[Shear Bliss]

Hey all, new to AudioCircle but a huge fan of Brians designs from the Tower IIr originals to the SE with two 12" woofers. I now own the RM-1s in oak. I"m in the final stage of woofer upgrades, to the 8" Megas once my other 2 arrive.

I read a little on vitrified passive cones from this site. Was wondering if this would be worthwhile looking into ?? Understand it stiffens the passive by glue.
By the way ... Picked-Up these gems in 9/10 condition locally for  $450.00 the pr. !!! My deal of the century. Also looking forward to trying bi-wire or bi-amping them.

Any help on the passive results greatly appreciated.

Sincerely, Shear Bliss

[John Casler]

Welcome to the VMPS AudioCircle.

Seems we are enjoying a lot of "legacy design" members which is great.

And the great scores some of you are getting is fantastic.

Yes the vitrification of the PR is a GOOD thing to do as it stiffens the paper Passive Cone for less deformation and cleaner wave launch at higher SPL's.

Look HERE for instructions on how to vitrify your PR.

[mjosef]

I would also recommend you install the BH5...it made a big difference ++ with the quality of the bass IMO.

ANd definitely try biamping...even better sound overall.
Good luck.

[7x57]

Buy 5 pounds of Acousta-Stuf damping material from Parts Express for about $50 delivered and trash the fiberglass damping material that came with the RM-1. I'm getting useful bass down to 25 Hz, and I also did the vitrified cone thing with TWO coats of wood glue (front and back of cone).

I have used the Acoust-Stuf in a bass guitar practice amp and a set of old Polk RT-5 monitor loudspeakers, and it lowered and improved the bass in both units.

The stuffing rate for Acousta-Stuf is about 1 to 1.5 pounds per cubic foot of cabinet space. You may need cheesecloth or something similar on the backs of your woofers to prevent the puffballs from contacting the cones. I used thin sheets of fiberglass insulation directly behind the woofers on my RM-1. You MUST pull out and fluff up the Acousta-Stuf by hand as it is shipped very compressed in a small box. Do NOT stuff the material as it comes from the shipping container.

The Acousta-Stuf upgrade should work fine in any VMPS speaker that was stuffed with fiberglass at the factory. Therefore, do NOT consider this just an RM-1 upgrade or VMPS upgrade, but for almost any speaker or subwoofer that has been stuffed with fiberglass damping material. Not necessarily a good thing for a transmission line design unless you want to do lots of experimentation. In a closed or PR or bass reflex system, it is basically a no-brainer upgrade as it has far more surface area than simple circular cross sectional fibers.