Radio Shack MINIMUS 7 crossover upgrade


I understand there were articles talking about upgrading the crossover of these bookshelf speakers.
Where can i get more information about this discussion and how to do it?
shsu
Ummmm, search function or google usually works to get more information.

I tried both and all types of things popped up, Try it.
Any speaker x-over can be upgraded. But you have to know what you're doing and what kind of (sonic) results you want from upgrading. Last article I saw was about 25 years ago. basically addressed changing out the cheap stock parts with higher quality parts. have fun!
A DIY company offered a upgrade kit many many years ago but basically this is what you can do:

1. Replace the stock gray capacitor with a 4.7 microfarad Solen rated at 250 volts. The old one may be hot-melt-glued to the crossover board so instead of trying to remove it, just snip the leads and solder in the new cap.

2. Remove the fiberglass insulation and affix / dampen the top, bottom and sides with a sticky dampening material (like Dynamat) since the one used is no longer available. Be carefull handling the FG. Reinsert the FG (you may want to replace the FG with some Poly).

3. Dope the woofer. It seems Damar varnish is the "dope" of choice. Damar varnish is not a brand name, but a type of varnish typicaly used by artists who paint with oils. It would be available from a local art supply store. Grumbacher's Damar Vanish (2 1/2 oz. was the smallest bottle I could find at Michael's or other artist supply store). Do not get the type used for airplanes Coat just the woofer with a small brush and be VERY CAREFUL not to get any on the rubber surround. Allow it to dry eight hours and then apply a second coat. Allow second coat to dry 24 hours before playing music. DO NOT ATTEMPT TO TREAT THE TWEETER!

[u]Special Note if you cannot find the Grumbacher Damar Varnish.[/u]
Run a test of a couple of whatever Damar varnishes you can find on 24# or higher copier paper or paper grocery bags cut into 4" square and let dry over night. The successful varnish will dry without warping the paper. Michael's was very accommodating in allowing me to return the ones I didn't use so long as I didn't gum up the containers.

You can google to see if there are other options. Good luck and have fun.
My first reply to your question doesn't seem to have made it past the moderators, perhaps because I gave the user ID of the guy who sells replacement crossover kits for the Minimus 7.

I don't have any connection to him other than having bought three of the kits and been very happy with them. He sells the kits on ebay and if you search for 'minimus 7' you'll find them.

The instructions that come with them are pretty primitive but it's definitely worth the effort to figure it out. Just take your time, stare at the innards of the speaker for a few minutes and you'll do fine.

The only thing that takes a little figuring out is where to mount the new crossover board so that you have enough clearance to put the woofer back in. I used a hot-glue gun to stick it against the side wall of the speaker enclosure.
I recently replaced the crossover in my Minimus 7s. I considered the kit that Sfar refers to (sold on ebay), I also searched Audio Asylum where there's lots of advice. In the end I simply built a 1st order crossover from parts I purchased at Parts Express. I also replaced the sprung wire connectors with good 5 way binding posts. I used acrylic from Home depot for the structural parts (ie to fasten the caps, inductors, and binding posts to). The only challenge was positioning the cap so it wouldn't interfere with the woofer.

This is an easy DIY project, even if you haven't done anything like it previously figuring it out yourself is a good learning experience.