SSS.6.25 - EA VOX S and the Q mini FIX 300 BLK Subsonic
/Energetic Armament VOX S on a Q mini FIX 300 BLK with 8-in Barrel
The VOX S is manufactured by Energetic Armament. It is a 30 caliber centerfire rifle silencer, intended to suppress most cartridges with projectiles appropriately sized to travel through the bore, including 300 RUM. It has a 1.55-inch diameter and is 5.9 inches in length when using the direct-thread adapter. The user may choose to use other third-party adapters compatible with the 1.375”-24tpi system. The silencer is tubeless and constructed of heat treated C300 nickel-cobalt maraging alloy, with the end cap and direct thread adapter being constructed of 17-4 PH stainless steel and Grade 5 titanium, respectively. The silencer weighs 12.5 ounces with the direct thread adapter. An optional wipe and wipe-retainer may be used which increase the weight by 0.4 ounces. The VOX S can be obtained by your local dealer from the distributor Allen Arms Tactical.
This review contains single-test results using the VOX S on the Q mini FIX bolt action pistol, chambered in 300 BLK with an 8-inch barrel. Discreet Ballistics 190gr ammunition was used in the test.
Summary: When paired with the Q mini FIX 8” 300 BLK and fired with Discreet Ballistics 190gr Target ammunition, the EA VOX S in the direct-thread configuration achieved a Suppression Rating™ of 48.4 in PEW Science testing.
The performance of the VOX S on supersonic .308 is detailed in previous PEW Science Sound Signature Review 6.3, in which it achieved a Suppression Rating of 29.5.
6.25.1 VOX S Sound Signature Test Results (Direct Thread)
A summary of the principal Silencer Sound Standard performance metrics of the VOX S in its direct thread configuration is shown in Table 1. The data acquired 1.0 m (39.4 in) left of the muzzle is available for viewing to all. This is a members-only review and includes pressure and impulse waveforms measured at the shooter’s ear. PEW Science thanks you for your support; further testing, research, and development of PEW-SOFT and the Silencer Sound Standard is made possible by members like you!
Table 1. EA VOX S (Direct Thread Configuration) Sound Metric Summary
6.25.1.1 SOUND SIGNATURES AT THE MUZZLE
Real sound pressure histories from a 5-shot test acquired with PEW-SOFT™ are shown below. The waveforms are not averaged, decimated, or filtered. The data acquisition rate used in all PEW Science testing is 1.0 MS/s (1 MHz). The peaks, shape, and time phasing (when the peaks occur in relation to absolute time and to each other) of these raw waveforms are the most accurate of any firearm silencer testing publicly available. PEW-SOFT data is acquired by PEW Science independent testing; the industry leader in silencer sound research. For more information, please consult the Silencer Sound Standard, here.
Figure 1 shows a 2-millisecond long sequence of events during the first test shot of the VOX S, as measured 1.0 m left of the muzzle. There are four significant events shown:
During firing system manipulation (trigger and striker actuation) the signature reaches a 107.9 dB amplitude.
The next peak of 115.9 dB occurs during combustion within the weapon system.
As the pressure pulse exits the silencer, an initial peak of 141.9 dB is measured.
Jetting increases out of the silencer end-cap, and a 145.8 dB peak occurs. This is the maximum peak pressure amplitude of the first shot.
This is the typical sequence observed when firing subsonic 300 BLK ammunition from a bolt-action weapon system with an attached silencer; however, internal silencer design can significantly influence the measured timing and pressure amplitudes.
Fig. 1 Early-Time Shot History, EA Vox S Direct Thread Configuration Bolt Action 300 BLK Muzzle Sound Pressure Signature, 24-OCT-2020
The primary sound signature pressure histories for all 5 shots are shown in Figure 2a. A zoomed-in timescale displays the region of peak sound pressure in Figure 2b. The real sound impulse (momentum transfer potential) histories from the same 5-shot test are shown in Figure 3. Again, full and short timescales are shown. Note that the Shot 2 data records are shifted forward in time by 0.5 ms in Figure 2b and Figure 3b to illustrate a direct comparison of Shot 1 and Shot 2 waveform timing. Trigger time differential is a result of PEW-SOFT system settings during the test.
