Alexander_S
06-01-2009, 01:52 AM
Hi All,
I used for a long time 12" JBL 123A drivers in self made closed box 3-way system (130 L for 123A). As the mid driver I tried various speakers: original alnico LE5-2, LE104H, varous fostex drivers (87E, 107E, 120fx), modern 5" seas 1262. Honestly speaking, the seas was the winner in terms of distortion and tonal balance. What I didn't like with it - its comression (perhaps comming from Qms=1.5 and modern surround). It is a modern driver, and sound like all other modern speaker, even there are much better among them, i.e. scan-speak revelerator.
Among all other mid drivers I used I liked most of all original alnico LE5-2. But this is a quite problematic one, peaking arround 7 kHz. An excellent review on it can be found at Troels Gravesen site, who made the recreation of L100 crossover.
The second problem with LE5-2 is it is the upper midrange. Trying varous combinations of crossover points I believe now the heavy 12" bass driver should never go up to 800-1000 Hz and no way to 1500 Hz as in the original JBL L100 (old style desing). L100 is simple but the cost of symplicity is it sounds wrong.
I want now to make 4-way system with a 8" midbass between 12" 123A and 4.5" LE5-2.
Can You advice on the midbass driver for this? It will work from 300 to 800 Hz. Having the bass and mid from JBL, it will be reasonable to use JBL again. My original thought was 16 ohm JBL 2118J, but it is not alnico. Any other drivers?
Thanks,
Alexander
I used for a long time 12" JBL 123A drivers in self made closed box 3-way system (130 L for 123A). As the mid driver I tried various speakers: original alnico LE5-2, LE104H, varous fostex drivers (87E, 107E, 120fx), modern 5" seas 1262. Honestly speaking, the seas was the winner in terms of distortion and tonal balance. What I didn't like with it - its comression (perhaps comming from Qms=1.5 and modern surround). It is a modern driver, and sound like all other modern speaker, even there are much better among them, i.e. scan-speak revelerator.
Among all other mid drivers I used I liked most of all original alnico LE5-2. But this is a quite problematic one, peaking arround 7 kHz. An excellent review on it can be found at Troels Gravesen site, who made the recreation of L100 crossover.
The second problem with LE5-2 is it is the upper midrange. Trying varous combinations of crossover points I believe now the heavy 12" bass driver should never go up to 800-1000 Hz and no way to 1500 Hz as in the original JBL L100 (old style desing). L100 is simple but the cost of symplicity is it sounds wrong.
I want now to make 4-way system with a 8" midbass between 12" 123A and 4.5" LE5-2.
Can You advice on the midbass driver for this? It will work from 300 to 800 Hz. Having the bass and mid from JBL, it will be reasonable to use JBL again. My original thought was 16 ohm JBL 2118J, but it is not alnico. Any other drivers?
Thanks,
Alexander