A Zero-Noise Mic

[DaikenTana]

Hi all

I've heard some ambience recordings in films that are of SUCH quiet sounds yet there still remains hardly any hiss what so ever. Truely amazing. What the hell mics do these guys use?! Sheit! I have a pair of TFB-2s myself but even they give off some pretty harsh hiss when recording nature/trees in the wind.

I guess my other question is, just for fun, how would you go about developing a zero-hiss/hoise mic? Wouldn't that mean a zero-electricity microphone too?

Edited March 19, 2006 by DaikenTana

[greenmachine]

Generally speaking, the larger the diaphragm, the less self-noise. But large diaphragm microphones do not only have advantages. Read more about general differences, pro and contra, here:

http://www.dpamicrophones.com/page.php?PID=28

[AllanH]

Hi

Quietest mic around is Rode NT1A. Low cost - for a condensor mic- and reasonably happy used outdoors if you build into a bespoke windshield. Bulky but good, as others have found. Needs a portable phantom power supply for use with HiMD (eg ARTcessories Phantom II), and some dedicated leads to get from 2x XLR 3 pin to 3.5mm minijack.

[DaikenTana]

Quietest mic around ey? Well that's gotta be pretty damn quiet. I'll definately take a looksy into that one. Thanks fellas

Oh and um, I don't suppose there are any sample recordings with this mic floatng around are there?

Edited March 20, 2006 by DaikenTana

[AllanH]

Hi

Rob Danielson has lots of tests on his site: http://www.uwm.edu/~type/Mic%20Preamps/

The ones comparing NH900 and SD722 use NT1A I recall.

There's also test on these pages that Rob did last year comparing NT4. NT1A and two phantom units into NH900. You might find them with a 'Search'

[Jazzworkerbee]

It's all about how clean the power is feeding the mic as well. The preamps aren't that good with these HI MD units. If you want super clear and transparent sound, you'll have to get a high end phantom powered pre amp to go with your large condenser mic. One way around that is to use a decent self powered mic. I use the RODE NT4 and it works pretty well. But if you're going to be really nit picky about the sound, then you'll have to go with a high dollar unit from Tascam or Sound Devices.

[clyborne]

Hi--

A listen to this test I made could be useful:

http://www.uwm.edu/~type/audio-art-tech-ga...es/page_38.html

Eric Benjamin of the micbuilders list tested the Rolls PB-224 unit that I used in these tests and found that in a one-third octave spectrum noise test with Schoeps MK-2 mics, the Rolls came in at -120 dBV. The output impedance of the phantom supply is 6k81, so Eric surmised, "I don't think that the noise from the Rolls is a problem." The Rolls also output 47.6 volts. Rob D.

It's all about how clean the power is feeding the mic as well. The preamps aren't that good with these HI MD units. If you want super clear and transparent sound, you'll have to get a high end phantom powered pre amp to go with your large condenser mic. One way around that is to use a decent self powered mic. I use the RODE NT4 and it works pretty well. But if you're going to be really nit picky about the sound, then you'll have to go with a high dollar unit from Tascam or Sound Devices.

[King Ghidora]

Another self powered mic that has a very low self noise level is the Nady CM-2S. For a budget mic it's really pretty good. It will cost about $119. It was made to emulate the Audio Technica AT822. It has nearly the exact same specifications and looks almost identical. People thought they were actually the same mic for a while. They aren't but it's a very good mic and it can be argued that it is better than the AT.

Low self noise is probably the best feature of this mic. It's a little big for stealth recording but if you need a good stereo cardoid this could be a very good choice.

[spzkt]

Another self powered mic that has a very low self noise level is the Nady CM-2S.

My interest was piqued by the "very low self noise" comments. It seems however that the CM-2S has a self-noise of 24dB which hardly qualifies as very low. Probably not too bad compared with the AT single point stereo mics, but far noisier than other mics mention in the thread. The NT-1A self noise is less than 6dB, and the NT-4 self-noise is about 16dB.

[Strungup]

I take issue with the Nady being better than the AT , 86 db S/N is what most CD's will register when you consider that the Nady has 24 db of self noise . that would mean it S/N would be close to 62- 64db

The AT-822 is at a S/N of 70 db on paper but in actual work, depending on the equipment it is plugged into can be much higher than that .

