(Last updated 09/22/2020)
Bruce Bartlett wrote a comprehensive review for
"The TetraMic is a huge advance in recording technology, and a great
value. Highly recommended."
For a comprehensive review written by Paul Hodges, please see
"... over the main part of the frequency range all the component
outputs are extremely flat; their on-axis curves are flatter than those
of my AKG C414s..."
"Not a lot more to say, really - it just works, and works well; and what
more can one want? I am very pleased indeed."
Richard Lee, one of the designers of the original Calrec Soundfield
As the last living Soundfield designer, may I say that, of the half
dozen or so Soundfields I've seen [measurements of] this century, only
[one] early Mk4 is IMHO properly aligned and EQ'd.
If anyone is conducting listening tests on 1st order Ambisonics, may
I suggest they beg, borrow or steal a TetraMic for their recordings.
While it is not perfect, TetraMic does many things which I would have
given my eye teeth for the Soundfield to do, more than 25+ yrs ago. It
is the true examplar for Peter Craven & Michael Gerzon's invention.
From his files in the Micbuilder Yahoo Group files section:
...more extended [bass] than a Soundfield Mk4... Flatter responses
and more consistent polar patterns...
Fons Adriaenson, one of the world's audio DSP gurus, analyzed TetraMic's performance and wrote:
...Actually, almost no classical (non-tetrahedral) directional mic would
have a LF response and LF polar diagrams as good as this one.
...the results are really excellent, and much better than what could
be achieved with analog A-B processors [as used by SoundField]. Note the
perfect matching of the responses for the two directions, for both the
omnidirectional and the first-order components, and also between
them. This is confirmed by looking at the other directions.
Near-perfect omnis may exist (most still have a 'preferred'
direction), but no real figure-of-eight mic will have such accurate
polar patterns [as TetraMic] over almost the entire frequency range.
This means that after calibration this microphone is not only an
excellent Ambisonic mic, but that it will also be a very good one for
Five years later he wrote:
Recently I've been using my TetraMic as an intensity probe
in an industrial noise control project - works perfectly!
JJ Wiesler, at Pollen Music Group, wrote:
We love our Tetra. Len has been lovingly building these for many
years. We used it on Pearl to record singer Kelley Stoltz performing No
Wrong Way Home from the viewers perspective in the passenger seat of a
car. We also captured IRs using the Core Sound microphone. Thanks
(JJ Wiesler is one of the principals of Pollen Music Group. They were
key participants in Google's short animation "Pearl", the first VR
project ever to receive an Oscar nomination.)
Adam Somers, at Jaunt VR, wrote:
At Jaunt we use Core Sound TetraMics. They are inexpensive and made
with obsessive attention to detail, sourcing excellent components and
undergoing rigorous capsule matching & calibration. Paired with a Tascam
DR-680 the whole setup costs around $2k.
J.A., from CCRMA at Stanford University, wrote:
The TetraMic you sold us a while back has been working well; we're
making solid spatial impulse response measurements of some interesting
I wanted to ask about the availability of another TetraMic and PPAc
and associated cabling and connectors, etc. We have a recording session
coming up in a couple weeks that could really make use of another
D.P., a researcher at Marshall Day Acoustics, wrote:
We are using Harpex to decode, and it sounds superb. I've run a bunch
of tests with finger snap sounds at different directions and it all
seems spot on.
I don't have any of my own TetraMic recordings (just heaps of impulse
responses), so I also listened to some recordings... from Ambisonia and
man they sound good. Localisation is fantastic.
(They've bought tens of TetraMics for their IRIS acoustic measurement systems.)
D.F., a sound designer for a video game company, wrote:
So I've been using the TetraMic pretty solidly for about a month and
I wanted to give you my impressions. I'm a sound designer at a video
game company, so my use of it so far is limited to sound effects
recording and soundscape recording. I'm using it with a Sound Devices
First off, the thing is clean and flat. In the field I feel like I get
great frequency response across the board, the low end is especially
nice, there's plenty to work with, but not so much that I have to worry
about my takes getting rumbly or blown out. The highs are crisp and
natural without being harsh at all.
