What mics do I need?

[Steve House]

Originally Posted by Michael Hamilton

Steve,

I've been listening in on this conversation and have learned alot from your comments. Thanks.
Is there a diagram of a Double MS arrangement that you can point me toward? A complete arrangement from mic to recording device is what I am serching for.
I do alot of outdoor documentary work and would like to be able to find the simplest way of doing 5.1.
I use an XL2. Can I go directly to that? Or should I use a separate audio recorder? If so which one would you recommend?

Michael Hamilton

Hi Michael: Take a look at the newletter #6 on the Schoeps website that give a good overview of surround techniques ... http://schoeps.de/PDFs/Newsletter-No6-E.pdf

As to recording - the Double M/S requires at least 3 channels - the front mid mic, the side mic, and the rear mid mic. That means, of course, simultaneously recording at least 3 tracks if you're going to decode them in post. While you can do it by using 32kHz 12 bit audio in the XL2, using that low resolution means a much lower recording quality and I doubt it could be recommended. A better bet would be a mutli-track recorder that would be suitable for double-system sound. One example would be a Sound Devices 744t which would give you an outstanding recorder with top quality audio, that can sync to the video clock, produces bwf files, and incorporates timecode.

[Michael Hamilton]

Thanks Steve,

I looked at the site and think that the simple IRT cross using four cardiods for ambient sound might be the best way for me to go. Now I have to find a relativley inexpensive 4 channel field recorder to go into.
Unfortunatley the 744T is way to costly for me.

Michael Hamilton

[Seth Bloombaum]

Take a look at the Edirol R-4. Good (not best) performance, 4 mic preamps with phantom hard drive recorder. I think street price is about $1600.

Boy there's been a lot of talk in this thread about the (obvious? assumed? proven?) desirability of quad or 5.1 recording in the field.

Anybody actually heard playback on these recordings? Is there demonstrated benefit? Is this what all the hot hollywood sound recordists are doing?

Just askin'.

(I'm not questioning 5.1-7.1 mixing and playback, just acquisition. What I hear in theaters is efx, not room tone, in rear and side channels. But maybe I'm not going to the right movies.)

[Ty Ford]

Originally Posted by Dale Paterson

Mostly my footage is of Seminars and Corporate Events i.e. Speeches, Interviews, and the occasional Banquet afterward (where there is live music and some on-the-fly interviews etc. etc.).

I would also like to try and cover some of these events in 5.1 Surround using 5 mics to get 5 distinct audio tracks (following the layouts that I got from the Schoeps website due to responses from an earlier posting of mine).

I will in the future be shooting some live band and concert footage (staged) and would also like to try my hand at recording these events in 5.1 Surround with 5 mics.

What Sony mics could I / should I use to cover all of the above possible scenarios???

I had a look on the web and found a Sony F-740/9X mic that appears to be sort a sort of 'general purpose' unidirectional cardiod mic. Anybody have any experience with this range?

Regards,

Dale.

Dale,

There was a company at the AES NY show last fall showing surround capture and repro with a magic box and a handfull of Schoeps. Try reaching out to redding audio in CT to see if they can hook you up with the company.

Regards,

Ty Ford

[Dale Paterson]

Hello again all.

Sorry - I have been a bad boy for not following up on this thread that I started!

I have given up on the Sony mics (finally) - I had an event come up and I needed mics urgently so I contacted Sennheiser and eventually settled on 4 x e935's and 2 x e945's (Evolution Series). I used these mics at the last event (along with Sony UWP-C3's, Alesis FireWire Mixer, and Crest Audio PA's) and got what I feel to be fantastic results.


Steve - I did have a very strange issue that I managed to solve in post (the synchronizaton of the audio and video from different sources) and I just noticed that you mention the Sound Devices 744t... 'that can sync to the video clock'. Does this mean that, for example, a Sony VX2100E or Sony FX1E has a 'video clock' (or any other camcorder for that matter)? That might sound like a really strange or stupid question but does this mean that if I were to daisy chain the FX1E, the VX2100E, and the Alesis Mixer (all FireWire devices) that I could choose which 'Master Clock' to use (the Alesis software does have a selection for this but the mixer is the only option that is available to choose although I have never plugged in the cameras at the same time - read too much about blowing FireWire ports)?

Regards,

Dale.

[Steve House]

Originally Posted by Michael Hamilton

Thanks Steve,

I looked at the site and think that the simple IRT cross using four cardiods for ambient sound might be the best way for me to go. Now I have to find a relativley inexpensive 4 channel field recorder to go into.
Unfortunatley the 744T is way to costly for me.

