SSS.6.38 - EA VOX S (Wiped) and the Q mini FIX 300 BLK Subsonic
/Energetic Armament VOX S (Wiped) 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 silencer in this review was tested with a wipe installed. The wipe material used is fabric-reinforced 70A durometer silicone rubber, of 0.125 inch total thickness. 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 with an installed wipe 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. The following should be noted by the reader:
Twenty (20) shots were fired in the test used to generate data analyzed for this report. The PEW Science Suppression Rating computation in this review only considers the first five (5) shots fired, to maintain consistency with published PEW Science data and Suppression Rating Rankings, to date.
First-round-pop (FRP) through an un-punctured virgin wipe is still significant and may be influenced by membrane puncture. Test data indicates that post-puncture sound suppression increases, with a gradual decrease in sound suppression performance upon continued wipe damage. PEW Science postulates that wiped FRP sound suppression performance may increase by using pre-perforated wipes. However, it is further postulated that pre-perforated wipes will be less effective at mitigating FRP of silencers with severe unwiped FRP. More testing is needed.
Due to the initial increase in sound suppression after FRP, then gradual decrease in Suppression Rating upon continued wipe damage, the suppressed weapon system performance will shift on the Suppression Rating scale during continued suppressed weapon system operation.
Based upon PEW Science analysis of the test results presented in this review, sound suppression performance is postulated to remain above the presented 5-shot Composite, Muzzle, and Ear ratings for the duration of at least a 20-shot continuous string of fire.
Wiped use of a silencer is non-standard and should be performed with extreme caution by the suppressed weapon system operator. PEW Science recommends that the use of wipe materials in a silencer end cap be in accordance with the silencer manufacturer’s instructions. The type, material, geometry, thickness, condition, installation, and other factors may influence system behavior.
Wiped silencer use induces purposeful mechanical interaction of the projectile (bullet) with a barrier (wipe), in the weapon system. Accuracy of the weapon system may also be negatively influenced, significantly, by this mechanical interaction. Serious injury or death can result from improper use not in accordance with silencer manufacturer instructions.
Summary: When paired with the Q mini FIX 8” 300 BLK and fired with Discreet Ballistics 190gr Target ammunition, the EA VOX S with an installed wipe in the direct-thread configuration achieved a Suppression Rating™ of 58.9 in PEW Science testing.
The unwiped performance of the VOX S with subsonic 300 BLK is detailed in previous Sound Signature Review 6.25, in which it achieved a Suppression Rating of 48.4. Sound Signature Review 6.3 showcases the supersonic .308 performance of the unwiped VOX S, in which it achieved a Suppression Rating of 29.5.
6.38.1 VOX S (Wiped) Sound Signature Test Results (Direct Thread)
A summary of the principal Silencer Sound Standard performance metrics of the VOX S (Wiped) in its direct thread configuration is shown in Table 1. Data in the table is based on the first five (5) shots of this twenty (20) shot test. 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 (Wiped; Direct Thread Configuration) Sound Metric Summary
6.38.1.1 SOUND SIGNATURES AT THE MUZZLE
Real sound pressure histories from a 20-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 2.6-millisecond long sequence of events during the first test shot of the VOX S, through a virgin unpunctured wipe, as measured 1.0 m left of the muzzle. There are seven significant events shown:
During firing system manipulation (trigger and striker actuation) the signature reaches a 107.0 dB amplitude.
The next peak of 118.6 dB occurs during combustion within the weapon system.
As the bullet impacts, deforms, and begins to pierce the wipe membrane, a pressure pulse is emitted and an initial peak of 128.5 dB is measured.
The combustion gasses are momentarily retained within the silencer by the wipe; upon mechanical crack initiation by bullet impact in (3), the fracture propagates at the sound-speed within the two rubber layers of wipe material. Upon eventual complete bullet exit and wipe failure, this membrane burst produces the N-wave shown with a positive phase peak of 134.2 dB.
The pause in gas flow due to peak mechanical deformation of the wipe, and subsequent rupture, is evident upon the signature return from rarefaction at a positive phase decay amplitude of 101.8 dB.
Gas jet velocity is throttled by the wipe’s new orifice and the first major gas jet is measured to possess an amplitude of 135.8 dB.
Finally, throttled gas jetting increases out of the wipe’s orifice, and a 137.5 dB peak occurs. This is the maximum peak pressure amplitude of the first shot. Subsequent gas jetting is long duration.
This is a highly atypical subsonic 300 BLK sound signature from a bolt-action weapon system with an attached silencer. The FRP signature is unique in that it possesses a significant membrane rupture feature from the wipe puncture and extreme gas propagation delay in addition to excessive gas pulse from FRP combustion. As always, internal silencer design can significantly influence the measured timing and pressure amplitudes. Wiped FRP can be significant.
