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-   -   5.1 Portable Recorder? (https://www.dvinfo.net/forum/all-things-audio/485295-5-1-portable-recorder.html)

Andrew Clark September 25th, 2010 10:20 PM

5.1 Portable Recorder?
 
Just curious....does anybody know if there is a portable field recorder that records in 5.1?

Alex Donkle September 25th, 2010 11:08 PM

Well, nothing records in "5.1" since 5.1 is encoded audio that is made up of 6 discrete channels. So you're first off looking for a portable, 6 channel recorder.

Sound Devices 788T would work great for that.

However, why do you want to record anything in 5.1? (Most surround effects in movies are mono, or at most stereo sounds that are then moved around to create surround effects)
What mic's are you recording with? What are you recording?

Andrew Stone September 25th, 2010 11:14 PM

Almost all multi-channel mixing is done in post. In other words in ProTools or Logic, Cubase or the like DAW. Rarely will you see mic trees set up to do multi-dimensional sound capture but extremely rare as you have much more control in a multi-channel DAW setup for 5.1, 7.1 or whatever output you are going to.

Geoffrey Cox September 26th, 2010 02:28 AM

Soundfield do surround sound microphones which is where you would need to start really:

SoundField: Surround Sound Microphones For HD Broadcast & Film Location Recording

As you can see it is not as uncommon or unusual as the other posters suggest. For recording natural ambiances it is much better than trying to do it in post.

Geoff

Brian P. Reynolds September 26th, 2010 02:56 AM

Holophone produce a couple of smaller surround 5.1 mics that are encoded to 2 channel for recording, I have not seen this model (in real life) but have used one of the more upmarket Holophone mics with STUNNING results.

PortaMic pro

With one of these mics and a Zoom H4n recorder the results could be quite interesting

Steve House September 26th, 2010 06:47 AM

Quote:

Originally Posted by Geoffrey Cox (Post 1572985)
Soundfield do surround sound microphones which is where you would need to start really:

SoundField: Surround Sound Microphones For HD Broadcast & Film Location Recording

As you can see it is not as uncommon or unusual as the other posters suggest. For recording natural ambiances it is much better than trying to do it in post.

Geoff

To a certain extent, for ambience you have a point. But the front centre and the ".1" channels of the final 5.1 track would still usually be mixed and placed on their destinations in post rather than recorded directly there in the field, thus the field recorder for surround needs 4 channels, not 6. You record LF, RF, LR, RR in the field and then in post derive C (LF+RF) while sending low bass and bass FX to the sub (".1") channel.

Andrew Clark September 26th, 2010 06:10 PM

Quote:

Originally Posted by Alex Donkle (Post 1572965)
Well, nothing records in "5.1"...

** Sony's CX550 camcorder records in 5.1.

Quote:

Originally Posted by Alex Donkle (Post 1572965)
.....since 5.1 is encoded audio that is made up of 6 discrete channels. So you're first off looking for a portable, 6 channel recorder.

** I thought it was 4 or 5 channels...with the .1 being a post process?

Quote:

Originally Posted by Alex Donkle (Post 1572965)
....Sound Devices 788T would work great for that.

** Nice unit...thanks for the tip!!

Quote:

Originally Posted by Alex Donkle (Post 1572965)
....However, why do you want to record anything in 5.1? (Most surround effects in movies are mono, or at most stereo sounds that are then moved around to create surround effects)
What mic's are you recording with? What are you recording?

** Like I posted on my original question, I'm just curious if there is such a device that does this other than using a camcorder like the Sony CX550...not necessarily going to do 5.1 recording.

Andrew Clark September 26th, 2010 06:12 PM

Quote:

Originally Posted by Geoffrey Cox (Post 1572985)
Soundfield do surround sound microphones which is where you would need to start really:

SoundField: Surround Sound Microphones For HD Broadcast & Film Location Recording

As you can see it is not as uncommon or unusual as the other posters suggest. For recording natural ambiances it is much better than trying to do it in post.

Geoff

** Thanks Geoff; this is very interesting!!

Andrew Clark September 26th, 2010 06:17 PM

Quote:

Originally Posted by Brian P. Reynolds (Post 1572989)
Holophone produce a couple of smaller surround 5.1 mics that are encoded to 2 channel for recording, I have not seen this model (in real life) but have used one of the more upmarket Holophone mics with STUNNING results.

PortaMic pro

With one of these mics and a Zoom H4n recorder the results could be quite interesting

** Interesting as well; thanks Brian!!

Andrew Clark September 26th, 2010 06:24 PM

Quote:

Originally Posted by Steve House (Post 1573008)
.....thus the field recorder for surround needs 4 channels, not 6. You record LF, RF, LR, RR in the field and then in post derive C (LF+RF) while sending low bass and bass FX to the sub (".1") channel.

** That's what I thought as well.

Thanks Steve (and all other posters) ....as I'm no expert with audio by any means, just curious how people go about obtaining a 5.1 recording/mix....whether it be in the field or in post and what kind of portable devices are out there (besides using a camcorder with built in 5.1 recording capabilities) for recording 5.1 stuff.

