Loudspeaker Designs and Articles for the DIY Enthusiast
Links to:
Aviatrix Main / Design Goals
Driver Selection

Sealed MTM Cabinet Construction
MLTL MTM Cabinet Construction
MTM Crossover Design

MT Cabinet Construction
MT Crossover Design

This is a very compact and easy speaker to build, since it is of butt joint construction, and only the tweeter flange needs to be flush mounted.

The flattest L/R mains response was with the speakers orientated orthogonally with the room, only toed in slightly. 3/4" MDF is  specified for the enclosure. I
stuffed each speaker with about 8 oz. of acousta-stuff, so figure 1 bag per pair of speakers. The crossover can easily be mounted on the top or bottom
panel and presuming the crossover board is no wider than 4.5", can be removed and reinstalled through the woofer cutout.
Sealed MT Version

External dimensions: 7.5" x
12.5" x 8.5" deep.
The sealed MT version,
with is diminutive 0.25 cubic
foot enclosure, was
envisioned as a small
surround sound speaker,
computer speaker, or
simply a nice speaker for
small venues. While the
enclosure provides a Qtc of
approximately 1.1,
capacitive loading of the
midwoofers allow the
system to emulate a lower
Q transfer function, and
lower the f3 by nearly 15 Hz
as well. Even though the
transfer function ultimately
reaches 18 dB per octave,
the f10 has not been
compromised, and is still
roughly 40 Hz. A
conventional sealed
alignment with a Qtc of .7
would require an enclosure
4 times larger, yet would
still have an f10 of around
40 Hz.  
Mass Loaded Transmission Line MT Version:

Reducing the enclosure depth by about half, the MT MLTL is really small. I moved the 2" port to the rear, as a flared port would run out of enclosure depth.
This is an inch narrower than the MTM MLTL, and the same width as the sealed MTM. The crossover for both MT versions is identical, and the best place to
mount it will likely be from at the top or upper rear of the enclosure. The actual bracing positions are not critical, and with an enclosure this small, serve
more to hold the polyfill in place than stiffen up the enclosure walls. Use your good judgement as their number and placement.