Michael Hamilton

I'm with Seth in his comments that surround is best achieved in post. I was addressing the issue of "how" and not whether it's a wise idea. I can only imagine a few situations where actually shooting in surround would be worthwhile.

The advantage of using an MS technique for 5.1 front is that the "mid" mic by itself is your front-centre channel. Whether you're shooting conventional stereo or surround, remember too that a large percentage of your audience will be viewing you program with mono sound (or it might as well be mono because of the crappy TVs they have - 2 4-inch speakers separated by 10-12 inches) so unless you're shooting for theatrical release you need to keep that in mind. Non-coincident mic placements, such as the IRT Cross, can give all sorts of phasing problems when downmixed to mono.

[Steve House]

Originally Posted by Dale Paterson

...

Steve - I did have a very strange issue that I managed to solve in post (the synchronizaton of the audio and video from different sources) and I just noticed that you mention the Sound Devices 744t... 'that can sync to the video clock'. Does this mean that, for example, a Sony VX2100E or Sony FX1E has a 'video clock' (or any other camcorder for that matter)? That might sound like a really strange or stupid question but does this mean that if I were to daisy chain the FX1E, the VX2100E, and the Alesis Mixer (all FireWire devices) that I could choose which 'Master Clock' to use (the Alesis software does have a selection for this but the mixer is the only option that is available to choose although I have never plugged in the cameras at the same time - read too much about blowing FireWire ports)?

Regards,

Dale.

"Sync" and "clock" are terms that are used in a lot of different contexts. Digital audio and video are based on sampling the analog waveform as specifc intervals, as you know. The clock is the controller for that process so all digital devices have a clock. In audio, if you are mixing data from different sources, let's say doing an overdub where you're playing back a recorded guitar track, mixing it with a live vocal and recording the result to another track, mixing in the digital domain, the samples from the digital converter for the new vocal must occur at exactly the same rate and and at the same point in time as the samples laid down in the original instrumental track. If they don't coincide exactly, the resulting mix will have clicks and pops and other grunge. The same thing can happen when you have more than one midi instrument also. So many professional audio interfaces, recorders, digital mixers, etc have what is called "Word Clock" or "Midi Clock" inputs and outputs. One device in the system is chosen to be the Master clock, feeding a clock signal to the Work Clock input of the other devices. Sometimes there's a physical input, some devices can extract the clock from the incoming data stream. But unless you're mixing digital streams in real time, it's not an issue - if you import a number of different audio files into an audio editing program to mix down, the software lines up the samples in the process.

I misspoke when I said the SD recorders could sync to incoming video. Checking the manuials, their TC clocks will sync to incoming timecode and their sample clocks can sync to incoming Word Clock or extract clock from incoming digital audio on the AES or SP/DIF inputs and sync to it. BUT AFAIK, you can't plug a video signal into any of their inputs and have 'em sync up. There are products such as the MOTU Digital Timepiece that can extract word clock from various sources, including video and timecode, and you could do it that way if you needed to [camera video out] --> [Timepiece] --> [SD Recorder WordClock In]. But for maintaining sync between picture and sound it's not necessary.

Definitely "daisy chaining" the firewire ports of the camera and mixer won't won't provide clock sync.

What was the "strange issue" you encountered?

S

[Dale Paterson]

Steve - thanks for the great explanation - much appreciated.

The 'strange issue' to which I refer is detailed in the following thread:

http://www.dvinfo.net/conf/showthread.php?t=64559

In other words - given the exact same sample rate/bit depth - one hour of video/audio captured from the camera via firewire should have been exactly equal to one hour of audio captured via firewire from the mixer. This was not the case and although there are explanations in the thread detailed above I find that I am still searching for answers.

Regards,

Dale.

[Michael Hamilton]

Seth,
Thanks, I found that recorder. I might get it.

Michael Hamilton

[Michael Hamilton]

Steve,

I just would like my audience to have a more complete feeling of being in the environment that is shown on the screen.

Also, has anybody tried surround using two ms mics facing 180 degreees in opposite directions front to back?

Michael Hamilton

[Steve House]

Originally Posted by Michael Hamilton

Steve,

I just would like my audience to have a more complete feeling of being in the environment that is shown on the screen.

Also, has anybody tried surround using two ms mics facing 180 degreees in opposite directions front to back?

Michael Hamilton

Nothing at all wrong with that - just you might be a ble to create a better illusion by mixing it up in post rather than recording it in surround in the field.