Fig 2a. EA Vox S Direct Thread Configuration Bolt Action 300 BLK Muzzle Sound Pressure Signature, 24-OCT-2020
Fig 2b. EA Vox S Direct Thread Configuration Bolt Action 300 BLK Muzzle Sound Pressure Signature, Short Time Window,24-OCT-2020
Figure 3a. EA Vox S Direct Thread Configuration Bolt Action 300 BLK Muzzle Sound Impulse Signature, 24-OCT-2020
Figure 3b. EA Vox S Direct Thread Configuration Bolt Action 300 BLK Muzzle Sound Impulse Signature, 24-OCT-2020
Figure 2 shows a significant pressure regime first-round-pop (FRP). Note, however, the similarity in pressure magnitude of the combustion event early in time between Shot 1 and Shot 2. Another way to view this constant phenomenon is to examine the early-time momentum transfer potential (impulse) in Figure 3. This observation is directly comparable to that noted in the testing of this silencer on the supersonic .308 platform in Sound Signature Review 6.3. The small blip and plateau occurring at approximately 29.5 milliseconds is very similar in each shot when viewed in the impulse regime. The overall sound signature, however, differs after the first shot in both pressure and impulse space, solidifying the FRP conclusion, and should clearly illustrate what can change with silencer performance with a particular design and what can’t, from shot to shot.
PEW Science Note 1: Figure 2b illustrates significant signature change during Shot 2 starting at a time of approximately 30 ms. Note how the relatively severe jetting in Shot 1 is significantly suppressed in Shot 2 until almost 0.5 ms later, at which time Shot 2 reaches peak sound pressure. This phenomenon is well characterized in Figure 3b, in which two distinct waveform characteristics are noted; not only does the impulse record of the first shot have a faster rise-time (higher slope), it reaches its peak more quickly and the peak is of significantly higher magnitude than the second shot. The FRP signature of the VOX S is significant. This phenomenon in the measured test data is consistent with shooter and bystander perception in both PEW Science analytical inner ear modeling and anecdotal shooter and bystander observations.
PEW Science Note 2: First-round sound signatures always differ from subsequent shots, as the atmosphere within the silencer changes. The FRP phenomenon cannot always be shown by viewing only the peak sound pressure. This is one of the reasons why The Silencer Sound Standard requires examining multiple sound signature metrics.
The sound signature of the VOX S when suppressing subsonic 300 BLK significantly differs from its signature when suppressing supersonic .308. While the peak sound pressure is lower in this test, the impulse is significantly lower than measured in the .308 test. This phenomenon is a result of the significantly different propellant loads of the 300 BLK and .308 / 7.62x51mm cartridges.
6.25.1.2 SOUND SIGNATURES AT SHOOTER’S EAR
Real sound pressure histories from the same 5-shot test acquired with PEW-SOFT at the shooter’s ear are shown below. Again, the waveforms are not averaged, decimated, or filtered. The data acquisition rate used in all PEW Science testing is 1.0 MS/s (1 MHz).
The primary sound signature pressure histories at the ear for all 5 shots are shown in Figure 4. The primary sound signature history is shown on the left. A zoomed-in timescale is displayed on the right, in the region of peak sound pressure. The real sound impulse (momentum transfer potential) histories at the ear from the same 5-shot test are shown in Figure 5. Full and short timescales are shown. Again, note that the Shot 2 data records are shifted forward in time by 0.5 ms in Figure 2b and Figure 3b to illustrate a direct comparison of Shot 1 and Shot 2 waveform timing. Trigger time differential is a result of PEW-SOFT system settings during the test.
