Core Sound TetraMic™ 1st-order Ambisonic Microphone
The first portable, single point, stereo & surround sound Ambisonic soundfield microphone to be available for under $900 fully configured for most multi-track recorders and audio interfaces. Individually calibrated, each TetraMic is the finest performing microphone of its type in the world.
Individually calibrated, each TetraMic is the finest performing microphone of its type in the world. Compare its performance to similar soundfield microphones selling for $3000 or more and you'll be quite amazed.
Each and every TetraMic is individually calibrated and comes with its own calibration files. All other first-order ambisonic mic from major manufacturers use a single generic calibration file for all of their microphones.
Based on the principles of Ambisonic recording developed by Michael Gerzon and Peter Craven during the 1970's, TetraMic allows you to place a single exceedingly accurate tetrahedral microphone in a sound field, record four channels of audio in "A" format, transform them using software into "B" format (W, X, Y and Z), and later interpret those four channels to essentially any single-point configuration of microphones:
omni
sub-cardioid
cardioid
super-cardioid
hyper-cardioid
figure-8
multiple combinations of those including:
Blumlein (two crossed figure-8 microphones in the azimuth plane))
Height-enabled Blumlein (three orthogonal figure-8 microphones)
M/S (Mid/Side)
XY (two crossed cardioids) separated by any arbitrary angle
binaural, using personal HRTF and head tracking information
Three hypercardioids facing forward and two cardioids facing rearward (for 5.1 surround)
any combination and arrangement of microphones for surround sound or other effects
The apparent orientation can be rotated, tilted, tumbled or zoomed at will.
The four channels of "B" format can also be interpreted into almost any playback format, including:
mono (without "sum to mono" phase cancellation issues)
stereo
binaural, using HRTF information
four speakers arranged as a square or rectangle
six speakers arranged as a regular or irregular hexagon
5.1 (ITU)
7.1
10.1
any of the above plus height information (e.g., two hexagonal arrays of speakers, one above the listener and one below)
and many, many more.
In addition to modelling any number and type of coincidently positioned first-order microphones, you can model spaced microphone arrays (e.g., ORTF) by using more than one TetraMic.
This process allows your audio projects to have unparalleled flexibility in post-production.
How good a microphone is TetraMic? We believe TetraMic has the flattest and most extended fig-8 response of any commercially available microphone, bar none; so it's among the best Blumlein arrays in the world. Its free-field omni response is not quite as good as a Bruel & Kjaer 4133 1/2-inch measurement microphone; it's only as good as the wonderful DPA 4003 that we use for calibration -- i.e., sensational! However its diffuse-field response is better than the 4003. This combination of capabilities makes TetraMic one of the world's finest microphones.
When used as an acoustic sensor to locate sound sources in space, TetraMic is capable of resolving angle-of-arrival to five degrees or less, over all three spatial axes. This is better performance than any competing sensor.
Until now, a tetrahedral Ambisonic microphone and its associated electronics cost over $4000 and sometimes as much as $7000. TetraMic is priced under $1000 including its processing software. And its angular accuracy performance surpasses all other microphones of its type.
TetraMic is more than four microphone capsules on a tetrahedral mount. Building a TetraMic starts with a large batch of carefully assembled microphone capsules, pre-selected for sensitivity and frequency response. Each capsule is then exhaustively tested for sensitivity, frequency response, directivity pattern and other parameters. We select four well-matched capsules and confirm their compatibility. Then another round of exhaustive testing begins, this time for the complete tetrahedral assembly. All in all, each TetraMic undergoes more than seven hours of assembly, testing and calibration. Each TetraMic exits the test phase with its own calibration and correction files, used with VVEncode plug-in to ensure that each TetraMic is a fine example of one of the best sounding microphones in the world.
VVEncode on PCs and Macs
To ensure that TetraMic is the finest sounding Ambisonic microphone in the world, it is supported by a custom version of David McGriffy's fine VVEncode encoder plug-in. software. With design assistance from some of the world's experts in Ambisonic microphone design and testing (including those involved with the original commercial Ambisonic microphones), VVEncode performs detailed equalization based on both individual capsule-level and fully integrated TetraMic-level calibrations. It includes functions for A- to B-format encoding and configuration for upright, inverted and two endfire orientations,
VVEncode outputs B-format in the world-standard ambiX format and operates on PCs and Macs.
