Low pass crossover setting & slope for Kappa 9?
Here is a link to an excellent Infinity site (in German) and the specific page for the Kappa 9, listing crossover points. http://www.infinity-classics.de/infinity/models/Kappa-series-1987/index-Kappa.htm |
Looking at the schematic, it would be easy to bypass the low-pass, wiring directly from the terminals to the woofers. Easily reversible. The high-pass can't be bypassed without digging into the PCB, which requires expertise. The low-pass is unusual, combining a low frequency filter and what looks like a 6db/oct, first order. The subsonic filter is optional if the amp is up to the challenge. Some active crossovers incorporate their own 20 Hz rolloff. A one or two ohm, high wattage series resistor can be added to increase impedance but gain will have to be adjusted. High pass (mid bass coupler) looks more like a backwards 18 db/oct bandpass. Crossover points could be asymmetric as well. |
Might be a dumb question, but why do you need an active crossover? The way these are set up, if you remove the metal insert between the twin binding posts, you eliminate the crossover at 80 Hz....you drive the woofers with the low end amp and the mid-bass and up with the high end amp. Worked well for me with an Aragon 2004 MkII for the bottom and an ARC D-130 for the top. Sounded good, but I still didn't have enough current to drive the damn things. Infinity told me that at high loads, total resistance can dip below 1 ohm. That's a load that requires an amp with some serious current. Kept blowing fuses on the Aragon, and the D-130- admittedly not ARC's finest piece of work by a longshot- kept going into protect mode after prolonged listening. What exactly will an active crossover add? |
I am having a problem with the woofers on my Kappa 9s. The woofers were working but I just wasn't getting any real bass slam. I spoke to Bill at Millersound. Bill said that, and don't quote me here I was up early, that he believed that the inductors were shot. that's the name for the part I think he said, and he suggested that instead of trying to get my crossovers repaired, which would be very difficult and costly, that I purchase an active cross over and Bi amp my Kappa 9. By doing this I would run the active crossover to my adcom 565s connected directly to the woofers and have my Hafler 9505 going to the rest of the speaker. My question to you folks, do you know where I would set the crossover for the woofer at 100, 80, any thoughts??? Bill also thought that my sound would be cleaner because the woofer portion of the internal crossovers would not be creating any magnetic fields and polluting the other crossovers. So I'm off to the store to get an electronic crossover and see if I can get some bass out of my kappa 9s |
