what are Good Microphone Specifications?

P

Pier Calacino

New member
Hello Guys,

As far as mic specs go, what are considered good specs and what do they mean? Like what is better for sensitivity -38dB or -36? Signal/noise ratio and so on.....

If I am looking at specs which ones and what numbers should I be comparing and looking at.

Thanks
Pier
 
Are you serious !!!!

Are you guys serious ? So specs as far as mics are concerned mean nothing ?

Is this correct ?

I know if they sound good that's the real test. But what are good numbers as far as specs go. Like the lower the number here the better, and the higher the number here the better.

Thanks
Pier
 
As far as specs go...

You almost need a degree in acoustic engineering to REALLY sort out those specs. This is especially true when you start to look at S/N data. There are several tricky ways to get specs to look great at first glance. So, like Bruce said, use your ears. You know you can trust those right? :)

Just saw the last post... If you take for instance the specs of a Nt1 and a 4033 you get this...


Frequency response: 20 Hz-20kHz
Noise: 17dB
Max SPL: 135 dB
Output impedance: 200 ohms
Power requirement: 48V D.C.

Frequency Response: 30 Hz to 20 kHz
Maximum Input Sound Level: 145 db SPL
Noise: 17 db
Signal/Noise Ratio: 77 db
Requires 48 volt phantom power

Which would you choose on specs alone? :) Basically what I'm saying is if you just want a good sounding mic, use your ears. Period. If you really want to dig deep into specs etc. then go to the library and read up. Understanding the specs isn't going to help you a whit in most cases if your goal is to get the "best" mic. Most of 'em are identical, and in the end you can't trust them anyhow. Far more important than specs is the wiring, the quality control etc.

If I misunderstand your intent, and you are basically asking "what do they mean?" out of curiosity then I apologize. If such is the case then I'll have to pass to someone who has a better understanding of the more arcane specifications.

-Val
 
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my two cents:

Frequency Response: generally the broader the spectrum encompassed, the better. Of course it does you no good if the response extends outside your hearing range. I think you already know that 20Hz to 20KHz is the best most humans can do. Beyond that we're in dog territory, and below that we're in bat country. This specification typically denotes the 3dB or 6dB roll-off points in the response and says nothing about the peaks and valleys that may be encountered between these upper and lower bounds. Generally, the flattest response is "truest".

Noise: I believe this is related to "noise figure" or "noise factor" as typically expressed for a receiver and is a measure of noise level relative to the thermal noise floor at standard temperature, or 273 Kelvin. The lower the better. I could be wrong here and welcome someone's feedback.

Max SPL: implies the maximum signal level the mic can deal with. I can't recall the acronym, but more is generally better, and this is so only in applications where you need to record extreme volumes at close proximity to the source.

Output impedence: more or less is not necessarily better; this must match the input impedence of the recording/amplification device to which the mic is fed in order to achieve maximum signal transfer. The worse the mismatch in terms of "ohms", the greater the signal loss incurred, so "the greater the difference" in impedences, the worse off you are. Matching transformers are available at low cost (like $15 or so) to create proper matches if you intend to stick a low impedence mic into a high impedence device or vice versa.

Signal-to-Noise ratio: is a measure of sensitivity. This is the ratio, in units of decibels, of the signal amplitude to the noise floor. In a tape recording application, the higher=> the less audible the tape hiss. In a radar system, higher sensitivity means we can detect smaller targets further way (i.e. weaker signals in the noise), so I must say that more is unilaterally better. Again, if I misrepresented anything, please set me straight.

Phantom power requirement implies the voltage which must be supplied (usually D.C.) by an external source to power the active device.
 
Thank you all for your input

I Appreciate all of your input and you are all right in what you said. I just wanted to know a little more in-depth technical knowledge in which I got.

Thanks again
Pier
 
pchorman said:
my two cents:

Frequency Response: generally the broader the spectrum encompassed, the better.
Click to expand...

You know, the more I acquire the "great" microphones with "great" specs (Lomos, U87s, 84s, and a U47 that I recently picked up for 1K--gloat gloat...), the more I respect the older dynamics whose specs are shit, but whose character is gold on tape.

For instance, after reading a little blurb on it in Tape Op, I went out and found an American D22, a mic that goes all the way up to 8K Hz...whoopee!...
You can check out a pic of it here:

http://www.k-bay106.com/amer_d22.jpg

Anyway, the thing rocks on a lot of things, especially drums and weird vocals. There is no other way of getting that sound, even drastic EQ'ing, so these things are as indispensable to me as a mic that might cost 6K...

Unless you're doing something like orchestral recording, you really need a broad assortment of mics with all kinds of weird specs--I'm discovering that that's really a key to making interesting recordings....
 
frequency response

Of all specs, this is probably the least important. I mean, hundreds of mics will represent 20Hz-20kHz to some degree. I think if you;re looking for a super-accurate mic, you would want this qualified (e.g. 20Hz-20kHz +/-.5db would be an extremely "flat" or accurate mic). But even an old ribbon mic which has a severe rolloff above say 15k will still probably have some measure of the 20k spectrum represented, though it may be -10db to the rest of the mic frequency range, so technically, you could say it had a frequency response of 20-20... A better indicator of what a mic will sound like is the frequency graphs of the mic response that many mic manufacturers now include, or post on their websites. These will show you, for example, that most condensors have a little bump between 3-5k, and another bump at around 7-10k. But very few people can look at a frequency response graph and determine what that dip at 800Hz and that extra 2db at 12k are going to mean for them. So the best idea is to test the mic out.

Also, if you are using a digital recording system, you might want to check out the noise floor or self-noise spec--some mics are very noisy, and not in a pleasant way--and the signal to noise ratio.
 
starting out problems

im just starting out on this board. and i must say you people know your stuff. i have some issues i would find helpful if solved. 1 to a previous question i was refered to start with mics. what is an outstanding yet affordable snare drum mic.and how do you know? 2 wahat is good for bass drums. and how do you know? the 3rd is how should i do overheads? and whats a good usage of mics? with all the other stuff ive read in this site, this question should be as hard as asking what color is an orange? thanks alot .. empty promises..
 
Re: starting out problems

empty promises said:
im just starting out on this board. and i must say you people know your stuff. i have some issues i would find helpful if solved. 1 to a previous question i was refered to start with mics. what is an outstanding yet affordable snare drum mic.and how do you know? 2 wahat is good for bass drums. and how do you know? the 3rd is how should i do overheads? and whats a good usage of mics? with all the other stuff ive read in this site, this question should be as hard as asking what color is an orange? thanks alot .. empty promises..
Click to expand...
1. The Shure SM-57 is a great snare mic, used for about 95% of the albums made today. A less recognized great snare mic is the Beyer M201 which has a little more definition.

2. There are a lot of good kick mics out there. Among the ones I've used, I like the AT25, the ATPro25, the AKG D112, the AKGD12E, the EV RE-20, and sometimes even the Shure SM-57.

3. A good placement of the overheads is to set them up to where they're exactly equadistant from the snare, and up high enough to capture the sound of the set accurately. I have some pictures on my web site of a typical drum set up at:

http://www.ITRstudio.com/anonftp/

That might help get you started.
 
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