Swerd

mdemeem A friend recently told me about this thread, which I hadn't noticed before. I'm alway happy to hear people who built this crossover and I'm very glad to see how much you like it . I originally wrote that thread about the new crossover for JBL L-100s, years ago, and posted it on the Audioholics forum http://forums.audioholics.com/forums/diy-corner-tips-techniques/25014-vintage-jbl-west-coast-sound-becomes-%85.html and later on the Lansing Heritage forum http://www.audioheritage.org/vbulletin/showthread.php?13105-New-crossover-design-for-L-100A When I built these crossovers for my L-100s, I used no variable L-pads in them. The balance among the three drivers is done correctly (in my opinion) by crossover, and those variable L-pads develop such oxidation that that, new or old, they all become noisy. Someone commented that the new crossovers lower the sensitivity by 5 dB. That was my original guess, but more carefull measurments showed it was in the range of 1 to 3 dB depending on the frequency. The loss was small enough to not be a problem. Someone else had commented that the "3.9µF in parallel with the tweeter doesn't look quite right." A cap going directly to ground (see the 3.9 µF cap on the tweeter circuit) should, in theory, be avoided because it might create a significant impedance dip at high frequencies. In practice it was fine and caused no trouble. See the attached impedance plot. The tweeter impedance is the green line, and the total impedance is the black line.

mdemeem A friend recently told me about this thread, which I hadn't noticed before. I'm alway happy to hear people who built this crossover and I'm very glad to see how much you like it . I originally wrote that thread about the new crossover for JBL L-100s, years ago, and posted it on the Audioholics forum http://forums.audioholics.com/forums/diy-corner-tips-techniques/25014-vintage-jbl-west-coast-sound-becomes-%85.html and later on the Lansing Heritage forum http://www.audioheritage.org/vbulletin/showthread.php?13105-New-crossover-design-for-L-100A When I built these crossovers for my L-100s, I used no variable L-pads in them. The balance among the three drivers is done correctly (in my opinion) by crossover, and those variable L-pads develop such oxidation that that, new or old, they all become noisy. Someone commented that the new crossovers lower the sensitivity by 5 dB. That was my original guess, but more carefull measurments showed it was in the range of 1 to 3 dB depending on the frequency. The loss was small enough to not be a problem. Someone else had commented that the "3.9µF in parallel with the tweeter doesn't look quite right." A cap going directly to ground (see the 3.9 µF cap on the tweeter circuit) should, in theory, be avoided because it might create a significant impedance dip at high frequencies. In practice it was fine and caused no trouble. See the attached impedance plot. I've tried to attach an impedance plot to illustrate this, but I'm having difficulty doing it.

mdemeem A friend recently told me about this thread, which I hadn't noticed before. I'm alway happy to hear people who built this crossover and I'm very glad to see how much you like it . I originally wrote that thread about the new crossover for JBL L-100s, years ago, and posted it on the Audioholics forum http://forums.audioholics.com/forums/diy-corner-tips-techniques/25014-vintage-jbl-west-coast-sound-becomes-%85.html and later on the Lansing Heritage forum http://www.audioheritage.org/vbulletin/showthread.php?13105-New-crossover-design-for-L-100A When I built these crossovers for my L-100s, I used no variable L-pads in them. The balance among the three drivers is done correctly (in my opinion) by crossover, and those variable L-pads develop such oxidation that that, new or old, they all become noisy. Someone commented that the new crossovers lower the sensitivity by 5 dB. That was my original guess, but more carefull measurments showed it was in the range of 1 to 3 dB depending on the frequency. The loss was small enough to not be a problem. Someone else had commented that the "3.9µF in parallel with the tweeter doesn't look quite right." A cap going directly to ground (see the 3.9 µF cap on the tweeter circuit) should, in theory, be avoided because it might create a significant impedance dip at high frequencies. In practice it was fine and caused no trouble. See the attached impedance plot. The tweeter impedance is the green line, and the total impedance is the black line.