The Mic pre of the RH1 is almost 100db S/N it is one of the quietest portable pre's there is the R50 clocks at 101 db S/N I have both units

And have posts on these boards that verify the quietness of the AT-822 , I have yet to hear a NADY as quiet. or as good.

The Rode's I can agree with they are good mics , the NT4 with a decent pre such as a Rolls MX34 would be a great feild setup , the MX34 states a 101db S/N but it would very much depend on the impedance of the mics being used .

There is a Key statement . "Impedance " most of the Audio tests I have heard were based on stuff who's Impedances were improperly Matched

Which introduces Noise. The AT-822 is basically Designed for the Impedance load of the Mic pre's in Dats , which were Sony"s by default so the nearly identical pre's in the Sony MD's are perfectly suited . I have used the AT-822 with a Sharp MD and was mortified at the Noise in the Sharp preamp.

Learn something about impedance matching , you will reduce your noise levels.

SPECIFICATIONS

ELEMENTS Fixed-charge back plate, permanently polarized condenser

POLAR PATTERN X/Y Stereo

FREQUENCY RESPONSE 30-20,000 Hz

LOW FREQUENCY ROLL-OFF 150 Hz, 6 dB/octave

OPEN CIRCUIT SENSITIVITY -45 dB (5.6 mV) re 1V at 1 Pa

CHANNEL BALANCE <=2.5 dB

IMPEDANCE 200 ohms unbalanced

MAXIMUM INPUT SOUND LEVEL 125 dB SPL, 1 kHz at 1% T.H.D.

DYNAMIC RANGE (typical) 101 dB, 1 kHz at Max SPL

SIGNAL-TO-NOISE RATIO 70 dB, 1 kHz at 1 Pa

BATTERY TYPE 1.5V AA/UM3

Warning: The AT822 is designed for battery operation only. Do not attempt to use when phantom power is present. Possible damage to the microphone may result.

BATTERY CURRENT / LIFE 1.2 mA / 1000 hours typical (alkaline)

SWITCH Off, flat, roll-off

WEIGHT 5.8 oz (165 g)

DIMENSIONS 7.76" (197.0 mm) long,

2.44" (62.0 mm) maximum head width,

0.83" (21.0 mm) body diameter

OUTPUT CONNECTOR Integral 3-pin XLRM-type

CABLES 1.7' (0.5 m) long, 3-conductor, shielded, vinyl-jacketed, stereo cable with 3-pin XLRF-type connector at microphone end, 3.5 mm stereo mini plug at output end.

10.0' (3.0 m) long, 3-conductor, shielded, vinyl-jacketed, stereo cable with 3-pin XLRF-type connector at microphone end, two 3.5 mm mono mini plugs with 1/4" phone plug adapters at output end.

ACCESSORIES FURNISHED Gun-grip snap-in stand clamp for 5/8"-27 threaded stands; camera shoe mount adapter; battery; AT8120 windscreen; soft protective pouch

AUDIO-TECHNICA CASE STYLE S3

Nady

Specifications and design subject to change for improvement purposes without prior notice.

SPECIFICATIONS

ELEMENT: Fixed-charge back plate permanently polarized

condenser

POLAR PATTERN: Cardioid (Unidirectional) stereo

FREQUENCY RANGE: 30 to 20,000Hz

LOW-FREQUENCY ROLL-OFF: 150Hz, 6dB/octave

SENSITIVITY: -45dB (5.6 mV) re 1V at 1 Pa

IMPEDANCE: < 250 Ohms unbalanced

CHANNEL BALANCE: < 2.5dB

MAX. SPL (1% THD @1000HZ): 128dB

S/N RATIO re 1Pa: 70dB

DYNAMIC RANGE (TYPICAL): 101dB, 1kHz at Max SPL

BATTERY TYPE: AA alkaline battery

BATTERY LIFE: More than 1000 hrs

SWITCH: Off, flat response, low-roll-off

SIZE: Diameter: 0.83" (21.0mm), Length: 7.76" (197.0mm),

Width: 2.44" (62.0mm),

NET WEIGHT: 5.8 oz (165 g)

See the difference AT-822 200 ohms unbalanced , ... Nady 250 ohms that equals lower output which means you have to crank the gain higher which means more noise.Both have the same open circuit sensitivity , at -45 db 0ne pascal

But the 50 ohms difference IS a BIG difference it is amounts to about a 3-4 db lower output

Edited July 10, 2007 by Guitarfxr

[whatswisdom]

The AT-822 is at a S/N of 70 db on paper but in actual work, depending on the equipment it is plugged into can be much higher than that .