I love how small it is. I love that even though it's small it feels
The decoding process is fun and excellent. I love being able to record
an entire surround field and then accent it by adding in cardioids.
Being able to define a stereo pair with arbitrary azimuth offsets is
very cool as well.
The isolation when decoding to cardioid mono is quite good.
You guys have made a really cool mic that is a blast to use and gets
great results. It's got a permanent place in my field rig.
S.L., a studio owner in Ireland, wrote:
My first recording of my piano and even if I will not record with
this mic anything else except my piano - I am DELIGHTED with this
microphone! This recording is without doing any extra treatment to the
room or putting effects or anything else and it sounds better than any
other piano recording that I ever did before - by FAR. I think that
perhaps treating the room a bit more and removing the piano's lid will
even improve the results.
I've been using the TetraMic for two years now, both for
environmental recordings and for live music performances. The sound
quality of this mic is excellent, it's one of the best mics I've ever
used, and my whole kit (including 25-foot Ethercon cable, accessories
and DR-680 recorder) fits in an attache case.
Later he wrote:
I've been using TetraMic for a couple of years. It's wonderful --
small and unobtrusive, lightweight, sound excellent, extended low-frequency response.
I am currently finishing a VR documentary about the Entartete Musik
composers detained in the Terzin concentration camp and a quartet of
Pittsburgh symphony musicians that perform their music to make it heard.
I used the Tetramic to record a 360 performance of the Clarion Quartet
as well as to record a good deal of the ambiences used in the documentary.
We are editing now. I will send a link once finished.
Thanks for a great mic!
S.L., at a VR production house, wrote:
I've been using the tetra mic on several vr projects since purchasing
it in March and I've been loving the sound from it. It adds so much to
our productions. I used it on a documentary that I shot in Malawi and
that project just got released publicly this week, all of the ambient
sound was recorded with the tetramic...
T. B-C wrote:
I am getting an increasing amount of work for the Tetramic. It has
Paul Ledford, a film sound mixer working on a project for a TV pilot,
Last Thursday I went down to New Orleans to listen on a proper film mix
stage to tracks recorded with various surround microphones.
I must say listening to the TetraMic in 5.1 is awesome with a broad
and natural fill to the surround monitoring. The movement with the field
is without phase shifts and is just natural as your ears would hear
The brass band material along with a saxophone had clarity and depth
with a huge low end. We found some very low freq handling noise when we
had it on the boom, but I think that can be handled easily enough with
EQ, as I do not think the low frequency material will make it to TV in
any event and it is low enough as to not degrade the music experience.
Now once listening to 5.1 going back to stereo is a bit of a let
down, but still good.
To date I have not heard any distortion or overload from the music when
the band was on the move and got close ... The movement passing a static
position is lots of fun as well.
In comparison to the Schoeps MS and the DPA 5100 ... Well the Schoeps
was just stereo and I like that sound from the Schoeps, but the TetraMic
seems to have more space for all the instruments .. I could hear the
different players a little more clearly than the MS and the low end on
the TetraMic was still huge ... We called it more hairy.
The DPA 5100 is a very nice microphone as well. Did great in the wind
and very little if no handling noise. I think it has a nice natural
spread across the 5.1 .. Not as much low end as the TetraMic .. Even
with gaining up the LFE channel on it. All the instruments were there
clearly, crisp and in a balanced and natural position.
I just think the TetraMic has more hair on the sound .. More energy.
D.W., a RED Digital Cinema Camera user in Culver California,
Thank you Len, amazing and potentially very useful capability.
Just to report... We've had our Tetramic for a bit over a month and
absolutely love both the microphone and the astonishing spatial sense
we've been able to create in the recordings made with it.
Nine months later he wrote:
We've been using the TetraMic for many months now. The mic itself is
very tough. Some of the connecting parts could be considered a bit
delicate just given their small size but we've had no problems at all.
The microphone itself is as rugged as any good microphone. We have used
it primarily out-of-doors and have had no problems. It's vulnerability
to inclement weather is, in my experience, neither greater nor less than
any other microphone I have ever used.
The TetraMic itself and the remarkable world of ambisonic sound that it
ushers in, we have found to be utterly superb.