For real-time processing you would use the VVEncode and any industry-standard VST (or AAX) decoder plugins with your recording software. VVEnode perfroms A- to B-format transformation using the calibration data for your TetraMic. The decoders create virtual microphones and configure the output for different playback configurations. VVEncode operates with any recording application that can use four-channel VST or AAX plugins (e.g., Pro Tools, SONAR, AudioMulch, Plogue Bidule, Wavelab, Cakewalk, Cubase, Samplitude, Ableton Live, Nuendo, Reason, FL Studio, Sound Forge, Nuendo, Reaper).
Linux
Fons Adriaenson's powerful and great sounding Linux-based TetraProc application can be found here.
AMBDEC can be used for playback under Linux. For details see the Ambisonia Wiki (www.ambisonia.com) and search for AMBDEC.
Jack and Ardour also work fine under Linux.
TetraMic Sound Samples
You can find a variety of recordings made with TetraMic at www.ambisonia.com . Charles Veasey (user name: cveasey), Paul Hodges (pwhodges), John Leonard (soundmanjohn), Hugh Pyle (hughpyle), and Len Moskowitz (LenM) have posted recordings made with TetraMic.All can be downloaded as B-format files, to be played back on any ambisonic player. Most can be downloaded as stereo and 5.1 files too.
Specifications
Microphone Type: tetrahedral, single-point Ambisonics surround sound
Raw capsule information:
Number: four
Medium-sized diaphragm: ~12 mm
Pattern: cardioid
Type: electret condenser
TetraMic pattern: variable, selected at decode
Capsule ordering and channel assigment (the "front" of TetraMic is indicated by the "Core" logo; the "left/right" assignment is based on viewing the TetraMic capsule from its rear):
Channel 1: LFU (left/front/up)
Channel 2: RFD (right/front/down
Channel 3: LBD (left/back/down
Channel 4: RBU (right/back/up)
Capsules tested, selected and matched into sets, with calibration data supplied to "VVMic for TetraMic" decode software
Spatial resolution: Five degree or less, when used with appropriate software
Frequency response:
Raw: 40 Hz - 18.5 KHz +/- 4 dB
Corrected: 30 Hz - 18.5 KHz +/- 2 dB
Self noise: 19 dBA per capsule. Self noise can decrease or increase depending on selected decode
Phase: non-inverting when used with the PPAc (shipped with all orders after July 1, 2015); inverting when used with the earliest Core Sound PPAs
Maximum SPL per capsule: 135 dB
Sensitivity per capsule: 7.0 mV/Pa nominal (-43 dB ref: 1V/Pa)
PPAc output impedance: 85 Ohms
Output connector:
compatible with Switchcraft TB6M (mates with TA6F)
breaks out via breakout cable to four XLR-M plugs via PPAc system
Power:
48 Volt Phantom Power with optional PPAc, and older PPA2, or PPA3 (Phantom Power Adapters)
approximately 8 mA @ 48 VDC total (2.0 mA per capsule)
If 48V is not available, PPAc can be powered by an external battery pack or power supply: 9 to 12 VDC, DC power connector: 4.0mm x 1.7mm, center pin +. An alkaline 9 Volt MN1604 "transistor radio" battery lasts 5 hours or more.
Shaft diameter: 1/2-inch (12.5 mm)
Overall length: 5-1/16-inch (12.9 cm)
Weight: 3 ounces (85 grams)
Re-calibration interval: 3 years (general usage), 2 years (precision acoustic measurements)
*Using TetraMic with 48V phantom power adapters other than those provided by Core Sound will void all performance specifications.
TetraMic Usage
Getting a Copy of "VVMic for TetraMic", VST Plugins and Your Calibration Files
When you've received your TetraMic, please contact us. We'll send you a link to download "VVMic for TetraMic", VVTetraVST, VVMicVST and the calibration files for your specific TetraMic.