Figure 4a. EA Vox S Direct Thread Configuration Bolt Action 300 BLK Ear Sound Pressure Signature, 24-OCT-2020
Figure 4b. EA Vox S Direct Thread Configuration Bolt Action 300 BLK Ear Sound Pressure Signature, Short Time Window, 24-OCT-2020
Figure 5a. EA Vox S Direct Thread Configuration Bolt Action 300 BLK Ear Sound Impulse Signature, 24-OCT-2020
Figure 5b. EA Vox S Direct Thread Configuration Bolt Action 300 BLK Ear Sound Impulse Signature, 24-OCT-2020
Similar to the measurements at the muzzle, there is significant FRP evident when examining the waveforms measured at the shooter’s ear, and this is clearly observed in both Figure 4b and Figure 5b. Note that, again, the fast rise-time to peak impulse after silencer gas exit is evident in Shot 1. Also note the very similar pressure and impulse magnitudes during Shot 1 and Shot 2 prior to the gas completely exiting the weapon system. Even the subsonic 300 BLK platform creates measurable sound signature even before the gas completely exits the barrel and silencer.
The overall sound signature measured at the shooter’s ear possesses significantly less amplitude in both the pressure and impulse regimes than the signature measured at the muzzle (refer to Table 1). Furthermore, the application of both pressure and impulse at the shooter’s ear is delayed when compared to the pressure and impulse at the weapon muzzle. The combination of varying amplitude and rise time to peak amplitude influences the response of the human ear. Note the significantly lower impulse at the shooter’s ear in this test when compared to that in the .308 test.
6.25.2 Review Summary: Energetic Armament VOX S on a Q mini FIX 300 BLK with 8-in Barrel
When paired with the Q mini FIX 8” 300 BLK and fired with Discreet Ballistics 190gr Target ammunition, the EA VOX S in the direct-thread configuration achieved a Suppression Rating™ of 48.4 in PEW Science testing.
The performance of the VOX S on supersonic .308 is detailed in previous PEW Science Sound Signature Review 6.3, in which it achieved a Suppression Rating of 29.5.
PEW Science Subjective Opinion:
The EA VOX S is a machine gun rated silencer with a diameter and weight conducive to dual-use on semiautomatic or bolt-gun hosts. The ability to configure the silencer mounting scheme differently based upon mount type preferences may be attractive to some users.
It is interesting to note that the overall Suppression Rating of the VOX S on a bolt-action subsonic 300 BLK host weapon is similar to that of a high performing 30 caliber silencer on a bolt-action supersonic .308 host weapon. This performance similarity between two significantly different platforms highlights the wide variance in product sound signature performance in the current market. For example, the Thunder Beast ULTRA 9 actually achieves a slightly higher Suppression Rating at the shooter’s ear with supersonic .308 than the VOX S does with subsonic 300 BLK ammunition. This suppression performance differential is significant.
Clearly, the VOX S is not the quietest on the market. However, the silencer is advertised to be extremely durable. C300 material properties after continued temperature cycles within the temperature regimes of supersonic centerfire rifle semi- and fully-automatic firing schedules have not been evaluated by PEW Science and are a subject of continued research interest. Subsonic 300 BLK durability of the EA VOX S is expected to be a non-issue for all practical purposes. The durability of the various third-party mounts that interface with the VOX S are also a subject of research interest, as silencer durability is a function of the entire suppressed weapon system.
The wiped end-cap is an interesting addition to this silencer and has recently been evaluated by PEW Science. Test data with the EA VOX S in the wiped configuration will be published at a later date. The capability to use a wipe may be attractive to some users.
In this review, the EA VOX S performance metrics depend upon suppressing a subsonic intermediate rifle cartridge. While the sound signature of such cartridges can be suppressed to levels that may result in the desire of the shooter and bystanders to not wear hearing protection, PEW Science encourages the reader to remain vigilant with regard to all subsonic rifle cartridge suppression claims. The gas volume and combustion products created by firing a subsonic intermediate rifle cartridge such as 300 BLK are still significant; the measured pressure and impulse magnitudes, and their durations, illustrate this fact.
The hearing damage potential of subsonic rifle use is not insignificant. PEW Science encourages the reader to consider the Suppression Rating when deciding on an appropriate silencer and host weapon combination for their desired use.
