The LT-PMS (Long Throw-Planar Magnetic Speaker) series is a collection of speakers designed specifically for long throw, speech transmission. Tailored with a frequency response that is perfectly match for the voice range, the LT-PMS planar systems can transmit a live or prerecorded spoken message with perfect articulation(1). Even at maximum volume, the sound remains absolutely clear and distortion is virtually undetectable.
The secret to the LT-PMS exceptional performance is the MAD-1 planar driver. This highly efficient, full range speaker when used in a single driver configuration, has a frequency response from 180 Hz to 18 KHz. In addition, the diaphragm’s extremely low mass produces a lightning fast response which explains why the LT-PMS systems have such exceptional clarity and intelligibility. With just one driver, the commanding power, throw distance, and vocal clarity from a single speaker is startling. When multiple drivers are used together in a single enclosure, the acoustical results are absolutely staggering!
The seven speakers in this series are all built around the same MAD-1 driver. The speaker’s model number indicates how many drivers are used in each unit. As more drivers are combined together, two significant performance characteristics change. The speaker produced greater volume and the dispersion pattern tapers down into a smaller, tighter area. With a tighter pattern and more available power, these speakers can produce a longer throw while maintaining their clarity and volume. Since the volume from planar speakers falls off at a much lower rate than conventional speakers, typically 1.5 dB for each doubling of distance, the potential working distance from the LT-PMS devices is unmatched by any other product.
Actual distance and SPL performance may vary from the distances listed as a result of adverse weather conditions, variable atmospheric conditions, variations in the physical terrain, and other unpredictable human factors.
Potential throw distances & coverage angles for LT-PMS speakers
|Number of Drivers*
| 1 w/Wave Guide
|| 50-200 meters
|| 30°H x 20°V
| 2 w/Wave Guides
|| 20°H x 20°V
| 4 w/Wave Guides
|| 200-600 meters
|| 15°H x 15°V
|| 6 w/Wave Guides
| 300-800 meters
|| 10°H x 10°V
|| 24 w/o Wave Guides
|| 600-1200 meters
|| 5°H x 5°V
|| 24 w/Wave Guides
|| 650-1300 meters
|| 5°H x 5°V
|| 54 w/o Wave Guides
|| 800-1400 meters
|| 3°H x 3°V
|| 54 w/Wave Guides
|| 850-1500 meters
|| 3°H x 3°V
|| 96 w/o Wave Guides
|| 1000-2000 meters
| 2°H x 2°V
*All of the LT-PMS speakers can be equipped with a wave guide assembly. By mounting this four-sided acoustical device in front of the driver, the mid-band's acoustical output is increased and the speaker’s overall sensitivity is elevated by approximately 5 dB. The chart above shows how the speaker’s throw distance is increased when using the wave guide compared to identical devices without the wave guide.
LT series speaker are all powered and include a 3 input mixer to accommodate one microphone and 2 line inputs. In addition some units are battery powered and can operate at maximum volume for over 10 hours on a single charge. Other options available on selected models include the following.
• Tripod mounts for stationary ground support.
• Custom mounts to attach speakers to bicycles, ATV (All Terrain Vehicles), golf carts, utility vehicles, cars & trucks, boats and aircraft.
• A motorized pan and tilt assembly to allow precise remote aiming and control.
• A wireless headset microphone system that can be used with any LT speaker.
The clarity and size of the LT-PMS series makes them a powerful tool especially in situation where clear and articulate verbal instructions or commands must be understood. Applications where LT-PMS systems are currently in use include:
• Law Enforcement: bicycle and patrol cars, crown control, SWAT mobile command centers.
• Military Training: training facilities, mobile command centers & check-points.
• Harbor Patrol: safety, security, & drug interdiction.
• Maritime: hailing and security.
In recent months, the Los Angels Police Department (LAPD) and the Orange County Sheriff Department have used several LT-PMS models to help maintain civil order at events where thousands of people had gathered for public demonstrations. Of one particular event with the LAPD, Deputy Chief Mike Hillman wrote to Vahan Simidian, CEO of HPV Technologies, with these observations about the effectiveness of their MAD speakers.
Thank you so much for all of your help. I have heard so much about you and your dedication to public safety and finally, I was able to meet you.
You have a tremendous reputation within our community. The new audio system has revolutionized the way bicycle patrol officers do their job."
As you can see we (LAPD) have a lot of heart and need your assistance. I believe your product will greatly enhance our (as well as others) ability to manage crowds. Your attention to our needs cannot be appreciated enough.
You are great. Thanks!
Deputy Chief Mike Hillmann, LAPD”
Mr. Vahan Simidian II:
Thank you very much for your support and dedication in assisting local law enforcement agencies. Your cooperation with the Los Angeles Police Department has been greatly appreciated. You have enhanced our communication abilities with the use of your Magnetic Audio Devices. Deputy Chief Hillmann extends his appreciation and authorizes you to quote him in saying, 'This new audio system has revolutionized the way bicycle patrol officers do their job'.
Sergeant Eric Lee
Officer in Charge, Bicycle Coordination Unit
Training Division , LAPD”
LAPD Patrol Bicycle w/LT-PMS-1/BM
& wireless microphone
• To obtain application information on any LT-PMS speaker, click here.
• For specifications on the LT-PMS speakers, click here.
• For additional technical explanations about MAD's Planar technology, go to the MAD Technical pages.
• For more information on the physics of sound and loudspeaker design,
In 2007, an independent testing laboratory performed articulation tests on the LT-PMS speakers where they achieved a 100% perfect score on the word intelligibility test.