Subwoofer design with SLAPS passive radiator

This page will guide you through subwoofer design with a SLAPS passive radiator. Detailed introduction.

SLAPS is a patented system that dramatically increases subwoofer efficiency and capability for ultra low frequency reproduction. SLAPS stands for Symmetrically Loaded Audio Passive System. As the name indicates, SLAPS is built symmetrically which distinguishes it from traditional passive devices. SLAPS integrates identical components in its suspension and design ensuring the unit is moving identically in both directions. The revolutionary efficiency and performance are the result of the pneumatic coupling between SLAPS and the active driver. SLAPS overcomes the limitations known from conventional closed and ported designs that prevent radical excursion and deep response. The unique design allows the active driver compression-free movement resulting in deep, dynamic and hard-hitting bass response. The only thing a SLAPS has in common with a traditional passive device is that it is passive, besides that few similarities exists. Conventional computer modeling software will not work correctly with SLAPS and will in most cases greatly overestimate the internal volume of the optimal cabinet.

First, you need to decide the size of the bass speaker. Theoretical SLAPS information and comparison.

Why use SLAPS radiator instead of a sealed or ported cabinet?

  • SLAPS increases a subwoofer efficiency and capability for ultra low frequency reproduction (very deep Sub-bass) without the drawbacks of traditional designs.
  • SLAPS opens up new subwoofer designs where even very small enclosures can be tuned to quite low frequencies. SLAPS can be custom tuned for optimum performance in a wide range of housing sizes and device configurations.
How does SLAPS work?
  • A subwoofer design with SLAPS consists of an active sub woofer driver and a cabinet (sealed cabinet) and a SLAPS passive radiator.
  • The SLAPS device is controlled by the active device through the alternating pressure and counter- pressure (vacuum) which occurs in a sealed cabinet when the active device plays bass. It gives you much better performance due to the increased surface area and the fact that the particles of air inside the enclosure and outside the cabinet moves with the same speed and in a near phase relationship.
A traditional bass reflex port design- the system is limited in performance due to the air in the reflex port not being in phase or at the same speed of movement as the air in front of the active driver.

(Phase means that the active device and SLAP work almost concurrently and simultaneously creates respectively pressure and counter-pressure at the same time)

How do I get started with my own design?
  • You have to decide on what size bass speaker to use.