penguin
11-16-2009, 07:13 PM
I carried on a thread a few years ago regarding putting together a pair of monitors along the general idea of the JBL 4333s. I made a handful of compromises (against the advice of some forum members) and have come to see that some of those compromises were mistaken. Key among them (but not a complete list) a) going with the 4333 configuration; b) using the 2461 compression driver rather than the 2420; c) using the JBL 2370 horn.
I am now considering revamping what I have but am once again not taking the purist route (sorry it’s my nature). I am seeking an appraisal of my design idea and also some help in solving a problem I encountered last time.
The design idea seems simple enough and less compromised than my previous one. I am intending to use the same MF, HF, and UHF drivers as JBL uses in the 4315 monitor (2108, 2105 and 2405) and a modified version of that crossover network (3114 or 3114a). I will keep the 2231 for the LF and keep everything in the same enclosure (except for a new baffle). I would set up the crossover to accommodate bi-amping (although I don’t have the active crossover yet).
Three problems: Problem #1) the 3114 and 3114a have a tapped autotransformer in the high pass circuit. Giskard from this forum was able to suggest an alternative to a similar tapped autotransformer for the mid-range circut in the network I built for the 4333 approximation a few years ago. Would anyone be able to suggest a similar modification to the 3114 high pass circuit? Problem #2) The 3114 and 3114a schematics are similar but there is at least one difference each for the LF, MF and HF circuits. Assuming that I am able to find a substitute circuit for the high pass, which of these two network designs would be better suited to my project? Problem #3) I have the LF driver (2231), and the UHF driver (2405). The HF driver (2105/LE5) seems pretty easy to find on ebay. The 2108 seems to be less common and I don’t see any on ebay currently. I have a pair of L 116H drivers out of an old pair of L19s. Would these serve as acceptable placeholders until I can find a good pair of 2108s?
I am now considering revamping what I have but am once again not taking the purist route (sorry it’s my nature). I am seeking an appraisal of my design idea and also some help in solving a problem I encountered last time.
The design idea seems simple enough and less compromised than my previous one. I am intending to use the same MF, HF, and UHF drivers as JBL uses in the 4315 monitor (2108, 2105 and 2405) and a modified version of that crossover network (3114 or 3114a). I will keep the 2231 for the LF and keep everything in the same enclosure (except for a new baffle). I would set up the crossover to accommodate bi-amping (although I don’t have the active crossover yet).
Three problems: Problem #1) the 3114 and 3114a have a tapped autotransformer in the high pass circuit. Giskard from this forum was able to suggest an alternative to a similar tapped autotransformer for the mid-range circut in the network I built for the 4333 approximation a few years ago. Would anyone be able to suggest a similar modification to the 3114 high pass circuit? Problem #2) The 3114 and 3114a schematics are similar but there is at least one difference each for the LF, MF and HF circuits. Assuming that I am able to find a substitute circuit for the high pass, which of these two network designs would be better suited to my project? Problem #3) I have the LF driver (2231), and the UHF driver (2405). The HF driver (2105/LE5) seems pretty easy to find on ebay. The 2108 seems to be less common and I don’t see any on ebay currently. I have a pair of L 116H drivers out of an old pair of L19s. Would these serve as acceptable placeholders until I can find a good pair of 2108s?