Paul Hodges, an Ambisonic microphone veteran from Oxford (UK), wrote:
The first impression, of course, was how tiny it is. I'm surprised
at how small it really is - even after seeing the photos (the box is
seriously nice, too)! I also have only listened in stereo, and only on
headphones at that, but I'm very pleased so far. The sound is clean, and
the extended bass is remarkable (once I used phones that went that
low!). It's the first time the basses in the choir have sounded OK in
the low registers (we don't have any really low basses) - there may be
an element of acoustic reinforcement because the choir was placed hard
against the back wall (well, in front of the organ). Not having to play
about with equalisation is a great relief too; and there's clearly more
bass than even my equalised mics were finding.
... over the main part of the frequency range all the component
outputs are extremely flat; their on-axis curves are flatter than those
of my AKG C414s...
Not a lot more to say, really - it just works, and works well; and
what more can one want? I am very pleased indeed.
http://www.ambisonic.info/tetramic.html for a full review.
John Leonard, the respected sound designer in London (U.K.),
I did my first real session with the TetraMic a couple of days ago; a
last-minute informal concert recording for an up and coming string trio
in a local church with almost no time to set-up or check. After the
recording, I burned a stereo CD for the group with basic post-processing
and got an almost instant "Wow!" as a first response from them; then I
set up for a 5.1 surround decode and the results are jaw-droppingly
good. Localisation and definition are superb with all the detail of the
venue faithfully captured along with the passionate playing of the
I bought this microphone primarily because when I'm not working on
theatre shows, I'm out making recordings in all sorts of situations and
locations and lugging my other system around was becoming a bit of a
chore, so I'm looking forward to the arrival of the 4Mic pre-amp and a
full surround system that I'll be able to take anywhere, without having
to worry about excess baggage charges or incipient back strain. It's an
excellent advance in recording technology and I'm extremely
A few weeks later, on the Sursound mailing list he wrote:
...I've owned, listened to and recorded with many microphones over
the years, including Neumann, Pearl (I used to own an S8 and an ST-8)
Milab and Schoeps. Based on the tests and recordings I've done so far,
I'd say that the TetraMic compares very favourably indeed, and in some
cases -- some later year Neumann microphones spring to mind -- easily
And a few months later he wrote:
The TetraMic through the [Metric Halo] ULN-8 is stunning...
And a bit later...
Off to Holland for a few days and taking the small rig with me just
in case anything interesting comes up. Without the TetraMic, I wouldn't
have contemplated taking an Ambisonic rig with me on this little trip,
but thanks to you, I can now just chuck everything in a backpack, which
Recently he wrote to Svein Berge, the author of the wonderful
Harpex B-format decoder:
Last week, I was asked, at very short notice, to record a
site-specific community opera in a disused factory, with both audience
and performers moving around the space, but with the orchestra in a
fixed central location, around which was a circular runway, used by the
singers in some parts of the action. I wasn't allowed to use wireless
mics on the six principals and I was restricted to two positions in the
orchestra area, neither of which was in any way particularly useful. As
this was to be an archive recording only, I decided to use my Core Sound
TetraMic in a central position in the orchestra pit, attached to a large
chain, which was part of the scenic design, and a Schoeps Mid/Side
set-up and a couple of spot mics immediately in front of the conductor's
position. ... The TetraMic and the Schoeps mics fed my ULN-8, which I
had to hide under the piano and set and forget as there was no
opportunity to set levels during a performance as the orchestra space
became closed off.
... I'm using Harpex to decode ... the ... recordings. I have to say
first that the sound of the orchestra in surround, using just the
TetraMic and Harpex is stunningly good and beautifully detailed; in fact
I've spent rather too much time listening just to the orchestra rather
than checking the vocals. ...I have an extra set of tools which is
enabling me to focus on performers on the walkway that I couldn't reach
with the boom, so I can do more passes of the playback, isolating those
sections for feeding into the final mix.
Very many congratulations and thanks to you (and to Len, of course) for
producing superb tools that make my job so much more rewarding. I think
I'm happier with my set-up now than I've ever been since I started
working in surround.
