The long story of a RAAL upgrade
I have a pair of Green Mountain EOS speakers. Some of you may be familiar with Roy Johnson's designs. Every few years I look around to find something better and can never find the right combination of price, efficiency and sound quality.
So about 5 years ago, Roy (who has always been very talkative) called me with an idea he had. He had found a RAAL tweeter that he thought would integrate well with his phase and time coherent designs due to its extended frequency range and impedance characteristics. I thought it sounded like a great upgrade and signed on immediately. About six months later, Roy was diagnosed with Stage IV Lung Cancer. He kept hanging on and working but was sick a lot of the time so things went very slowly. To make a longer story a bit shorter, Roy died before completing the last parts of the project. So I never got the upgrade from him. What I did have was all of his designs and drawings including most of the xover circuit for the tweeter integration.
Months later, I decided I would finish the project. So with the help of Alex at RAAL, I was able to obtain the parts I needed, get the last values for the cross over and that left me with the difficult task of building the enclosures. As you may know, Roy uses molded epoxy concrete for his cabinets. Since I couldnt do that, I modified the original tweeter housing and made wooden pieces that attached and accommodated the new dimension of the tweeter. It actually turned out to be a very difficult project without a lathe but I got it done.
I am very happy with the results and that I was able to complete a project that I know Roy had really wanted to get done. It is another great Roy Johnson design and The RAAL tweeters are living up to their great reputation. I am looking forward to another 5 years of enjoyment before I start looking for the next upgrade. i have attached some photos in case anyone is interested.
BTW I drive the speakers with a heavily modified Bottlehead 300b SET, Ayre DAC, and JRiver Media Server.