Author Archives: Acoustic Magic

An Interesting Podcast by Conference Rooms Systems About Acoustic Magic

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Conference Room Systems is a well regarded AV integrator that puts together VoIP conferencing system packages for easy implementation n by its customers. These packages have been designed meticulously by their engineers and installers using only the best components available on the market. Voice Trackers are included in many of their packages.

We recently sat down with Conference Room Systems for a podcast about Acoustic Magic and our products:


Read The Full Interview Here

Connecting a Voice Tracker II array microphone to an iPhone or iPad

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We often get inquires on how to use the Voice Tracker II with iPads and iPhones for enhanced recording range, and for inexpensive conferencing/telemedicine.

There are two “tricks” for doing this.

First, a TRRS splitter is required. This is connected to the 3.5mm jack on the iPad or iPhone and creates separate 3.5mm connections for the mic and loudspeaker. See the photo of such a splitter. Such splitters are readily available commercially.

Second, the output impedance of the Voice Tracker II must be adjusted to match the expectation of the iPad/iPhone. These devices require an input impedance of less than 10Kohm. If the output impedance of the mic in higher than that, the iPhone/iPad will default to their internal mic.

The output impedance of the Voice Tracker II is higher than that, so an adapter is needed in the 3.5mm cable to reduce the output impedance to below 10K.

When the Voice Tracker is connected thru the TRRS splitter and impedance adapter, you can hear the improved pickup range:

 

Because the Voice Tracker II has built in acoustic echo cancellation, it can be used with iPads or iPhones for inexpensive conferencing. Connect the speaker jack from the TRRS splitter to the ref in jack on the Voice Tracker II, and connect an external powered computer loudspeaker to the speaker out jack on the Voice Tracker II. Provide power to the Voice Tracker II from USB battery, or a USB wall power supply. Then run a VoIP app on the iPhone or iPad.

See the photo below. Note the thicker 3.5 cable to the middle jack on the VT II (the audio out jack). That is the impedance adapter.

If you are using Zoom or Skype for Business as the VoIP App, they have good AECs, so the AEC in the Voice Tracker II is not required.

This reduces the number of cable connections (clutter). You can then connect the speaker jack from the TRRS splitter directly to the loudspeaker. See the photo below.

Bob Feingold

Bob@AcousticMagic.com

Using Voice Tracker Array microphones in open area Huddle Rooms

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A well known eastern insurance company is employing Voice Tracker I microphones throughout cubicle areas to facilitate Skype for Business based collaboration meetings.

The Voice Tracker is mounted, together with a camera, on top of a large display monitor. A loudspeaker bar is mounted below the display.

Also below the display is a shelf to hold a laptop. The participants bring along their laptop, place it on the shelf, and connect it for the meeting. The team then stands around the monitor to engage in their conversation.

The Voice Tracker picks up the talkers around the monitor, and ranges of 25 feet or more, and with an extremely wide field of view.

The Voice Tracker I can be used since the AEC in Skype for Business is robust enough to adjust to the Voice Tracker’s listening beam as it moves rapidly from talker to talker. The Voice Tracker II can also be employed, using its own internal fast adapting AEC.

The Voice Tracker’s low cost make it possible to build several huddle areas on each floor.

The Growing Legitimacy of Array Microphones

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Acoustic Magic exhibited at InfoComm for the first time this year.

We learned a great deal.

The professional audio world is now taking array microphones seriously and the catalyst for this is the MXA 910 array microphone from Shure, a respected Pro-Audio microphone leader.

Two other companies introduced array microphones, so there are now six or seven companies offering array microphones for conferencing.

The good news is that all these competitors price their microphones much, much higher than the Voice Tracker. And according to a lot of our Resellers, these competitive microphones do not perform any better than our microphone. In some cases, they don’t perform as well.

Part of the reason for this is that they use a different technology. The Shure microphone, the Clear One microphone, and the Phoenix Audio microphone create several listening beams that are fixed (but adjustable) to cover certain parts of the room (where talkers are expected to be).

In contrast, The Voice Tracker creates a scanning listening beam so one beam covers the entire room. A single beam is inherently less complicated, and less expensive. And with our technology you can’t miss talkers that happen to be in between the competitor’s listening beams.

