SLAPS-M12v2 Passive Radiator

SLAPS-M12v2 Passive Radiator

The Earthquake SLAPS-M12v2 passive radiator differs from the original SLAPS by having a pre-fitted tuning bolt centered on the device. This provides an easy addition of weight for tuning the device. The M series boasts impressive performance and extended excursion capability. It also features a very rational price due to the annular stamped steel chassis.

SLAPS is a patented type of passive device that significantly increases subwoofer efficiency and ability for ultra-low frequency reproduction. SLAPS is short for Symmetrically Loaded Audio Passive System. As the name indicates, it is built symmetrically, distinguishing it from traditional passive devices. SLAPS integrates identical components in its suspension design, resulting in identical strokes regardless of forward or backward motion. The high efficiency and performance are a result of the pneumatic coupling between SLAPS and an active driver.

SLAPS overcomes the limitations known from the conventional sealed and ported enclosures that tend to limit excursion. The unique design allows the active driver compression-free excursion, resulting in deep, dynamic, and powerful bass response.

SLAPS’ design differs from other passive devices in that it has a double-edged suspension and no center spider. Traditional passive devices are often just normal active drivers where the primary motor system (voice coil and magnet) has been removed. Conventional devices are designed to be powered electrically, in which the force emanates from the driver’s conical center. A passive device is operated pneumatically by air pressure from the active driver. A traditional unit does not perform identically in positive and negative pressure environments for pneumatic operation. (imploding edge suspension and positive over ring).

SLAPS have a dual structure of identical opposites, i.e., there is an introvert and an extrovert edge suspension and no spider. This gives identical properties in both the negative and positive pressure domains. SLAPS thus behaves pistonically and accurately, they do not have the “hesitation” traditional passive devices seems to have when you observe them in operation.

SLAPS opens up new subwoofer designs, where even very small enclosures can be tuned to low frequencies. The low weight allows great flexibility in terms of weight attachment. SLAPS can be custom-tuned for optimum performance in a wide range of enclosure sizes and active device configurations.

Damping is very important in a passive device because it does not have a magnet motor system to control it. It is essential that the passive device is constantly “leaning” up against the pneumatic environment in the cabinet. If the device’s compliance is too weak, the result is over-shoot and over-ring. For example, a transient in the music causes a rapid pressure ratio change in the cabinet, and control over the device can be lost – making it move more than it should. The same thing can happen to a normal woofer unit if the suspension + motor system is not built correctly. The design of the edge suspension itself is important. If not correctly designed, it may implode, i.e., be sucked backward if the pressure in the enclosure is too strong. A full implosion is rare, but in most typical slave/passive/drone designs, some “dimples” in edge suspension can be visible already at medium load. A normal passive device only has a one-way edge suspension, so the dimples will only occur when negative pressure is present.

The dual structure of SLAPS is based on the principle of – identical opposites – eliminating the circumstances that would allow asymmetric nonlinearities because the device is subjected to identical loads. You could argue that it does not fundamentally resolve dimples at high loads, as they will still occur, but they are offset as they now occur similarly under both positive and negative pressure.

SLAPS enables the transfer of high amplifier power into low frequency output. Since the device does not have to fight against increasing pneumatic pressure in a closed cabinet or over-excurt close to a port tuning frequency. SLAPS has no annoying port noise and enables deep bass from a compact volume. SLAPS promotes the dynamics of a small system in which a closed enclosure design has difficulties. In a closed cabinet design the pneumatic loading of the woofer increases as a function of its travel, this causes compression. SLAPS technology possesses none of these limitations. SLAPS allows tuning below 20hz, making any worries about tuning frequency superfluous.