Basics of tweaking audio...

R

ryanwaggoner

Member
Hey all,
You guys have been so great with answering my questions...well, I have a few more. I'll be shooting a DVD over the next few weeks, with quite a few interviews. Due to extreme budget constraints (ie, we don't have one) I'll be using a cheap lav mic as my sole source of audio. I know, I know, you get what you pay for, and I shouldn't expect great audio from this mic. Well, what I need is to figure out how I can at least get USABLE audio. I'll be editing in Vegas 5, which is said to have great audio tools, but I'm a little out of my element when it comes to sweetening the audio mix. I am needing some pointers about getting audio from a cheap mic to sound better. Any online tutorials and basic pointers would be helpful. To give you an idea of what I'm working with, I had my wife read something for me and I'll be posting it below. Please give a listen and let me know what I could do to sweeten this a little. Thanks all!

Click http://www.geocities.com/ryanlwaggoner/test.wma for the audio file.
 
Re: Basics of tweaking audio...

Ryan--audio postproduction consists of a lot of trial and error with your individual material and there are limits to what you can do with changing the sound of a low cost mic. I recommend getting to know your parametric equalizer--you can begin to address some of the issues with your mic. I can't access your page, but you have to deal with the problem areas specific to your mic. Do you need better intelligibility? More power in the voices? A clearer high-end? If you email me your file, I'll see if I can give you some more specific recommendations.
 
Re: Basics of tweaking audio...

[quote author=oleg link=board=audio;num=1090783075;start=0#1 date=07/25/04 at 12:40:42]the difference between bad lav and good one is 150$ [/quote]
Exactly. You can get a cheapo lav for $20, or a superb Countryman EMW for $170. It's the cheapest way in the world to dramatically upgrade your audio. And yeah, you could probably rent an EMW for ... what, $10 a day or so? Why use junk?
 
Re: Basics of tweaking audio...

Yeah, the Countryman EMW was my option if I felt I couldn't get usable sound from what I've got. Does anyone want to post a sample or point me to one from the Countryman EMW so I can judge for myself the difference? By the way, I'm shooting in Italy in the middle of nowhere, so renting isn't really an option. Trust me, there probably isn't a Countryman EMW within 500 miles of here. :)

Ryan
 
Re: Basics of tweaking audio...

Ryan-- I got your audio file and will see what I can do in Vegas as far as sweetening. As I guessed, your lav has some self-noise and sounds a bit thin. However, given your circumstances--I think it's workable. Try to keep the lav as close to the talent's mouth as possible--close miking will forgive a lot of sins. Also, be very careful when setting your levels on the DVX. If you can set your levels so your peaks are at -2 to -4 db, that would be good. With a good hot signal on tape, you won't have to raise the levels in post and have the problem of bringing up the noise floor. I think you'll be fine, though.
 
Re: Basics of tweaking audio...

I'd spring for the Countryman now, and avoid the hassle, and added expense in post.
 
Re: Basics of tweaking audio...

BarryS - Thanks for the help. I really appreciate it! :)

For the rest of you ;) I appreciate the advice, but unfortunately, the Countryman is out of my budget right now and if you'd like to explain to my wife that I need to spend yet another $175 (where are you finding it that cheap, anyway), be my guest. I would love to have a great audio setup, but I'm afraid that my options are limited at this point. If I can make this mic work, then that's what I'll do. I do appreciate the advice, though...
 
Re: Basics of tweaking audio...

Ryan,

There hasn't been an audio editing/effects program yet which can overcome the problems of poorly captured audio.

I've worked on million-dollar audio production systems that were rendered worthless for the project b/c the original sound recordist wouldn't spring for an extra $200 for a good mic, aim it properly, and prevent digital overs.

Any truly professional audio engineer will ALWAYS tell you to spend you money on mics first, everything else later.

I admit I have a somewhat smug attitude about audio, but that's been my primary field of work for the past decade. I can point to good projects and bad projects I've worked on, and from a technical perspective the difference was in the mics.

My personal rule of thumb is this: The further down the recording chain you get - the further away you get from the source - the less important that tool is to the end product. In order of importance:

Mics
Mic preamps (typically onboard the DVX and fairly decent)
Monitors (headphones, speakers, etc.)
A/D conversion (again done inside the DVX, and again, pretty good)
Mix Monitors
Effects like Equalization, Compression, Verb, etc.
Mix buss
Summing Buss

The three most important things, in my opinion, are mics, preamps, and headphones. The more limited these, the more compromises you may have to make down the line.
 
Re: Basics of tweaking audio...

Additionally:

If you are completely unable to rent or buy a better microphone, then I recommend you budget additional time for the project to do a lot of trial and error checking with your source sound recording.

Do a lot of sound tests before the shoot and listen to them on your mix speakers, burn them off onto a DVD-R or VHS cassette tape and listen to them through your TV.

