Guest " " Posted December 22, 2006 Share Posted December 22, 2006 I'm mainly using a pair of LaScala's. With ALK contant impedance network, they come in at 6 ohms. I want to consolidate a list of commonlly used speakers and their impedance values. Quote Link to comment Share on other sites More sharing options...
pauln Posted December 22, 2006 Share Posted December 22, 2006 2004 LS with AL-4 (no clue as to the actual impedence characteristic - nominally 8 ohms... Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted December 22, 2006 Share Posted December 22, 2006 B&W N801's. They are rated at "8 ohms" but dip down to about 3 ohms. Quote Link to comment Share on other sites More sharing options...
Arky Posted December 23, 2006 Share Posted December 23, 2006 05 cornscalas - see BEC for specs 85 cornwalls Quote Link to comment Share on other sites More sharing options...
sunburnwilly Posted December 23, 2006 Share Posted December 23, 2006 My 5 old Belles are 8 ohm , or so they say . My main amp was designed to power electrostatics and does not seem to be taxed in any way . Even if they dipped into the 4 or 2 ohm region I don't think it would have a problem . Quote Link to comment Share on other sites More sharing options...
ZAKO Posted December 23, 2006 Share Posted December 23, 2006 Two JBL 130B 32 ohm In a JBL 55 scoop enc. Quote Link to comment Share on other sites More sharing options...
Klipsched with Yamahas Posted December 26, 2006 Share Posted December 26, 2006 Interesting question: I thought (gets me in trouble every time) most 2-ch setups were 8ohm. Of course, I'm applying 1980's thought processes in a 21st century environment. I do have a spare set of modern "junk" speakers that run @ 4ohm. Quote Link to comment Share on other sites More sharing options...
oldbuckster Posted December 27, 2006 Share Posted December 27, 2006 Heresy 2's upfront...................8 ohm KG4's in the back....................6 ohm Quote Link to comment Share on other sites More sharing options...
SilverSport Posted December 27, 2006 Share Posted December 27, 2006 Klipschorns Quartets Quartets Academy Heresys Heresys KSB 1.1 RB-5 I believe nominally 8 ohms but you know they can vary... Bill Quote Link to comment Share on other sites More sharing options...
Jay481985 Posted December 27, 2006 Share Posted December 27, 2006 RF-83 8 ohm acceptable 2.8 ohms dip around 30 hertz I believe. Quote Link to comment Share on other sites More sharing options...
oldtimer Posted December 27, 2006 Share Posted December 27, 2006 I'm not sure I understand the purpose of this. If it is to see who has measured their ohms count me out. Forte II's 8 ohms according to Klipsch. Quote Link to comment Share on other sites More sharing options...
pauln Posted December 27, 2006 Share Posted December 27, 2006 Just for the record, the impedence attribute is defined for speakers in IEC standard (IEC60268-3) which allows any "increase" above the rated value, but limits the "decrease". The standard does not allow the impedance to fall below the 80 % of the nominal value at any frequency, including DC. The old Heresy I is called 8 ohms by convention, but since it's lowest impedence is about 10 ohms, it actually qualifies as a 16 ohm speaker (80% of 16 is 12.8). The 80% levels for nominal values: 4 Ohm - - lowest point above 3.2 ohm 8 ohm - - lowest point above 6.8 ohm 16ohm - - lowest point above 12.8 ohm Also to keep in mind, the nominal ohm taps on the output transformer of a tube amp may be slightly different than the printed convention - some Magnequests' "8ohm" taps are really 9 ohm on the spec sheets... every little bit helps. Quote Link to comment Share on other sites More sharing options...
pauln Posted December 31, 2006 Share Posted December 31, 2006 Didn't mean to kill this thread - do you have enough data points yet? What are you up to? Quote Link to comment Share on other sites More sharing options...
