Audio FAQ

[ullanta]

Introduction
--------------

Greetings! Welcome to the fledgeling DVX100 Audio FAQ. *This first message of the thread will contain an index with links to *continuously updated helpful information culled from the rest of the Audio topic. *Right now, I'm keeping everything within the DVXUser space... but I haven't yet found a way to do so EASILY (there are message size limits, and limited referencing capability), so it may eventually move to my web site (but with the index remaining here, with links).

To aid in this project, I'd ask that people post anything they find generally useful in later messages to this Audio FAQ thread; and I'll try to go through them in a timely manner. The goal: a comprehensive FAQ up front, that will hopefully avoid redundant questions, a record (the rest of the FAQ thread) of any discussions leading up to inclusion in the FAQ, and the Audio thread in general, with new and/or situation specific questions. Hope it works! Below, I'll lay out some preliminary FAQ categories. So: post away with some filler material!

INDEX
-------

I. DVX100 Audio
*A. Connections & Settings

*B. Metering - see http://www.DVXuser.com/cgi-bin/DVX2/YaBB.pl?board=audio;action=display;num=1086814247; start=4#4

*C. Maximizing Quality

*D. ALC - Automatic limiting control - see http://www.DVXuser.com/cgi-bin/DVX2/YaBB.pl?board=audio;action=display;num=1086814247; start=5#5
* * *
*E. Audio Sync of Recorded Material - see http://www.DVXuser.com/cgi-bin/DVX2/YaBB.pl?board=audio;action=display;num=1086814247; start=3#3

II. Audio in NLEs

III. Audio Creation/Editing/Mixing

A. Recording sound feed from a venue's house console - extensive discussion at http://www.dvxuser.com/cgi-bin/DVX2/YaBB.pl?board=Links;action=display;num=1080751160

IV. Microphones
http://www.DVXuser.com/cgi-bin/DVX2/YaBB.pl?board=audio;action=display;num=1086814247; start=2#2

V. Wireless Systems

VI. Headphones - see http://www.dvxuser.com/cgi-bin/DVX2/YaBB.pl?board=audio;action=display;num=1085005505

VII. Production Technique and General Info
A nice article: http://www.kenstone.net/fcp_homepage/location_sound.html

[ullanta]

a. Quick notes and comparisons
------------------------------------
Below, I'll start gathering some more quick notes on various microphones.

Also, you may want to check out http://www.kenstone.net/fcp_homepage/review_shotgun_mics.html - although I'm concerned by the frequent mention of an "omni cardioid"

This is not a comprehensive list, but it should give you an idea of what range you want to be in.
*
Audio-Technica AT897 -- ~$280 *Good low-priced shotgun. *Sensitivity is not great, but can produce good quality, if not natural sounding dialogue.
*
Sennheiser ME66/K6 -- ~$400 *High sensitivity, low self-noise, the ME66 is good for ENG or non-critical applications. *The ME66 can record intelligible speech under difficult conditions, but does not have a natural sound. *A benchmark for producing clean, good dialogue for low budget productions. *The K6 module can be used with other microphone capsules including the ME64 cardioid and ME67 long shotgun.
*
Audio-Technica AT4073a -- ~$500 *This shotgun has high sensitivity and a good overall, but not warm sound. * Excellent off-axis rejection and a fuller sound than the ME66--if you're considering the ME66, don't rule out spending a little extra money for the AT4073a.
*
Sennheiser MKH-416 -- ~$1000 *High sensitivity with a fairly full sound for a shotgun. *Up to top professional standards.
*
Neumann KMR81i -- ~$1200 *Top quality shotgun with very neutral and natural sound. *
*
Sennheiser MKH-60 -- ~$1400 *Outstanding mic with some of the most natural tone possible from a shotgun. *Frequently used on big budget film productions.
*
Schoeps CMC641 Set -- ~$1400 *This setup includes the highly respected MK41 super cardioid capsule. *while not a shotgun, this mic is highly directional and will produce the most natural and uncolored sound of any mic used for dialogue recording. *Also frequently used on big budget productions.
*
Sanken cs-3e, Oleg's favorite - best side rejection of all the short guns, very natural sound.

Important note: *A shotgun microphone may be a poor choice for a small sound-reflective room. *Shotgun mics (particularly sub $500 ones, but all to some degree) can color off-axis sound and cause problems with reverb in small or reflective rooms. *Hyper or super cardioid mics are directional, but lack the strange off-axis coloration that can be a problem with shotguns. * * * * * * * * * * * * *

b. Sennheiser ME64 vs. ME66 (Cardioid vs. SuperCardioid)
---------------------------------------------------------------
(see http://www.dvxuser.com/cgi-bin/DVX2/YaBB.pl?board=audio;action=display;num=1086215011 )

* *ME64 is Cardioid - wide directional, with maximum rejection at * * *rear, less off-axis coloration
* *ME66 is SuperCardioid - narrower directional, but with some pickup directly to the rear, more off-axis coloration
* *Barry_S has some example usage suggestions:

*******ME66*******
- Boomed outdoors (where there's nothing to reflect sound back to the the rear lobe)
- ENG-style outdoors (mounted to the camera, shooting in noisy run 'n gun situations the ME66 will attenuate off-axis noise)
- ENG-style indoors with high ambient noise levels.
- Boomed in large interiors with some uncontrolled noise.

