High Efficiency Speaker Asylum

Posted by freddyi (A) on May 20, 2007 at 10:06:37

In Reply to: RE: Ping* freddiy posted by tweakk on May 20, 2007 at 08:02:03

Hi Bill - I think you're referring to the little X15 which was hand-built by John Karlson and now in my hands (Carl Neuser got the slotted waveguides and replicated them and buit varients)- at one time these x15 had faux formica blonde finish.

the original patents expired but Alan Weiss holds a K patent. imo building original K and slotted waveguide for home use should (?) be ok.

X15 was punchy, no low bass due to only about 54% chambers volume compared to K15 so `1/2 octave was lost.

the CTS woofer had pretty good specs and apparently ran with no lowpass choke.

I think you could build a x15-size coupler with less hassle than the 3-panel reflector and do as well or better graph-wise. It could be 20"W x 15-16" deep, 28" tall ~23-25 degree baffle, nearly perpendicular middle panel and an upper deflector. Look down in X15 stuff for rough drawing and views.

Freddy

X15 Stuff

CTS woofer specs
Revc = 7.1648 ohms
Fs = 41.8850 Hz
Zmax = 153.1167 ohms
Qes = 0.2856
Qms = 5.8182
Qts = 0.2723
Le = 3.1031 mH (at 1 kHz)
Diam = 323.2150 mm ( 12.7250 in )
ConeArea =82048.9302 mm^2(127.1761 in^2)
Vas = 265.6837 L ( 9.3825 ft^3)
BL = 18.4180 N/A
Mms = 51.3835 g
Cms = 280.9952 uM/N
Kms = 3558.7798 N/M
Rms = 2.3242 R mechanical
Efficiency = 6.5893 %
Sensitivity= 100.1884 dB @1W/1m
Sensitivity= 100.6672 dB @2.83Vrms/1m

******************************

KARLSON AND KARLSON-RELATED SPEAKER PATENTS

RELATED:

W.O Swinyard US 2020166 filed 1935 “Sound Reproduction Apparatus” - wedge-shaped 20 degree coupler with “V” deflector having non-parallel walls -“Proto-Karlson”!

N.C. Fulmer US 2787332 filed 1952 “Loud-Speaker System” - folded 1/4 wave pipe with last section broadbanded with tapered slot - Fulmer’s patent apparently conflicted with RCA/Olson and Karlson’s 1st “Acoustic Transducers” delaying grants on both.

R-J Enclosure:

(1) "The R-J Speaker Enclosure" by William Joseph and Franklin Robbins. Published in Audio Engineering Magazine December 1951.
(2) "Practical Aspects of the R-J Speaker Enclosure" by William Joseph and Franklin Robbins. Published in Audio Engineering Magazine January 1953.

"Acoustic System for Loud-Speaker" US# 2694463; Robbins et al filed April 17, 1952 granted 11/54 (btw-Jeff Joseph = nephew of William - Jeff's Loudspeakers: http://www.josephaudio.com/

J.J. Baruch US2766839 "Loudspeaker System" Filed March 16th 1953, granted Oct. 16th 1956 - deals with math of distributive resistive vents & Rayls using round holes

John A. McKenzie US 3590941 filed 1969 “Speaker Enclosure” - a dual mouth K-coupler like stacked “Asymmetric-Projector” having a final deflector at each mouth

Robert W. Reams US 4196790 filed 1978 “Acoustic Transducer having Multiple Frequency Resonance” - novel use of Karlson’s slot to create a broad-banded throat in a PA-application quasi-scoop horn with sealed back chamber.

Rodden, M. Raymond US 4313521 filed Feb. 2 1982 "Speaker Housing"

Sapkowski September 3, 1996 "Exponential multi-ported acoustic enclosure" United States Patent 5,552,569

Weiss et al US 5943431 August 24, 1999 “Loudspeaker With Tapered Slot Coupler And Sound Reproduction System” - basically a wedge-whaped asymmetric projector waveguide for 1” compression driver. Alan Weiss marketed an 8" assymetric projector.

KARLSON PATENTS:

J.E. Karlson US 2586827 “Directive Radiating System” Filed March 31 1945 -
Parabolic dish microwave antenna with variable directivity pattern


J.E. Karlson “Acoustic Transducers” US 2816619 filed Dec. 1951, granted 6 years later

J.E Karlson “Acoustic System” US 2896736 filed Aug. 1955 - use of a modified Karlson laying on its back using either corner or wall to create a diffused sound image - HiFiLit’s website shows a Karlson 12 used in this fashion (laid on back) on the 1955 Karlson brochure page

J.E. Karlson “Open End Waveguide Antenna” US 3445852 filed 1968 - essentially analogous with the K-tube waveguide used in Karlson’s X15 2-way speaker ~1966.

J.E. Karlson “Acoustic Transducers” - US 3540544 filed 1968 - concurrent with X15 and described Karlson’s use of ellipse based reflectors to improve the Ultra-Fidlety type via Fig.6 and Fig 8’s reflctors (Fig6 upper reflector was used in the X15) and introduced the Asymmetric Projector with tapered elipse profile which appeared commercially as the AP-9C ceiling speaker - also- slotted mirocphones were
discussed.

J.E. Karlson “Jet Engine Silencer Nozzle...) US 3543876 filed 1968 - jet engine muffler and rocket nozzles.




LIST OF KARLSON'S INVENTIONS 4/24/50

J.E. (Edward) Karlson

1. ELECTRONIC POTENTIOMETER. A variable element which is capable of linear variations of resistances with infinitesimal mechanical motion yet also have capabilities of broad variations in resistance.
2. CAPLESS DISPENSING TUBE. This device permits the use of toothpaste tubes, etc. without the necessity and bother of removing and replacing the cap after each usage.
3. GEOLOGICAL PROSPECTING SYSTEM. A system for use in the prospecting for oil, minerals, etc. This system may also be used for radar applications.
4. RADAR ANTENNA WITH AUTOMATICALLY VARIABLE BEAM PATTERN. This invention provides a simple means of automatically changing the beam pattern of a radar antenna from a pencil beam to a cosecant beam.
5. DIELECTRIC ANTENNA. This invention provides a technique for designing commercial and military antennas which will have overall dimensions than conventional antennae, and yet have equivalent gain and directivity characteristics.
6. BRUSHLESS DC MOTOR
7. ASHTRAY. An extremely simple design for an ash tray which quickly extinguishes cigarettes.
8. PRECISION DELAY CIRCUIT. This circuit provides a delayed pulse at a precise interval following an initial pulse.
9. CHATTERLESS CONTACTS FOR RELAYS
10. TELEVISION ANTENNA. This invention provides a simple, low cost antenna which can be readily hidden or obscured in the average room and is suitable for both F.M. and television.
11. SLOT ANTENNA. This design provides a slot antenna with broad band matching possibilities.
12. HYBRID WAVEGUIDE JUNCTION. This is a wave guide section which has variable propagation characteristics dependant upon the direction of propagation.
13. R.F. TUNER. a simplified tuner for F.M. and television use.
14. ADVERTISING SIGN. Novel electric sigh with quick change possibilities.
15. LIGHT VALVE FOR TELEVISION PROJECTION AND PICKUP TUBE.
16. ACOUSTIC TRANSDUCER. A novel loudspeaker enclosure with improved matching characteristics and controlled reverberation.
17. FISHING DEVICE
18. TELEPHONE AMPLIFIER WITH SPECIAL ACOUSTIC CHARACTERISTICS