jcidave

I was wondering if you would consider adding a single heil on a speaker stand behind each left and right array to give you better HF coverage at a higher floor to ceiling measurement in the room? Then again, if you are happy with your listening position, there is no need for this. Also curious how your diaphragms are holding up with your lower crossover frequency? If there is no melting of pleats together, then you are doing well.

I don't think there is too much I can tell you guys. You seem to have it all figured out pretty well. All my Heils are attached to stock ESS speaker cabinets from the 70's with ESS passive crossovers. I don't do any EQ or DSP. It is an analog system playing vinyl. I do have a passel of these speakers as there are 30 Heil units in the sound room. The diaphragms have changed over the years. The substrate has changed and the pleating has changed. The earliest diaphragms from the early 70's had 17 pleats and I think used mylar as the substrate. At that time, they had no bridal veil across the surface. Current diaphragms have 12 pleats. Don't remember the current substrate. At one point in the early 2000's they used Kapton as the substrate. Don't know why they started using that, don't know why they stopped. That was before Ricky's time at ESS. I have several pair of these earliest diaphragms in use today. I'm not hearing any deficiencies with them. In the attached pic, the diaphragm at lower right is a second generation. they put 3 rows of silicone across the surface to control pleats melting together. Then they abandoned the silicone and added the bridal veil. There are also Kapton diaphragms in the pic. I have several pair of Kaptons in use with the collection. I think one would be hard pressed to find any other driver to sound as good as the Heil that can be repaired so easily or quickly by anyone with virtually no skills or special equipment. Sorry I don't have any experience with PK speakers. I am friends with the brother of Gary Shinall. I did hear his Shinall corner horns once briefly. I thought they were pretty spectacular.

Someone on Audio Karma linked this thread to an ESS rebuild thread which is how I am here. This was a great read and very informative for someone like me who is past technical tinkering. I am very impressed with the technical abilities of the participants and the DIY projects are gorgeous. I have owned and collected ESS speakers for 45 years starting when I worked for an ESS dealer store in the mid 70s. It does me good to see others enjoying the Great Heil as I have all these decades even though we use it in different ways. I hope you will always enjoy your Heil setups. Best Dave