View Full Version : Recording sound in 5.1


Francois Dormoy
June 17th, 2009, 07:29 PM
May be this subject has been discussed before but I could not find the right thread, so I am raising it here.

I would like to make a video clip of a sport event such as an air show, but would like the sound to be in 5.1.

The camera itself is a Sony PMW-EX1 which has 2 built in microphone, so I preume I could not do it unless I have as an additional equipment a digital audio recorder with 4 channel such as the one shown in this link:

Zoom | H2 - Ultra-Portable Digital Audio Recorder | H2 | B&H (http://www.bhphotovideo.com/bnh/controller/home?O=workaround.jsp&A=details&Q=&sku=480163&is=REG)

Can someone guide me on how to build in my video a 5.1 sound?

(I have Final Cut Studio 2 witj Soundrack Pro, does that help?

Pete Cofrancesco
June 17th, 2009, 09:02 PM
I once looked into it. From what I remembered 5.1 is usually never recorded that way. Instead, different mono and stereo sources are mixed after the fact. Might be hard to achieve quality, plus a fair amount of work that only ppl with a 5.1 system hooked up to their tv will be able to appreciate.

http://www.dvinfo.net/conf/all-things-audio/137895-converting-stereo-5-1-a.html

Don Xaliman
June 17th, 2009, 09:35 PM
Here are some VST plug-ins for audio manipulation in the surround field. These are for performing post production mixing with your recorded sound.
AcousModules : Surround 5.0 7.1 (http://acousmodules.free.fr/acousmodules_s_en.htm)
Look at the bottom of the page for one that is designed to turn the H2 recordings into 5.1

You have to use a multi-channel audio recorder, mixer and many microphones to record surround on location.

Steve House
June 18th, 2009, 06:49 AM
5.1 is a delivery format rather than a recording format. AFAIK, when you do the recording in surround you usually record 4 channels. The 5th, centre, channel is synthesised in post as is the ".1" sub bass channel. There are a number of ways to go about it such as the Holophone mic system. Also take a look at the Wikipedia articles on the Soundfield Mic and Ambisonics and they'll lead you to some detailed discussion of techniques and vendors.

Rick Reineke
June 18th, 2009, 06:18 PM
The Holophone H2-PRO 5.1 Surround Sound Recording Microphone sounds incredible. So is the price. It does not encode any 5.1 file formats.

Don Xaliman
June 18th, 2009, 11:29 PM
The Holophone H2-PRO 5.1 Surround Sound Recording Microphone sounds incredible. So is the price. It does not encode any 5.1 file formats.

This would be great for my acoustic orchestra recordings but it would be too revealing in many live sound or video/film studio situations. It would expose all of the audio noise of the production crew and machinery. You could, fix in the mix, the rear channels.
Just as a video lens only gets aimed at the important vision, the directional microphone helps create an audio scape that is, in part, an illusion.
This mic would be a great for location ambiance and then use the recording as one part, to assemble an audio landscape in post that would complement the visual illusion.

Jim Andrada
June 18th, 2009, 11:49 PM
You can also record surround with a "double MS" setup, ie a figure eight and two cardioid mics aiming front and back. Schoeps makes a setup that holds the three capsules - but maybe I shoud say $choeps instead of Schoeps. Or maybe $$$choeps.

Don Xaliman
June 19th, 2009, 01:26 AM
You can also record surround with a "double MS" setup, ie a figure eight and two cardioid mics aiming front and back.

This recording could be enhanced in post to simulate your head aimed at a certain sound direction by EQ filtering certain frequencies that would be less sensitive to your ears. ie. turn down the high frequencies on the back mic... and low frequencies if mixing for 5.1.
This is probably part of the built-in directionality of the Holophone.

Francois Dormoy
June 23rd, 2009, 06:40 PM
OK. I got my H2 today and indeed I have 4 independent microphones giving 4 separate channel. Once the sound file is created, I presume I can import it in SoundTrack Pro and at this stage assemble it whislt the software simulate the fifth channel (central) and the sub-woofer by choosing the right freq levels from each channel to reallocate it to the 5.1 distribution.
Am I correct.

I look forward to testing it.

Anthony Ching
June 23rd, 2009, 07:43 PM
You can also record surround with a "double MS" setup, ie a figure eight and two cardioid mics aiming front and back. Schoeps makes a setup that holds the three capsules - but maybe I shoud say $choeps instead of Schoeps. Or maybe $$$choeps.

It did $$$, but it sounds excellent. I did use Schoeps DMS with CMIT5, and another special way: Cardioid + Figure-8 + Omni (CCM4, CCM8, CCM2) to made surround sound.
However, the stereo image still sound best with simple ORTF or AB. Coincident DMS is convenient with blimp for outdoor. Spaced arrangement still sound better for indoor concert.

Andrew Stone
June 23rd, 2009, 09:54 PM
You can do surround sound in Soundtrack Pro. Easy to set up in the app but you will need a 4.1 or 5.1 speaker setup with the appropriate audio interface to monitor your efforts.

In Soundtrack Pro, select your track and then in the pull down menu at the top of the screen go to Multitrack > Use Surround Panner. This will add the "panner" you need to move the sound around in the aural landscape.

Setting up Final Cut Pro for 5.1 sound is a bit tricky. Ken Stone's site has a good tutorial on it. Have a search on his site and you will find it.

Again you will need a Firewire/Audio Interface like a Motu 828 mkIII (as an example) and at least a quadraphonic monitor/speaker setup to be able to place the sound properly.