Fig. 1 Early-Time Shot History, EA Vox S (Wiped) Direct Thread Configuration Bolt Action 300 BLK Muzzle Sound Pressure Signature, 26-SEP-2020
The primary sound signature pressure histories for all 20 shots are shown in Figure 2a. The individual shot waveforms are color-coded in groups of 5, in accordance with time order, to illustrate wipe damage influence on sound signature. 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 20-shot test are shown in Figure 3. Again, full and short timescales are shown.
Fig 2a. EA Vox S (Wiped) Direct Thread Configuration Bolt Action 300 BLK Muzzle Sound Pressure Signature, 26-SEP-2020
Fig 2b. EA Vox S (Wiped) Direct Thread Configuration Bolt Action 300 BLK Muzzle Sound Pressure Signature, Short Time Window, 26-SEP-2020
Figure 3a. EA Vox S (wiped) Direct Thread Configuration Bolt Action 300 BLK Muzzle Sound Impulse Signature, 26-SEP-2020
Figure 3b. EA Vox S (Wiped) Direct Thread Configuration Bolt Action 300 BLK Muzzle Sound Impulse Signature, 26-SEP-2020
Figure 2 shows a significant pressure regime first-round-pop (FRP). Note the disappearance of the N-wave membrane rupture portion of the sound pressure signature after the first shot. The wipe has ruptured and now is both free to let the projectile pass with reduced mechanical interference, yet still throttle jetting of combustion gasses.
PEW Science Note 1: Sound suppression performance of a wiped system is at its peak in the second shot, immediately after the initial wipe puncture from the first shot. Although the membrane rupture itself may not contribute significantly to sound impulse accumulation, the time-dependent orifice behavior post-puncture may influence initial gas jetting. This phenomenon, along with anecdotal observations, supports the hypothesis that pre-perforated wipe material may increase wiped FRP performance. However, it is further postulated that if the silencer has poor FRP performance without a wipe, the benefits of a pre-perforated wipe will be less pronounced. The FRP signature of the VOX S may not benefit from a pre-perforated wipe on this platform. This the subject of future PEW Science research.
PEW Science Note 2: Figure 3b shows 5 waveforms in impulse-space. Note the pronounced FRP waveform (highest of the black group in Figure 3a) and the lower amplitude Shot 6 (blue group in 3a). As the shots progress during the test, and the wipe is continuously damaged, Shot 12 and 16 (red and green group in 3a) are shown to have increasing amplitude (3b). The impulse waveform of Shot 20 reaches almost the same amplitude of the FRP waveform. This does not mean that Shot 20 is as loud as Shot 1. On the contrary, the discretized Suppression Rating of the shots actually differ by a category (note the extreme differential in impulse rise time). However, this extremely similar end result of peak impulse amplitude between that of Shot 1 and Shot 20 does illustrate the gas flow increase and the decrease in suppression performance directly correlated with wipe damage from continuous firing. Furthermore, the rates of initial impulse accumulation clearly trend upward with wipe damage, indicating a decrease in back pressure as the wipe orifice size becomes larger. This is consistent with the postulations of the Rev.2 PEW Science back pressure hypothesis.
PEW Science Note 3: 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. The FRP is severe. When using a wipe, the FRP is still severe, but not of the same magnitude as when the silencer is used in the unwiped configuration on this platform. Suppression Rating performance, overall, is significantly increased with the use of a wipe. As noted in the introductory notes in this review, significant cautions must be observed during wiped use and projectile accuracy detriments are expected to occur with unpredictable results.
6.38.1.2 SOUND SIGNATURES AT SHOOTER’S EAR
Real sound pressure histories from the same 20-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 20-shot test are shown in Figure 5. Full and short timescales are shown.
Figure 4a. EA Vox S (Wiped) Direct Thread Configuration Bolt Action 300 BLK Ear Sound Pressure Signature, 26-SEP-2020
Figure 4b. EA Vox S (Wiped) Direct Thread Configuration Bolt Action 300 BLK Ear Sound Pressure Signature, Short Time Window, 26-SEP-2020
Figure 5a. EA Vox S (Wiped) Direct Thread Configuration Bolt Action 300 BLK Ear Sound Impulse Signature, 26-SEP-2020
Figure 5b. EA Vox S (Wiped) Direct Thread Configuration Bolt Action 300 BLK Ear Sound Impulse Signature, 26-SEP-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 N-Wave from wipe membrane rupture is evident in the pressure history of Shot 1 in Figure 4b, as it was measured 1.0 left of the silencer end cap. The wipe membrane rupture sound signature is evident at the shooter’s position.
Again, as presented in the analysis of the sound signature measured at the weapon muzzle, the waveforms in impulse-space in Figure 5b illustrate initial sound suppression performance increase after FRP with gradual increase of loudness. This loudness shifting trend, directly correlated to wipe damage, is observed by both the shooter and bystanders. FRP is also severe to both parties. The reduction in FRP perception to the shooter by used pre-perforated wipe membranes is the subject of future PEW Science research.