Which side of TetraMic is the front and which capsule is channel #1?
TetraMic's front side is indicated by the "Core" logo.
Viewed from the rear, channel number 1 is the capsule facing up on the logo side: that's the Left Front Up (LFU) capsule. Channel number 2 is the Right Front Down (RFD) capsule. Channel number 3 is the Left Back Down (LBD) capsule. And channel number 4 is the Right Back Up (RBU) capsule. The capsule ordering can also be found on the TetraMic Ordering page.
Cabling
TetraMic's base houses a 6-pin mini-XLR-M jack. The six pins carry four unbalanced microphone signals, power and ground.
Cabling for the PPAc System
We recommend the PPAc system for almost all applications. It is very compact, converts the TetraMic's unbalanced audio signals to balanced ones, and allows a maximum separation between TetraMic and your recorder/soundcard of 800 feet or more. It is very immune to picking up electromagnetic noise and hum.
One end of a PPAc Adapter Cable connects to TetraMic and the other end to the PPAc Transmitter. Connect one end of a rugged shielded Ethercon cable (or a low-cost shielded CAT5e cable) to the PPAc Transmitter, and the other end to the PPAc Receiver. The PPAc receiver has four short cables coming out of it; each short cable terminates in a color-coded XLR-M plug. Plug those four XLR-M plugs into your recorder/soundcard.
Shielded Ethercon cables are, in general, much better shielded than shielded CAT5e cables, so if you are operating in a high RF interference situation we strongly recommend using shielded Ethercon cables.
TetraMic is normally powered by your recorder's or mic pre-amp's 48 Volt Phantom Power via the PPAc System. (The PPAc system can also be powered by an external battery pack - see the TetraMic accessories page for details.)
Microphone Pre-amplifiers and ADCs
Ideally, to preserve TetraMic's calibrated performance, all four TetraMic channels should be gain-matched to within 0.1 dB. To do that requires either mic pre-amps and A-to-D converters that are designed to hold those gain tolerances, or you have to invest the extra effort to calibrate your mic pre-amps and ADCs.
We've found that a few commercial mic pre/ADCs will do the job. They are the MOTU Traveler, MOTU 4Pre, Metric Halo's ULN-8, Prism Sound's Orpheus, Apogee's Quartet and RME Fireface UFX.
Other mic pre-amps/ADCs that may work are the Roland Octa-Capture and Quad-Capture, and the Steinberg UR-44.The MOTU Traveler can be used as an excellent quality, low-cost, stand-alone mic pre-amp, in addition to its FireWire interface for PCs. Its Line level outputs can be connected to a Sound Device's 744T four-channel recorder's Line inputs to make fine sounding recordings.
The MOTU 4Pre is similar, uses both Firewire and USB, costs less than the Traveler, and is easily powered by a battery for mobile use.
The excellent sounding Metric Halo ULN-8 can also be used as a stand-alone mic pre/ADC. Orpheus and Ensemble can also operate stand-alone once they have been configured with a computer.
Apogee's Ensemble Mobile is one of the few mic pre/ADCs that can easily be battery powered.
Care of the Shock Mount
The shock mount has a rubber suspension that requires a bit of care. Please twist TetraMic as you insert it into the shock mount and as you remove it. Don't push it straight in or pull it straight out, as it can tear.
Battery Power
When TetraMic is used with the PPAc system, it can be powered either by standard 48 Volt Phantom Power or a local DC battery that provides between 9 and 12 Volts DC. A single alkaline 9 Volt battery (type MN1604) will power TetraMic for approximately 5 hours.
Recording with the TetraMic
Typical Recording Set-ups
TetraMic has an unusually extended low frequency response. If we wanted to go a bit overboard, we could calibrate it to be flat to well below 20 Hz and you could use it as an earthquake detector! But we reasonably limit its response so that it's usable down to around 25 Hz. As with any high quality microphone that works well down to those very low frequencies, you must use a shock mount unless you really want to pick up footsteps, trucks rumbling by, distant thunder and subway trains. So please always use the compact shock mount we supply with TetraMic or another one of your choice that is at least as effective.
