These JBL Series Studio Monitors were made for recording studios and introduced nearfield monitoring (see definition below) which became a huge hit. Their success led to the creation of a consumer version: L100 Speakers.
4311B: LE25-2 tweeter (no longer available) which can be repaired with D8RLE252, LE5-10 midrange (no longer available) which can be repaired with C8RLE510 recone kit, and the 2213H woofer (available brand new) which uses the C8R2213 recone kit
4410: 035TIA tweeter which is still available brand new and can be repaired with the D8R035TIA diaphragm, the 104H-2 midrange which is still available brand new and the C8R104H-2 recone kit, and the 127H-1 woofer which uses the C8R127H-1 recone kit or RFK10 JBL125 refoam kit
4410A, 4410A-1: 052Ti tweeter which is still available brand new and can be repaired with the D8R052Ti diaphragm, the 104H-2 midrange which is still available brand new and the C8R104H-2 recone kit, and the 127H-1 woofer (which is still available) uses the C8R127H-1 recone kit or RFK10 JBL125 refoam kit
4411: 044 tweeter (tweeter and D8R044 diaprhagm both no longer available), the LE5-9 midrange (which is no longer available) and is repaired with C8RLE5-9 recone kit, and the 128H woofer (no longer available) which uses the C8R128H recone kit and the RFK128 refoam kit
4412: 035Ti tweeter (different from the 035TIA- both tweeter and D8R035TI diaphragm no longer available), the 104H-2 midrange (still available brand new) and the C8R104H-2 recone kit, and the 128H-1 woofer (available brand new) which uses the C8R128H-1 recone kit and the RFK128 refoam kit
4412A, 4412A-1: 052Ti tweeter which is still available brand new and can be repaired with the D8R052Ti diaphragm, the 104H-2 midrange which is still available brand new and the C8R104H-2 recone kit, and the 128H-1 woofer (available brand new) which uses the C8R128H-1 recone kit and the RFK128 refoam kit
Wikipedia states: In the late 1960s JBL introduced two monitors which helped secure them preeminence in the industry. The 4320 was a direct competitor to the Altec 604 but was a more accurate and powerful speaker and it quickly made inroads against the industry standard. However, it was the more compact 4310 that revolutionized monitoring by introducing the idea of close or “nearfield” monitoring. (The sound field very close to a sound source is called the “near-field“. By “very close” is meant in the predominantly direct, rather than reflected, soundfield. A near-field speaker is a compact studio monitor designed for listening at close distances (3’-5’), so, in theory, the effects of poor room acoustics are greatly reduced.)
The 4310 was small enough to be placed on the recording console and listened to from much closer distances than the traditional large wall-(or “soffit”) mounted main monitors. As a result, studio-acoustic problems were minimized. Smaller studios found the 4310 ideal and that monitor and its successor, the 4311, became studio fixtures throughout the 1970s. Ironically, the 4310 had been designed to replicate the sonic idiosyncrasies of the Altec 604 but in a smaller package to cater for the technical needs of the time.
The 4311 was so popular with professionals that JBL introduced a domestic version for the burgeoning home-audio market. This speaker, the JBL L-100, (or “Century”) was a massive success and became the biggest-selling hi-fi speaker ever within a few years. By 1975, JBL overtook Altec as the monitor of choice for most studios. The major studios continued to use huge designs mounted on the wall which were able to produce prodigious SPL’s and amounts of bass.
