What's the quietest mic available (lowest noise)? for nature recordings

[matt_r]

I'm looking to do some nature recordings, some of which will be very quiet sounds coming from a distance. I would like to know from peoples experience what is the best mic for this. The first priority for me is lowest self-noise. I have a matched pair of AKG 414 XL II, would they be any good? (guessing LDC is quieter, but maybe less natural sounding?)

I read on another post that some mics are succeptible to problems from humidity, like schoeps. Any info on this too, would be appreciated.

I will be recording in stereo, what's generally the best setup for capturing ambience in a variety of different places, AB, XY, ORTF etc?

My other question was what recorder would people recommend for this? It would need to be silent in operation and ideally have good pre's and AD...

Thanks for any suggestions.

Matt.

[bcgood]

I really like the Sennhieser 416 with it's furry wind stop coat on for that sort of thing. I noticed you want stereo, so I suppose you could use two. It really depends on your budget.

[matt_r]

Thanks for your reply, sorry I probably wasn't very clear in my original question. I'm looking to capture the overall ambience including very quiet sounds, not only the distant things...

ie, probably looking more for an omni/card than shotgun.

[Fran Guidry]

Rode advertises their NT1a to be the quietest mic around. Rob Danielson has a site with field recording info and he seems to find these mics useful.

Rode NT1-A Mics & Field Recording

Fran

[klaukholm]

The sennheiser MKH800 is very quiet and sounds lovely.
One of the quietest mics I have worked with, andclearly the quietest multipattern I have worked with.

[John Willett]

To answer your question - probably the MKH 20 or 40 (or the cheaper 8020 or8040) - quiet, high output and RF condensers that work well in damp conditions without adding noise.

Recorder - if it's stereo I would look at the Nagra LB or the Sound Devices 702.

If you want to ask the experts go the site of the Wildlife Sound Recording Society.

[matt_r]

Thanks to everyone for your suggestions. Would the Sennheiser mics be quieter and more suited to this kind of work than my 414's?

Thanks John for advice on recorders, have you used the korg mr1000, how does it compare with the others? I know it's cheaper and probably not as good in many respects, but is it close in terms of preamp quality?(high gain, low noise)

Matt

[John Willett]

Originally Posted by matt_r

Would the Sennheiser mics be quieter and more suited to this kind of work than my 414's?

Although the C414 is a nice mic. in many respects it, like pretty well all AF condensers, is not that good in damp conditions. So for outdoor use the RF condenser MKH mics are the safest.

Originally Posted by matt_r

Thanks John for advice on recorders, have you used the korg mr1000, how does it compare with the others? I know it's cheaper and probably not as good in many respects, but is it close in terms of preamp quality? (high gain, low noise)

I have not tried the MR 1000 I'm afraid.

[Martin Kantola]

The 13dB noise level of the Sennheiser MKH40 is not bad, but not excellent either. Remember that this is not a large diaphragm capsule. Have a pair of these, use them in my studio, but my experimental surround mike with larger capsules has much less noise.

Been involved mostly in music recording before, and suddenly realized how important a low self noise microphone is in nature recordings. As always, please check out my panphonic.com site for some real examples. Not selling these (yet...) but it might still be a good comparison.

What I found important is also the actual spectrum of the noise, lower frequencies tend to blend in with the natural ambiance, while an "electronic" kind of high frequency hiss is very disturbing with faint sounds.

Martin

[anechoic]

the NT1A (card) and my AT-3032's (omni) are very quiet mics
and I've made some amazing field recordings with both

check out Rob's mic Excel spreadsheet:
http://www.uwm.edu/~type/audio-art-tech-gallery/pages/MicSpecs-Cover.html

[Track 7]

Rode NT1A

[John Willett]

Originally Posted by Martin Kantola

The 13dB noise level of the Sennheiser MKH40 is not bad, but not excellent either. Remember that this is not a large diaphragm capsule. Have a pair of these, use them in my studio, but my experimental surround mike with larger capsules has much less noise.

A couple of other things to remember, though......

Firstly, the MKH range have a higher output than a lot of other condenser mics., meaning that you add less noise from the mic. pre as you are running it at a lower level.

Also the MKH are RF condensers and are not bothered by the damp like normal AF condensers. An AF condenser tends to go a bit noisy and crackly in damp conditions due to the leakage of the capacitor charge on water molecules in the air - that's why the RF condenser is the preferred option for outside work.

[David Spearritt]

Originally Posted by John Willett

A couple of other things to remember, though......

Firstly, the MKH range have a higher output than a lot of other condenser mics., meaning that you add less noise from the mic. pre as you are running it at a lower level.

