Fullrangedriver Forum

only 1400 Karlson a month are selling



-they sound "different"  - it was Karlson's intent to add a certain amount of reverberation.   Karlson presented a simplified equivalent circuit in his 1952 Audio Engineering article.   There were some outlandish claims extrapolated by the 15 inch cabinet's impedance curve  -- that said,  it has very low distortion (including "Doppler") in its passband and has been admired from the late Hans Dietz (RCA Engineer) to Cogent's (Ultra-fi horn system) Steve Schell.    I suspect K15 was sized to be somewhat lower in bulk than the bass reflex prevalent in its day and IIRC, Wayne Green (vice president of the company) commented that K15 was sized to fit his car trunk.    The 12" enclosure appeared in fall of 1954 and followed by a little 8" driver enclosure.   The 15" enclosure provided sound for GE and Ford exhibits at the 1964 Worlds Fair.

Fullrange typically have narrow high frequency dispersion so that beams though the opening.   Radial arc wings aren't difficult to cut.    Carl Neuser said straight-cut wings didn't work.  Perhaps that meant the wave release was too fast.

for vented Karlson couplers, there's two vents - the rear chamber vent and the coupler - the initial gap and flare of the aperture can affect "air", midrange and midbass presentation.

Carl presented a starting estimate of rear chamber volume:  Vbr ~ (Vas*fs*qts)/fc

some weak motor but bright and cheerful fullrange can sound good as the coupler is enhancing the "reverberation"

really small couplers may not work so well but some have been built for fun and are probably no worse than some little reflex - just different.   

to avoid the math, some folks just look at them these days as BP6A & B type.

George Augspurger felt they were related to the RJ - I would separate the two.   Here's a bit on the RJ
http://gainclone.com/Karlson/index.php?topic=667.0

my old scans of the 1952 Audio Engineering article http://db.audioasylum.com/cgi/m.mpl?for … p;n=107261

The Audio League (fronted by the late and great Julian Hirsch,) October 1955
http://db.audioasylum.com/cgi/m.mpl?for … p;n=144523

Karlson Patent list and an interview
http://db.audioasylum.com/cgi/m.mpl?for … p;n=144771

Last edited by karlsonkab (2010-03-02 14:06:33)

hey Pit - I attempted to update my wardrobe but the result was a "stretch"
http://img638.imageshack.us/img638/4862/shirt2f.jpg