Richard Crowley September 26th, 2010 07:24 PM

Quote:

** Sony's CX550 camcorder records in 5.1.
"5.1 recording" is a marketing gimmick on a plastic consumer gadget (as are most built-in microphones, for that matter.) And they do it with no visible microphones! Amazing! And it has "120x zoom" too. Another marketing gimmick.

99.9% of "5.1" and "7.1" mixes are artificially synthesized in post-production mixing. The whole concept of ".1" is a reference to the fact that ONE of the channels has a lower sampling rate when everything is compressed together (as Dolby, et.al.)

When location sound mixers can scarcely negotiate 30 seconds of silence to record " room tone", recording useful 5.1 ambiance out in the field seems like a fantasy.

Steve House September 27th, 2010 03:59 AM

Quote:

Originally Posted by Andrew Clark (Post 1573173)
** That's what I thought as well.

Thanks Steve (and all other posters) ....as I'm no expert with audio by any means, just curious how people go about obtaining a 5.1 recording/mix....whether it be in the field or in post and what kind of portable devices are out there (besides using a camcorder with built in 5.1 recording capabilities) for recording 5.1 stuff.

If you're looking for a portable device actually capable of recording all the tracks of a 5.1 mix in the field, any multitrack recorder with 6 or more channels would be able to do it - Sound Devices, Nagra, Deva, Foxtex, Tascam, Cantar and others make 'em. Add 6 microphones positioned appropriately and you're in business. Probably won't sound like what you want after the fact but putting together the hardware to meet the physical requirements isn't any problem - all it takes is money. You can't escape the fact, though, that a full 5.1 mix is a delivery format, not a master recording format.

For post, many audio workstations and NLEs handle a 5.1 mix easily. Vegas, Nuendo, Premiere, etc. You need a multichannel interface for your sound card and the proper monitor speaker setup. Mixing for theatrical release and broadcast requires a fairly sophisticated setup because of the licensing requirements in order to use Dolby or DTX'es encoding of the 6 output channels. The specs of the mixing stage required to qualify to use that little Dolby logo are pretty stringent.

Geoffrey Cox September 27th, 2010 02:46 PM

Quote:

Originally Posted by Steve House (Post 1573008)
To a certain extent, for ambience you have a point. But the front centre and the ".1" channels of the final 5.1 track would still usually be mixed and placed on their destinations in post rather than recorded directly there in the field, thus the field recorder for surround needs 4 channels, not 6. You record LF, RF, LR, RR in the field and then in post derive C (LF+RF) while sending low bass and bass FX to the sub (".1") channel.

Point taken Steve. Agree about the .1 though the centre channel can be used for many things, it just depends on the purpose so perhaps 5.0 would be more accurate. I've worked using both methods (post manipulations and recording in the field) and found both rewarding in their own way. 7.1 and 8.0 is the way to go anyway and that is done in post!

I'm not sure what you mean that .1 is a lower sampling rate Richard. Surely it means it is a discrete channel filtered at about 50Hz for Low Frequency Effects as opposed to 5.0 where the sub is a sum of all the low frequencies of the other channels and not controllable independently. Sampling rates do not change. These are certainly the set-ups that I and colleagues use.

Andrew Clark September 27th, 2010 03:27 PM

Quote:

Originally Posted by Steve House (Post 1573253)
....You can't escape the fact, though, that a full 5.1 mix is a delivery format, not a master recording format.

** That is what I had thought all along ... but was curious as to why a camcorder as I mentioned earlier here, would have such a thing. But even though it comes out as 5.1 when played back through a home theater system, it's still pretty much a marketing thing...but not a gimmick; as it does truly work.

Quote:

Originally Posted by Steve House (Post 1573253)
....For post, many audio workstations and NLEs handle a 5.1 mix easily. Vegas, Nuendo, Premiere, etc. You need a multichannel interface for your sound card and the proper monitor speaker setup. Mixing for theatrical release and broadcast requires a fairly sophisticated setup because of the licensing requirements in order to use Dolby or DTX'es encoding of the 6 output channels. The specs of the mixing stage required to qualify to use that little Dolby logo are pretty stringent.

** The good ole licensing stuff!! Yes, I have seen many posts from people who have such NLE's and get frustrated when they try and make a (set top compliant) DVD or BR with a 5.1 mix and it doesn't allow them to.....unless they purchase the above license's you mention.

Richard Crowley September 27th, 2010 03:42 PM

Quote:

Originally Posted by Geoffrey Cox (Post 1573421)
I'm not sure what you mean that .1 is a lower sampling rate Richard. Surely it means it is a discrete channel filtered at about 50Hz for Low Frequency Effects as opposed to 5.0 where the sub is a sum of all the low frequencies of the other channels and not controllable independently. Sampling rates do not change. These are certainly the set-ups that I and colleagues use.

Back in early days of multi-track digital sound and limited bandwidth for delivery methods, they actually had to budget a lower bandwidth to the LFE channel. Of course sample rate and high frequency response are directly correlated. But it is true that modern production and delivery systems treat the ".1" LFE channel as just an additional full-range channel. In fact in some cases it is used for other purposes (like "height") vs. low frequencies.


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