The Mic pre of the RH1 is almost 100db S/N it is one of the quietest portable pre's there is

I know this is a little off the main subject, but I'd like some advice on choosing the right mic. I'm going to record solo acoustic guitar, banjo and mandolin at home with my RH1. All I have at the moment is an AT-PRO24. Based on what I've been reading, and considering my budget, I'm thinking of going with the AT-822. Would that be adequate to produce a professional level recording for cd release? Or would it really require a very expensive studio mic?

[Strungup]

I know this is a little off the main subject, but I'd like some advice on choosing the right mic. I'm going to record solo acoustic guitar, banjo and mandolin at home with my RH1. All I have at the moment is an AT-PRO24. Based on what I've been reading, and considering my budget, I'm thinking of going with the AT-822. Would that be adequate to produce a professional level recording for cd release? Or would it really require a very expensive studio mic?

"Proffesional Level Recording" requires a couple things in the initial stages of recording , that is control over the mic , not neccessarily the mic itself( But good mics ar also needed)

The idea of "Limiting" the signal or "Compressing" the signal (Or both ) in order to smooth out the dynamic peaks so as to be able to get a "Hotter " signal to the recording device . If you record a Beautifull Noise free peice , but the softer parts get "Lost " in the mix of other things then the recording loses dynamics ( sounds odd huh, first clamp down on the dynamic , in order to get dynamics????) yes that is part of it

for digital recording you absolutel MUST avoid clipping , which is signal overload. But to do that your LOUDEST sounds have to be just below 0 db.

So what happens to the soft sounds when the loudest are under 0 db ..... ? think about it

The Limiter is designed to let you get the Loud sounds capped so you can Increase the gain in order to get softer passages to come out better .

Pro recording is a Balancing act , some of it can be done in post proccessing but generaly the initial recording NEEDs to be as good as it can possibly get before Proccessing it

A mixer that has two effect send and returns , and insert points on the mic channels, a Good compressor , and limiter ,

A touch of Reverb, and several mics so that you get more detail out of eac h band member and control over each mics level and position in the sound field ( Left or Right , and depth) ... now you get closer to Pro level recording.

[whatswisdom]

"Proffesional Level Recording" requires a couple things in the initial stages of recording , that is control over the mic , not neccessarily the mic itself( But good mics ar also needed)

The idea of "Limiting" the signal or "Compressing" the signal (Or both ) in order to smooth out the dynamic peaks so as to be able to get a "Hotter " signal to the recording device . If you record a Beautifull Noise free peice , but the softer parts get "Lost " in the mix of other things then the recording loses dynamics ( sounds odd huh, first clamp down on the dynamic , in order to get dynamics????) yes that is part of it

for digital recording you absolutel MUST avoid clipping , which is signal overload. But to do that your LOUDEST sounds have to be just below 0 db.

So what happens to the soft sounds when the loudest are under 0 db ..... ? think about it

The Limiter is designed to let you get the Loud sounds capped so you can Increase the gain in order to get softer passages to come out better .

Pro recording is a Balancing act , some of it can be done in post proccessing but generaly the initial recording NEEDs to be as good as it can possibly get before Proccessing it

A mixer that has two effect send and returns , and insert points on the mic channels, a Good compressor , and limiter ,

A touch of Reverb, and several mics so that you get more detail out of eac h band member and control over each mics level and position in the sound field ( Left or Right , and depth) ... now you get closer to Pro level recording.

Guitarfxr, thanks a lot for all this. As a newbie, I am grateful for your insight. The easy thing about this project is that it's just me playing solo (unaccompanied) so the variables are few. Essentially, I'm shooting for a very good quality field recording; I'm playing folk (dance) tunes and some original compositions (instrumental, no vocals) on the aforementioned acoustic instruments (no direct inputs). Besides my RH1 and mic, I have an old 6-channel Peavy mixer amp. Can you recommend a decent compressor/limiter--if they're essential at this stage?