Guest " " Posted December 31, 2006 Share Posted December 31, 2006 I want to consolidate a list of commonlly used speakers and their impedance values. There have been a few very intresting responses....some speakers claim 8 ohms, but dip down very, very low, or in some cause, very high. If you look at a LaScala, most believe it is an 8ohm speaker, but it is actually 28 ohms thru most of it's mid range. I have a simular question cooking about amplifiers and tap settings. Quote Link to comment Share on other sites More sharing options...
pauln Posted December 31, 2006 Share Posted December 31, 2006 Somewhere in the Dope From Hope there is a paper on the effects of high impedence on compression horns - it's a good thing! The rising impedence matches well with horns by supressing the potential 'blastyness' that a horn might produce with a lower impedence signal - it's a mechanical/electrical negative feedback loop that almost perfectly compensates itself for all levels of impedence. This is why the high imp.s are OK; the old Heresy peaked at about 70 Ohms without concern. Quote Link to comment Share on other sites More sharing options...
Guest " " Posted December 31, 2006 Share Posted December 31, 2006 Somewhere in the Dope From Hope there is a paper on the effects of high impedence on compression horns - it's a good thing! The rising impedence matches well with horns by supressing the potential 'blastyness' that a horn might produce with a lower impedence signal - it's a mechanical/electrical negative feedback loop that almost perfectly compensates itself for all levels of impedence. This is why the high imp.s are OK; the old Heresy peaked at about 70 Ohms without concern. Absolutely...with qualification. For horns, there are impedance factors which change based solely on the horn compression area in front of the diaphram. You will often see different spec's for drivers depending on how it is mounted. Recent example is the ev182x data that Gil posted. For horns, the right amount of accoustic induced impedance makes for less distortion. Now in the case of amps, intresting senerio. If you take an amp that is reated at 8 homs, x amount of power, x amount of distortion, x amount of dampening factor, intresting things start to happen with amp and speaker compo's outside of the 8 ohm spec. A 4ohm load on such an amp, will lower dampening factor, increase distortion, but increase watts. Amps with poor signal to noise ratios will sound noisy, hss, buzz, humm, etc. A 16 ohm load on such an amp, will increae dampening factor, reduce distortion, but decrease watts. Amps with poor signal to noise ratios will function quieter in the area of hiss, buzz, and hum. Now in the case of high spl horn drivers, the cost penalty for decreased watts at high impedances is very acceptable. Quote Link to comment Share on other sites More sharing options...
sredmyer Posted January 5, 2007 Share Posted January 5, 2007 Just for the record, the impedence attribute is defined for speakers in IEC standard (IEC60268-3) which allows any "increase" above the rated value, but limits the "decrease". The standard does not allow the impedance to fall below the 80 % of the nominal value at any frequency, including DC. The old Heresy I is called 8 ohms by convention, but since it's lowest impedence is about 10 ohms, it actually qualifies as a 16 ohm speaker (80% of 16 is 12.8). The 80% levels for nominal values: 4 Ohm - - lowest point above 3.2 ohm 8 ohm - - lowest point above 6.8 ohm 16ohm - - lowest point above 12.8 ohm Also to keep in mind, the nominal ohm taps on the output transformer of a tube amp may be slightly different than the printed convention - some Magnequests' "8ohm" taps are really 9 ohm on the spec sheets... every little bit helps. I have been told that my RF-7s will dip to about 2.8 Ohm at around 70hz by someone on this forum (do not remembr who)...If that is true and your table is acurate then they should be rated as 4 Ohm speakers...but they are rated (by Klipsch) as 8 Ohms. Quote Link to comment Share on other sites More sharing options...
marems Posted January 5, 2007 Share Posted January 5, 2007 Epic CF-4 Version 1. 8 Ohm normal, dips to 3.7 Ohms. Run off the 4 Ohm Taps on the McIntosh MC150. Quote Link to comment Share on other sites More sharing options...
Islander Posted January 8, 2007 Share Posted January 8, 2007 Has anyone seen an impedance curve for La Scalas with AA crossovers? I'm curious to see it. Quote Link to comment Share on other sites More sharing options...
nomathjobs Posted January 8, 2007 Share Posted January 8, 2007 KG4 mains running off the 4 ohm tap on bone stock Dynaco Mk III. doug Quote Link to comment Share on other sites More sharing options...
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