noise reduction help

A

Arachnid

Hi guys! I need some help with reducing static/noise/hiss from my audio. I have a rode svm connected onto a canon hfs10 via 3.5mm insert. Here's the problem: I have to reduce the mic level (on hfs10) to about a little less than 1/3 of the gauge in order to not hear a constant hiss: i use headphones connected via headphone jack on hfs10 to listen to audio). Going on, when I reduce the mic level to the point of no hiss, recording sound becomes quite hard; either the mic has to be very close (5 to 10 inches for decent sound) to the sound source or the sound source has to be quite loud.

Now the question! Will something like the juicedlink cx231 or other such preamps (beachtek dxa 6) allow me to reduce noise AND up the sensitivity (volume gauge) of the mic? I think solving my problem is what preamps are for but I just wanna be sure I haven't misunderstood what preamps do.

...I understand 3.5mm is not the best but I'd already bought the svm before I found this site :(. Thank you for your help and advice!
 
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Reducing the mic level DOES NOT reduce the hiss, it only reduces your ability to hear it. The hiss/noise is intrinsic to the mic and camera you are using, a phenomenon known as Self Noise. Self noise is the amount of noise - usually hiss - created by a piece of gear. High impedance devices - and both your mic and cameras audio system are high impedance - are especially prone to self noise. And the cheaper the audio device the more self noise it will generate.

A mixer/pre-amp like the juicedLink will not noticeably improve the self noise if you do not upgrade to a low impedance mic at the same time.

Another contributing factor to hiss is improper gain-staging. This is the balance of input (sound source) levels, input gain (the level before the pre-amp circuitry distorts), channel volume levels (the channel output level before the channel distorts), master volume level (the level before the device output distorts) and recording device input levels (the level before the recorders input distorts).

There is also the possibility that the headphone output also generates additional hiss.

One more thing - you should not be recording dialog in stereo.
 
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Finally my two years of studying music technology will come in handy.

There might be a solution to your problem outside of upgrading your hardware. Are you using any separate software to process your audio? If you are you could try applying a 'gate'. In most basic terms a gate 'opens' when there is sound that matches the criteria you set going through the circuit (or software in our case). So for example, if you set it so that the gate doesn't open for sounds less then -5 decibels, all sounds under that threshold will be blocked out. On some gates you can also set the permitters in pitch, so if you've got a low rumble bleeding in from a passing truck you can set the gate so that it doesn't let sound pass that is lower than (for example) 500 hertz.

My advice, download Audicity, a free DAW (Digital Audio Workstation).

http://audacity.sourceforge.net/

And then read this http://wiki.audacityteam.org/index.php?title=Noise_Removal

Just my 2 cents.

Edit: I'm assuming that you can't hear the hiss while people are talking as the speech drowns it out? If that is the case you could simply 'cut up' the audio. Open the track in Audacity and (I haven't used Audacity for a while so bare with me) there should be a scissor tool or similar doodad. When there is a break in the speech cut the audio and just before it begins again cut again and delete the dead space in the middle. *IMPORTANT!* DO NOT move the blocks of audio, leave them exactly where they are or they will be out of sync with the video. When you're done there will be an option somewhere to 'export' the audio (the correct term here is to 'bounce' the audio) which will form it into one continuous track, the speech will be in the same place as before just without the hissing.
 
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Monkey: I was trying to avoid post cause it'll add a significant amount of workload. But thanks for the input. I was looking at a bunch of clips on youtube.com on how to reduce noise, sounds ticks, and other junk from audio...it's work i'd want to avoid doing for most if not all audio.

Alcove: Did you mean that noise may also come from the inbalanced settings of ALL the audio components? Darn, I was trying to avoid having to get a new mic also. I've read some other posts that you recommend the mko12 for indoors and ntg2 for outdoors as low budget mics; I think those'll be my things to get then. Of course on top of a pre-amp too.
 
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hmm. If my recording hardware is high impedence (and high impedence is not good for my application), then I should also consider another device to record sound. zoom h4n or tascam dr-100?
 
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M1chae1 -

Dialog is almost always dead center in the stereo field or in the center speaker when mixing 5.1 surround. Your brain has an "automatic editing" function that will place most sounds in the "center" of your head in real life even if the speaker is off to one side; panning voices around detracts from a sense of reality as recorded audio is a sort of sonic hyper reality that does not truly represent real life. That being said, off-camera dialog can be panned to the sides when, for example, someone calls to one of the characters and the characters react by looking in that direction. Put on a pair of headphones and really listen to how dialog is placed in the stereo field.

Arachnid -

Okay, the CX-231 is not just a pre-amp it is a mixer.

Since the juicedLink is $300 you may want to consider getting the Zoom H4n or the Tascam DR-100, which are the same price (about $300). True, having to sync the audio in post is another step, but having a separate audio recording system will provide more flexibility on the set, allows for much higher bit/sample rates, and gives you an unobtrusive recorder for capturing sounds for your sound library. However, neither one allows for easy mixing on the fly which the manual controls on the CX-231 facilitate. As you can see, there are positives and negatives to both approaches.

The NTG-2 and MK-012 are good mics in their price range.

cameramonkey -

Traditionally "bouncing" audio refers to the combining of multiple tracks of audio onto another track. When Queen did "Bohemian Rhapsody" Freddy Mercury did 48 tracks of vocals (several times, in fact) that were bounced to a stereo track. So, despite the terminology used in some of the current programs, you are exporting and importing multiple tracks between programs for further manipulation. When you finally mix you are "bouncing" the multiple tracks on to a combined mix track.
 
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