MSE Audio Patents

Induction Dynamics’ engineers have tested hundreds of high-end drivers and crossover parts. Along the way, they’ve even patented unique technologies to further improve these world-class electronics


Balanced cantilever spring bracket

Designed to hold a Solid Drive against a vertical surface such as dry wall, so there is no stress on the glue joint. The drive is cantilevered to keep it balanced on the center line of the bracket, thus eliminating any twisting force on the glue joint.

Excursion limiter

This limiter operates around a selected frequency of maximum excursion in a subwoofer, and does not affect other frequencies. The limiter responds faster than the rise time of a subwoofer driver, so there is effectively no delay. Amplitude is reduced smoothly, so the operation of limiter does not create audible distortion.

Speaker grille frame

A special manufacturing process is used create openings in a wood grille frame. The openings allow some of the sound running along the face of a speaker to go through the frame, thus reducing undesirable reflections.

Coaxial speaker with step-down ledge to eliminate sound wave distortions and time delay

Used on a coaxial speaker having a large circular baffle around the tweeter that is attached to the frame or magnet structure of the speaker. A step down ledge is created on the circular baffle, forcing a diffraction of some of the high frequencies, which are then reflected away from the woofer cone, thus reducing undesirable reflections, delays and Doppler distortion coming off of the woofer cone.

Speaker enclosure and mounting method for isolating and insulating faceplate and heavy speakers from surrounding mounting surface

This is an enhancement to patent number 6,415,886 below, ”In-wall speaker mounting apparatus”. Steel springs are placed around the stand offs in the back box to beef up the suspension for face plates containing heavy speakers, such as subwoofer drivers.

Speaker mounting device

Corner mounting bracket for box speakers that has mounting holes aligned to facilitate screwing into typical corner stud configurations at the proper location and angle. The speaker can be installed or removed without removing the bracket.

In-wall speaker mounting apparatus

Metal back boxes can be attached directly to studs using special fasteners called “stud grabbers” that can be adjusted and attached from inside the box. The speaker faceplate is then attached to stand offs in the back box and suspended on a large rubber gasket that is attached to the front of the back box. Neither the back box nor the face plate are in contact with the dry wall.

Attachment fixture for the front panel and grill of a speaker assembly

Dual purpose fasteners are used to 1) attach removable face plates to speakers, and 2) attach grilles to the same face plates.

Audio crossover circuit

Coils in a 3-pole or 4-pole low-pass circuit are coupled together to produce an extra-steep slope. This is especially useful with many drivers that have either a frequency response curve or impedance curve that works against achieving the desired slope and phase. The circuit is more compact than a normal 3-pole or 4-pole low pass because two coils share the same location on the circuit board.