But the mic pre is often not as significant noise contributor as the mic so the said benefit of higher sensitivity cannot be realized.

With a modern preamp, the self noise of the mic will tell you more about how quiet the recording will be.

[matt_r]

If ldc's are lower noise, is there a natural sounding one that is an RF type?

Would moisture be less of a problem in cooler conditions? Eg. Dartmoor

[John Willett]

Originally Posted by matt_r

If ldc's are lower noise, is there a natural sounding one that is an RF type?

No, there are no RF LDCs (but the MKH are MDCs as the diaphragm is 16mm diameter).

Originally Posted by matt_r

Would moisture be less of a problem in cooler conditions? Eg. Dartmoor

No - an AF condenser has a very high impedance and stored charge and this charge leaks away on water molecules in the air, so if the air gets damp you can hear it happening.

[Martin Kantola]

Originally Posted by John Willett

An AF condenser tends to go a bit noisy and crackly in damp conditions due to the leakage of the capacitor charge on water molecules in the air - that's why the RF condenser is the preferred option for outside work.

No - an AF condenser has a very high impedance and stored charge and this charge leaks away on water molecules in the air, so if the air gets damp you can hear it happening.

Good point, the capsule I'm using have been tested and tried in a rain-forest without problems, so guess it depends a bit on which LDC capsule we are talking about. Traditional Neumann style would be problematic.

It makes a huge difference if the polarized part of the capsule is exposed or not. In my prototype, the polarization high voltage is applied to the completely insulated backplate, while both the diaphragm and capsule body stay at low voltage potential.

As for the output level, I sometimes have to switch my SD744T to line input mode, so there's plenty there. Agree that high output level seems helpful with modest mike pre-amps, maybe less with good ones.

We want ultra low noise, great sound and reliability in difficult conditions. I would not sacrifice any of these. It's possible to have all three, but not at a budget price.

Martin

[matt_r]

Originally Posted by John Willett

No, there are no RF LDCs (but the MKH are MDCs as the diaphragm is 16mm diameter).



No - an AF condenser has a very high impedance and stored charge and this charge leaks away on water molecules in the air, so if the air gets damp you can hear it happening.

Thanks for the reply.

I thought there has to be a threshold at which it starts to happen. Maybe in lower temps when the air is able to hold less moisture it may be ok? I may give it a try just as a test.

[Gaston69]

Dpa 4006

[d_fu]

Originally Posted by Gaston69

Dpa 4006

Is it really? 15dB(A) is not so spectacular IMHO. Even the AKG 480 is a 4 dB or so below that nominally. (I know, DPA claim that their measurements are more accurate)

I'd probably try MKH 20. Very quiet, true pressure transducer, and as such less sensitive to wind than LDCs or directional SDCs.

[Martin Kantola]

Originally Posted by d_fu

Is it really? 15dB(A) is not so spectacular IMHO. Even the AKG 480 is a 4 dB or so below that nominally. (I know, DPA claim that their measurements are more accurate)

Accurate or not, what the dB(A) figure doesn't tell you all about is the spectrum of the noise. In my experience the noise of the 4006 actually peaks in the sensitive 1-2 kHz area. Again, it's a small diameter capsule, so not the lowest noise, but impressive as such, good mike. As for humidity, all exposed parts are at ground potential, remember the mike-in-a-glass picture?

Martin

[Roland]

Argueably the Sennheisers have always had the reputation for being the quietest mic's out there these days, the DPA's a good too, most of the top range Schoeps, Neumann's AKG's, all have very low noise these days, low enough that other environmental noise is often more of an issue.

Regards


Roland

[John Willett]

Originally Posted by Roland

Arguably the Sennheisers have always had the reputation for being the quietest mic's out there these days, the DPA's a good too, most of the top range Schoeps, Neumann's AKG's, all have very low noise these days, low enough that other environmental noise is often more of an issue.

Agreed - but for outdoor recording the Sennheiser MKH are the best in the wet (as they are RF condensers) and the AKGs have the reputation of being the worst.

The Schoeps are AF condensers, they seem to hold up not too bad, but Joerg Wuttke suggested they go back for cleaning now and again to keep them at their best.

DPA are electrets and I have no knowledge of them outdoors.

An RF condenser is the safest, just because of the laws of physics.

[Martin Kantola]

Originally Posted by John Willett

An RF condenser is the safest, just because of the laws of physics.

Hmm, still don't see how a microphone with no exposed high voltage or impedance parts would be problematic. But thank you for giving me the motivation to try to build my next prototype all but waterproof! Will report back when I have it built and tested. Would you say high humidity in general or condensation is the worst problem?

Built a hydrophone (AF-style) last summer, saltwater-resistant electronics are a true challenge, but gave me some good experience. That one is waterproof no doubt.