6.38.2 Unwiped vs. Wiped Sound Signatures with Subsonic 300 BLK
The Energetic Armament VOX S suppressor is intended to possess light weight, relatively high durability, and moderate sound suppression performance. The use of a wipe in the VOX S end cap is intended to significantly increase sound suppression performance when compared to unwiped suppressor use. Figure 6 shows a performance comparison of the four .30 rifle silencers tested with the subsonic 300 BLK cartridge shown in public PEW Science testing, to date, along with the wiped performance of the VOX S detailed in this review. Unsuppressed and suppressed Suppression Ratings are shown for both the shooter and bystanders.
Figure 6. Suppression Rating Comparisons Of .30 Rifle Silencers Using PEW-SOFT 300 BLK Subsonic Test Data
The wiped Suppression Rating of the VOX S, to both the shooter and bystanders, is a category higher than its unwiped Suppression Rating. This indicates a significant increase in sound suppression performance with the use of a wipe. Interestingly, the Q Half Nelson (from Sound Signature Review 6.29) possesses a Suppression Rating at the shooter’s ear on this platform that is almost equal to that of the wiped VOX S (the Half Nelson cannot use a wipe). The difference in muzzle Suppression Rating is more pronounced, which indicates that bystanders may perceive the sound signature of the wiped VOX S to be much quieter than that of the Half Nelson on this host weapon platform. This conclusion is reasonable, given the extreme gas propagation delay exhibited by wiped systems. This phenomenon is detailed below.
Figure 7 presents a comparison of the FRP sound signatures of the unwiped and wiped configurations, 1.0 m left of the end cap. Note the continuity in the presence of the initial pressure pulse generated by the subsonic bullet end cap exit event between 29.9 ms and 30 ms (either through the unwiped free orifice or through piercing the membrane in the wiped test). Then, note the N-wave generation by wipe membrane burst and the approximate 0.2 ms delay of gas jet propagation initiation in the wiped system ending at approximately 30.2 ms. This prevents the major jet shown in the unwiped waveform from occurring. Both waveforms show FRP, but the wiped system shows significant gas jet delay when compared to that of the unwiped system. Figure 8 presents the same comparison, this time of Shot 2 with both configurations. The significant gas jet suppression of the wiped configuration is clear.
Figure 7. EA Vox S (Unwiped and Wiped) Direct Thread Configuration Bolt Action 300 BLK Muzzle Sound Pressure Signature Comparison (FRP)
Figure 8. EA Vox S (Unwiped and Wiped) Direct Thread Configuration Bolt Action 300 BLK Muzzle Sound Pressure Signature Comparison (Shot 2)
Figure 9 and Figure 10 present the same data as shown in Figure 7 and Figure 8, but this time in impulse-space. Both the peak amplitude and the rate of rise to peak amplitude differ significantly between the wiped and unwiped configuration. Therefore, it is observed that wiped use of the VOX S may significantly increase back pressure. This intuitive conclusion from practical observation of wiped suppressed weapon system use, along with the previously presented observation of initial impulse slope increase proportional to wipe damage (orifice size), are consistent with the postulations of the Rev.2 PEW Science back pressure hypothesis.
Figure 9. EA Vox S (Unwiped and Wiped) Direct Thread Configuration Bolt Action 300 BLK Muzzle Sound Impulse Signature Comparison (FRP)
Figure 10. EA Vox S (Unwiped and Wiped) Direct Thread Configuration Bolt Action 300 BLK Muzzle Sound Impulse Signature Comparison (Shot 2)
6.38.3 Review Summary: Energetic Armament VOX S (Wiped) 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 with an installed wipe in the direct-thread configuration achieved a Suppression Rating™ of 58.9 in PEW Science testing.
The unwiped performance of the VOX S with subsonic 300 BLK is detailed in previous Sound Signature Review 6.25, in which it achieved a Suppression Rating of 48.4. Sound Signature Review 6.3 showcases the supersonic .308 performance of the unwiped VOX S, 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.
Interestingly, the Q Half Nelson possesses a Suppression Rating at the shooter’s ear on this platform that is almost equal to that of the wiped VOX S (the Half Nelson cannot use a wipe). This empirically and quantitatively demonstrates that louder silencers can achieve the Suppression Rating of quieter silencers with subsonic ammunition by using a wipe, which is a well-known anecdotally observed phenomenon. However, the use of a wipe is also associated with severe ancillary performance detriments, to include accuracy unpredictability, only short-term suppression performance gains, and inefficient FRP mitigation for silencers that exhibit significant unwiped FRP.
It is also worth noting (as stated in the unwiped subsonic 300 BLK review of the VOX S) that the overall Suppression Rating of the unwiped 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 unwiped 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. This review illustrates that the use of the wipe with the VOX S will bring its Suppression Rating to Q Half Nelson levels on this platform, at the shooter’s ear. Again, the FRP is still severe, albeit lower than in the unwiped configuration. The capability to use a wipe may be attractive to some users. PEW Science encourages the reader to review the notes given in the introduction to this review.
In this review, the wiped 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. Wiped use of a silencer, if not in accordance with silencer manufacturer instructions, may result in serious injury or death.
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.
