About this project
About the Microphone
The Brahma microphone is a high quality electrets based, phase accurate ambisonics microphone that captures the true 3-dimensional representation of an acoustical ambiance. It owes its design to an original paper on Ambisonics written by Michael Gerzon and Peter Craven in the 1970's. Due to technological and price limitations it has not seen wide-spread use, until now.
We have designed and packaged the entire microphone system to be affordable, easy to set up and simple to use without sacrificing the quality of the recording.
Design And Manufacturing
Four cardioid capsules are mounted on a 3d printed tetrahedron. The entire structure is shielded in a satin finished stainless steel mesh and two-piece ring.
The Zoom H2N is modified by removing the supplied microphone capsules in the recorder and mounting a 5 pin Amphenol connector in its place, to act as a 4 channel recorder for our Brahma Microphone.
Though the Brahma system is designed for use with the modified Zoom H2 and H2n recorders, they can also be used with our adaptor on any phantom equipped four channel recorder.
After the microphone is produced, each microphone is carefully calibrated.
The microphone is designed in house and manufactured at the Noida factory. Additional components like the Zoom H2n and microphone capsules are sourced from international suppliers.
Once the Kickstarter campaign closes, we will adhere to the following schedule and expect to ship in February 2014.
Why get the Brahma Microphone
If you are a passionate film maker or sound recordist and understand how hard it is to capture true surround sound, you should get the Brahma. Our prototypes are currently being used by documentary film makers, sound recordists, nature recordists, musicians, musical performance recordists and university professors around the world.
1. Affordability and Ease of Use
- The Brahma microphone is the least expensive ambisonic microphone in the market
- No additional components or software is needed if the Brahma built into the Zoom H2n or standalone Brahma with the modified Zoom H2n versions are opted for
- No rigs of multiple microphones need to be set up to make genuine surround sound recording
2. Post Processing Versatility
- In post processing, the sound image can be panned, tilted and zoomed.
- From a single four-channel recording, mic patterns such as omni, cardioid, hyper-cardioid, sub-cardioid, super-cardioid and figure-8 can easily be created
- Combination patterns such as blumlein, height-enabled blumlein, Mid/Side, XY (two crossed cardioids) separated by any arbitrary angle, three hypercardioids facing forward and two cardioids facing rearward (for 5.1 surround) can also be created.
- The B-format files can be processed in the following playback formats – mono, stereo, biannual, 4 and 6 sided array, 5.1 surround, 7.1 surround with height, 8 channel surround with height.
3. High Sound Quality with Reduced Noise, Errors and RF Pickups
- Brahma's unique tetrahedron design has enabled larger diaphragm (14mm) capsules to be brought very close together (15mm sphere radius). This design feature reduces noise and increases the sound quality and frequency response
- The calibration process ensures that each individual microphone is corrected and enables the creation of an accurate sound image
- An advantage the Brahma has over stereo microphones or stereo images from 2 or more microphones is that the capsule error between multiple capsules is much smaller and resolved in the calibration files, thus there are no set-up or placement issues.
- Brahma's tetrahedron capsules are shielded in a stainless steel mesh that reduces reflections and nearly eliminates electrical interference. The Stainless steel mesh also functions as a mount for the supplied windshield.
Brahma is available in 3 versions
What we will use the money for
1. Calibration Room and equipment
2. Manufacturing dies and equipment
3. Bulk sourcing of components and raw materials
Nakul Sood, is a working video-audio professional, with 12 years of experience in various fields of expertise that include direction, writing, videography, editing, location sound recording and as line producer for documentary films. He holds a Bachelor’s degree in English (Honours) from Delhi University and certificates in screenwriting and cinema workshops from New York University. He is the founder of Embrace Cinema Gear, a company that makes over 85 original devices for filmmaking.
Umashankar is a sound recordist who has worked on over 100 films and television shows, followed by his current occupation as consultant to the archive at the Archives and Resource Centre for Ethnomusicology of the American Institute of Indian Studies in Gurgaon. He is also an associate member of the Audio Engineer's Society and the Acoustical Society of America. He has been a hobbyist most of his life, first making a crystal radio at the age of 8.
Umashankar and Nakul Sood are the engineering and manufacturing force behind the Brahma. They are supported by a strong management, marketing and technical team.
Risks and challenges
Product & Quality: Over 10 prototypes have been tested by audio professionals around the world for over a year and have given excellent reviews. We expect similar quality for the production run as well.
Manufacturing: Embrace Cinema Gear has been manufacturing various cinema and audio products for the past 4 years and as such do not expect any unexpected manufacturing related problems. The factory has been fully functional for over 3 years and have 16 full time staff members and 3 consultants.Learn about accountability on Kickstarter
I was wondering if you have any specs on the mic[s] available? Dynamic range, self-noise, etc…? Thanks!
Right now we can answer only a part of the question. The Zoom H2n has a noise floor of about 96 db below 0 db, measured with a 2k2 dummy resistor. it will be better with a microphone connected.
The electret capsules we are using are the well-known TSB 140As. These come with built in FETs, which makes for simple interfacing to PIP circuits. We are using the same capsules in both the Brahma built into the Zoom H2N and the external Brahma microphones.
