PD-150 Audio Problem

Ahoy, there, all you stalwart PD-150 users out there in video land. Be it known that your favorite camcorder has a potential audio glitch that can be fixed with a simple menu setting.

In the menu that's identifed by the little cassette icon, there's a MIC NR (noise reduction) setting. With this item switched on, you'll hear a low-level buzz in the background of your audio, which rises and falls with the volume of your content. With a single talking head in a quiet room, for example, you'll hear the buzz under spoken words, and for a fraction of a second afterward. Then the buzz goes away until the next word is spoken.

If you're not aware of this problem, either you've never switched that feature on, or you're not monitoring your audio critically enough i.e. through Sony MDR-7506 headphones at a fairly hot level.

So what's this weird feature for? And why ever use it? Theoretically it's supposed to suppress or cancel out camera noise (tape drive motor and head buzz) picked up by the on-camera microphone but instead, it seems to generate more of what it's designed to eliminate! In other words, this "feature" is
actually a bug.

So just keep MIC NR switched off, and you'll never encounter this problem.

Dan "learned this one the hard way" Drasin
Producer/DP
Marin County, CA

An old problem with the PD150. The supposed fix was basically a noise gate, as you sadly discovered the hard way. Interestingly there have already been reports of audio issues on the PD170.

Mitch Gross
NYC DP

Dan Drasin reveals :

>With this item switched on, you'll hear a low-level buzz in the >background of your audio...

Thanks oh so much! That has plagued me for years now. On my camera it's more like a "spring", buzzy kind of sound. That's gotta be it!

I'll be shutting that bad boy off first light tomorrow.

A double thanks!

Allen S. Facemire
DP/Director
SaltRun Productions,inc.
Atlanta

Mitch Gross writes:

>The supposed fix was basically a noise gate, as you sadly discovered >the hard way.

Right. Sony obliged us by providing some extra noise along with their noise gate.

If this were a piece of professional audio gear, mobs of audio engineers would show up in the dead of night and burn the manufacturing plant to the ground.

>Interestingly there have already been reports of audio issues on the >PD170.

What kinds of issues?

Allen Facemire writes:

>On my camera it's more like a "spring", buzzy kind of sound.

That's exactly what it sounds like.

>A double thanks!

Hey, it's all in a day's work. But don't thank me yet. Shut that sucker off and let us know if that did the trick. For all we know there are other audio bugs in there we don't know about.

Dan Drasin
Producer/DP
Marin County, CA

>Interestingly there have already been reports of audio issues on the >PD170.

>What kinds of issues?

Couldn't tell you as I don't generally deal with these cameras. But I have glanced over some discussions of it on some newsgroups and forums.

Mitch Gross
NYC DP

Jim Feeley wrote :

>The bad news : MiniDV cameras don't record great sound. The good >news:
>You can still get usable tracks with them.

"usable"

Wow....

I hope that we all aspire to produce fruit of our labors that is
something more than "usable."

Taking the liberty to speak for audio professionals everywhere, I am compelled to trumpet:

NEWS FLASH!!!

BAD NEWS : bikes with flat tires are hard to pedal
GOOD NEWS : you can still get from here to there if you don't mind sweating a lot

BAD NEWS : really cheap beer doesn't taste very good
GOOD NEWS : after a couple of six-packs, you don't care

GOOD NEWS : with modern computer technology, a monkey can edit a feature film
BAD NEWS : you end up with a film that looks like it was edited by a monkey

John McDaniel
Audio Post Facility Owner
Sonic Arts Digital Audio Services, Inc.
Cincinnati, OH USA

> reports of audio issues on the PD170.
> What kinds of issues?

When the flip-out LCD is opened, a high-pitched whine is picked up in the audio. Sony reportedly halted production to incorporate a fix. Don't know if there's a fix for cams already owned by early-adopters, though.

Jan van der Meer of www.global-dvc.org spearheaded the investigation on that one.

Adam Wilt
Video Geek
Menlo Park
CA USA

FWIW : A fellow from New York has apparently replicated the "BBC modification" to the PD-150, which allows you to bypass some of the offending circuitry in the PD-150 audio chain, and input directly from an external mic preamp (e.g., Mix-Pre or Shure FP24) to the A/D converter.

http://www.gregjwinter.com/modification.htm

He reports these results :

http://www.gregjwinter.com/compare.htm

I haven't had this work done, and don't know Greg Winter, so I cannot attest to the quality of his work. If I do have him modify my PD-150, I'll report the results.

Justus J. Schlichting
S&S Datalink, Inc.

John McDaniel writes :

> "usable" Wow....
>I hope that we all aspire to produce fruit of our labors that is something >more than "usable."

I agree absolutely... and wish prosumer camcorder mfgrs would spend the extra dime or two to incorporate circuitry that would max out the audio quality of their products. Theoretically there's no reason why mini-DV can't lay down DAT-spec tracks.

But with that said: For newsgathering and many documentary applications, if you know what you're doing you can indeed produce sound with a PD-150 that is, to most listeners under most circumstances, not obviously deficient or annoying.

It's easy for us audiophiles and videophiles to criticize "sub-standard" media technology, but I think we should remember that we all quite happily use products every day that some specialist somewhere considers "mere consumer crap."

In some contexts our finely-tuned senses and professional pride are not always appropriate or constructive.

OK. Now I'll get off my soapbox. .. Uh-oh... Oops...! ARRRGHHH!!
<SPLAT!!!!>

Dan "dusting myself off" Drasin
Producer/DP
Marin County, CA

I'm glad I discovered that "Sci Fi Buzz" the "Noise Reduction" created and turned it to off. What I nightmare. The PD 150 has turned this cameraman into a bit of a soundman.

In fact I'm writing a new book called lighting for sound. I hope you like it.

Bob Hayes

Justus Schlichting writes :

>FWIW: A fellow from New York has apparently replicated the "BBC >modification" to the PD-150, which allows you to bypass some of the >offending circuitry in the PD-150 audio chain

I checked this out and it looks legit. He provides the mod for both VX2000s and PD150s. The only limitation of this mod is that the RCA audio jacks on the right side of the camera become audio-recording inputs ONLY, and function only in camera mode -- not in VTR mode. This limits the overall functionality of the camcorder.

Also, you must feed this unit preamplified audio at professional levels (+4dBm). Most professional mixers and mic preamps put out that level, but consumer gear generally delivers audio 14 dB below that level.

For now I think I'll stick with the unmodified cameras, using mics that have some high-frequency emphasis and watching my levels carefully.

Dan Drasin
Producer/DP
Marin County, CA

By the way...the PD-150/ VX2000 audio modification can be found at :

http://www.gregjwinter.com/modification.htm

Dan Drasin
Producer/DP
Marin County, CA