I listen to both 4311's and 4312's.
The 4311 was the speaker that allowed JBL to corner the professional monitor market. At one time 8 out of 10 studios used 4311's so chances are that rock album you want to listen to was mixed with 4311's. Because of this dominance, JBL decided to create a home version and cash in on the 4311's popularity and the L100 was born.
I prefer the 4312's becaues they seem to have more presence and sound stage. The 4312B's introduced the tituanium drivers. I had a pair of 4312B's but felt the 4312s were more neutral.
The 4311 was the speaker that allowed JBL to corner the professional monitor market. At one time 8 out of 10 studios used 4311's so chances are that rock album you want to listen to was mixed with 4311's. Because of this dominance, JBL decided to create a home version and cash in on the 4311's popularity and the L100 was born.
I prefer the 4312's becaues they seem to have more presence and sound stage. The 4312B's introduced the tituanium drivers. I had a pair of 4312B's but felt the 4312s were more neutral.