Originally Posted by
RMC
RE post 20
Eargle's Loudspeaker Handbook 2nd ed., conversion table from efficiency (%) to sensitivity (db 1w 1 m) used here.
2245H 2.1 % = 95 db (same as spec), more hi-fi style VLF driver, linear response, while some others are SR style
2269H 1.2% = 93 db, but it has other assets such as huge input power capability and large cone travel ability
2241H 2.9% = 97 db (rated 98 db by JBL)
2242H 4% = 98 db (rated 99 db by JBL, but they used 100-1000hz range for that test)
Haven't shown 2240H since its been replaced twice by 2241 then 2242, somewhat outdated, but the numbers would be similar.
The AES standard to test woofers is usually 50-500hz, however manufacturers are free to use the decade of their choice, according to Eargle. The previous range used by JBL for such woofer measurements was 100-500hz.
Now go figure why the E-155 (plus the E-140 for BASS guitar) were measured at 500-2500hz (midrange territory) and the 2242 also higher than usual. Obviously the Marketing dept. won those discussions, in order to show higher numbers...
Richard