*******ME64******* **
- Boomed in small sound-reflective interiors with low ambient noise (i.e., an indie set)
- Boomed in any size interior with low ambient noise where you need to pick up 2-3 closely placed actors with only one mic.

c. An underdog?: Oktava MC012
------------------------------------
* *These are small multi-capsule condensers (available capsules include cardioid, hypercardioid, omni; and some funky custom large-diaphragm capsules from http://sound-room.com . These can be bought super-cheap (with potential quality problems) at the Guitar Center or for a bit more at places like http://sound-room.com, which provide well-tested mics, as well as stereo or surround-matched sets.
* *Great for music, "absolutely amazing in controlled environments", but less directional than shotgun mics and thus more susceptible to unwanted ambient sound.

[ullanta]

Audio sync on the DVX100 (and most camcorders) can be a little funky. This seems to differ based on camera model (P or A), frame rate (60i, 30p, 24p), and to a lesser extent, the way in which your NLE captures sound. *For a thorough explanation, please see:
http://www.adamwilt.com/24p/index.html#AVsync
In brief, the audio leads the video by:
DVX100P: 60i - 2 fields; 30p (3 fields), 24p (3-4 fields)
DVX100A: 60i, 30p - 0 fields (perfect), 24p (LAGS about 1/60th sec)

[ullanta]

** *The DVX100 audio meter, in contrast to most other meters, * * begins the "red zone" at -12dB. Thus, by avoiding any indications in the red zone, you'll have low audio levels. *
DVX100 AUDIO METERS: **
*-----------+------| *
*-----------+------| *
Everything up to the '+' is white; after that, red; *
'+' is -12dB, *'|' (or maybe the one before) is 0dB. * *
*
ALC prevents the signal from ever going more than 4 bars above the '+'. *
**
You should get undistorted sound at least that far; in fact, it should be fine as long as the '|' is never hit. Many people at DVXUser report good results when audio peaks reach the last '-' or two before the '|'.

[ullanta]

(see also http://www.dvxuser.com/cgi-bin/DVX2/YaBB.pl?board=audio;action=display;num=1085627709; start= )

The DVX has an audio limiter, which can be turned off using the menus. *A limiter shouldn't be confused with an AGC (auto gain control) circuit which raises or lowers the audio level to meet a certain value... a limiter only prevents the signal from going over a certain level. * * * * * * * * * * * * *

DVXUsers report that the limiter starts at about -6db (3 dots down from max) and puts up a ceiling at -4.5db. *Spikes may punch through, but overall loud noise gets clamped at -4.5. *It does not limit each channel independently, so strange things can occur with ALC when feeding radically different signals into the camera at the same time. * * * * * * * * * * *

[Slapdragon]

Anyone interested in this:

http://www.dvxuser.com/cgi-bin/DVX2/YaBB.pl?board=Events;action=display;num=1089245105 ;start=0#2

I need an audio editor and some authors.

[Bariona]

A. Connections & Settings
I would love it if somebody would post on that matter and explained precisely what each button does

[darmar]

looking for ideas in a wireless mic set-up.
I'm having a hard time figuring out where on
my DVX to moun the receiver

[Guest]

Go to the website www.thebecgroup.com this will soplve your problem.

[TGS]

Go to the website www.thebecgroup.com this will solve your problem.

[Jim Brennan]

I learned the hard way about the level meters. I kept the peaks out of the red and had very low audio. Luckily, I was able to boost the sound in post with minimal noise, but I won't make that mistake again.

[bvanberkum]

looking for ideas in a wireless mic set-up.
I'm having a hard time figuring out where on
my DVX to moun the receiver

[sojrn]

Can anyone recommend a consumer and or professional cd player that will sync playback with the DVX100A in 24p mode?

???

[Barry_Green]

Unless there's something about your question that I'm not understanding, you can use *any* CD player and get perfect sync with the DVX. CD's are a speed-governed digital system that play back at a fixed sample rate, and the DVX is a speed-governed recording system, so any CD player should sync perfectly with the DVX in any mode, 24P, 30P or 60i.

[sojrn]

Thank you Barry, your answer was on the mark. With the 24P drift problems I read about (1 field), I wasn't sure if the sync would hold for long for the music video I've been hired to shoot. But then I guess it could be slipped in post with a b-roll insert to hide the move. :)

[Barry_Green]

The thing is, there's no drift. There's a sync offset, but there's no drift.

On the DVX100, the audio gets recorded two frames ahead of the video. But it stays consistently at two frames... in fact, the DVX is one of only a couple of DV cameras in the world that uses locked audio, so it's going to be more consistent than any other miniDV camera.

On the DVX100A, the sync offset is fixed, and all audio gets recorded in perfect sync with the video in all modes.

[sojrn]

Barry, your reassurance is appreciated.

[wabbit]

Unless there's something about your question that I'm not understanding, you can use *any* CD player and get perfect sync with the DVX. *CD's are a speed-governed digital system that play back at a fixed sample rate, and the DVX is a speed-governed recording system, so any CD player should sync perfectly with the DVX in any mode, 24P, 30P or 60i.


Unless the recorders are jammed sync to each other (dvx100 does not do this) there will almost always be some drift. The crystals in each unit, although very accurate, will often start to drift by a frame or so after 10 to 20 minutes.

Since most takes and/or edits are never that long it is usually not a problem but something you should be aware of (provide an additional tail slate at end of long take to check the drift).