Upgrading of Minimus 7's


I guess I'm late but;

I have read several posts on here and other forums about upgrading the Realistic Minimus speakers from using a homemade kit purchased for $39 plus shipping on ebay (if I can use this word) to building your own 2-way crossover (which could be more $$ than expected), doping or the replacing the drivers and adding binding posts (easily done on the 7W due to its round hole in the back where the terminals are located).
I have a pair of both the metal cabinet Minimus 7's (made in Korea) and the Minimus 7W (made in Japan). The simple crossover in both differ only by the capacitor; a 4.7 uF 50v in the 7's and a 4.7 uF 100v in the 7W's. I had discovered that the voltage on the cap is its limit; if more than that voltage is sent to the cap they can pop or explode! So, does it help to change them out for a higher limit when the stored voltage is the same? I know most upgrades suggest a polypropylene cap replacement.

Anyway, I doped the woofers.

Onto what I found:
I looked at Amazon for 2-way crossover and found a pair for just under $13 and a pair of gold plated binding post terminals for about $8. The 2-way crossover had some very good reviews (2 especially) and a couple not so good. I was hesitant because of the brand and made in China but I did order them. The crossover is a circuit board with a choke coil for the woofer (fairly long) and for the tweeter there is a 2.2 ohm resistor, a 3.3 uF 250v polypropylene cap and a spool coil. Dimensions are Dimension: 8.5 x 6 x 2cm or 3.3 x 2.4 x 0.8 inches (L*W*H)
The post terminals fit perfectly, no problem. I salvaged the parts from the crossovers, wires for the speaker leads on the new circuit board and caps & coils.
I soldered the speaker leads and terminal leads to the board, hot glued the board into place and soldered the terminal leads from the board to the terminal contacts.
I tested the speakers and they really sounded much better to my surprise!
I ran the Audyssey setup with these upgraded Minimus 7W's as surround back speakers mounted on the wall. Before the upgrade the Audyssey setup would set the size as small speakers and the crossover frequencies at 90 to 100 Hz, but this time the crossover frequency is 40 Hz!
The sound from these upgraded speakers is great! I really couldn't believe that I could have done this improvement and spent under $21 for the whole thing!
I am sure the new crossover will fit the Minimus 7's but I would probably have to keep the spring clip terminals because of the metal cabinet.
If you're thinking of upgrading a pair or more of the Minimus 7's I think this is the way to go. This crossover would probably fit the Minimus 77's also.

128x128bobcat1950

Showing 2 responses by bobcat1950

hey templetech, HAPPY THANKSGIVING

here’s the link for the crossovers, https://www.amazon.com/gp/product/B016FBNNCY/ref=oh_aui_

detailpage_o00_s00?ie=UTF8&psc=1&pldnSite=1

You might want to consider adding screw-down terminal posts; here’s a link to start; https://www.amazon.com/Speaker-Terminal-Binding-Connectors-Subwoofer/dp/B07BQJT9H7/ref=sr_1_4?s=elec...

I still own the metal Minimus 7’s from the late 80’s early 90’s I bought at Radio Shack and took the capacitors and inductors I salvaged from the others and incorporated them into these to make a 2-way crossover so each speaker now has a crossover and they work great. Of course I researched how to connect the parts.