Audio for MiniDV film

[roxics]

Hello I'm shooting a MiniDV film with an XL1 in a couple of weeks. I'm curious to know the best route for recoding audio on location. I have a Audio Technica 835b short shotgun mic, a Behringer Eurorack Mx 602A mixer and a Phillips CDR 778.

I'm looking to get the best sound I can as I know audio is often one of the things overlooked by indie filmmakers of a no/low budget shoot.

The current idea is to bring the mic into the mixer via XLR from the mixer to the XL1 camera via a 20 foot RCA cable and perhaps to a backup recording device such as the phillips CDR deck.

But I have also lately been considering switching out the CDR deck for an analog recorder but I do't have the budget to rent a nagra. So I was curious. If I use a cheaper non sync 1/4 inch reel to reel how much variation in speed will I encouter if trying to later sync that sound to the DV footage? Also what would be an inexpensive 1/4 inch reel to reel I could purchase for the job?

On another note does anyone know a place I could rent a better shotgun mic for a pretty low price? Perhaps a Sennheiser 416.

thank you

[Eric Toline]

First thing I would suggest is that you get a Beachtek (www.beachtek.com) unit for your camera so you don't run a long unbalanced RCA line to the camera.

Check around in your area for filmsound/ video rental houses, they'll have everything you asked about.

As to using a RtR machine for back up, don't. It won't hold sync and will drift all over the place causing more problems in post then you want to deal with.

If you can rent/beg/borrow a portable field mixer like a Sound
Devices 442, 302 or even a Mix-Pre
you'll be way ahead over using the Beringer.

Watch your levels going into the camera (keep them at -12dbfs peak), turn off any auto level controls the camera has and you should be fine.

Good Luck with your project.


Eric

[jayrose]

I did measurements on the XL1, among other cameras, for my book "Producing Great Sound for Digital Video". Under the best of circumstances, XL1's native audio isn't wonderful - certainly nowhere near what you'd get from a CD recorder.

But a BeachTek, in this situation, isn't the right answer. It drops your mixer's output to -50 dBu (microphone level), forcing the camera to add amplification and increasing hiss and distortion. You'll get better sound on your camera by running a 20' XLR cable from mic to mixer, keeping the mixer near the camera, and running the unbalanced -10 dBV recorder output of the mixer into the camera's minijack line input. You'll get even better sound by dropping the mixer out to -35 dBV (instructions are on my website, in the DV Readers section), and using the RCA inputs on the back of the camera.

[roxics]

Thanks guys for your input.

jayrose (hmm I used to know Jay Rose I made films with back in high school)

Are you saying then that it would be a good idea to back up the audio from the XL1 with the CD recorder deck?

I most definitely will be running from the mixer to the cameras RCA inputs. Unfortunately teh mixer doesn't have XLR outputs so I've never considered using a Canon MA100 and running from the mixer to the camera via XLR. So I know this is the weakest link in the chain. But if I can record the audio on a CDR deck that is on a 1.5 foot RCA line from the mixer I figured I'd do that and use the XL1's recording as a backup.

[jayrose]

Couldn't be me. I was an electronics geek in high school, not a filmmaker.
...
Don't use an MA100 as a line input on an XL1. It can't handle the signal.

Otherwise your plan is valid. Mixer to CD recorder. If the mixer has dual isolated outputs, pad from mixer to camera. Otherwise, pad from CD line out to camera.

Don't forget to check everything, to slap a slate on everything, and to monitor both the camera and the CD.

[sonicsoundnz]