TetraMic's output is a 6-pin mini-XLR jack. A 6-pin PPAc adapter cable plugs into TetraMic and connects to the PPAc transmitter. Since TetraMic's signal is unbalanced at that point and somewhat susceptible to picking up strong electrical interference, we recommend keeping that adapter cable length as short as possible and routing it away from sources of interference.
The TetraMic's PPAc system can feed the signal to either a four-channel recorder that has its own mic pre-amps, or a four-channel microphone pre-amplifier/ADC (analog-to-digital converter) that feeds a four-channel digital audio recorder. The recorder can be either a computer or a stand-alone digital audio recorder.
Using TetraMic with a Portable Digital Audio Recorders
We recommend using a Zoom F4 or Sound Devices MixPre-6 recorder with TetraMic.
Connect TetraMic to the recorders using our PPAc system. The PPAc receiver's XLR connectors plug directly into four of the recorders' XLR inputs.
All of the recorders mentioned have very accurate, digitally-set level controls so it's very easy to match the levels across TetraMic's four channels. The recorders can even gang the four channels so that you can control the levels with one knob.
Using TetraMic with an iPad
The folks at n-Track report that their n-Track Studio 7 application runs great on the iPad. You can record pristine 192 khz/24-bit multichannel audio without having to carry around a heavy computer and with the ease of use typical of the iPad.
The iPad is compatible with USB devices that support Class Compliant USB Audio. Those are typically the devices that work when you connect them to a computer without having to install any driver software.
Check with them for recommendations about audio interfaces that work well with Studio 7 and the iPad.
Using TetraMic with a recorder that doesn't have digitally-set levels
Connect TetraMic to the recorder's four XLR inputs using TetraMic's PPAc system.
If the recorder does not have level controls that are set digitally, you would first set each channel's Sensitivity and Level controls, lock them down so that they can't change, and then record a stable tone to each of the four channels. Low-cost tone generators are available from Behringer (the CT-100), Shure (the A15-TG) and other audio manufacturers.
In post-recording (back in the studio), adjust the levels of the four recordings of the tone so that they are within a tenth of a dB of each other. Note the adjustments in gain for each channel, and apply them to your recordings.
Using TetraMic With a MOTU Traveler or 4Pre
If you're using a MOTU Traveler or 4Pre mic pre-amp, plug the TetraMic's PPAc receiver cables into the Traveler's or 4Pre's inputs.
The MOTU Traveler can be used with PC, via a FireWire (IEEE-1394) interface, or as a stand-alone front end with four channel recorders that have Line inputs and excellent gain tracking between channels. The 4Pre can use FireWire or USB.
When used with a PC, you can use any of the many digital audio workstation software applications. Here at Core Sound we use Ross Bencina's AudioMulch. One requirement for the DAW software is that it has identical latencies for all four channels to preserve sample sync. ASIO drivers seem to do this well, and the MOTU Traveler is provided with ASIO drivers.
One stand-alone digital recorder that folks have used with great success is the Sound Devices 744. While it only has two microphone pre-amps (two short of TetraMic's four outputs), the MOTU Traveler's (or 4Pre's) four mic pre Line outputs can be plugged into the 744's Line inputs. The 744 has the ability to set the gains on its Line inputs digitally, precisely preserving gain matching across channels.
Recording with TetraMic, MOTU Traveler (or 4Pre) and a PC
We recommend recording using 24-bit word widths, at a minimum of 44.1 KS/s sample rate. Set gains for all channels to the same setting. If you're recording large choirs or orchestras, a good start is 15 dB. Try to get peaks at around -15 to -20 dB. If you're recording loud rock concerts, set levels to 0 dB; note that to keep from overloading the mic pre-amps you might have to also use the Traveler's (or 4Pre's) 20 dB pads (attenuators).
