pass-filter is essentially created. The longer the cable, the lower the “filter cutoff” and the more muffled the sound.

To add insult to injury, the higher the impedance, the more susceptible the signal is to external noise and interference. Electromagnetic and radio interference worsens the signal-to-noise ratio of the signal and worsens the quality.

Even though that article goes into greater depth as regards load impedance & output impedance etc, in real terms you don't need to know or understand any of this. Microphone & pre-amp standards have reached a level of conformity that means "if it's got an XLR plug on both ends, it will work". All you need to know is whether or not it needs phantom power switched on - & even that's handled for you. A mic that doesn't need phantom won't be upset at all if the circuit does provide it, so long as the connection is XLR>XLR. It will just ignore it.

7
  • Would phantom power upset any sort of mic - maybe ribbon mics? I have a nice old Beyer ribbon that I worry about using where there might be phantom power.
    – Tim
    Feb 25 at 8:55
  • Any 'modern' mic will have a transformer which will discard any DC power like phantom. The issue is usually if it's hot-plugged or patched, getting a sudden hit to ground. I'd avoid it, just to be safe. 99 out of 100… is not zero odds;)
    – Tetsujin
    Feb 25 at 9:12
  • This one actually has a transformer, built into the jack. I guess because it's a jack, no phantom power would come through anyway. It's an M260 from the '60s, so hardly modern.
    – Tim
    Feb 25 at 9:46
  • @Tim I know this is an old comment, but there were some older ribbon microphones with an output transformer that had a center tap that was grounded. Applying +48 phantom to them would damage the transformer.
    – Theodore
    Aug 3 at 16:09
  • 1
    @Theodore - even regular condensers up to the 70s weren't always phantom. i have a set of 4 Calrecs [in storage, can't remember the model] that require their own totally non-standard transformer & special cables - & then come out at line level on mono jacks. You couldn't get it wrong & plug them up to a regular XLR, so there's no real danger.
    – Tetsujin
    Aug 3 at 16:14

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.