Need help with improving my narration sound quality:

S

szimmer

Well-known member
Hello,

I am doing a narration for our non-profit organization. I use the HMC-150 with the Countryman B3 LAV MIC connected to it via the XLR connection.

I placed the microphone on a mini-stand and built my own portable audio booth similar to this: http://digitalprosound.digitalmedianet.com/articles/viewarticle.jsp?id=89503

My main problem is my audio has too much background noise (static). The actually voice sounds decent considering the equipment I own. However, I am still picking up too much static. I make sure I am upstairs away from any obvious sources of noise like my computer and refrigerator.

I am using Soundbooth CS4 to clean up the audio. See attached audio clips and configuration. However, the results are not very good. The static is gone but the quality of my voice definitively takes a hit. Almost sounds like my voice becomes a bit scratchy and/or I am in a fish tank.

Any advice on how to clean up the audio properly? Any specific audio filter that people recommend I should use? Any techniques? I am a newbie to audio so any help would be appreciated.

If you need any more information, please let me know.

Thanks,

Simon
p.s.
Here is the link for the audios clips and configuration file:
www.aguayuda.org/Uploads/AudioClips.zip
 
When removing noise, it's best to first remove the low end rumble, then take a noise sample and lower the amount of hiss using the software you used. But try not to remove all of the hiss, because then you start to degrade the vocal track.

Your camera is probably the culprit for the hiss (what you call 'static'). If you have a trim adjustment on the camera, turn that up. That will turn up the level before it gets to the camera's preamps. You don't want to turn your camera levels up too high, because that's what adds hiss usually. Try to keep the camera audio levels at 50-65% level. Get close to the mic - and use a pop filter. That will get your levels up louder over the camera hiss. If it's too low, you can always turn it up later in post without adding camera preamp noise.

Also if you will have any music in the background, it will cover hiss. I would try removing the hiss a little less aggressively. A little hiss won't be too bad. It is best to record right into the computer and skip the camera if possible.

Another thing I do is duck out the sound between sentences, so the only time there is hiss is when there is talking. Again, music will smooth everything so it just sounds like a clean VO.
 
Interesting.

So how do you get rid of "low end rumble"?

I am not familiar with the different filters. Which one do you recommend?

I will try to adjust the audio level more.

Thanks,

Simon
 
Hello,

Again, I am new to this area. Would there be some kind of equipment that I could buy that would improve the sound quality between the mic and the camera. pre-amp for example?

Anything affordable out there?

I am open to various options.

Thanks again,

Simon
 
I haven't listened to it, but there are much better mic's suited to this purpose than a lav. Just about any large diaphragm condenser mic with proper pop filter would be better.

Use a high-pass filter to cut out the lows. You could start around 60-80hz and go up from there if you need to.
 
First you can try a hi pass filter (low cut) to get rid of some of the rumble if there is any. Be careful not to cut too much (you'll hear it in the dialogue).

You can try to EQ some of the hiss out. The hiss might also extend to the higher frequencies.

Another process you can use is an expander. Don't use a gate since it'll be too rough and you'll hear an audible drop in volume.

If there is still noise, you can try Izotope RX.
 
To remove low-end rumble you need to use EQ, or what's called a "hi-pass" filter. This could also be calles "lo-cut". Basically with both you want to turn down anything lower than 80hz. Some mics have a "lo-cut" switch to remove rumble before it gets to the recording.

And yes a mixer would improve your sound depending on the mixer and how you use it. Something like the Sound Devices MixPre. 665.00 may be too expensive, but it will boost your level, and engage limiters so you don't clip, and it also has lo-cut filters. Cheaper mixers do not boost your level. Remember this. They are mic level mixers (as apposed to line level) and at the loudest they are exactly as loud as the mic, and you can only turn down from there. If you can boost your levels you can turn your camera levels down, which will result in turning your noise down. It's called "Signal to Noise Ratio". You want a strong signal, and weak noise.

If you are editing this audio on a computer then all you need is an audio interface to get your voice recorded.

Maybe something like this: http://pro-audio.musiciansfriend.com/product/Blue-Icicle-XLR-to-USB-Mic-Converter?sku=330275

That's all for now. I have a shoot to do.... Good luck! Use search for more answers. Look up hi-pass in your filters and set it to 80hz then turn down everything below 80. Or just get closer to the mic and re-record your voice louder so the noise is lower in the signal to noise ratio.

But really you should not be recording VO into the camera.
 
For a decent low cost low noise studio mic...look at the rode nt1 I believe, plus pop filter and that should help a lot. Remember too that the hmc is compressing all of your audio to I believe 384 Kbps.
 
The noise you are complaining about is "hiss" not static. "Static" is sharper and more random. We crinkle cellophane to simulate "static".

All audio equipment (all electronic equipment, for that matter) has noise at the bottom of the scale. Optimizing audio recording is a matter of keeping the desired signal comfortably between the noise floor and clipping at the top end.

It seems rather likely that your noise is coming from the microphone and the mic preamp in your camcorder itself. If you bury the microphone under all the blankets and pillows in the house, how much self-noise do you hear when recording?

The little "sound booth" gadget is appropriate for directional microphones to somewhat block room acoustics, but you are using an omni-directional microphone and it is possible that the "sound booth" isn't doing anything significant.

It may seem obvious, but how much ambient noise is present while you are recording? We can't tell at this end how much of the noise is electronic and how much is acoustic. (Hence the pillow test.)

To be honest, I didn't think the noise floor was that terrible, and I didn't hear any significant difference between the samples. Chadfish makes an excellent point that any kind of background music (or sound effects) will mask that noise floor. And I have done exactly what he is suggesting by "gating" or "companding" the track so that you attenuate (or mute) the gaps between words and phrases.

Note also that if the microphone IS the source of the noise, there are other suggestions here for mics that are more quiet.
 
Thanks for all the tips and advice. It was very helpful.

I will try out the different filters and various tests mentioned above.

And yes, you are right about the "gating" technique and the addition of music. I will definitely do that.

Enjoy your Sunday!

Simon
 
update:

update:

I used the "remove hiss" filter in Soundbooth cs4 to get better results. The default setting at 80hz was too much but at 120hz it was a good compromise.

Thanks again for the help.

Simon
 
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