Martin

[Roland]

As John say's AKG's and Neumann's are notoriously subsceptable to moisture and condensation. Even vocalists moisture in their breath was enough to sometimes cause problems.

Roland

[John Willett]

Originally Posted by Martin Kantola

Hmm, still don't see how a microphone with no exposed high voltage or impedance parts would be problematic. But thank you for giving me the motivation to try to build my next prototype all but waterproof! Will report back when I have it built and tested. Would you say high humidity in general or condensation is the worst problem?

Built a hydrophone (AF-style) last summer, saltwater-resistant electronics are a true challenge, but gave me some good experience. That one is waterproof no doubt.

Martin

The problem is the diaphragm and capsule itself. It's very high impedance with high voltage (60V) and it has a stored charge - and this charge tends to leak away on water molecules in the air.

So you would have to seal this completely against the outside air.

"Basically, AF capacitor microphones use the capsule as a capacitor to store charge. With one fixed plate and the other free to vibrate in sympathy with the sound, the capacitance varies, and the charge moves in or out of the capsule accordingly. This is measured by the head preamplifier and an audio signal results. All well and good, but the capsule is inherently in a high impedance circuit (over 1Giga-Ohms) - it has to sit there with stored charge until the diaphragm moves and any changes in the charge are perceived as audio. In a humid atmosphere the stored charge finds it easier to escape on water molecules in the air rather than through the input of the preamplifier, hence noisy and reduced output, and misery all round. The high biasing voltage also attracts dust particles to the diaphragm, reducing its efficiency and linearity.

The RF system uses the capsule (a low impedance capsule) in a completely different way: as a tuning capacitor for an RF oscillator – which inherently employs it in a low impedance circuit where a high frequency signal is being passed through the capacitor all the time. Changes in capacitance (caused by sound moving the diaphragm) alter the resonant frequency of the circuit (circa 8MHz) and so its frequency becomes proportional to the audio signal. A simple RF demodulator restores the output to a conventional audio signal. More complex and sophisticated (but still very rugged), this system is highly immune to the effects of humidity and is thus the preferred design to be used out of doors (or when moving from outside to inside on a cold day!)."


By the way - a friend made a cheap hydrophone by buying some of those very hard rubber high-bouncing balls. He drilled a hole to just beyond the centre and popped in a tie mic. The hole was slightly larger than the mic as there has to be some air inside. He then sealed the cable entry with silicon sealant and - viola - a very effective hydrophone.

[fader8]

Don't know what your budget is, but it's tough to beat a 1 inch B&K for noise floor. They sound great for nature recordings too. I have some 4145 capsules I have used for similar, but here's what's available these days:
http://www.bksv.com/doc/bp0389.pdf
They say -5dBA, but -2 is probably more realistic in real world conditions. YMMV.

You'd need a B&K 2804 Mic power supply too. Coupled with a decent parabola and if it's moving air, you'll hear it.

[Martin Kantola]

Originally Posted by John Willett

The problem is the diaphragm and capsule itself. It's very high impedance with high voltage (60V) and it has a stored charge - and this charge tends to leak away on water molecules in the air.

So you would have to seal this completely against the outside air.

Thank you for your reply. Please read what I wrote earlier, there are capsules where it is possible to do exactly this (except for the tiny pressure equalization vent). All exposed parts can stay a 0 Volts ground potential. My prototype uses 80V polarization voltage and the impedance is tens of GigaOhms, but it can be completely insulated from the surrounding air.

As for the diaphragm attracting dust, the microphone designer always has a choice here and can avoid this by connecting the polarizing voltage to the backplate instead.

While I agree that is important to have a microphone that can deal with high humidity, it's not necessary to sacrifice premium sound quality and noise level by only using RF-microphones outdoors. The Sennheisers are great, but not the best for all applications.

Martin

[Martin Kantola]

Originally Posted by fader8

Don't know what your budget is, but it's tough to beat a 1 inch B&K for noise floor.

Note that the trade-off with these super-quiet capsules is limited frequency response (beyond 10kHz), but good to learn that they work well enough for nature sounds anyway. Besides, any windscreen will eat some top anyway.

Martin

[excase]

I looked at this for a few years and found that a short shotgun Mic by Sennheiser, the mkh 60, at the B & H link below, is actually the lowest noise microphone. The akg 414 is in the same noise range but will fail in outdoor use (tempting but don't do it). the MKH-60 will handle temperature and humidity very well. This is also considered the # 1 for on location film sound.
Sennheiser | MKH-60 - (P48) Short Shotgun Mic | MKH60-P48 | B&H

[backindauk]

Akg c451.