Blocking Out Ambient Noises

S

Stetson F. Lienol

New member
My wife does audio and video recordings for her work, including things like Twitch, Instructional videos, ect.

Recently we moved into a new apartment. The apartment has all wood flooring and fairly thin walls, so a lot of the traffic and neighbors can be heard and is amplified. While my wife has been doing her recording for quite some time, we haven't ran into this issue and so are inexperienced in dealing with blocking out/reducing all this ambient sound within recordings. Specifically, we need to be able to block out/reduce the passing traffic and the Thud/Voices of the neighbors, but other odd sounds like running appliances are things we're looking to address.

She uses a DSLR Canon 80D for filming/audio, with no other recording equipment. Preferably, she'd like to do as little sound editing/processing as possible, so any solutions that could/would work without running anything through a program would be best.

Any help is greatly appreciated.
 
Does the DSLR have an external mic input? You could theoretically use a dynamic mic with a tight pattern. Like a hypercard. You will not hear the neighbors fighting or lawnmowers sweeping.
 
LazerBeakShiek said:
Does the DSLR have an external mic input? You could theoretically use a dynamic mic with a tight pattern. Like a hypercard. You will not hear the neighbors fighting or lawnmowers sweeping.
Click to expand...
Yes, the 80D does has a Mic Input.

Could you explain how a dynamic mic works and why it could help solve this issue?
 
Hi,

Using a separate dedicated microphone, much closer to the speaker, increases the ratio between wanted and unwanted noise.
In a busy room where you can barely hear someone talk you move closer to them. Same thing.

It's not magic - background noise will still always be in there somewhere but, if your DSLR is any more than a few feet away, the difference between that and a microphone at less than a foot would be huge.
If you don't want a microphone to be obvious in the shot you could look into lapel/lavalier mics.
 
It's more to do with signal to noise ratio. The camera mic is quite wide in it's polar pattern. So everything in frame should be within it's capture area. The trouble is that sound dies away at a rate called the inverse square law. So if you double the distance, the volume does not drop to half, it drops to a quarter. The upshot is that a mic close to the subject's mouth will make the background noise quieterIf the camera is say 1m away, moving the mic to half that distance makes it 4 times louder, so the volume level can be turned down quite a way, taking the room noises down far more. Dynamic mics are the popular type of mic that does not need power. Condenser mics have to be powered. You camera can't do this, so you need extra gizmos. In honesty, that's why some people like to use separate recorders like the zooms - but that means combining the audio and the picture before you edit. A cable and a simple mic closer in is the simplest solution.

In real terms, DSLRs have pretty awful audio capabilities. Usually automatic level controls that can manage 'averageness' - but they are also often quite poor sounding - hiss, occasional distortion - that kind of thing. Gizmos can solve this kind of thing, but for simplicities sake - a cable with the correct connector for the camera and a dynamic mic could be the improvement you need.

Moving the mic in closer also reduces the 'room sound' - the peculiar sound that any closed space has. So not just your neighbours or passing cars but the reflections from walls, hums of refrigerators or aircon - that kind of thing. It's usually quiet, but it's there. It's about wanted vs unwanted sound. Moving in closer is the simplest and most effective way to do it. A mic on a small table stand could be the easiest. I always mention your Presidents - They have the budget to buy the most expensive system they want, but they buy a Shure SM57 dynamic for around $100 and stick it on a short stand, close to the President and it works great!
 
rob aylestone said:
It's more to do with signal to noise ratio. The camera mic is quite wide in it's polar pattern. So everything in frame should be within it's capture area. The trouble is that sound dies away at a rate called the inverse square law. So if you double the distance, the volume does not drop to half, it drops to a quarter. The upshot is that a mic close to the subject's mouth will make the background noise quieterIf the camera is say 1m away, moving the mic to half that distance makes it 4 times louder, so the volume level can be turned down quite a way, taking the room noises down far more. Dynamic mics are the popular type of mic that does not need power. Condenser mics have to be powered. You camera can't do this, so you need extra gizmos. In honesty, that's why some people like to use separate recorders like the zooms - but that means combining the audio and the picture before you edit. A cable and a simple mic closer in is the simplest solution.

In real terms, DSLRs have pretty awful audio capabilities. Usually automatic level controls that can manage 'averageness' - but they are also often quite poor sounding - hiss, occasional distortion - that kind of thing. Gizmos can solve this kind of thing, but for simplicities sake - a cable with the correct connector for the camera and a dynamic mic could be the improvement you need.

Moving the mic in closer also reduces the 'room sound' - the peculiar sound that any closed space has. So not just your neighbours or passing cars but the reflections from walls, hums of refrigerators or aircon - that kind of thing. It's usually quiet, but it's there. It's about wanted vs unwanted sound. Moving in closer is the simplest and most effective way to do it. A mic on a small table stand could be the easiest. I always mention your Presidents - They have the budget to buy the most expensive system they want, but they buy a Shure SM57 dynamic for around $100 and stick it on a short stand, close to the President and it works great!
Click to expand...

For most of her filming needs, she is going to be anywhere between 1-1.5m away from the camera, often looking away/moving/ect (she does yoga/mediation videos/streams) would the SM57 pick up properly under these circumstances?
 
Putting an SM57 where the camera is isn't going to be much help at all - The main point of using a separate microphone is that it can be much closer to the speaker.
If there's going to be a lot of movement I'd be considering a wireless lapel mic.
 