Recently he wrote:
Probably the best 1st Order Ambisonic mic that I've
owned... Excellent customer service and brilliant products.
Thanks for your assistance in my recent purchase of a Tetramic and
related accessories. I've just returned from a trip to Europe where I
was engineering a variety of concerts. I was able to use the Tetramic
to record several high-profile concerts with excellent results.
I have attached an mp3 of a recording made a year or so back. I like
the sound, especially given that it was a live performance in a church
with totally muddy acoustics. (Close-miking can be your friend - and so
can having a TetraMic that turns into nice, tight Hypercards at the
twist of a mouse.) My TetraMic was set as a steerable center channel
with two MKH8040 flanking mics. (Two MKH 8020 in the rear were not
part of this mix.) Being able to rotate the pattern of the TetraMic
meant I could center the marimba image without having to accept a weak
right channel signal. Fantastically useful tool in a live stereo
Since I have added a TetraMic to my collection I've used it on nearly
every recording session. It's a great center mic, you can nicely extract
directional "spots", and in some contexts it even constitutes a usable
Hauptmikrofon--for (Ambisonic) surround as well as stereo.
...very good sounding stereo decodes with a wonderful spatial
resolution... I can hardly wait to start using the TetraMic more
This is a great mic. I am thoroughly pleased.
...I can say that the TetraMic is much clearer and cleaner than my
ribbons. I can't wait to get to a good organ recital in a place I have
The TetraMic has produced very impressive sound fields, in my initial
recordings with mic #2221. Thank you for developing this excellent
I'm still enjoying the TetraMic, and clients have noticed a
difference (un-prompted) from previous recordings made with MS or
Blumlein configurations. I love the flexibility!
N.F., a soundscape designer in Australia, wrote:
...The recording session using Tetramic (and MOTU Traveller and
MacPowerbook) last month went extra well. I love the mic and was
very impressed by the way it handled the very windy conditions out at
S.T., a TetraMic user in France, wrote:
TetraMic sounds great. I've recorded different soundscapes. I've got
very good results.
...this mic is wonderful.
S.K., in New Zealand, wrote:
We really love the Tetra mic and have been having amazing fun recording
all sorts of things.
Hugh Robjohns, Technical Editor, Sound On Sound magazine in the UK
I was very impressed with the Tetramic -- it is well manufactured and
easy to use, and its compact size is a real bonus."
Pro Audio Review magazine awards its PAR Excellence award to
At the 2006 AES Convention in San Francisco, Pro Audio
Review magazine selected TetraMic to be a recipient of the 2006
PAR Excellence Award.
Recording Magazine's December 2006 issue said:
... but we may as well spoil the surprise and let you know right now
about the hands-down cutest new product at the [AES] show: the Core
That photo isn't retouched -- it really is a four-element microphone
for in-place surround recording that's a bit larger than a ball-point
pen. There are four 12mm (roughly 1/2") cardioid electret condenser
elements arranged in a tetrahedral pattern...
This pocket-sized surround recording setup is one of many cool
field-recording devices from Core Sound, which has a decades-long
history of providing high-quality and very portable location recording solutions.
Electronic Musician magazine wrote:
Core Sound held the buzz of the show with its TetraMic ($TBA), a "tetrahedral" mic for
ambisonic recording. The mic has four small capsules on a metal shaft
and is shorter than a pencil. The company says the price will be under
David Battino, on O'Reilly Digital Media, wrote:
At every trade show, there's one product everyone says you have
to see. The gadget that kept coming up at last month's AES conference
was the Core Sound TetraMic
This tiny microphone contains four capsules arranged in a tetrahedral
pattern to pick up sound in the Ambisonic format. Basically, the mics
together encode front-back, left-right, up-down, and level information
that can later be presented in a variety of ways. According to
Ambisonic.net, the technique produces a 3D audio image -- including
elevation information -- that's "largely unaffected by listener
position." In other words, with just four speakers, you hear a true
surround recording, and there's no sweet spot. The four channels can
also be decoded into conventional two-channel, 5.1-channel, 7.1-channel,
and other speaker systems.
Before now, Ambisonic mics cost thousands of dollars. Core Sound
expects to sell the TetraMic for
less than $1,000.