SSS.6.30 - YHM Resonator K and the Q mini FIX 300 BLK Subsonic
/YHM Resonator K on a Q mini FIX 300 BLK with 8-in Barrel
The Resonator K is designed and manufactured by YHM. It is a 30 caliber centerfire rifle silencer, intended to suppress most cartridges with projectiles appropriately sized to travel through the bore, including 300 Remington Ultra Magnum. It has a 1.56-inch diameter and is 4.8 inches in length without a mount. The silencer possesses 1-3/8”-24tpi rear mount capability and includes the YHM Phantom Q.D. adapter and a muzzle brake or flash hider mount. The included mount adapter results in a silencer system length of 5.65 inches. The user may choose to use third-party mount adapters that interface with the rear mount thread. The silencer is tubeless and constructed of heat-treated 17-4 stainless steel with a a heat treated 718 Inconel blast baffle. The silencer weighs 15.7 ounces with the Phantom Q.D. adapter and brake, as tested. The silencer weighs 9.5 ounces with no mount, as tested. The Resonator K can be obtained from Silencer Shop.
This review contains single-test results using the Resonator K 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 Subsonic Target ammunition, the YHM Resonator K with the Phantom Q.D. muzzle brake achieved a Suppression Rating™ of 40.9 in PEW Science testing.
6.30.1 Resonator K Sound Signature Test Results
A summary of the principal Silencer Sound Standard performance metrics of the Resonator K 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. YHM Resonator K Sound Metric Summary
6.30.1.1 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 3-millisecond long sequence of events during the first test shot with the Resonator K, as measured 1.0 m left of the muzzle. There are six significant events shown:
During firing system manipulation (trigger and striker actuation) the signature reaches a 108.0 dB amplitude.
The next peak of 119.3 dB occurs during combustion within the weapon system.
Subsequent first round combustion inside the silencer produces a peak amplitude of 120.4 dB.
As the pressure pulse exits the silencer, an initial peak of 145.6 dB is measured.
Jetting increases out of the silencer end-cap, and a 147.1 dB peak occurs.
The maximum peak pressure amplitude of the first shot is measured to be 148.0 dB.
This is a somewhat atypical sequence observed when firing subsonic 300 BLK ammunition from a bolt-action weapon system with an attached silencer. Internal silencer design can significantly influence the measured timing and pressure amplitudes.
Fig. 1 Early-Time Shot History, YHM Resonator K Bolt Action 300 BLK Muzzle Sound Pressure Signature, 24-OCT-2020
One distinguishing feature of the signature shown in Figure 1 is the immediate rise to a significant peak amplitude during the end-cap exit event. This is postulated to occur as a result of the compact size of the Resonator K. For comparison, the reader is encouraged to examine the subsonic 300 BLK test first round signatures of the Q Half Nelson in Sound Signature Review 6.29 and the Energetic Armament VOX S in Sound Signature Review 6.25. One notable difference between the early-time signature of the Resonator K and those two silencers with subsonic 300 BLK is the significantly higher amplitude of the end-cap exit event with the Resonator K. Overall subsonic 300 BLK performance comparisons of the two silencers are shown in Section 6.30.2 of this review.
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.
Fig 2a. YHM Resonator K Bolt Action 300 BLK Muzzle Sound Pressure Signature, 24-OCT-2020
Fig 2b. YHM Resonator K Bolt Action 300 BLK Muzzle Sound Pressure Signature, Short Time Window, 24-OCT-2020
Figure 3a. YHM Resonator K Bolt Action 300 BLK Muzzle Sound Impulse Signature, 24-OCT-2020
Figure 3b. YHM Resonator K Bolt Action 300 BLK Muzzle Sound Impulse Signature, 24-OCT-2020
Figure 2 shows a significant pressure regime first-round-pop (FRP). Figure 3 shows the same phenomenon in impulse space. The first round pop is postulated to be significantly noticeable to bystanders, as determined by PEW Science inner-ear response analysis.
An interesting behavior noted in the muzzle measurements is that the combined end-cap exit and jetting events after the first shot are lower than that during FRP. This phenomenon illustrates that due to the small size of the Resonator K, the initial pulse out of the silencer as the bullet leaves the end-cap also contains significant combustion byproducts. This can also be seen in the impulse waveform history immediately prior to 30 ms, at which time the first shot possesses higher impulse than all other subsequent shots, well before peak impulse from primary jetting.
PEW Science Note 1: After FRP, the initial combined end-cap exit events are extremely consistent between shots in impulse space. It is postulated that the abnormal early-time FRP behavior is a result of the YHM’s perforated blast baffle, coupled with the presence of only three primary baffles; a configuration conducive to relatively high gas flow rate, and often more severe sound signature amplitude.
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.
PEW Science has also evaluated the Resonator K on the supersonic 7.62x51mm bolt action platform. The results of that testing are the subject of a future PEW Science Sound Signature Review. With subsonic 300 BLK, the Resonator K is louder to bystanders than the Energetic Armament VOX S and Q Half Nelson. Direct comparisons are provided in Section 6.30.2, below. The FRP of all three silencers is noticeable to bystanders. In-depth comparison of the sound signatures of these silencers is the subject of a future PEW Science Member Research Supplement.
