05-20-2023 Post does not mapped to Knowledge Tree Bill Kensington, NH Posts 117 Joined on 03-15-2010 Post #: 1 Post ID: 27087 Reply to: 27087 Yamaha ns1000m speaker problem These were my first high end speakers purchased in 1980. They have been sitting in my basement for about 30 years as I've gone through everything from VMPS super tower 2 ar's to B&W 800 to my self built Edgar horns, which I’ve been using for about 20 years. As I’m getting ready to go to retirement community, I brought up the Yamaha’s from the basement to see how they sound. Happily, the beryllium mids and tweeters sound great. Unhappily the both 12 inch woofers have lost about 20 dB of volume compared to the other drivers. The crossovers seem fine and the drivers look normal, so suspect it could be due to demagnetization. Any ideas as to how this could have occurred and any ideas as to whether it is repairable, and if not, where could I get replacement drivers for them.Hanks, Bill

05-20-2023 Post does not mapped to Knowledge Tree rowuk Germany Posts 454 Joined on 07-05-2012 Post #: 2 Post ID: 27088 Reply to: 27087 I suspect the crossovers The electrolytic capacitors in the woofer low pass circuit are certainly dead. They look perfectly normal when old, just lose capacity in a serious way. The NS1000 had ferrite magnets that don't need remagnetization. Whenever I feel blue, I start breathing again.

05-22-2023 Post does not mapped to Knowledge Tree Bill Kensington, NH Posts 117 Joined on 03-15-2010 Post #: 3 Post ID: 27089 Reply to: 27088 Caps Thank you Roku. Will try replacing them first.Bill

07-07-2023 Post does not mapped to Knowledge Tree Bill Kensington, NH Posts 117 Joined on 03-15-2010 Post #: 4 Post ID: 27163 Reply to: 27089 Yamaha It wasn't the caps. The 12 inch drivers were both frozen solid after being stored in a dry basement for 30 years. Looks like the coils somehow fused to the magnets.Ordered a used pair from Japan for $300 with shipping and they arrived after 20 days in great shape looking and sounding almost new. Will be using them as my side speakers in a surround system with my Self built Edgar horns.Surprisingly they sound very good compared to what I remember from the early 80's when I got on the high end band wagon. May be because I am using them with a rebuilt Yamaha b3 amplifier which they were originally tested with in Japan back in the 70's.