SSS.6.17 - Research Supplement: Razor, Sandman-S, Trash Panda, and Radiant Further Analysis
/Rugged Razor, Dead Air Sandman-S, Q Trash Panda, and Rugged Radiant on a .308WIN Bolt Action Rifle with 20-inch Barrel
The previous Sound Signature Reviews of the Rugged Razor (6.16), Dead Air Sandman-S (6.11), Q Trash Panda (6.4), and Rugged Radiant (6.12) presented typical sound signatures of the silencers on a .308 bolt-action rifle with an 20-inch barrel. In PEW Science testing, the Razor achieved a Suppression Rating of 28.4. The Sandman-S achieved a rating of 32.6. The Trash Panda achieved a rating of 33.1. The Radiant achieved a rating of 32.9. Detailed muzzle and ear Suppression Ratings of the silencers are provided in the respective reviews.
This members-only research supplement is intended to provide more information to PEW Science members with regard to specific sound signature characteristics of the tested configurations in the aforementioned reviews and to help frame objective loudness comparisons between the four silencers. This supplement is part of ongoing PEW Science small arm weapon system sound signature research.
The four silencers in this comparative analysis were included based upon their similar or overlapping categories of physical characteristics and performance parameters, such as length, weight, suppression, and back pressure.
Below, summaries are presented for a four-way comparison of first round pop (FRP) and 5-shot average sound performance. Detailed data and analysis follows.
Overall Summary:
The Rugged Radiant exhibits superior muzzle performance (which correlates to bystander perception) in both first round pop (FRP) and on average. The Q Trash Panda exhibits superior at-ear performance (which correlates to shooter perception) in both FRP and on average. The Rugged Razor is louder, overall, than the Sandman-S, Trash Panda, and Radiant, but has an FRP at the muzzle similar in magnitude to that of the Trash Panda, albeit with a higher pitch. The Trash Panda earns the highest Suppression Rating overall, and seems to exhibit a “lower pitched” sound signature than the Sandman-S, as shown in analytical human inner ear modeling. The Radiant is slightly louder at the ear than the Trash Panda. The Radiant’s low frequency signature may sound exaggerated to shooters, compared to the Trash Panda, resulting in a possible “lower pitched” subjective impression.
FRP Summary:
When paired with a .308 bolt-action rifle with a 20-in barrel, the Q Trash Panda may have an FRP up to approximately 2.5% less intense than that of the Rugged Razor, 1.0 m left of the weapon muzzle. The FRP of the Dead Air Sandman-S may be up to approximately 52% less intense than that of the Razor. The FRP of the Rugged Radiant at the muzzle is the quietest and 56% less intense than that of the Razor.
At the shooter’s ear, the Trash Panda may have an FRP up to approximately 1% less intense than that of the Sandman-S, and up to approximately 41% less intense than the Razor. It is likely that the Sandman-S will be perceived by the shooter as louder and higher-pitched than the Trash Panda. It is possible that the Radiant may sound louder to the ear than the Sandman-S during the first round.
5-Shot Average Summary:
When considering a 5-shot average, the Trash Panda may have a sound signature up to approximately 20% less intense than that of the Razor, 1.0 m left of the weapon muzzle. The sound signature of the Sandman-S may be up to approximately 43% less intense than that of the Razor. Similar to FRP, the average sound signature of the Rugged Radiant at the muzzle is the quietest and 47% less intense than that of the Razor.
At the shooter’s ear, when considering a 5-shot average, the Sandman-S may have a sound signature up to approximately 33% less intense than that of the Razor. The sound signature of the Trash Panda may be approximately 39% less intense than that of the Razor. On average, the Radiant signature at the ear is approximately 35% less intense than that of the Razor. The Trash Panda is predicted to sound lower-pitched to shooters, on average, than the Sandman-S. The Radiant is louder than the Trash Panda at the ear but may have an exaggerated lower tone.
6.17.1 Comparisons of Muzzle Waveforms Measured in the Free Field
It is not always possible to determine relative, objective loudness from only the measured average peak sound pressure amplitude and measured peak sound pressure momentum transfer potential (impulse). Therefore, the Suppression Rating also considers physical ear response to measured sound signatures. The human inner ear responds to different sound pressure frequencies with varying sensitivity. Physically, these frequencies excite different regions of the basilar membrane within the cochlea. The human ear is typically most sensitive to sounds that excite the membrane near a frequency of 4,000 Hz. However, the ear may be exercised, and therefore damaged, at different physical regions. It is postulated that this inner ear response directly correlates to the perceived loudness of suppressed small arms.
