Primacoustic RX7 DF Recoil Stabilizer Isolation Pad
The Primacoustic RX7A Recoil Stabilizer Monitor Isolation Pad is a unique speaker mounting device that at once eliminates disruptive resonant coupling from the loudspeaker to the stand, while providing a stable base that reduces the recoil caused by the forward energy of the loudspeaker motion. The DF versions offers a 5º downward angle for those monitoring below their monitor height.
Made from three basic components, the Recoil Stabilizer is essentially a platform for the loudspeaker that features a high-density urethane base that isolates the speaker from the shelf, monitor-bridge or stand. This effectively decouples the loudspeaker to eliminate vibration-borne resonance to the substructure. A heavy laser-cut steel plate is added and sandwiched between the isolation layer and a no-slip neoprene top. The steel plate introduces significant mass to the structure and serves to stabilize the speaker. By reducing the backward 'recoil' energy as the speaker coil pushes energy forward, initial waveform transients no longer suffer lag and the sharpness of the resulting pulse is more defined. The result is significantly greater detail at all frequencies, with tighter bottom end and improved depth of field. The Recoil Stabilizer is available in various sizes and weights to address different speaker designs and may be ordered in both standard and custom angles to precisely aim the loudspeakers for critical listening environments.
How it WorksBefore we get into how the 'Recoil' works, it is worth understanding some of the scientific principles involved and what problems are actually being solved. Sound travels through air and other mediums in waves. These waves compress at various frequencies called the wavelength. Longer wavelengths tend to travel further while shorter ones travel in a more direct line. Longer wavelengths require more energy to generate and once in motion, are very difficult to contain. With sufficient energy, long wavelengths will cause walls and floors to vibrate. Thunder shaking your house is a very good example of lots of energy applied to a low frequency.
Ok, so what does this mean in human speak? Simply put, bass travels through just about anything while high frequencies are fairly simple to control. And has all of this got to do with near field monitors or reference loudspeakers? Those speakers produce bass and bass will transmit through the speaker stand to the floor, the walls and whatever is connected. This is called acoustic coupling. When sound vibrates in the speaker stands, they resonate and produce unwanted sound. To sum up, coupling causes a frequency bump at the resonant frequency which in turn changes the speaker's performance.
To solve the problem, engineers often employ urethane foam pads or other insulating materials under their nearfield reference monitors as a means to eliminate the resonance that occurs when the speaker and the speaker stand, (shelf or monitor bridge) couple. Good news: this does in fact effectively decouple the two devices. Bad news: it introduces a new problem that is best described as recoil.
Think of a riffle firing a bullet. The hammer strikes the firing pin which in turn causes the shell to explode, propelling the bullet forward. As the bullet pushes forward the rifle recoils backwards to absorb the energy. This is exactly what is happening when you place your speakers on a soft, spongy material; during a transient such as a sharp kick drum thump, the forward momentum of the speaker is dulled by foam as the soft malleable substance allows the speaker to tilt backwards and recoil. This 'recoil' may be desirable when firing a rifle, but with a loudspeaker, the movement dulls the initial transient at the start of the wave, and the result is predictable: you lose clarity and detail.
What we really need is to both decouple the source and provide a stable platform. The Recoil Stabilizer solves the problem by introducing a heavy mass on top of a high-density urethane isolation pad. By significantly increasing the mass of the base platform, the loudspeaker's forward momentum is no longer sufficient to move the platform backwards. It is stabilized and the recoil is significantly reduced.
If you think about it, this is exactly how a gyroscope works. Gyros are used in airplanes, torpedoes and missiles to stabilize the navigational system so that the device stays on course. By rotating a heavy mass very quickly (like the earth around itself - around the sun!) the centrafugical force retains the gyro's position relative to all axes. Since we need only control the effect from the speaker excursion in a single axis (front to back) we do not need a centrafugical force to steady the device, we can do the job with a simple, heavy steel platform that acts as the stabilizing mass.
This heavy platform is in turn, sandwiched between the isolation pad and a non-slip neoprene layer. This works double duty by providing the speaker with a comfortable resting place on which to sit while also working in symphony the bottom urethane foam and mass of the speaker to dampen the steel plate. To further reduce self-resonance, a curved front panel aids in the process by varying the impedance thus eliminating internal standing waves. This also adds more mass without increasing the footprint.
A wide range of Recoil Stabilizers is offered to adapt to various loudspeaker manufacturer offerings. This includes smaller recoils for compact monitors like Auratones and larger recoils for midfield monitors and sub-woofers. After many listening tests, we have found that a 4:1 ratio appears to work well whereby the mass of the Recoil should equal 25% or more of the loudspeaker being used.
A roundup of various loudspeaker brands and popular models is available to help individuals select the most suitable Recoil Stabilizer to suit their needs. Furthermore, a choice of horizontal and angled models is presented as a means to precisely aim the reference monitor to the engineer's listening position. Custom angles may also be ordered at a premium to address special needs.
So there you have it"¦ By first isolating the speaker from the stand or shelf, you eliminate harmful resonance and by stabilizing the speaker by increasing the mass of the base, we directly affect the loudspeaker's inertia and recoil is significantly reduced. The result: greater clarity and improved depth of field is immediately apparent. The Recoil Stabilizer is likely the most cost effective means to improve reference monitor accuracy for engineers at all levels.
Recoil Stabilizers are available in a variety of sizes and weights to coincide with various monitors being produced today. Primacoustic has produced a monitor cross-reference page to make the selection as easy as possible. If your monitor is not in the cross-reference, we recommend using a 4:1 ratio whereby the weight of your monitor should not exceed more than four times the mass of the Recoil Stabilizer you intend to use. (ex. If monitor weighs 40 lbs - Recoil should weigh at least 10 lbs.) You should also consider the firing angle and the positioning (vertical or horizontal). It is also a good idea to check the deck size to meet your monitor's footprint.
Primacoustic RX7 DF Recoil Stabilizer Monitor Isolation Pad Specifications
- Height: 3.4" \ 2.625", 86 mm \ 67.5 mm
- Width: 10.5", 263mm
- Depth: 13", 330mm
- Load Limit: 44 lbs (20 kg)
Primacoustic RX7 DF Recoil Stabilizer Monitor Isolation Pad Links
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The physics and theory are solid and so are the results !!! I was somewhat skeptical to start , but the bass on my monitors bled off less into the desk and tighten up too. I've used all foam units , And I do feel that the extra mass in the plates on these helps keep the transients a smidgen tighter , and every little bit helps !!!!