If you are using a DAW that can use VST plugins, you'll be able to monitor the recording in real-time, fully decoded, and record either A-format (four channels), B-format (also four channels) or files decoded to any specific microphone and playback configuration (from 1 to a very large number of channels). The VVEncode plugin does the calibration corrections and the A- to B-format conversions. There are many decoder plugins that allow you to define virtual microphone parameters (e.g., number of microphones, the angles at which they point, each one's directivity) and match your playback system configuration.
Recording With TetraMic, a MOTU Traveler (or 4Pre) and a Sound Devices 744
If you're recording with a standalone digital audio recorder, make sure that the gains on all channels are set identically. What you'll be recording is the raw TetraMic output, called "A-format".
TetraMic Accessories
Phantom Power Adapters For Tetramic
Core Sound now offers the amazingly flexible PPAc system to power TetraMic. PPAs accept 48 Volt phantom power and converts it to the correct voltage to power TetraMic. It also converts TetraMic's unbalanced audio signals to balanced, uses a single Ethernet or rugged Ethercon cable, and allows TetraMic to be separated from the recorder/pre-amp by 850 feet or more.
PPAc Transmitter, Receiver and PPAc Adapter Cable
PPAc (pronounced pea-pack) is TetraMic's most flexible and compact Phantom Power Adapter (PPA). A single PPAc provides power to all four TetraMic channels.
PPAc has two parts: a transmitter and a receiver. The transmitter has two connectors: a 6-pin XLR-F and a CAT-5e/CAT-6/EtherCon connector. The receiver has a CAT-5/CAT-6/EtherCon connector on one end and four XLR-Ms on the other. To easily identify the four channels, the four XLRs are numbered and color-coded.
The PPAc transmitter is connected to the TetraMic with a short PPAc adapter cable having a 6-pin mini-XLR-F plug on one end and a 6-pin XLR-M on the other end. An 18-inch adapter cable comes with the PPAc system. Longer adapter cables (e.g., 6-foot) are available as an option.
The PPAc transmitter and receiver are connected by a shielded CAT5e/CAT6 LAN or a more rugged EtherCon cable. The cable can be as short as you want, or as long as 850 feet (or more). That makes it especially convenient when the recorder must be located far from TetraMic.
Because there are so many different possibilities and everyone has their own preferences, the PPAc system does not include a shielded CAT5e/CAT6 or the more rugged EtherCon cable. Please select and order one (or more) as an option.
When 48 Volt phantom power is not available, PPAc can also be powered by an external battery pack or AC power supply ("wall wart") via a DC power connector (1.7mm) on the PPAc transmitter. It requires 9 to 12 Volts DC at 10 mA minimum. The center pin is positive (+).
The normal cabling configuration for TetraMic when using PPAc is:
TetraMic
PPAc adapter cable (6-pin mini-XLR-F to 6-pin XLR-M)
PPAc transmitter
Shielded CAT5e/CAT6 or more rugged EtherCon cable (up to 850 feet long - or more)
PPAc receiver
The PPAc receiver's four XLR-M connectors plug directly into your recorder or mixer.
The PPAc System reduces the amount of equipment needed to use TetraMic remotely.
Microphone Stand Mount -- Fixed and Shock
TetraMic should be used with a shock mount. We offer a very compact and effective one as an optional accessory. It mounts to any standard 5/8"-27 threaded microphone stand or fixture. A fixed stand mount (non-shock mounted) is also available.
If you need the most effective shock mount for TetraMic, we highly recommend Rycote's part number: 041120 (available from Rycote dealers). It uses their INV-7 62-shore Lyres & split grommet, mounted onto an InVision bar.
TetraMic Fixed Mount
TetraMic Shock Mount
Wind Screens
Wind screens are available to reduce wind noise when recording outdoors with TetraMic.
The two-part foam wind screen fits over and under TetraMic's capsule head. It should be used in light wind conditions without significant gusts/blasts.
The two-part foam wind screen fits over and under TetraMic's capsule head. It should be used in light wind conditions without significant gusts/blasts.
The windscreen with a combination furry outer layer and foam inner layer should be used in medium wind conditions without gusts/blasts. (The furry/foam wind screen includes the foam wind screen -- there's no need to order both.)
