Single or Double System?

[Mike Dunning]

I'm curious as to which is becoming more "mainstream" when shooting digital video - single or double system. I come from a traditional film background, so shooting double system feels natural for me. But I've seen several small productions recording audio directly to camera through XLR inputs. I realize that the convenience is attractive to many, but are these newer generation cameras able to record audio of a quality better than that of previous camcorders?

Is anyone recording to a separate audio recorder these days? And if so, which one(s)?

[Marco Leavitt]

I don't know anybody who bothers with double system sound. It's a shame really. I did have a paying job last weekend that asked for backup audio, so we slated everything. It was nice actually.

[Chris Leong]

Agree with that.

Just DP'd on a production that was mainly film, so we had a decent sound guy on the crew. Recorded 4 track audio straight to HDD with timecode.

So then when we shot some HDV, we just continued on the same pattern, just switched cameras.

Not having shot film in awhile (mainly tape these days), I was struck by how much better everything sounded, and, because we were shooting tape with film discipline, how much better the tape looked.

That's how I'm going to do it for myself, whenever I can, in the future.

[Petri Kaipiainen]

What do you mean by "newer generation camcorders"? MiniDV camcorders record at 16bit depth and 48 kHz sample rate, which is slightly better than audio CDs have, which itself is as good or better than human hearing. I have not read anything about some newer cameras recording better than that, it would be an overkill anyway. New HDV cameras actually used MPEG compression also for audio and it can be argued that is a step for the worse what comes to audio quality.

Thus all miniDV camcorders in theory record with higher quality than DATs or Nagras of professional film crews. The problems are the microphones and built-in mic preamps, not the audio specs of the miniDV system itself.

With a good field mixer with line in to DV camcorder the quality is great, better than DAT or Nagra with the same mixer/mic combo. So why use double system (unless for backup or for more channels)?

[Marco Leavitt]

"With a good field mixer with line in to DV camcorder the quality is great, better than DAT or Nagra with the same mixer/mic combo."

I don't think this is true.

[Mike Dunning]

Thanks for the responses so far.

Petri - I suppose I should have mentioned my concern was more focused around the analog/digital converters that do the work, and not so much the bit depth and sample rate. Though now that you mention MPEG compression, that brings up more questions.

Marco - Please elaborate why you don't think Petri's statement about the field mixer is true. I think I know what you're thinking. While a field mixer would cerntainly improve the sound, by recording the audio to the DV camcorder, you're still using the camcorders AD converters. Is this flawed logic? Is there something I may be missing?

[Ervin Farkas]

... on what you're recording, and what is your final product, where will your final product play. While theoretically 16 bit and 48 KHz is higher quality than most of us can hear, in practice the quality of camcorder audio is nowhere near CD quality on most camcorders - at least this is my opinion. The higher you go in video quality, the higher the audio quality will go as well, but if you want quality, you need to go with a separate, dedicated audio system.

It also depends on how much post work you need to do on your audio. For general event videography (speech, electronic music) most prosumer camcorders will record good audio off of a field mixer, so anything better than that would be overkill. But if you're filming a symphonic orchestra, you better have serious gear. I can list here two concerts I filmed in the last half year where I would have looked very bad on the audio side if I would have relied on my Z1U even with a proper mixer - luckily the customer was already professionally recording the audio to a DAT machine (using eight $1500/piece mikes), my part was the video only... one of them was a bell choir, the other one a brass band. If you ever tried recording any of these types of music, you know what I'm talking about!

[Marco Leavitt]

Jay Rose did a comparison for DV Mag that's pretty infamous (if I get time later I'll look for the link) that pretty definitively established that all camcorders have pretty crappy front ends compared to even consumer audio recording devices. I believe even the $20,000 professional camcorder he tested didn't even measure up to the little Sony minidisc that he tested. I don't think you can even say that a mixer will improve your sound, unless the microphone has a very low output or something. I believe that when you use the line inputs on a lot of these camcorders you just go through either an attenuator or some other electronic trick is applied. You can't bypass the incamera gain completely. Whether there is enough improvement to justify doing double system sound depends a lot on how the footage will be viewed later.

[Mike Dunning]

Thanks for the information.

Marco, is this the article from Jay Rose you were referring to?

http://www.dv.com/features/features_...cleId=23902929

Also, thanks for mentioning Jay Rose's name. He's got a lot of useful information over there. Looks like I have my weekend homework. ;)

[Marco Leavitt]

That be it. If you don't already have his book on sound collection, you really should get it. Order it through his site and he gets more money from royalties. He seems to be a heck of a nice guy, by the way.

[Steve House]

Originally Posted by Petri Kaipiainen

What do you mean by "newer generation camcorders"? MiniDV camcorders record at 16bit depth and 48 kHz sample rate, which is slightly better than audio CDs have, which itself is as good or better than human hearing. I have not read anything about some newer cameras recording better than that, it would be an overkill anyway. New HDV cameras actually used MPEG compression also for audio and it can be argued that is a step for the worse what comes to audio quality.

Thus all miniDV camcorders in theory record with higher quality than DATs or Nagras of professional film crews. The problems are the microphones and built-in mic preamps, not the audio specs of the miniDV system itself.

With a good field mixer with line in to DV camcorder the quality is great, better than DAT or Nagra with the same mixer/mic combo. So why use double system (unless for backup or for more channels)?

16bit for the original is fine if you're not going to be doing much mixing and processing of the sound in post, but if you are, 24 bit from recording through post with the final output rendered to 16bit gives you a decided quality advantage and better preserves the dynamic range.

The pros are rapidly moving away from Nagra and DAT in favour of file-based recorders such as those from Sound Devices, Fostex, and Zaxcom.

[Petri Kaipiainen]

It is true that using 24 bits helps in post, or actually helps the recording. In controlled situations (studio) I record extra tracks or general audio from fixed mics to Fostex FR-2 at 16 bits to make post faster. If I anticipate broblems I use 24 bits.

We have to remember to separate the capabilities of in-camera audio recording and the way it is usually used. With built in mic to 16/48 with crappy preamps and A/D converters the result is bad. With better cams like DVX100 with line-in form good mics/mixers the result is great, I maintain better or equal to any DAT (and forget analog recorders).

The point of un-bypassable preamps in cheap cameras and so-so A/D converters is a good one, though.

Still the choice of mics, their placement, setting of levels etc. are often the limithing factor, not the in-camera electronics.

[Abe Dolinger]

The preamps on my budget DA-P1 sound so much better than the preamps in the DVX or the HVX. Noisy and cold is how I would characterize those two cameras . . I always push for double system if they have the time/budget. .

[Marco Leavitt]

The HVX is supposed to have pretty good preamps compared to other cams, but it's still a compromise. Whether DAT is better or not would depend on the quality of the DAT recorder I suppose. The Fostex won't do honest 24 bit recording by the way. You're just recording hiss at a higher bit depth.

From DV Mag review:

"The noise figure in the analog preamp makes recording any higher quality than 16 bit, 48 kHz moot."

http://www.dv.com/reviews/reviews_it...leId=160400659

[Petri Kaipiainen]

Have to run some tests with FR-2 fed with SD302, maybe line in would bypass the preamps. That's the combo I use now anyway.