Duck Twacy Posted November 30, 2002 Share Posted November 30, 2002 Hi, I'm thinking of using a pair of La Scala of Heresy with my Nelson Pass Alpeh5 amps. These babies dont like low impedance (< 6 ohm or so). Can somebody tell me what the minimal impedance for a La Scala of Heresy II is. Maybe also a picture of the impedance curve? Thanks Quote Link to comment Share on other sites More sharing options...
artto Posted November 30, 2002 Share Posted November 30, 2002 I don't know if the LaScalas exactly match the K-horns' impedance curve, but their components are all the same (except, obviously, the bass horn). Richard Heyser did a pretty thorough technical review of the Klipschorn in Audio magazine back in fall 1989 (The Best of Audio Volume IV). "The lowest value within the audio range is 4.5 ohms and occurs at 55Hz, while the highest value is almost 10 times that amount, 42.3 ohms, at 2,155Hz. "From the standpoint of amplifier drive requirements, a worst case frequency appears to be around 5,200Hz, where the phase angle lags by 70 degrees, although the magnitude of impedance is 11 ohms." "Fortunately, from the standpoint of amplifier drive requirements, none of these deviations can cause any problems whatsoever, as long as the power amplifier can drive 4 ohms at modest power." Quote Link to comment Share on other sites More sharing options...
Duck Twacy Posted December 1, 2002 Author Share Posted December 1, 2002 Thnx for the reply. What about the Heresys, are they even more "well behaved" (because of closed system)? Anyway I have a change to buy a pair of 5 year old La Scala for 3500 euro (for the pair). Is that a good price? They have a new crossover (so I understood, don't know if thats important). (The new price in Holland is 3500 euro for a single speaker.) Quote Link to comment Share on other sites More sharing options...
JohnA Posted December 1, 2002 Share Posted December 1, 2002 Half of new is a fair price. I believe a euro and a $US are similar in value, so $US3500, would likely be a new price for 2003 models over here. Find out what crosover they have. At 5 years old, they should Type AL-3s from the factory, with K-55-M squawkers (black magnet cover) and K-77-M tweeters (rectangular magnet). The impedance curve of a Heresy is more radical than a K-horn. It goes up to about 70 ohms in the midrange. La Scalas require so little power that your power amp will not be stressed, even though it will have to drive a 6 ohm bass system that dips to 4.5 ohms. By the time you are challenging the thermal or current limits of the amp, your ears will be hurting a lot! John Quote Link to comment Share on other sites More sharing options...
Duck Twacy Posted December 2, 2002 Author Share Posted December 2, 2002 Thanx for the replies Quote Link to comment Share on other sites More sharing options...
WMcD Posted December 2, 2002 Share Posted December 2, 2002 The Heresy (I) went down to 10 ohms in the bass region. I don't have information on the Heresy II but would think they are not too different. I have a scan of a spec sheet for an Industrial LaScala. It uses a K-43 woofer rather than the K-33 on the ordinary LS. The impedance goes down to 4.9 ohms. I'd think the story is about the same on the ordinary LS. I'd agree with John that since the K-Horn and LS use the same K-33 and are both horn loaded in the bass, the minimal impedance may well be about the same. Hmmm, I thought Mr. Pass built amps which were capable of driving low impedances. Gil Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.