In the end I took a chance and ordered two diaphragms 689-1109
https://essspeakers.store/products/ess-amt-heil-speaker-diaphragm-689-1109 and when they arrived I was surprised to find that they both measured around 6.2 Ohms DC - not 3.7 Ohms as stated on the web page. That was close enough to a nominal 8 Ohms impedance in my book so I fitted them and they worked fine.
They must have been on a special sale at the time becase the pair cost me AUD144.00 plus AUD90.00 for shipping - a total of AUD234.00 all up. If I had to pay the current price shown on the web page (AUD151.00) above I would give it a miss. I see Simply Speakers is currently selling them at USD79.00 ea.
https://essspeakers.store/products/ess-amt-heil-speaker-diaphragm-689-1109 and when they arrived I was surprised to find that they both measured around 6.2 Ohms DC - not 3.7 Ohms as stated on the web page. That was close enough to a nominal 8 Ohms impedance in my book so I fitted them and they worked fine.
They must have been on a special sale at the time becase the pair cost me AUD144.00 plus AUD90.00 for shipping - a total of AUD234.00 all up. If I had to pay the current price shown on the web page (AUD151.00) above I would give it a miss. I see Simply Speakers is currently selling them at USD79.00 ea.