6.30.1.2 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.
Figure 4a. YHM Resonator K Bolt Action 300 BLK Ear Sound Pressure Signature, 24-OCT-2020
Figure 4b. YHM Resonator K Bolt Action 300 BLK Ear Sound Pressure Signature, Short Time Window, 24-OCT-2020
Figure 5a. YHM Resonator K Bolt Action 300 BLK Ear Sound Impulse Signature, 24-OCT-2020
Figure 5b. YHM Resonator K 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.
In PEW Science inner-ear modeling of the at-ear sound signatures, FRP at the shooter’s ear appears to be less pronounced than FRP at the muzzle. Although at-ear FRP is still present, it is postulated that personnel shooting the weapon system may perceive there to be less FRP than bystanders observing the weapon system being fired. The comparison of FRP signatures to shooters and bystanders is the subject of a future PEW Science Member Research Supplement.
Note the very similar pressure and impulse magnitudes of all shots 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.
PEW Science Note: The sound signature at the ear with the Resonator K when firing subsonic 300 BLK on the Q mini FIX is significantly louder than with the Q Half Nelson and noticeably louder than with the Energetic Armament VOX S. This is evident in both pressure and impulse measurements, as well as in detailed PEW Science inner-ear response analysis, which is the subject of a future PEW Science Member Research Supplement.
6.30.2 Suppression Rating Comparison - Subsonic 300 BLK
The YHM Resonator K suppressor is intended to possess adequate sound suppression performance in a compact size. Figure 6 shows a performance comparison of the three .30 rifle silencers tested with the subsonic 300 BLK cartridge shown in public PEW Science testing, to date. 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 Data 300 BLK Subsonic Test Data
Note that the performance of the YHM Resonator K at the weapon muzzle, which is an indicator of nearby bystander sound signature perception, is lower than that of both the Energetic Armament VOX S and Q Half Nelson. At the shooter’s ear, the performance gap with the Resonator K is smaller, with its at-ear Suppression Rating less than 6 points away from that of the VOX S. This indicates that although bystanders will experience a significantly higher sound signature suppressing subsonic 300 BLK with the Resonator K when compared to the VOX S, the difference to personnel firing the weapon may not be as great. However, it is important to note that the difference in signature between the Resonator K and VOX S with subsonic 300 BLK is noticeable, and the Q Half Nelson silencer is significantly quieter than both of them. At the ear, the Half Nelson is almost 15 Suppression Rating points higher, denoting a drastic difference in signature. The Resonator K is an objectively louder silencer. Bolt-action host weapon testing allows strict isolation of sound suppression performance variables.
Back pressure characteristics of the YHM Resonator K in the supersonic flow regime is the subject of ongoing PEW Science research. PEW Science members help fund such research efforts; PEW Science thanks you for your support.
6.30.3 Review Summary: YHM Resonator K 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 Subsonic Target ammunition, the YHM Resonator K with the Phantom Q.D. muzzle brake achieved a Suppression Rating™ of 40.9 in PEW Science testing.
PEW Science Subjective Opinion:
The YHM Resonator K is a very compact, relatively lightweight, and durable .30 rifle silencer. The Resonator K is versatile in that it may be used on many cartridges and with a variety of third-party mount adapters. The user should note that it is a compact silencer and therefore its sound signature suppression performance is lower than that of larger silencers in both the subsonic and supersonic flow regimes.
The Resonator K contains four baffles. The ported Inconel blast baffle is unique among them, as the three primary baffles are an iteration of a curved cone with center “mill-cut” similar to those used by SilencerCo, Rugged, Dead Air, and a variety of other manufacturers. The ported blast baffle in conjunction with the presence of only four total baffles results in a silencer that exhibits relatively high flow rate and significantly less sound signature suppression than larger silencers.
The included YHM Phantom Q.D. mount adapter and muzzle brake is relatively simple to operate. The mount system is ratcheting and a true “QD” system with coarse threads on the brake (or flash hider) and tooth-engagement notches. The mounts possess a taper interface forward of the coarse threads; a welcome feature to avoid debris build-up in the thread interface. The user may choose to use aforementioned third party mount adapters with the Resonator K. Note that third party mounts may influence the allowable barrel length and cartridge restrictions used with the Resonator K; the user is encouraged to contact the YHM prior to selecting a mounting system for their desired use case.
Small rifle silencers may still offer acceptable performance for users on the subsonic 300 BLK platform. However, it is also important to note that the subsonic 300 BLK cartridge is intended to excel at highly reduced sound signature. Users primarily concerned with sound signature suppression on this platform should know that they will not achieve high performance with the Resonator K.
On subsonic 300 BLK, the Suppression Rating Performance delta between the Resonator K and the Energetic Armament VOX S, for example, is significant at the muzzle and less significant at shooter’s ear; albeit noticeable. Detailed waveform and inner-ear response comparisons of the two silencers is the subject of a future PEW Science Member Research Supplement.
As stated in the previous review of the Q Half Nelson, first round pop (FRP) performance in the subsonic flow regime is lower with compact silencers, and the Resonator K is very compact. Note that the use of different third party mounts may influence the FRP of the Resonator K, but it is postulated that the influence is not significant, given the size of this silencer.
In this review, the Resonator K 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.
