The different projects


Martin J Kings Compact Back Loaded Horn

Martin J King has written exensively on quarter wave pipes, developed models and extended the knowledge about this family of loudspeakers. When he published an article about a compact horn and I was thinking about getting new computer speakers I was intrigued. Less than a meter high and 40 cm deep and about 22 cm wide they really are compact for this kind of loudspeaker
Any expectations should be framed in the context of a 4"-5" driver in a box that is not to be compared to the bigger Klinger horn to the right with a 12" driver. I built mine in 11 mm OSB as a prototype so it not a thing of beuty.

Kings model use a lot of damping material in various places
25 gram in the speaker chamber 23 gram in the internal Helmholz resonator 2.6 gram in the first section of the pipe and 15 and 25g in P2 and P3 respectively.  The aim is to get a substantial gain in bass output below 100 Hz and taming unwanted peaks above that. More to follow


  1. Looks like a devce that should work Very well ! Bravo, any way to get these in kit form or spec sheets ?

  2. Osb is a poor choice of material for speaker construction. Low densisty, voids and poor stiffness make this a less desirable material to construct speakers. Try MDF or high quality plywood such as Baltic birch.

  3. Hi,
    What should be changed in this box design to use with 6.5" Audio Nirvana fullranges?
    Tks & rgds