I made the test using a Genelec studio monitor placed in front of the
camera, equipped with the external microphone TA1, playing pnk noise
filtered in the 1kHz octave band.
then I rotated manually the camera, so that the spurce goes also on left,
back, right and back to front (you see the rotations in the the video). And
finally I lower the camera, so that the source becomes Front-Up at 30
I uploaded on my web server both the original .MOV coming out of your Movie
Converter app, and the version where I edited the channel order and reduced
by 3 dB the gain of channel W.
Here you see a photo of the setup:
Here you see the sound track (imported in Adobe Audition CC). Please look
at the initial part of the recording, when the sound source was in front,
along axis x; it is expected that the amplitude of W is almost equal to X,
and the other two channels should be much weaker.
This is the original .MOV coming out:
As you see, initially the loudest channel is the second one, which becomes
weak when the source is Left or Right. Hence chennel 2 is X. Channel 3 is
the opposite, hence it is Y. And channel 4 is weak for most of the
recording, except at the end, with the source Front-Up, when it becomes
louder, almost equating X. Hence channel 4 is Z. So the order is WXYZ,
which is wrong!
Furthermore, the amplitude of W is always too large.
Here the soundtrack after channel reordering and reducing the gain of W by
Now the channel order is the correct one (WYZX), and the amplitude of W is
matched with X. Indeed, the amplitudes of Y and Z are still a bit too low
for me (when the source is far Left of far Right, the amplitude of Y should
I will do better measurements the next week, exploring several frequency
bands, and not just the 1 kHz octave band as in this test.
You should look and listen to the recordings using a smartphone equipped
with a good “cardboard” VR visor, we are using a Samsung S7 with a BoboVR
Z4 visor, and the Jump Inspector program.
Or you can upload the recordings to Youtube, if you prefer (I applied
proper metadata injection also to the fixed video).
Finally, you can visualize graphically the direction-of-arrival of sound
using the free plugin called “O3A Flare”, being part of the O3A Core suite
by Richard Furse (Blue RIpple Sound):
Here what is shown when the initial part of the original .MOV file coming
out from Movie Converter is analysed:
As you see, the sound does not appear to come from the loudspeaker, it
appears on far left instead!
And here instead what happens analysing the fixed version of the video file:
Now the sound is perfectly centered with the real position of the sound
I hope you can fix easily the Movie Converter app. It should be easy…
Indeed, I would also be able to extract my self the original 4-channels
soundtrack from the MP4 file recorded by the camera.
In reality I was expecting that the MP4 file did already contain the
4-channels soundtrack, instead when opening it with Audition I see only a
mono track (which is substantially identical to W):
Having to reprocess the MP4 for converting to MOV using the Movie Converter
app is not practical.
I wpould have access directly to the 4 channels on the MP4 file, instead of
having to use a converter app.
One buys the Ricoh Theta V mainly for its 4-channels microphone system, if
it was just for the 4k Video there are better alternatives at smaller
price. So one expects to have immediately access to the 4 channels
So I hope that in a subsequent camera firmware update you can jut save
directly an MP4 or MOV file with a single soundtrack containing plain
4-channels Ambix signals.
Of course, also a much larger camera memory would be appreciated, as 19
Gbytes are really poor. I attempted to record Verdi’s Messa da Requiem past
week (the same day I received my Ricoh Theta V), but the recording stopped
approximately after 40 minutes due to filling the camera internal memory,
so I did loose half of the concert! At least 64 Gbytes of memory would make
this camera much better value for the money, although I would go directly
to 128 Gbytes if there was the possibility to replace the internal SD-card,
as in our previous Ricoh Theta-S unit…
prof. Angelo Farina
University of Parma, ITALY