Furry/Foam Windscreen Usage:
Furry/Foam Windscreen Usage: Push the bottom foam collar up onto the TetraMic shaft as far up as it will go, seated against the bottoms of the two lower capsules. Fit the top foam over the top of the TetraMic and push it down as far as it will go. Then fit the furry sleeve over it.
An even more effective (and considerably more expensive) windscreen system is available from Rycote dealers. You would order the TetraMic Kit, Rycote part number: 086047. It includes a small Modular suspension, fitted with 62-shore 19/22 Lyres (non-soft grip) and split grommets to hold the 12mm body of the TetraMic. The kit also includes a Modular windshield, Windjammer and an XLR Holder Mk II (Rycote part number: 048493) for mounting the PPAc transmitter.
TetraMIc in Rycote Modular Shock Mount (Photo credit: John Leonard)
TetraMic in Rycote Modular Windshield
You can also get a suspension-only kit from Rycote (Rycote part number: 041120), without the windscreens. It uses the same INV-7 62-shore Lyres & split grommet, but mounted onto an InVision bar.
Slightly less effective but much less expensive than the Rycote system described above, is the Rycote S300 using the Lyre suspension. One user reports that it is considerably better at reducing wind noise than a similarly priced Rode blimp.
Cables for the RED Digital Cinema Camera
TetraMic works great with the RED Digital Cinema Camera. Its microphone pre-amp inputs are four mini-XLR jacks. We offer 6-foot cables that plug into the TetraMic PPA (XLR-F) on one end, and the RED camera mic inputs (mini-XLR-M) on the other. If you need other lengths please contact us.
TetraMic News
November 14, 2019: Facebook Reality Labs released two photos of their 6-degrees-of-freedom Sociopticon research dome. It is instrumented with 420 Core Sound TetraMics.
Each TetraMic first-order ambisonic microphone is individually calibrated for the highest precision sound source location cues.
OctoMics offer even higher precision location cues!
(Photos taken from: https://tech.fb.com/codec-avatars-facebook-reality-labs/)
June 20, 2019: All new TetraMics come with the VVEncode plugin from VVAudio.
September 29, 2017: Zoom released the new v4.0 firmware for their F8 recorder today. It features support for first-order ambisonic microphones, including TetraMic.
We recommend using the F8's "Ambisonics A" mode. That mode configures the F8 to record TetraMic's four A-format tracks, while also allowing you to monitor in real-time via speakers or headphones.
By recording in A-format you'll retain the ability to apply your TetraMic's unique calibration files. Those files make your TetraMic into one of the world's finest ambisonic microphones. But even monitoring without the calibration files, TetraMic is pretty fine.
At first listen, the Zoom monitoring function decode seems to be XY using two virtual cardioid microphones. We haven't measured the patterns yet, so we can't tell you what angle they selected between the virtual microphones.
June 12, 2017: We recently heard from the noted sound designer/supervising sound editor Paula Fairfield. She told us that she used TetraMic widely for the 2016 Robert De Niro film "Hands of Stone".
May 15, 2017: TetraMic was used as part of Marshall Day Acoustic's IRIS measurement system to test and commission the Jiangsu Grand Theatre in Nanjing China.
April 25, 2017: TetraMic was used by JJ Wiesler (Pollen Music Group) on Google's Oscar-nominated short animation "Pearl". It was used to record singer Kelley Stoltz performing "No Wrong Way Home" from the viewer's perspective in the passenger seat of a car. It was also used to capture IRs.
You can watch and listen to "Pearl" on YouTube: https://www.youtube.com/watch?v=WqCH4DNQBUA.
February 5, 2017: We've further improved TetraMic's industry-best calibration procedure, making location cues even more accurate and reliable. No other first-order ambisonic microphone even comes close.
January 3, 2017: VVTetraVST v1.8 for Mac and Windows is now available for download from the VVAudio web site: vvaudio.com/downloads
November 11, 2016: Bosse Sandholm did a few live recordings comparing his TetraMic to a soon-to-be-released ambisonic microphone from a major manufacturer. The results confirmed the reason why we calibrate each and every TetraMic individually: much better location cues and much more natural sound quality.