The Shure MX a 910 is $4500 (plus mounting Hardware)

The ClearOne Beamformer Array is ~$2500 (plus it must be connected to a ClearOne DSP)

The Condor from Phoenix Audio is ~$1200

New Products:

The CS- 700 from Yamaha/Revolabs is $1200 (includes speaker and camera, but it has a small array that is only good to 12 feet)

The HDL 300 from a new Company called NUreva is $3000.

So clearly, we have a big cost advantage. Several Resellers told me this is their “secret weapon”.

From one reseller: “I just did a demo up against a competitor that was using a Shure MXA910 array microphone. The customer didn’t notice much of a difference between that and a VT I. I won the deal because on a $78,000 lecture system, I was $1,800.00 less than my competitor, and I went in with 50% mark-up. Nice, huh? Keep up the good work!”

From another Reseller: “I had to work too hard to make the Clear One work”.

Several Resellers came to our booth to tell us how great the Voice Tracker was. That made us feel good.

16 years of experience with array mics makes a difference.

Combining Two Voice Tracker I For Greater Room Coverage

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Note the Voice Tracker I mount on the ceilingTwo Voice Trackers can be combined for greater room coverage.

Outstanding sound quality can be achieved by connecting them through a mixer. I prefer mixing them through a Biamp Tesira digital signal processor. This allows me to adjust gain and frequency response to achieve terrific sound quality.

For example, I installed two Voice Tracker I in a 60 foot room, with one mounted on the ceiling in each end of the room. I invert one Voice Tracker I in the DSP meaning the tip and shield are reversed, so that way I don’t get any cancellation and get excellent, uniform pickup throughout the room. You can hear the talker perfectly anywhere in the room. The mics worked so well that they had to install weather stripping under the edges of their computer flooring tiles because you could hear noise from the tiles when they walked around. Pretty impressive. Take a look at the pics, you can just see the mics up at the ceiling.

Note the Voice Tracker I mount on the ceilingSince the cables runs are long, 89 feet in the 60 foot room, I convert the unbalanced signal from the Voice Tracker Is to balanced.

The microphone is just one small part of an expensive AV system, but it’s so important. I can do a better job with two VT Is than I can with a $4,000 Shure ceiling mic, believe it or not. All of my clients are impressed as heck with our systems’ speech quality. Just have to know audio and be innovative. I love this business, even after 43 years in it…finding your microphones has been a blessing for me, especially after all of my colleagues saying that these are not pro audio microphones. I just say let me demo it, and win every time so far except once, and that time they had me come back and change out their system after another contractor screwed it up..

Martin E. Pilewski
Lead, Systems Design
Harvest AV Solutions
1340 Burlington
North Kansas City, MO 64116

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.

StarTech-splitter

StarTech-splitter

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.

Conference Room Systems chooses the Voice Tracker™ II array microphone for their “All on the Wall” package

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Acoustic Magic Inc. is pleased to report that the well regarded AV integrator Conference Room Systems has selected the Voice Tracker II array microphone for several of their conference room and huddle room pre-packaged systems.

“These USB-based systems have been designed meticulously by our engineers and installers using only the best components available on the market” says Hugh Richards, President of CRS. “We have thoroughly tested each system to ensure functionality between components, operating systems, and web conferencing software so you can be confident that our solutions will work for you”.

According to Matthew Davis, CRS project manager, the Voice Tracker II is a key component of the packages because it is able to pick up talkers at long-range at various positions throughout the room. Additionally, it’s built-in AEC enables it to work with a wide range of VoIP systems, including those that do not have a robust AEC. “The 20+ foot pickup range, wide field of view and sound quality of the Voice Tracker II array microphone exceeds that of array microphones that are 3 to 5 times more expensive “. “Additionally, the Voice Tracker has proven to be reliable and easy to use.”

If the VoIP system has a robust AEC, Davis sometimes recommends the Voice Tracker™ I array microphone. The Voice Tracker™ I array microphone does not have a built-in AEC, which is not necessary if the VoIP system’s AEC is effective. For example, “we tested it with Zoom and the combination works well. The Voice Tracker™ I microphone has even greater pickup range (in excess of 30 feet) than the Voice Tracker II.”

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.”