Part of the project is to measure and calibrate these capsules. We will only know real world figures then, but when we do, we will publish them. At the moment all we can say is it is a major improvement over the built in capsules. The sound sample you can hear was recorded about 10 feet away from the performers, in an outdoor venue. The musicians are loud, but you will get some idea of the quality.
I think it's somewhat backwards idea to severly modify Zoom H2N when you could just buy H6 with 4 XLR ins stock, building it in H2N on the other hand is great!"
We are not very sure everyone needs phantom power and xlr inputs. For those that do, we are providing Brahma as a standalone. But we believe that in battery powered situations, especially outdoors, the two AA cells in the Zoom H2n can adequately power the four capsules of Brahma for more than ten hours while recording. Most battery powered recorders cannot deliver that kind of performance with phantom power on!
The microphone will connect to a small box with four XLR outputs. It can be accept either Phantom power or an internal 9-volt battery. Low-noise, low-impedance circuitry on all four channels.
What are the A and B formats, and what does the conversion involve? Is the necessary software included in any of the options presented? Or is it available separately? Is there any other software which does the job, like Audition?
A-format is the four channel recording produced by the four cardioid capsules mounted on a tetrahedron. it is specific to the particular microphone as the capsules vary a good deal. you can listen to the front pair (or the rear pair) as "stereo" but that is not what this is for.
B-format is a universal format, independent of the microphones used. It is a recording made by four theoretically accurate microphones - one Omni (called W) and three figure of eight microphones in the X, Y and Z axes. To go from one to the other requires calibration and software. We are providing both.
B format files can be played on a wide variety of programs. they can also be converted to stereo or binaural or 5.1. We are providing some software for doing this, but there are many more available, and most of them are free and open source.
What modifications do you make to the Zoom H2n for the Brahma built into the Zoom reward level? ($899)
The Zoom H2n undergoes several physical and electronic modifications to enable high quality ambisonic recording. Apart from replacing the original 10 mm capsules with 14 mm capsules in a tetrahedral arrangement, the grill is modified to improve transient response of the system and the capsules themselves are individually matched to the preamp circuitry in the ZoomH2n.
Moreover, this system comes with several goodies: a basket windshield, over which one can mount either a thin fabric cover or a thick furry, depending on wind conditions, an adaptor and a shockmount.
This is a great deal for those who want a complete system for ambisonics recording without any additional spending.
Can you give more details about the Brahma Volver tool? Will that be something you will offer? I know there are other softwares which can convert from A-format, but it would be nice to know about Brahma Volver.
Brahmavolver was developed at the University of Parma's team led by Prof Angelo Farina. Prof Farina has also helped us in developing the calibration system. We are providing it as part of a set of programs to allow users to start using their Brahma systems immediately.
Brahmavolver is available for Windows and Mac, and there are plans to port it to Linux distributions.
There are several A-B conversion utilities most of the free. The problem is that most of them require the calibration filters written in a particular form. We are at the moment producing filters to use with Brahmavolver, but it should not be too difficult to create filters for other programs - Fons Adriansen's Tetraproc, or Dave McGriffy's VV Mic (which can be used, post A-B conversion, even now).
If someone were deciding between a Tetramic and the Brahma, what would you tell them. Why would they choose yours, assuming they already had a mic-preamp?
We have so far avoided doing a one-to-one comparisons, but here are 5 reasons.
1. Price - if you take the standalone Brahma microphone the price is between a half and a third of the Tetramic, after you bought all the cables and adaptors you need for a four channel balanced output. Brahma standalone cost includes a small box which outputs 4 balanced XLR signals from the Brahma, as well as a windshield and shock mount.
2. Better Signal to Noise ratio - Our capsules diaphragms are significantly bigger, this would mean a higher output as well as a less noisy microphone. We use TSB140A electret capsules that have a v rounded frequency response and have a good reputation in the mic builders forums.
3. Better Calibration - Inspite of using larger capsules our microphone diaphragms are actually much closer because of our original capsule holding tetraheadron as well as the shape of our electret capsule. We 3d Print our Tetrahedron capsule holder. We are expecting our calibration process will be as good as any in the market.
4. Better RF shielding - There should be less RF and hum pickup because of the stainless steel mesh surrounding the Brahma Tetrahedron.
5. Windshield and other accessories - All versions of the Brahma Microphones come with windshields and shock mounting systems, that we don't charge extra for unlike most other microphone companies. We hope to deliver all accessories in the price of the microphone so that on unboxing it can be directly connected to a 4 channel recorder and is ready to record at no additional cost.
Out of interest will you still be supplying the microphones if you don't reach the full funding amount?
Our plan is to make the mics no matter what, it'll just be a lot harder. We had hoped that abt 40 people could back us with this development by picking up at least the Brahma Standalone. In any case we'll make a great set of ambisonics mics and get them reviewed and sell at a higher price than what we're offering now.
If we don't make our target the current backers won't get charged.
If we don't meet our target, we'll ask our current backers if they'd still like to preorder a mic and assuming we get 10-15 people saying yes we'll go ahead with everything on schedule, and deliver by Feb 2014. I'm still hopeful a lot more people will respond as there are still quite a few days left, but let's see.
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