Spatial audio. I was an early believer (my first VR experience, courtesy of Sarah Hill, featured spatial audio), but a relatively slow adopter. Despite how immersive (and important) it is, spatial audio quite frankly scared me.
But, when Sarah asked me to capture spatial audio using her Ambeo mic and Zoom F4 Multitrack Field Recorder for a shoot at the Women’s Memorial in D.C., I knew it was time to weather the storm.
With that challenge (and the technical know-how of John Hendicott from Aurelia Soundworks) in mind, not only was I able to conquer this cloud hanging over my head, but I was also able to capture the thunder spatially!
Am I still a total newbie? Yes. Does that mean you’ll read this guide and totally understand it? Probably so.
Here’s my (And John’s. And Sarah’s.) spatial audio workflow using the Ambeo and Zoom F4.
What you’ll need:
- Sennheiser Ambeo VR mic
- F4 Multitrack Field Recorder
- Four-channel 5-foot XLR cable and/or four-channel 1-foot XLR cable that comes w/ the Ambeo
- Mic suspension that comes w/ the Ambeo
- Clamp with screw (John’s pick: the Manfrotto 2909 Super Clamp)
- Eight AA batteries and/or DC power power supply device
- 2 SD cards
- Headphones with ¼-inch jack, or (more commonly) headphones w/ 3.5 mm jack and a ¼-inch to 3.5 mm adapter
- Wind sock (John’s pick: the Rycote Windjammer)–for all outdoor uses
- Windshield (John’s pick: the Rycote Baby Ball Gag Windshield)–for all outdoor uses
Setting up the Ambeo
Step 1: Attach the clamp to the tripod, adjusting the size with the crank. Ideally, it should be as close to the camera, vertically, as possible. If it’s super far away, the audio won’t be as immersive because, well, your eyes (camera) and ears (mic) are, on the average human, at the same level.
Screw in the mic holder, oriented to point the mic directly upwards.
We played (and played) with the heights of the Ambeo, both with the Z Cam and with a Freedom 360 GoPro rig.
By far, the GoPro rig worked better. When the top of the Ambeo was 6 inches below the bottom of the rig without a windshield and placed at the stitch, it was invisible to the cameras. When we put the windshield on…well…we think it’s still doable.
With the Z Cam, we tried quite a lot of distances, from 6 inches to 12 inches, with and without the windshield, but it was in every instance impossible to hide.
Step 2: Connect the XLR cable to the bottom of the Ambeo, and plug the four-channel outputs into the input side (left side) of the F4 Multitrack Field Recorder, in order.
Where you put the field recorder will depend on the accessories you have. If you have a 5-foot XLR cable and don’t mind carrying the recorder and tripod separately, you can just place the bag at the foot of the tripod–just be sure to tuck in any straps to make post-prod cleanup easier and avoid a trip hazard.
If you have another clamp, you can use the camera mount that comes with the F4 and mount it vertically onto the tripod. That means you could also use the short XLR cable that comes with the Ambeo.
Step 3: Clip the mic into the holder. The mic should be oriented directly up in nearly all cases.
The Ambeo has a logo on it that says Up/Front. This should be aligned with a recognizable object in the frame, like a pole or tree trunk. The narrower and more specific, the better. More on this in the “Recording with the Ambeo” section…
Setting up the F4 Multitrack Field Recorder for spatial audio
If this is the first time you’re setting up the recorder, I recommend plugging in the DC power to save batteries as you set it up.
Before messing with any settings, be sure to install the latest firmware update.
- To do this, remove the SD card from Slot 1 (must be Slot 1) located on the bottom on the F4 inside the battery compartment, and connect to your computer.
- Visit www.zoom.co.jp and download the latest firmware update for the F4.
- Unzip the file and drag in the .bin file from that folder onto the root directory of the SD card (the root directory is the top-most file organization structure).
- Remove the card from the computer and insertClose-up shot of an object or detail previously seen in a wider angle. into SD card Slot 1 on the F4.
- While pressing the Play/Pause button, turn on the F4.
- When prompted with the “Update System, Are You Sure” question, select yes. Do not turn the F4 off or remove the SD card while it updates! This could make the F4 un-usable.
- After the update is complete, turn the power off before doing anything else.
Now, you can change the settings to make sure you record your audio properly.
Step 1: Go to Menu, then Rec/Play.
Make sure both SD cards say Tr1-6 (Poly Wav).
Sample rate should be 48kHz.
WAV bit depth should be 24.
Step 2: Go to Menu, then Input.
Click Phantom, and turn on phantom power for inputs 1-4 so the Ambeo can draw power.
Click on HPF and set inputs 1-4 to 80Hz. This is to prevent any low frequency sound coming into the mic and overloading the recorder. This is a common problem with wind rumble when recording outside, even with a wind shield.
Click on Trim Link, and make sure boxes A, B, C and D under Group A are selected. This gangs all the mics so you can’t adjust the gain on only one channel and make the audio un-usable. Now, if you adjust the gain on Channel 1, all channels are automatically adjusted.
Click on PFL and make sure all inputs say PFL.
Step 3: Go to Menu, then TimecodeA numerical code that identifies videos by the hour, minute, second, and frame in the format HH:MM:SS:FF (eg. 23:59:59:2... More, then FPS.
The frames per second should match the camera for accurate timecodeA numerical code that identifies videos by the hour, minute, second, and frame in the format HH:MM:SS:FF (eg. 23:59:59:2... More syncing. Ask the videographer what the camera is set at!
Step 4: Click the PFL button that is right next to the Channel 1 dial. Click Fader and set to -12dB. We do this because the four channels, when combined to just LR, are way too loud.
Step 5: Then, of course, make sure your headphones are plugged into the right side of the F4, in the top left corner, so you can monitor some audio tests before running to your hidey holeSlang for the spot you hide in while you are recording 360 video..
Recording with the Ambeo and the F4
Recording is pretty self-explanatory. Click the button with the red circle to record 😉
As you record, you’ll see the levelsThe adjustable sensitivity settings of microphones. Levels are set (and changed as necessary) to best capture the vocals... More of all four tracks on the LCD screen. To get audio between -6dB and -12dB, the levelsThe adjustable sensitivity settings of microphones. Levels are set (and changed as necessary) to best capture the vocals... More should fall somewhere between the second and third vertical bar from the left.
If it peaksShort bursts of loud sound in an audio track. These are visible in an audio waveform as lines that stick up higher than ... More above the third bar, use the dial on Channel 1 to adjust the gain appropriately.
You can download the Zoom app to monitor gain from your phone at a distance. You won’t be able to adjust it using the app, or even listen to the audio you’re capturing, but at least you’ll have a visual reference point of the audio you’re capturing.
When you’re done with your tests and ready to record the real goods, get your gain set, click Record and then announce the orientation of the mic. For example Scene 1, TakeIndividual instance of a shot; a take = each time the camera is started and stopped. 1, Ambeo is upright, facing the Lincoln Memorial Statue.”
The more specific you can be with that last bit of info the better. For example, if you say “facing the door frame,” say which side of the door frame. This will help John, yourself, or whoever is going to actually be using this audio know how to place it in the scene.
If you’re also recording with lav mics, since the F4 only has four input tracks, we will use the lavs with the Tascam and hide it behind the subject. BUT, you need to make the above announcement and then clap a couple of times while recording to the Tascam, the F4 AND the camera, to sync everything later.
I’m not even going to begin to contemplate editing spatial audio–we’re leaving that to John–but at least we’ll be able to give him clean audio to work with. Step one down! Spatial audio FTW.