Gary R. Jones
1000 W. Wilshire Blvd. Suite 360
Oklahoma City, OK 73116
Tel: 405-848-3108
Fax: 405-848-3217
LARGE FORMAT HF COMPRESSION DRIVERS
Early 288 and 291 series high frequency drivers used Alnico motors, most with a
circumferential phase plug. Later 288, 291, and 299 series drivers used ceramic
motors with Tangerine® phase plugs. All use 2.8" voice-coils and the diaphragm
assemblies interchange. (The 290 series diaphragm will not interchange)
Three types of diaphragm assemblies have been manufactured. You can verify
which diaphragm you have by inspection. The "Symbiotik" diaphragm has a
Kapton (plastic) surround with an aluminum dome (500Hz - 12kHz). The
aluminum and “Pascalite” diaphragms (500Hz - 16kHz) are all aluminum or
aluminum alloy. The "Pascalite" diaphragm has the sonic quality of the aluminum
diaphragm and handles twice as much power.
Part #25884 (8 ohms) or Part #25885 (16 ohms) are recommended as
replacements for all drivers listed below . . .
288B Aluminum, 24 ohms. Direct replacement not available,
a modification can allow current diaphragms to fit.
288C Aluminum, 24 ohms. Original Altec part# 20221
288-8E,G,H,K,L Aluminum, 8 ohms. Original Altec part# 23763
288D
288-16G,H,K,L Aluminum, 16 ohms. Original Altec part# 23834
288-32G,H,K Aluminum, 32 ohms. Direct replacement not available
291-8K,L Symbiotik, 8 ohms. Original Altec part# 25692
291-16
A,B,C,K,L Symbiotik, 16 ohms. Original Altec part# 21531
299-8A Pascalite, 8 ohms. Original Altec part# 25884
299-16A Pascalite, 16 ohms. Original Altec Part# 25885