You can download the files here. Decode them into Blumlein for stereo playback, or into surround, and you can confirm what we're saying for yourself.
September 1, 2015: Station Film used TetraMic to record the audio for their 360VR dark comedy short "Red Velvet". You can see TetraMic at the lower right corner at 0:11 and later at 1:14 in "Station Film: Red Velvet (Behind The Scenes)".
July 10, 2015: Jaunt's virtual reality camera uses Core Sound's TetraMic as its audio sensor. It was used to record Sir Paul McCartney's concert. Watch it using Google's Cardboard viewer. (TetraMic is wearing its furry/foam windscreen.)
June 24, 2015: Since we introduced it a few months ago, the PPAc has been an overwhelming success. It's the best way to power TetraMic. It's compact, reliable, allows for powering via 48V phantom power, and allows separations between TetraMic and the recorder/pre-amp of 850 feet or more. It's also less expensive than the previous PPA2 and PPA3 packages.
As a result we've discontinued the PPA2 and PPA3 options.
February 12, 2015: Marshall Day Acoustics' IRIS system was used in the acoustic design of the new Philharmonie de Paris concert hall. IRIS uses TetraMic as its sensor.
You can see Simon Rattle's glowing review of the hall's acoustics here:
November 2014: Jaunt's virtual reality camera is using TetraMic as its audio sensor. It's being used in the field to record virtual reality cinema. In this photo TetraMic is wearing its furry/foam windscreen.
September 23, 2014: Based on TetraMic user feedback we can we can highly recommend the Tascam HS-P82 multi-channel digital audio recorder for use with TetraMic.
April 3, 2014: Jaunt VR's virtual reality camera prototype uses TetraMic as its audio sensor.
March 21, 2014: We're pleased to announce a new phantom power adapter: PPAc is a small transmitter/receiver pair, provides power for all four channels and sends TetraMic's audio over a CAT5/CAT6 cable up to 850 feet long.
June 10, 2013: We're pleased to announce that in addition to offering a precision calibration service for SoundField Ltd's SPS200, we are now also offering calibration for their Mk IV too. The results of our calibration far exceed what those two microphones come with from the factory. Please contact us for details.
July 28, 2012: Now you can use an iPad to record with TetraMic. The folks at n-Track have announced that their Studio 7 application can record on the iPad using Class Compliant USB audio interfaces.
November 17, 2009:We've replaced the Phantom Power Adapter (PPA) with a new model that maintains phase, instead of inverting it as the older model did. The new PPA2 will ship with all orders placed after December 1, 2009.
February 14, 2008: TetraMic seems to work fine with RED's digital cinema camera! For the first time, cinema cameras are now able to record surround sound in-camera, and also track individual sound sources during post-production!
Ambisonic Recording Links
Paul Hodges has a wonderful review of TetraMic and some good information about Ambisonic recording
Bruce Wiggins' Direct Show and VST plugins for Ambisonic playback using Windows Media Player
Richard Elen's Ambisonic Network
HARPEX-B - Svein Berge's Ambisonic B-format player
Daniel Courville's Ambisonic Studio -- Guides for using Ambisonic surround sound technology in audio production and post-production
"The Amibsonic Tool Kit" - Tools for the artist and composer from Joseph Anderson
Hugh Robjohn's fine article about Ambisonics in Sound On Sound magazine (October 2001)
Richard Furse's 3D Audio Links and Information page has lots of information about Ambisonic recording and playback
Joseph Lloyd Anderson's informative "What is Ambisonics?" page
Minnetonka Audio's discWelder Bronze is a great low-cost program for burning Ambisonic recordings to DVD-A for playback on your 5.1 home theater or audio system.
Minnetonka Audio's discWelder Bronze 1000m is a great low-cost program for burning Ambisonic recordings to DVD and DVD-A for playback on your 5.1 home theater or audio system.
TetraMic Ordering
February 24th, 2021: We are currently shipping TetraMics roughly two weeks from receiving an order. If you have an urgent need, we can usually accommodate - please call!
