LE 15 A vs. 2235 H

[Rafael]

Hi all,

I read the George Augspurger on studio monitor design article and wondered why he changed the LE 15 A´s against 2231/2235´s in almost all of his designs. I don´t want to reflame another alnico vs. ferrite debatte but I wonder what the technical diffences in both designs are. Since I have both LE 15´s and 2235´s I compared them and was surprised that the 2235´s are capable of lower bass and are more accurate in upper bass frequencies. I must confess I have expected this qualities from the beloved alnico´s. Any opinions or technical background would be welcome.

Thanks, Rafael

[DRG]

Don?
Would George feel like addressing this or will you take it?
Thanks.

[Don McRitchie]

You seemed to have discovered the answer for yourself; the 2231/35 is an all around better driver with higher output, greater extension, lower distortion and flatter response. However, if I had to speculate on the one most important factor that led George to substitute the later drivers, it was likely power handling. Main studio monitors in a prominent studio like Sunset Sound Recorders can be subjected to obscene playback levels. The LE15A with its short coil and limited excursion has nowhere near the power handling of the 2235.

This is why JBL dropped the LE15A from all of their monitors in 1973. Even back in the early 1970s, the LE15A could not keep up with the then new 2230. Since that time, the science behind transducer technology has become far better understood. Motor technologies, cone materials and fabrication and suspension designs have all been improved and optimized based on objective engineering as opposed to the largely empiriacal process that led to the LE15A. Issues like dynamic offset were not even fully understood, let alone dealt with in that driver.