jruhnke Posted June 15, 2003 Share Posted June 15, 2003 Hi there. I've had a pair of mid-1984 Cornwalls (S/N 8420715,6) for about five years now, and I've always assumed for some reason that they're 4-ohm speakers, though I can't remember where I got that information. I've just recently started trying to get a little smarter about these fine beasts, and how best to build up from my current, inexpensive stereo system to a "nice" multichannel system. I took a look at the Cornwall I and II product information pages on this Klipsch website, and both pages say those speakers were rated at 8 ohms. I finally decided to pull out the old multimeter, and they read ~4.7 ohms at the terminal screws when electrically isolated. What gives? I tend to trust my multimeter, but I'm loathe to dismiss the information from the manufacturer. I have heard reports that some of the receivers I'm considering (most notably the Pioneer Elite 45TX) can have trouble with speakers rated at 4 ohms. Honestly, I doubt that would be a problem in my townhouse environment, as my cheap stereo receiver has never had a problem at the volumes I use, but I still want to be as informed as possible. Thanks, Jim Quote Link to comment Share on other sites More sharing options...
jt1stcav Posted June 15, 2003 Share Posted June 15, 2003 Welcome to the Klipsch Forums, Jim. I've always assumed that the Cornwalls were always 8 ohms (from what I've read), and until recently, I've always connected them to 8 ohm taps. But since owning my latest McIntosh amp (the classic MC250), this amp has taps for 4, 8, and 16 ohms at 50 watts per channel, due to its patented Autoformers. I've read how many Heritage owners connect their horns to the 4 ohm taps for better sonic performance, and I've also tried this setup (sounds marvelous, indeed). I've also been told on this Forum that the Cornwall's woofers are actually 4 ohms. All I know is that I'm confused, but not dissatisfied with the sound qualities of these loudspeakers, no matter how they're connected to my Mac! Hope someone here with technical know-how can explain all this to us uninformed Klipsch owners who think we have 8 ohm horn speakers that are actually 4 ohms, or visa-versa. Fill us in! Quote Link to comment Share on other sites More sharing options...
djk Posted June 16, 2003 Share Posted June 16, 2003 The DC resistance of the K33 is 3.2 ohms, the inductor in the crossover raises this value to about 3.7 ohms, if yours measures much different than this you have a problem with either your meter or your speakers. On original Cornwalls the ring terminals connecting the crossover with the input terminal strip can be a source of problems. The tinsel leads on the woofer may be oxidized and in need of replacement. The real issue people want an answer to is: Do I hook it to my 4 ohm tap, or the 8 ohm tap? The minmum AC impedance is about 5.5 ohms so it won't likely hurt anything no matter which one you hook it to. Try both taps. Sometimes the bass sounds better on the 4 ohm tap. Sometimes the mids and highs sound better on the 8 ohm tap. Leave the speaker on the one that sounds the best. 1 Quote Link to comment Share on other sites More sharing options...
mopar dave Posted June 16, 2003 Share Posted June 16, 2003 jim, you may want to address your question to AL KLAPPENBERGER, he builds crossovers for these. dave Quote Link to comment Share on other sites More sharing options...
jruhnke Posted June 16, 2003 Author Share Posted June 16, 2003 ---------------- On 6/16/2003 2:50:59 AM djk wrote: The DC resistance of the K33 is 3.2 ohms, the inductor in the crossover raises this value to about 3.7 ohms, if yours measures much different than this you have a problem with either your meter or your speakers. ---------------- Very informative--many thanks! I'll go recalibrate my meter and see if I need to do some interior maintenance. Now... Why do you suppose the Klipsch Cornwall I and II sites (http://www.klipsch.com/product/product.aspx?cid=111 and http://www.klipsch.com/product/product.aspx?cid=115) both say "Nominal Impedance: 8 ohms"? Quote Link to comment Share on other sites More sharing options...
Malcolm Posted June 16, 2003 Share Posted June 16, 2003 Nominal impedance is just a number chosen by the manufacturer to give a simple indication of the kind of load the speaker presents to an amplifier. Actual impedance of the speaker varies with frequency. It will be several times the nominal value near the resonant frequency of a speaker. And it also typically rises with frequency. Typical curve looks kind of like a Nike logo. Put three speakers and a crossover in a box and it gets more complicated. The DC resistance you measured with your multimeter is only part of the impedance of the speaker system. It also has capacitive reactance and inductive reactance. Both of those vary with frequency. DC resistance is typically about 70% or nominal impedance. But there is no hard and fast rule. Quote Link to comment Share on other sites More sharing options...
jruhnke Posted June 17, 2003 Author Share Posted June 17, 2003 Thanks a lot. I've certainly never claimed to know everything, but I never realized how little I knew about speaker impedance. Thanks for the education! Jim Quote Link to comment Share on other sites More sharing options...
Chuckfastaxle Posted April 25, 2023 Share Posted April 25, 2023 I am attempting to test the impedance of the midrange and tweeter in my Klipsch Cornwall IVs I removed the strap and used a multimeter on the terminals with little success. Reads OL or sometimes very low ultimately changing to OL. Is this cause for concern? The woofer reads 3.8 in each speaker which is consistent with expected results. Quote Link to comment Share on other sites More sharing options...
JohnA Posted April 26, 2023 Share Posted April 26, 2023 You are reading through the crossover, so the capacitors make it read open. You'll have to disconnect each driver from the crossover to measure it. To measure impedance, you'll need a meter that can test at different AC frequencies. Mine will, but at only 400 Hz, below the HF crossover point. Quote Link to comment Share on other sites More sharing options...
pnort Posted April 26, 2023 Share Posted April 26, 2023 Maybe just move the resistance probes to the speaker connection from the crossover. No need to disconnect anything. 1 Quote Link to comment Share on other sites More sharing options...
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