VR

Model VR
A Sentry Siren Model VR-10 located in Jersey Village, TX. It is one of the only Model VR sirens in existence. Photo credit to Andrew Eidel.
Company	Sentry Siren, Inc.
Produced	2018-2020
Type	Omnidirectional Electronic
Sound output	120 dB (claimed)
Wattage	600-3200 W
Succeeded by	Model SV-8
Documentation	Product sheet

The Model VR is an electronic siren that was produced for a short time by Sentry Siren. Being Sentry's very 1st attempt to enter the electronic siren market, the Model VR was only produced for a short time as Sentry failed to establish a foothold in the market. It was later succeeded by the Model SV-8.

History

The Model VR was announced and introduced in 2018 on Sentry's website. The siren was advertised as a Giant Voice siren, being intended to function as a public address and notification system prioritizing voice clarity over raw sound output. This meant that it would be able to be clearly heard and understood over a great distance, which was the siren's main selling point, but aside from this the Model VR performed rather poorly as a siren due to its high-pitched and ineffective tone and mediocre sound output. The Model VR was a complete failure for Sentry and very few examples were ever produced due to being a niche product that was poorly marketed. In addition, Sentry's overall preference for mechanical sirens caused their attention to be focused away from the Model VR. This combined with the siren's overall performance lacking compared to competing sirens such as the Modulator or WPS-2900 led to the siren's quiet discontinuation in 2020. This wouldn't be Sentry's last attempt to enter the electronic siren market, however, as Sentry later announced the Model SV-8, which succeeded it in 2023. Today, only a handful of units exist, with a few units installed in Jersey Village, TX, while others were installed at a school campus.

Design

The 3 size options that were available for the Model VR; from left to right, the Model VR-1, Model VR-5, and Model VR-10.

The Model VR utilizes a varying number of HyperSpike MA speakers connected to a custom-built controller made by Sentry themselves, with 3 different sizes of speaker being available. The controller is limited to either 4 siren tones, voice messages, or a combination of the 2. The alert tone generated peaks at 800 Hz, which is not as effective as a lower tone. Each speaker is made up of 5-30 speakers and is available in 3 different sizes. Each speaker array contains 1-6 speakers per direction, in 5 different directions. The siren uses no horns to project the sound, instead using cone speakers attached to the drivers in order to provide a clear broadcast at the cost of overall range. To compensate for this, the siren runs at a higher voltage, with the smallest model, the 5-speaker Model VR-1, using up 600 W of power. Each speaker is contained inside a frame, with the Model VR-1 coming in a cube-shaped frame while the Model VR-5 and Model VR-10 come in a rectangular frame, with the speakers stacked vertically. The Model VR-1 has 5 speakers and runs on 600 W, the Model VR-5 has 15 speakers and runs on 1375 W, and the Model VR-10 has 30 speakers and runs on 3200 W. Each speaker is protected by a mesh screen to keep moisture out. These were advertised by Sentry as reaching up to 120 dB at 100 ft while having an incredible speech transmission index (STI) rating of 0.91 out of 1.00.

Gallery

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  A Model VR-5 mounted on a tripod at the Sentry Siren facility in Canon City, CO. A Model 14V is visible in the background.