If you have ever done professional audio on an XL 1 you can encounter numerous problems. My solution would be to buy the add on accessory for the XL1 that is included in the XL 1 S. The XLR adaptor. Not having the menu set up properly will cause distorted levels. The XLR adaptor is a mic to line adaptor, something to be aware when using a seperate mixer (some mixers have line level out and is not switchable) . By throwing -50 dB pads inline, you can attenuate the signal to a safe level. I have seen XL1s loaded with extra crap on it, to feed it high quality audio. XL1s are pro-sumer cameras and is not meant to take professional audio. The XL1 S is a afterthought and has some known issues. On one project , I encountered a wierd audio anomalily. We were running professional audio to 2 XL1s and 1 camera had the video output split to two monitors for the director and someone else. The Audio/Video portion of the XL1 is on one circuit board. When you split the video output, the drop in current will cause interference in the audio. We were confirmed this by Panavision in Hollywood, CA and Canon knows of this problem. Don't split the video outputs and you won't encounter this. Run a balanced line to the camera if possible. I would suggest a BETA snake. It terminates into 2 XLRs and a Headphone return. When mixing you want to be concerned on what the camera is doing and if there are any problems. It also has a quick release for fast paced productions. They are around $200-$300 for a 25 ft section. I would suggest a MKH 416 if possible and if you are doing anything outside make sure you have wind protection- a softie, zepplin or windjammer.

Jason.

[sonicsoundnz]

Generally when you run stuff wild and out of sync you will notice it is out of sync after a very short period of time. The human mind will notice audio out of sync within 4-5 frames. Good dialogue editors 2-3 frames. Running a professionally syncronized system variates motor speeds and frame rates so everything will be in time ---audio and video. You can try to run the audio wild to a CD-R or a 1/4" deck by slating the head and tail of the take. When you use a program such as Pro Tools, you can take the audio peaks from the sticks and expand or compress the audio file to the video portion with good results.....

Jason.

[jayrose]

If you're running double system (separate audio recorder) with an XL1 or similar, and a CD or other digital recorder, you should be able to hold sync within a frame for at least 15 minutes. The actual time depends on the quality of the crystals in each device. I've had some people report accurate sync for half an hour.

If you're recording to 1/4" analog (or cassette, for that matter), sync will be random unless you're using pilottone or timecode during both record and playback. But if you are using one of those schemes, it won't be any better than a non-timecode CD or digital recorder unless you've got a high-end external crystal box.

Slates are always handy, not only for sync but also to identify takes. But an alternative sync method for DV and digital audio is to feed reference audio to the camera (wired, using a cheap wireless, or even the camera mic if it's close enough). Then you just have to match the double-system track to the camera track in an NLE.

[roxics]

Thanks guys for all your help. Seems my situation has changed a little bit though.

The CD-R deck we were going to use has crapped out on me. it will record fine but once it's done it won't notice the existence fo teh disc inthe tray. Thus it cannot be finalized or used period.

Our money is extremely tight.

Today I bought a 10 foot sheilded stereo pair of RCA cable for the mixer to the XL1. But I'm considering using a portable minidisc recorder for the prime souce recording. To be more specific a Sharp MD-MT15

http://www.minidisc.org/part_Sharp_MD-MT15+MT16+MT20.html

This is nice since it's battery powered so I don't need to power it in the field with anything other then batteries. It also has a manual level control and level indicators. It also has a mic input aside from it's line input. I've had this unit for about three years and it's field tested to work gret. All metal body shock proof ect. I've used my AT835b with it runny froma 3 foot cable (XLR-1/4 with 1/8 adapter) into the mic input and it seems to recrd nicely this way. But I'll be going into the line input this time from the mixer.

But I'm not an audiophile I don't really have the ear for it. So from a techical aspect how is this solution? It's really the other other solution I have right now. That or just going solo with the XL1 recording. Will this be better quality then the XL1 recording or am I wasting my time with an extra step?

[jayrose]

When I was doing the camera measurements, I also ran an old Sony MZR37 pocket minidisk through the same tests. Surprise: it surpassed almost all of the miniDV cameras in response, freedom from aliasing, and distortion/noise.

However, you can lose a lot of MD's quality by going from a portable's analog line out to a generic sound card. Cameras don't have this loss, since you can FireWire the tape right to your hard drive. (Don't get the USB-equipped Sony MD. It can download from computer to disk, but can't upload stuff you've recorded ove the USB. Copy protection...)

And some MD recorders are very unfriendly to manual level setting.

...

As far as that long RCA cable to the XL1. It should work... but pay very close attention to levels. The Audio 1 (RCA) inputs on the XL1 work best with -35 dBV. A mixer's out can distort in the camera's analog circuits, long before the volume control. You'll need to pad the mixer down, or else you'll find yourself running it extra-soft (with increased hiss).

Aw heck, why don't you just invest $31 in my book...