mdemeem A friend recently told me about this thread, which I hadn't noticed before. I'm alway happy to hear people who built this crossover and I'm very glad to see how much you like it . I originally wrote that thread about the new crossover for JBL L-100s, years ago, and posted it on the Audioholics forum http://forums.audioholics.com/forums/diy-corner-tips-techniques/25014-vintage-jbl-west-coast-sound-becomes-%85.html and later on the Lansing Heritage forum http://www.audioheritage.org/vbulletin/showthread.php?13105-New-crossover-design-for-L-100A When I built these crossovers for my L-100s, I used no variable L-pads in them. The balance among the three drivers is done correctly (in my opinion) by crossover, and those variable L-pads develop such oxidation that that, new or old, they all become noisy. Someone commented that the new crossovers lower the sensitivity by 5 dB. That was my original guess, but more carefull measurments showed it was in the range of 1 to 3 dB depending on the frequency. The loss was small enough to not be a problem. Someone else had commented that the "3.9µF in parallel with the tweeter doesn't look quite right." A cap going directly to ground (see the 3.9 µF cap on the tweeter circuit) should, in theory, be avoided because it might create a significant impedance dip at high frequencies. In practice it was fine and caused no trouble. I'm trying to attach an impedance plot to illustrate this, but I can't seem to do it.

mdemeem A friend recently told me about this thread, which I hadn't noticed before. I'm alway happy to hear people who built this crossover and I'm very glad to see how much you like it . I originally wrote that thread about the new crossover for JBL L-100s, years ago, and posted it on the Audioholics forum http://forums.audioholics.com/forums/diy-corner-tips-techniques/25014-vintage-jbl-west-coast-sound-becomes-%85.html and later on the Lansing Heritage forum http://www.audioheritage.org/vbulletin/showthread.php?13105-New-crossover-design-for-L-100A When I built these crossovers for my L-100s, I used no variable L-pads in them. The balance among the three drivers is done correctly (in my opinion) by crossover, and those variable L-pads develop such oxidation that that, new or old, they all become noisy. Someone commented that the new crossovers lower the sensitivity by 5 dB. That was my original guess, but more carefull measurments showed it was in the range of 1 to 3 dB depending on the frequency. The loss was small enough to not be a problem. Someone else had commented that the "3.9µF in parallel with the tweeter doesn't look quite right." A cap going directly to ground (see the 3.9 µF cap on the tweeter circuit) should, in theory, be avoided because it might create a significant impedance dip at high frequencies. In practice it was fine and caused no trouble. See the attached impedance plot. The tweeter impedance is the green line, and the total impedance is the black line.

mdemeem A friend recently told me about this thread, which I hadn't noticed before. I'm alway happy to hear about people who built this crossover, and I'm very glad to see how much you like it . I originally wrote that thread about the new crossover for JBL L-100s, years ago, and posted it on the Audioholics forum http://forums.audioholics.com/forums/diy-corner-tips-techniques/25014-vintage-jbl-west-coast-sound-becomes-%85.html and later on the Lansing Heritage forum http://www.audioheritage.org/vbulletin/showthread.php?13105-New-crossover-design-for-L-100A When I built these crossovers for my L-100s, I used no variable L-pads in them. The balance among the three drivers is done correctly (in my opinion) by crossover, and those variable L-pads develop such oxidation that that, new or old, they all become noisy. Someone commented that the new crossovers lower the sensitivity by 5 dB. That was my original guess, but more carefull measurments showed it was in the range of 1 to 3 dB depending on the frequency. The loss was small enough to not be a problem. Someone else had commented that the "3.9µF in parallel with the tweeter doesn't look quite right." A cap going directly to ground (see the 3.9 µF cap on the tweeter circuit) should, in theory, be avoided because it might create a significant impedance dip at high frequencies. In practice it was fine and caused no trouble. See the attached impedance plot. The tweeter impedance is the green line, and the total impedance is the black line.

mdemeem A friend recently told me about this thread, which I hadn't noticed before. I'm alway happy to hear about people who built this crossover, and I'm very glad to see how much you like it . I originally wrote that thread about the new crossover for JBL L-100s, years ago, and posted it on the Audioholics forum http://forums.audioholics.com/forums/diy-corner-tips-techniques/25014-vintage-jbl-west-coast-sound-becomes-%85.html and later on the Lansing Heritage forum http://www.audioheritage.org/vbulletin/showthread.php?13105-New-crossover-design-for-L-100A When I built these crossovers for my L-100s, I used no variable L-pads in them. The balance among the three drivers is done correctly (in my opinion) by crossover, and those variable L-pads develop such oxidation that that, new or old, they all become noisy. Someone commented that the new crossovers lower the sensitivity by 5 dB. That was my original guess, but more carefull measurments showed it was in the range of 1 to 3 dB depending on the frequency. The loss was small enough to not be a problem. Someone else had commented that the "3.9µF in parallel with the tweeter doesn't look quite right." A cap going directly to ground (see the 3.9 µF cap on the tweeter circuit) should, in theory, be avoided because it might create a significant impedance dip at high frequencies. In practice it was fine and caused no trouble. See the attached impedance plot. The tweeter impedance is the green line, and the total impedance is the black line.