Right, will do. The Mach 1 woofer seems to have more bottom end, but lacking a Mach 2 woofer for direct comparison, this statement may be conjecture. Surprisingly, the thick rubber surround of the Mach 1 woofer seems equally stiff to that of the Mach 2 woofer's foam surround, although in truth, the Mach 1 surround feels more like a foam/rubber composite.
It is in fact a treated foam. They used it with most of their mid to upper line speakers. I recall my Two's sounding deeper (more mid bass), which I attribute to the porting more than the woofer, while the One seemed to be smooter. Below hearing they were awful close. Using Winisd I believe the Two did graph better than the One, deeper bottom end, though the One seemed flatter in response. Also Winisd came up with larger, much larger, volumes for cabs than original designs.
Why undersize? Simple, economics. RS had to distribute products to 7000 stores (close to that in the 70's, easily by the 80's). Many of those stores swap inventory, shortages, overages, etc. All shipped via UPS. 18 wheelers were only used for warehouse direct to stores. If you shipped UPS you had to meet size and weight requirements. When dealing with that many locations (points of distribution) you can't be eating up all your profits in shipping.
It's a concession, but one not one person seems to have taken into consideration when knocking down Mach One's, Two's and Three's. Not saying you of course, others do read these posts. HiFi stores had Truck shipments. They dealed direct with the public, so the type of inter-store exchanges didn't happen with the regularity of RS, so companies like JBL, Klipsh, etc. didn't have to keep this in mind. They also knew they were catering to clients who typically had deeper pockets.
Oh, I worked for RS for 10 years, sales, then computers, then full line manager.
Forgot, the treated foam was only on the 4024 and 4024a. All Mach's afterwards used standard issue foam. I've always wondered why so many of the "top dogs" never used that foam? There may have been shortcommings, though I'm not aware of one, but vs foam rott? Go figure.
