Junior loudspeaker
Junior is designed as a much sound for the money type loudspeaker. Two 6.5 inch woofers, one 4 inch midrange and one 1 inch tweeter. The selected loudspeaker units are all high quality units, but not state-of-the-art components. I wanted to make a loudspeaker with my special dual woofer layout that can provide excellent, clean/uncolored sound at a reasonable price. Cabinet is a prototype, to check out bass sound properties in respect to cabinet volume. It is bass-reflex, tuning is conservative, aiming at a good combination deep end and sensible impulse response.
Midrange unit gives a very flat response with much detail, and the chosen crossover frequencies allow all units to work without stress in their part of the frequency domain. Tweeter has changed during the long tryout period, the present unit is modified by me and for that reason no commercial alternative. It will be changed to a relevant new tweeter in the near future. Front board for midrange and tweeter is really thick, and a solid, well-designed front board is an important contribution to good sound.
The cabinet looks normal, but only 2 sides are parallel, front and rear. Sides and top/bottom are not parallel, to reduce standing wave issues. Some damping material and extra bracing inside. The amount of damping material in a bass-reflex box is different from a closed box system, if you fill a bass-reflex box with damping, you reduce the bass output from the bass-reflex port.
The cabinet was originally meant to stand on the floor, but I wanted the tweeter to be at the same height as my ears when sitting in a listening position, so legs were added. This tweeter position is generally a good idea, both in terms of floor/wall sound reflections and clarity of the sound stage. Thin legs and no spikes?? With my special woofer layout, there is virtually no cabinet vibration, and no need for extreme solutions when it comes to legs, spikes or stands (also for my Baby loudspeaker). No vibrations are transferred to the floor, and there are no secondary emission of sound generated by vibrating floor boards or similar – this is another unique feature of my special woofer layout!.
More Junior details.



Thoughts about Loudspeakers and DIY

Special Woofer Design

Proof of Concept

Image with Junior loudspeaker, side view,
Junior, front/side view.
Image with Junior Loudspeaker, front board
Junior front board. 50 mm massive plywood.
Junior Loudspeaker, front with midrange and tweeter units.
Junior front, mid and tweeter. Tweeter and mid foam ring to reduce off-axis radiation and front board diffraction.
Junior woofer side view with damping foam
Junior, woofer and foam detail. Foam shape can be adjusted to control side dispersion.
Junior open loudspeaker cabinet, top view
Junior, open cabinet, top view. Side support, mid cabinet wall reinforced, damping material, white bass reflex port.