In general, TV speakers are very forgiving creatures in that they don't reveal the little details of audio as well as someone's high-end A/V system will. But, you should check your audio on a couple of more "high-end" systems (Best Buy is a good place for this) before doing the shoot. Then, listen on your headphones you use at the shoot. That way you can establish a baseline for how you define what good audio sounds like and have something to compare it to at the actual shoot.
 
Re: Basics of tweaking audio...

Okay, let's say for the sake of discussion that I decide to buy a Countryman EMW (you guys are KILLING me here :) ) where should I buy from?  I was looking at it somewhere, and I saw a power module for sale for it that allowed the use of 48v phantom power.  Do I need this? I'll be running it (if I get it) hardwired XLR into the DVX.  What exactly do I need for this?  Just the mic?  Or the mic and the adapter...

Ryan
 
Re: Basics of tweaking audio...

Good advice, and I think we'd all agree that it's worth getting a good mic in the first place--especially with lavs where the cost for a professional one is comparatively low. However, Ryan is trying to work with his current situation and come up with the best possible recording. Let's not lose sight of the important considerations for documentary interview audio--clear dialogue, low distortion and ambient noise, no hum. Accurate voice timbre with good depth is nice if you can get it--but seems to be the exception in docs--just an observation. Recording with a close lav, getting a good signal without distorting, and trying to control ambient noise will get Ryan most of the way there. A little equalization and compression can thicken the voices and there is a good noise reduction plugin available for Vegas that may be able to deal with some self-noise. There's no substitute for a good mic and post-production can't turn garbage into gold, but you can always work with the tools you have. I'm sure Ryan will be upgrading after this shoot.
 
Re: Basics of tweaking audio...

..or sooner ;D. Ryan, you need the 48v phantom power option unless you're powering off of a wireless transmitter. If you can swing the Countryman before shooting--that would rock.
 
Re: Basics of tweaking audio...

[quote author=Barry_S link=board=audio;num=1090783075;start=0#11 date=07/28/04 at 13:24:00] However, Ryan is trying to work with his current situation and come up with the best possible recording.  Let's not lose sight of the important considerations for documentary interview audio--clear dialogue, low distortion and ambient noise, no hum.  [/quote]

I cannot stress this point enough: when you are walking into a situation where you know one of your tools may be less than "ideal" the key is preproduction, preproduction, preproduction.

If you are shooting an interview, do a mock interview first. Try to emluate the conditions as closely as you can, including:

SITUATING:
If the speaker will be seated, then have your mock interviewee seated. If they will be at a table, then place your mock interviewee at a table.

TRY DIFFERENT MIC PLACEMENTS:
Different people have different timbers to their voice. If you are going to interview a male, ideally have a male for your mock interview. (They will still differ dramatically in vocal timber). Try the mic closer to the mouth, further away, tilted, not. Listen with your eyes closed, then, when you hear something you like, roll camera. The BEST part about this is, when you find something that sounds right, you have a visual reference to show you where to place the mic.

AMBIENT NOISE:
The key to ambient noise is this little acoustic rule: a sound is lowered by 6db when the distance from the source to the mic is doubled. In other words, if you have an HVAC vent 6 feet away that is causing noise in your mic, moving the subject 12 feet away will lower that HVAC noise by 6db. While this isn't always feasible it's something to remember. Also, if you can block the vent with a plastic, non-breathable cover for the shoot (out of frame of course) that will help.

The same goes for other ambient noises.

Also, I like to record an ambient or "room tone." With the room empty, record 30 secs of the room with no noise but the ambient noise. You can use this in editing. Dead silence is a dead give away, having some ambient silence always helps ease those volume cuts.

Your key is mic preproduction and mic placement. Experiment before the gig and you'll be more prepared once you get there. At the very least, be aware of the limitations of your tool before you get to the shoot, and if you can, use those limitations to your advantage.

Even the worst mics have a sweet spot. Where they sound their best. Trial and error will help you find that spot.

heck, if you were in KC i'd let you borrow a mic. :)
 
Re: Basics of tweaking audio...

[quote author=Barry_S link=board=audio;num=1090783075;start=0#12 date=07/28/04 at 13:28:00]..or sooner  ;D.  Ryan, you need the 48v phantom power option unless you're powering off of a wireless transmitter.  If you can swing the Countryman before shooting--that would rock.[/quote]

Why would you need the 48v phantom power module when the DVX provides 48v phantom power? Did I miss something? ???
 
Re: Basics of tweaking audio...

[quote author=JBN link=board=audio;num=1090783075;start=0#14 date=07/30/04 at 06:55:23]

Why would you need the 48v phantom power module when the DVX provides 48v phantom power?  Did I miss something?  ???[/quote]

The 48V phantom power module converts the 48V phantom power from tthe DVX100 to the correct voltage for powering the lav. This is the voltage that is normally supplied by wireless transmitters.
 
Re: Basics of tweaking audio...

First of all, thanks to all for your recommendations. I really do appreciate it. Still unsure as to what I'm going to do...

Barry, did you have any luck with that file that I sent you?

Also, just so I have an idea, could someone post an unaltered example of a Countryman EMW (or similar wired lav)? Thanks...

Ryan
 
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