PEW Science Research Note: As stated in previous Research Supplements, it is important not misconstrue the frequency-domain data in this Research Supplement with a simple frequency analysis (Fourier transform) of the time-domain overpressure waveforms presented in the reviews. The data shown in this research supplement is the output from analytical human inner ear modeling with the measured test data used as free-field overpressure loading input.
6.17.1.1 FRP Muzzle Comparisons
Figure 1 presents the results of an inner ear analysis performed using measured sound overpressure waveforms from the first shots in the three previous tests presented in Sound Signature Reviews 6.4, 6.11, 6.12, and 6.16. The curves show normalized physical response of the human inner ear as a function of basilar membrane location within the cochlea and corresponding sensitivity frequencies. Fig 1a shows the response on the vertical axis with a linear scale. Fig 1b and Fig 1c show the same data on a logarithmic scale, in the low and high frequency hearing response regimes, respectively. Note that the data is normalized; this lets you see the relative theoretical ear response for the three silencers. To personnel located 1.0 m left of the weapon muzzle, the Q Trash Panda may have an FRP up to approximately 2.5% less intense than that of the Rugged Razor, 1.0 m left of the weapon muzzle. The FRP of the Dead Air Sandman-S may be up to approximately 52% less intense than that of the Razor. The FRP of the Rugged Radiant at the muzzle is the quietest and 56% less intense than that of the Razor.
Note that In the low frequency response regime, the Trash Panda is the quietest during the first shot, whereas the Radiant and Sandman-S sound similar. In the high frequency regime, the Radiant is the quietest at the muzzle during the first shot.
Fig 1a. Comparison of FRP Human Inner Ear Response - .308 at the Muzzle (Linear Scale)
Fig 1b. Comparison of FRP Low Frequency Human Inner Ear Response - .308 at the Muzzle (Log Scale)
Fig 1c. Comparison of FRP High Frequency Human Inner Ear Response - .308 at the Muzzle (Log Scale)
6.17.1.2 Five-Shot Average Muzzle Comparisons
Figure 2 presents the results of a second inner ear analysis performed using measured sound overpressure waveforms from the tests; this time, the curves are averages of the analysis of the five shots in each test. Fig 2a shows the response on the vertical axis with a linear scale. Fig 2b and Fig 2c show the same data on a logarithmic scale, in the low and high frequency hearing response regimes, respectively. Note that the data is again normalized. When considering a 5-shot average, the Trash Panda may have a sound signature up to approximately 20% less intense than that of the Razor, 1.0 m left of the weapon muzzle. The sound signature of the Sandman-S may be up to approximately 43% less intense than that of the Razor. Similar to FRP, the average sound signature of the Rugged Radiant at the muzzle is the quietest and 47% less intense than that of the Razor.
Fig 2a. Comparison of Average Human Inner Ear Response - .308 at the Muzzle (Linear Scale)
Fig 2b. Comparison of Average Low Frequency Human Inner Ear Response - .308 at the Muzzle (Log Scale)
Fig 2c. Comparison of Average High Frequency Human Inner Ear Response - .308 at the Muzzle (Log Scale)
PEW Science Research Note: There is a high frequency bias noted at the muzzle during the FRP of the Razor that may be perceived by bystanders as higher-pitched than the Trash Panda. After FRP, this bias is still present but because the Razor’s sound signature continues to be elevated, it will most likely be perceived as louder to bystanders regardless of tone perception. After the first shot, the Radiant’s low frequency signature at the muzzle matches that of the Trash Panda and it is still the quietest in the high frequency range.
6.17.2 Comparisons of Waveforms Measured near the Shooter’s Ear
The sound signatures measured at the ear during the tests of each silencer are significantly different than those measured at the weapon muzzle and this difference is not only shown in the average peak sound pressure and impulse measurements, but also with inner ear analysis.
