Thor

THOR a top-of-the-line loudspeaker design from SEAS. It is a full range, floor-standing system that provides
the very highest level of acoustic performance. This kit uses two W18E001 woofers and a single T25CF002 "MILLENNIUM" tweeter mounted in a D'Appolito configuration.

The enclosure uses a newly developed transmission line configuration, derived both from sophisticated computer modeling, and extensive experimentation.

The line is tapered, and filled with Dacron stuffing. The two W18E001 woofers excite the line at slightly different points, smoothing the response and increasing the range of bass output.

The transmission line produces 4 dB of bass lift from 20Hz to 110HZ, with less than 1 dB of ripple. The -3dB point is 45Hz, with roll off of 12dB per octave below 45Hz.
Usable in-room bass response extends well into the low 30Hz range.

The crossover network is conventional except for a parallel circuit which supresses the response peak due to the magnesium cone.
The crossover frequency is 2.5kHz.

THOR was designed by Dr. Joseph D'Appolito, who is world-renowned for his pioneering work on MTM-based loudspeaker configurations.
He offers the following comments on THOR:

"Transmission Line loudspeakers have long enjoyed a small, but dedicated following. The advantages of TL's are well known. They are essentially non-resonant enclosures, producing a deep, well-controlled bass response. For a given driver, bass response will extend well below that produced with either a vented or sealed enclosure using the same driver. Above a few hundred Hz, the line filling material completely absorbs the driver backwave, giving the TL an open, non-boxy sound."