If she does Yoga I'd suggest one of the packages that people like Sennheiser do with a headset. If she does Yoga in dance kit - they are often troublesome at attaching clip on mics - headsets work pretty well, and the extra advantage is the mic is in really close, making your noise problem even less obvious. If she's mobile long cables would be a pain, so wireless is a sensible solution, but of course, not exactly cheap! You do find them on ebay - but be aware they always make the seller proper money - cheap ones are rare. There are cheaper brands, but while the electronics are often OK for careful use, they tend to use plastics instead of metal and the mics are often a little fragile. SM57's are dynamics - so not really very suitable for distant miking - close in, as I explained - they're great, but at camera distance, the camera mic may even be better.
 
Did you ever do the physics experiment at school where you had a coil of wire and waved a magnet near it and Volts magically appeared on a huge meter? Pretty much the same process - the key feature with dynamic mics is to remember they are powered from the energy in the sound. It lands on a surface with a coil attached to it, next to a magnet and the tiny backwards and forward motion generates electricity - using the pressure of the sound wave hitting the diaphragm. If you drop a pin on the floor, the amount of sound it generates is extremely small - by the time it hits the mic, there really isn't much left - so dynamics need to be close enough to physically be moved by the sound pressure waves. Great for Donadl Trump, or somebody hitting a drum - not so good if you want to record a frog farting. The other type of microphone doesn't have a bug chunky coil, it has a microscopically thin metalised membrane that sits very close to a metal plate - size vary from 5 or 6mm to 50mm or so. Think back to school physics again and two surfaces very close but not touching have capacitance - they can even store a little electricity. The size and the gap set the value. If the membrane moves in sympathy with the sound wave it changes capacitance. Build an amplifier in the mic that produces voltage as the capacitance changes, and you have a mic that is self-powered and doesn't take energy from the sound wave - so responds to much smaller pressure levels. The upshot is that it might indeed be able to record the frog farting! The downside is it needs power. Dynamics don't. So the general rule is dynamics are good for louder sound sources and they don't need power. Condensers can be more sensitive, but they do need power. Engineering wise, they're also much more sophisticated - but the Chinese can knock out tiny condenser mic capsules for pennies! Better engineered ones cost more - often MUCH more.

There you go, how a dynamic mic works. If the working of a dynamic mic sounds vaguely familiar, it's exactly the reverse of a loudspeaker.
 
rob aylestone said:
Did you ever do the physics experiment at school where you had a coil of wire and waved a magnet near it and Volts magically appeared on a huge meter?
Click to expand...
No, but we did the one where..You hang the leads of the meter, let em dangle. Set the meter calibration really low. The dangling wire leads moving through the earths magnetic field shows voltage.
 
You might like to try the Rode Wireless Go.

This consists of a receiver that plugs into your DSLR, and a transmitter that includes a mike, but also has facility to plug in another mike. You can wear the transmitter as a clip on, or you could get a little lavalier clip on mike to plug into the receiver.

www.rode.com

Wireless GO Compact Wireless Microphone System | RØDE Microphones

The Wireless GO is the world’s smallest, most versatile wireless microphone system. Small and compact - it's perfect for content creators on the go. Learn more!
www.rode.com www.rode.com
 
rob aylestone said:
Did you ever do the physics experiment at school where you had a coil of wire and waved a magnet near it and Volts magically appeared on a huge meter? Pretty much the same process - the key feature with dynamic mics is to remember they are powered from the energy in the sound. It lands on a surface with a coil attached to it, next to a magnet and the tiny backwards and forward motion generates electricity - using the pressure of the sound wave hitting the diaphragm. If you drop a pin on the floor, the amount of sound it generates is extremely small - by the time it hits the mic, there really isn't much left - so dynamics need to be close enough to physically be moved by the sound pressure waves. Great for Donadl Trump, or somebody hitting a drum - not so good if you want to record a frog farting. The other type of microphone doesn't have a bug chunky coil, it has a microscopically thin metalised membrane that sits very close to a metal plate - size vary from 5 or 6mm to 50mm or so. Think back to school physics again and two surfaces very close but not touching have capacitance - they can even store a little electricity. The size and the gap set the value. If the membrane moves in sympathy with the sound wave it changes capacitance. Build an amplifier in the mic that produces voltage as the capacitance changes, and you have a mic that is self-powered and doesn't take energy from the sound wave - so responds to much smaller pressure levels. The upshot is that it might indeed be able to record the frog farting! The downside is it needs power. Dynamics don't. So the general rule is dynamics are good for louder sound sources and they don't need power. Condensers can be more sensitive, but they do need power. Engineering wise, they're also much more sophisticated - but the Chinese can knock out tiny condenser mic capsules for pennies! Better engineered ones cost more - often MUCH more.

There you go, how a dynamic mic works. If the working of a dynamic mic sounds vaguely familiar, it's exactly the reverse of a loudspeaker.
Click to expand...
I never knew flatulance of Anures was such a big thing in recording! Live and learn! :)
 
I'm going to amplify what others have said about mic distance. A mic element (not the grille) at 1 inch will pick up 24dB more of the desired signal than a mic element at 16 inches without much change in the amount ambient noise.
 
You must log in or register to reply here.
Back
Top