Originally Posted by man_traic
PS the similarity between the E&S and Mario G iso could be the GSA connection...? Both units have that logo on.
If Mario posts an inside picture of an RLA xover board, you'll also see that the iso resembles the RLA board, too.
The GSA labeled E & S iso was made for GSA by E & S, and was made to GSA.s specifications. This is a standard practivce called OEM, Harmans "Revel " brand of speakers have a model that uses a tweeter made for them by Audax. Wilson Audio used a JBL manufacutured 18in woofer, made to Wilson specs. Westlake Audio uses JBL manufactured drivers, cone drivers and tweeters, JBL custom makes the 2406/076 " Cats Eye " tweeter for Westlake Audio! Westlake also uses TAD compression drivers, as well.
Years ago, a highly regarded hi fi subwoofer, Janis, used an Altec 416-8B, Meyer Sound used custom made JBL 2441 WITH SPECIALLY MADE BERYLLIUM DIAPHRAGMS.
Yars ago, in the 1950,s and 60,s Klipsch used an Atlas compression driver, EV T-35 tweeters.
Audax, Vifa, and SEAS all make drivers for other manufacturers and Eminence also manufacturers drivers for other speaker companies.
Major amp manuifacturers also can, and do OEM products for other brand names!
This is a standard practice. However, when you have componments made for your brand, and give an outside manufacturer your companies design specification, they make the products to your specs, and DO NOT sell these components as individual drivers to the public, they make them for your company only, and do not disclose the designs to the public, either.
If you look at the E & S board vs the Marios GSA labeled board, they are different size boards, they are different layout of components, different capacitors, and resistors, and different IC,s, input and output connectors, and different power transformer. Also note that while we are looking at the top side of the board, seing the components, without looking at the trace side of the board or having a schematic, you have no way to tell or know if the circuits are the same, or not!