6.17.2.1 FRP Ear Comparisons
Figure 3 presents an inner ear analysis performed using measured sound overpressure waveforms at the shooter’s right ear from the first shots in the three tests. Fig 3a shows the response on a linear vertical scale. Fig 3b and Fig 3c show the same data on a logarithmic vertical scale, in the low and high frequency hearing response regimes, respectively. To personnel firing the weapon, the Trash Panda may have an FRP up to approximately 1% less intense than that of the Sandman-S, and up to approximately 41% less intense than the Razor. The Radiant possesses an FRP at the ear approximately 36% less intense than that of the Razor. It is likely that the Sandman-S will be perceived by the shooter as louder and higher-pitched than the Trash Panda. It is possible that the Radiant may sound louder to the ear than the Sandman-S during the first round.
Note the bias in the sound signature of the Sandman-S at 4,000 Hz and above. There is also a low-frequency bias during FRP below 2,000 Hz in which the Sandman-S has similar signature to the Razor. The Radiant has a varying low frequency signature with a high frequency signature similar to that of the Sandman-S above 8,000 Hz.
Fig 3a. Comparison of FRP Human Inner Ear Response - .308 at the Ear (Linear Scale)
Fig 3b. Comparison of FRP Low Frequency Human Inner Ear Response - .308 at the Ear (Log Scale)
Fig 3c. Comparison of FRP High Frequency Human Inner Ear Response - .308 at the Ear (Log Scale)
6.17.2.2 Five-Shot Average Ear Comparisons
Figure 4 presents the results of a second inner ear analysis performed using measured sound overpressure waveforms at the shooter’s ear from the tests; this time, the curves are averages of the analysis from the five shots in each test. Fig 4a shows the response on the vertical axis with a linear scale. Fig 4b and Fig 4c show the same data on a logarithmic vertical scale, in the low and high frequency hearing response regimes, respectively. Note that the data is again normalized. At the shooter’s ear, when considering a 5-shot average, the Sandman-S may have a sound signature up to approximately 33% less intense than that of the Razor. The sound signature of the Trash Panda may be approximately 39% less intense than that of the Razor. On average, the Radiant signature at the ear is approximately 35% less intense than that of the Razor. The Trash Panda is predicted to sound lower-pitched to shooters, on average, than the Sandman-S.
Fig 4a. Comparison of Average Human Inner Ear Response - .308 at the Ear (Linear Scale)
Fig 4b. Comparison of Average Low Frequency Human Inner Ear Response - .308 at the Ear (Log Scale)
Fig 4c. Comparison of Average High Frequency Human Inner Ear Response - .308 at the Ear (Log Scale)
PEW Science Research Note: In the five-shot average analysis the high-frequency bias of the Sandman-S is still discernible to the shooter at 4,000 Hz and above. This analysis of measured test data indicates that the Sandman-S may be perceived as having a “higher pitched” sound signature to the shooter, on this weapon system. This conclusion is not immediately obvious when examining data measured at the muzzle alone. This correlation and the potential correlation to anecdotal shooter impressions are both the subjects of continued PEW Science research interest. The Radiant is slightly louder at the ear than the Trash Panda, and because it has a more intense low frequency component but a very similar high frequency component, its low frequency signature may sound exaggerated to shooters, on average, compared to the Trash Panda, resulting in a possible “lower pitched” subjective impression.
6.17.3 Research Supplement Summary
Overall Summary: The Rugged Radiant exhibits superior muzzle performance (which correlates to bystander perception) in both first round pop (FRP) and on average. The Q Trash Panda exhibits superior at-ear performance (which correlates to shooter perception) in both FRP and on average. The Rugged Razor is louder, overall, than the Sandman-S, Trash Panda, and Radiant, but has an FRP at the muzzle similar in magnitude to that of the Trash Panda, albeit with a higher pitch. The Trash Panda earns the highest Suppression Rating overall, and seems to exhibit a “lower pitched” sound signature than the Sandman-S, as shown in analytical human inner ear modeling. The Radiant is slightly louder at the ear than the Trash Panda. The Radiant’s low frequency signature may sound exaggerated to shooters, compared to the Trash Panda, resulting in a possible “lower pitched” subjective impression.
This supplement is part of ongoing PEW Science small arm weapon system sound signature research. PEW Science thanks you for your support.