TetraMic is sold by itself and also bundled into a TetraMic Package that include pretty much everything you'll need to get started.
For most applications, we strongly recommend the TetraMIc Package - it includes the PPAc System. Add a rugged/shielded Ethercon cable or a shielded CAT5e cable in the length you want, and you're ready to record.
Payment
Payment is via any major credit card (Visa, Mastercard or American Express), a PayPal account, personal checks, money order (available from the Post Office or bank), traveler's checks, wired funds, cash or certified check, US funds only. Please allow some additional time for personal checks to clear the bank prior to shipment. COD shipments are available in some situations -- contact us for details. You may wire funds directly to our bank account -- please contact us for details.
PayPal handles our credit card processing. You need not have a PayPal account to pay with a credit card.
We also accept purchase orders from pre-qualified US universities, corporations, and state and federal governments.
Checks should be made out to "Core Sound LLC" and sent to:
Core Sound LLC
405 Cedar Lane, #1
Teaneck, NJ 07666
USA
Orders are typically shipped within two or three days but delivery times vary with our order load. We can usually accommodate "rush" orders, including same day shipments -- call and ask!
If you have questions, call and ask for Len Moskowitz. He can be reached at (201) 801-0812. His electronic mail address on the Internet is:
moskowit@core-sound.com
Customs Taxes
If you are ordering from outside the United States or Canada, your government may (or may not) charge you import taxes. Those taxes are your responsibility. If you are not certain, please ask your local Customs authority for more information.
VAT and Sales Taxes:
Core Sound LLC collects only State of New Jersey sales tax. We do not collect UK/Europe VAT taxes or any other taxes
TetraMic Trial Offer
To give you a chance to try it and decide if it's for you, Core Sound provides a 30 day trial period. All TetraMics returned within 30 days of shipment qualify for a full refund (minus shipping and handling charges) provided that they are returned in as-new condition.
TetraMic Limited Warranty
TetraMic is sold with a one year limited parts and labor warranty. If a TetraMic requires repair during that period, ship it back to Core Sound postage-paid with a description of the problem, and then please call us once we have received it to discuss the problem. We will repair or replace it and ship it back to you at no charge. No consequential damages are covered by this warranty.
Using TetraMic with power supplies other than those provided by Core Sound for use with TetraMic will void this warranty and all performance specifications.
TetraMic Customer Reviews
Bruce Bartlett wrote a comprehensive review for ProSoundWeb.com: http://www.prosoundweb.com/article/a_look_at_the/.
“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 http://www.ambisonic.info/tetramic.html.
"... 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 microphone, wrote:
“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 stereo recording.”
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 Len.”
(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 spaces.”
“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 TetraMic.”
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 788T-SSD.”
“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 totally solid.”
“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.
Thank you!”
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.”
R.J. wrote:
“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.”
A.H. wrote:
“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 worked impeccably.”
Paul Ledford, a film sound mixer working on a project for a TV pilot, wrote:
“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 it.
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, writes:
“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.”
See http://www.ambisonic.info/tetramic.html for a full review.
John Leonard, the respected sound designer in London (U.K.), wrote:
“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 musicians.”
“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 impressed.”
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 surpasses them.”
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 is excellent.”
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.”
J.S. wrote:
“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.”
J.C. wrote:
“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 recording.”
A.L. wrote:
“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.”
D.H. wrote:
“Very good sounding stereo decodes with a wonderful spatial resolution... I can hardly wait to start using the TetraMic more often.”
J.O. wrote:
“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 recorded before. Great job”
W.M. wrote:
“The TetraMic has produced very impressive sound fields, in my initial recordings with mic #2221. Thank you for developing this excellent device.”
J.A. wrote:
“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 the airfield.”
S.T., a TetraMic user in France, wrote:
“TetraMic sounds great. I've recorded different soundscapes. I've got very good results.”
L.H. wrote:
“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 wrote:
“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 TetraMic
“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 Sound TetraMic.”
“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 $1,000.”
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.”
TetraMic Recordings
There are a large number of TetraMic recordings at Ambisonia, including the following: