Category Archives: Array Microphones

Mic’ing an Entire Middle School Stage with Two Voice Tracker I Array Microphones

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We just did an installation in which we replaced 12 hanging choir microphones with two Voice Tracker I array microphones to cover an entire middle school stage, 50 feet wide by 30 feet deep. The Voice Trackers were much better than the 12 hanging mics for live sound re-enforcement.

Voice Tracker on Stage
The Theater Director is thrilled with the outcome. They just did a big speaking play (no choral singing), and didn’t use any other microphones at all. I was able to hear everything perfectly in the audience.

We placed the 2 Voice Tracker microphones on the sidewalls, mounted vertically and pointed inward towards the stage. See the diagram below and the photographs. The Voice Tracker is the black line near the flag on the sidewall.

We converted the Voice Tracker’s unbalanced output signal to a balanced audio signal with a RD LTX J2 summing transformer to prevent humming.

We used a dedicated compressor limiter on each microphone and adjusted as necessary to provide superior gain before feedback.

See this PDF diagram with set up instructions.

Martin Pilewski
Harvest Productions, Inc.
Kansas City, MO

Using the Voice Tracker™ Array Microphone as an External Microphone to an iPhone

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People use our Voice Tracker™ array microphones to record meetings, or for conferencing, because of its long pickup range (20 to 30 feet) and 360° field of view.

Our Voice Tracker™ array microphones are designed to be connected to PCs or other devices either through a 3.5 mm analog audio connection (through a soundcard) or a USB connection. The Voice Tracker I has only an analog output, but can he be easily converted to USB using a USB adapter like our part 102A. The Voice Tracker™ II has both an analog audio output and a USB audio output.

Their analog outputs are at mic level, with low impedance, and work well with sound cards. The boost in the soundcard is designed to bring the output up to usable levels. High levels of boost can be employed because of the good signal-to-noise ratio in the microphones.

From time to time we have received inquiries about connecting the Voice Tracker™ microphones to an iPhone (or other smart phones). Initially, this couldn’t be done because the iPhone required a very specific output impedance from the external microphone. If the impedance didn’t match what the iPhone was looking for, it would default to the built-in microphone.

Fortunately, impedance matching connectors have become available to eliminate this roadblock.

KVconnections adapter

KV connections adapter

We have tested an “ iPhone 1/8 inch microphone adapter to 3.5 mm four conductor TRRS male” adapter from KV connection (part number code KM-iPhone-mic), and it works just fine. Similar adapters are available from other manufacturers. Rode has told us that their adapters also match the iPhone’s impedance requirement, but we have not tested one.

Note that when the KV connection adapter was connected to the iPhone, we lost the speaker output.



This can be corrected by first connecting a” 3 .5 mm 4 pin to 2 x 3 pin 3.5 mm headset splitter adapter” to the iPhone.  This adapter is available from companies like StarTech. The arm labeled microphone was connected to the Voice Tracker, and the arm labeled headset was connected to our PC speaker to create a long-range speakerphone with the Voice Tracker I as the mic and the PC speaker as the speaker.

The Best Way to Record Audio in a Courtroom

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Using Voice Tracker I array microphones in Court for sound reinforcement as well as proceedings recording.

Getting microphone coverage in a courtroom is a challenging task. Depending on the type of proceeding, coverage may be needed not only at the Judge’s bench, Witness chair, and Attorney tables, but coverage may also be required at the Jury box for Jury polling, or at the Gallery for Voir Dire (Jury selection).

Historically this was accomplished by using large numbers of goose neck, wireless or ugly hanging microphones, combined thru elaborate mixing systems.

The automatically and electronically steered listening beam of the Voice Tracker I array microphone provides an economical and easily maintainable alternative.

In the hands of expert Lead Designer Martin Pilewski from Harvest Productions in North Kansas City, Missouri, Voice Tracker I array microphones not only cover the “recording gaps” in the courtroom layout, but also solve a variety of sound reinforcement needs.

An example would be the setups at the 16th Circuit Court of Jackson County Courthouses in downtown Kansas City and Independence Missouri.

One Voice Tracker I microphone is mounted in front of the witness chair. There is no gooseneck microphone for the witness to play with (and misalign or break). With the addition of a compressor in the output of the Voice Tracker, the witness can’t escape being picked up, or overpower the microphone with loud speech or coughing. The compression also provides unique gain-before-feedback capabilities, while the microphone’s beam steering provides the perfect defense against highly reverberant spaces.

Another Voice Tracker I is mounted on the ceiling near the jury box to capture questions/polling from the Jurors. Two are mounted above the left and right side of the Gallery to provide pick up of potential Jurors during Voir Dire. These three usually can cover the ground in between in case the attorneys move about. The pick up pattern of the microphones is such that anyone speaking up to 35 feet away in the pattern can be heard as if the microphone were placed directly in front of them. This eliminates the need to use wireless mics, which adds complexity to the system and suffers from the fact that sometimes their batteries run out.

Voice Tracker I’s also work well at the Judge’s bench, almost too well, as caution must be taken in the system design to be able to mute the microphone to the PA system during side-bar conversations. This rule also applies to the Attorney table’s, where more often a conventional gooseneck microphone would be used as conferring with a client could be picked up by accident. Pilewski recommends a temporary push-to-mute arrangement as Attorneys may sometimes fail to turn their mics back on after conferring, another annoyance that can easily be avoided.

The multiple Voice Trackers are powered from a single, regulated DC power supply to save real estate that would otherwise be taken up by multiple “wall warts”. Martin then converts their audio outputs to balanced via a simple transformer, and compresses their outputs to provide more controlled gain structure.

The balanced microphone outputs go to a Biamp Tesira, where Martin does just a little EQ to improve sound quality.

The audio is available in several modes for recording, as well as a hearing loop broadcast. Most of the time they are set up for FTR recording, but in Harvest Production Systems, output is available in analog, headphone and USB connections so courtroom personnel can record or transcribe them however they want. The systems are also set up for VoIP and networking.

Touch panel control systems are set up for the Judges and Clerks to provide intuitive, simple control. According to Pilewski “The sound system should be transparent, allowing people to speak and be able to hear that speech as a natural extension of the normal voice. Only the Judge should be able to be overly loud. The sound system should be a help, not a hindrance, so simple control is a must. We see way too many control systems with too small screens requiring the user to descend through several pages to get to what they need to do.”

Because the Voice Trackers are so sensitive, Martin has to be careful to eliminate feedback from the sound reinforcement loudspeakers in the courtroom. He uses a mix minus in the Biamp, and that, combined with the compression, eliminates the need for speaker feedback exterminators. Martin uses small Atlas 10 watt 1/4rack space amplifiers for the mix minus.

The economic advantage of the Voice Tracker array microphones is compelling. Four Voice Trackers cost just a little more than $1000. More importantly, all audio is captured.

Besides installing these systems in several court rooms, Pilewski has utilized Voice Tracker array microphones in board rooms for meeting recording and in medical operating rooms for a high-tech “intercom” so the operating doctors can confer with experts during the operation. Harvest Productions also uses the Voice Tracker™ II array microphone for internal videoconferencing.

“The USB version, the VoiceTracker II, is perfect for groups of people using VoIP based conferencing. When used by a group in a room, the VT II’s on-board acoustic echo-cancelling removes the need for “muting”. Simply have individuals with their own devices that join the meeting wear headphones, and the groups use the VTII, and you’ve solved your acoustic echo cancellation problems.”

How To Properly Position The Voice Tracker Array Microphone In Different Rooms

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One of the questions you may ask yourself is “where do I place the Voice Tracker Array Microphone to optimize performance?” Let us help you with the following tips.

How Best To Use The Voice Tracker Array Microphone In Different Rooms

With these tips learn how to best use the Voice Tracker array microphone in different rooms.

Conference Room

Although the Voice Tracker picks up through an impressive 360° field of view, it is more sensitive from the front. Therefore, when placing the Voice Tracker on a conference table, we recommend situating it towards the front of the conference table pointing towards the far end.

Classroom Lecture Recording

For classroom recording, it is often placed on the podium in the front of the room, facing the rear of the room. This position helps to best pick up both the professor’s and the student’s voices.


hamish-commentOften, users want to place the Voice Tracker on the ceiling to remove clutter from the conference table or to reduce the possibility that the microphone will “walk off”.

If the Voice Tracker is placed on the ceiling, the same positioning rules apply- place it near the front of the room pointing towards the rear. Note that if you place it on the ceiling you will have a longer audio cable to run to the PC or other microphone input device. The Voice Tracker I has an unbalanced analog output through a 3.5 mm Jack, so 3.5 mm audio extension cables work fine.

The Voice Tracker™ II has both USB audio output and analog audio output. Since there are restrictions on the length of USB cables, and USB extension cables often do not work well, we recommend using the analog audio output for long runs. If you are using the AEC feature in the Voice Tracker™ II, you’ll need two 3.5 mm audio extension cables, one for the audio out of the Voice Tracker and one for the reference signal in. You also need to provide power to both the Voice Tracker I and the Voice Tracker™ II, using a wall power supply.

The Voice Tracker I has a built-in ceiling mount. There is a weight in its base to give it heft. The weight can be unscrewed (making the Voice Tracker I very light). Removing the weight reveals 4 screw holes so the Voice Tracker can be attached (upside down) to the ceiling. The microphone array itself can be swiveled to point slightly downward.

The Voice Tracker™ II also has a weight in the base that can be removed. It comes with a ceiling mounting plate that is connected to the screw hole that holds the weight.

Note that the Voice Tracker array microphone has background noise correction algorithms to filter out stationary noise from fans, air conditioner docs etc. If the microphone is placed too close to such a noise source, the algorithm can create some distortion in the audio output (voices sound like they are underwater); so be sure to locate the Voice Tracker away from such noise sources. The long pickup range of the microphone should make such placement possible.

Large Rooms

If the room is large, or reverberant, you may want to combine the output of 2 or more Voice Trackers. This can be done easily combining the analog outputs through a simple 3.5 mm Y or a mixer. If the room is wider than it is long, place both Voice Tracker’s toward the front of the room, pointing towards the rear. If it’s longer than its wide, place one (or more) in the front and one (or more) in the back.

Experience The Difference In Acoustic Magic Voice Tracker Array Microphones

Whichever type of room you are using your array microphone in, you can be confident in knowing that Acoustic Magic Voice Tracker Array Microphones will give you the best clarity, noise reduction and functionality. Learn more about our innovative.

Questions? Call Us Now!

Which Voice Tracker Should I Get?

The question we probably get most often is which Voice Tracker model should we purchase?

Some people think that because the Voice Tracker™ II is newer and more expensive it is “better”. But actually, which one is better depends on the application.

Voice Tracker

Taking A Look At The New Voice Tracker II, Compared To Voice Tracker I

Here’s a closer look at the new Voice Tracker II, compared to the Voice Tracker I:

Voice Tracker I

The Voice Tracker I is targeted at meeting and lecture recording applications. It has more microphone elements in its array and a wider aperture than the Voice Tracker™ II, therefore, it has longer pickup range. It is a little easier to use than the Voice Tracker™ II (it only has one connection into the PC, which is the analog audio cable to the soundcard) so it requires less IT support.

This is important to schools that may have 50 or more Voice Tracker’s in various classrooms but not a large IT support team. It is also less expensive than the Voice Tracker™ II, which is important to schools with tight budgets and a lot of classrooms to “mic”. It is easy to combine several Voice Tracker I models using a simple mixer or 3.5 mm Y’s.

Voice Tracker II

The Voice Tracker™ II is targeted at VoIP conferencing and distance-learning applications. It has a built-in acoustic echo canceler for those situations where there is not an echo canceler available in the system the Voice Tracker is connected to (or the AEC in the system is not robust). But the Voice Tracker™ II’s pickup range is a little less than the Voice Tracker I, 20 feet in front rather than 30 feet.

Additional Factors To Consider When Deciding Which Voice Tracker You Should Get

There are other considerations that may lead you to choose one model versus the other:

  1. The Voice Tracker I can be used for conferencing if it is connected to a system that has a good built-in acoustic echo canceler (AEC). Voice Tracker I’s have been connected to conventional conferencing systems like LifeSize, Polycom, ClearOne, etc. or can be connected to a VoIP systems with good AEC’s like Zoom.
  2. The Voice Tracker™ II is more portable. It is powered by USB. This (combined with its smaller size) improves its portability since it can be powered from a laptop. The Voice Tracker I must be powered from its wall power supply.
  3. The Voice Tracker™ II has both a USB audio output and an analog audio output. Consequently, several Voice Tracker™ II’s can be combined (like the Voice Tracker I) using the analog outputs connected to a simple mixer or a combination of Y’s. But if the acoustic Echo cancellation feature is being used, each Voice Tracker II must receive a reference sample of the signal going to the loudspeaker. This makes the wiring connections a little more complicated.

How To Choose The Right Voice Tracker Array Microphone

Using the above comparison and factors will help you choose the right Voice Tracker array microphone for you or your company’s needs. Both Voice Trackers are multipurpose microphones. Besides meeting recording or conferencing applications they can be used for hands-free/headset free automatic speech recognition with products like Dragon NaturallySpeaking. The Voice Tracker™ II actually is a little better for this application because its smaller pickup range minimizes spurious words from talkers across the room (if there are any).

Compare Voice Tracker I and Voice Tracker II for yourself with our easy ! When you are ready, go here to buy the array microphone that best fits you and your company’s needs.