klipschhornfan Posted March 14, 2019 Share Posted March 14, 2019 (edited) Does this mid 70s Heresy 1 HWO look all original to you including the cabinet and internal wiring? It has the Type E crossover, K-77 tweeter, K-55V midrange and K-22EF woofer. Are all the drivers alnico? Thanks. Edited March 14, 2019 by klipschhornfan Quote Link to comment Share on other sites More sharing options...
carlthess40 Posted March 14, 2019 Share Posted March 14, 2019 Does this mid 70s Heresy 1 HWO look all original to you including the cabinet and internal wiring? It has the Type E crossover, K-77 tweeter, K-55V midrange and K-22EF woofer. Are all the drivers alnico? Thanks. Looks all original to me. Looks just like my H1’s from 1984/86 Quote Link to comment Share on other sites More sharing options...
klipschhornfan Posted March 14, 2019 Author Share Posted March 14, 2019 Are the drivers alnico? Quote Link to comment Share on other sites More sharing options...
glens Posted March 14, 2019 Share Posted March 14, 2019 Can't say by the photo whether the top two are but the square magnet is definitely mud. Quote Link to comment Share on other sites More sharing options...
glens Posted March 14, 2019 Share Posted March 14, 2019 Reference this recent photo in the General forum ("Heresy troubleshooting"): I'm calling that woofer magnet "alnico." Quote Link to comment Share on other sites More sharing options...
klipschhornfan Posted March 15, 2019 Author Share Posted March 15, 2019 (edited) If I'm looking for Heresy I with all alnico drivers, the date code has to be 1975 or earlier? Is the midrange "dome" in the middle the video shield? If so, is it possible to tell whether the midrange driver is alnico or not without taking the shield off? Edited March 15, 2019 by klipschhornfan Quote Link to comment Share on other sites More sharing options...
glens Posted March 15, 2019 Share Posted March 15, 2019 Haha, they didn't "do" video shields back then, though the cap you're seeing does suffice for that, usually. I'd call it a magnetic field return and good drivers were made that way (using a ductile cap to direct the magnetic energy forward to the outside of the voice coil gap) back in the day, usually using an internal alnico magnet. This is as far as I can be of assistance to you in this matter. Quote Link to comment Share on other sites More sharing options...
JohnA Posted March 16, 2019 Share Posted March 16, 2019 The squawker and tweeter in that Heresy have AlNiCo magnets. That K-22 does not. All K-55-Vs and -Xs have AlNiCo magnets. All K-77s have AlNiCo magnets. There were several woofers used in Heresies, interchangeably and I don't think anyone can say when the change was made to only ceramic magnets. From what I've seen the change happened between 1970 and 1972. My '67 and '68 H700 have all AlNiCo magnets. In general, AlNiCo is not superior to ceramic, especially now. AlNiCo is prone to lose strength with age and bumps/shocks and ceramic is not. Quote Link to comment Share on other sites More sharing options...
Pats3of4 Posted March 17, 2019 Share Posted March 17, 2019 Those are identical to the 77’s I just took apart to refinish. Quote Link to comment Share on other sites More sharing options...
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