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.
Oh man, blast from the past. I had the Minimus 7s as a teenager. Never knew anything about them in terms of reputation at the time, but they absolutely amazed me with their sound. They sounded so weighty given their size. Perfect for a room that couldn't handle anything larger. Can't remember what I ended up doing with them but would love to hear them again. |
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. |
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Hey Bobcat, You should also research and post in DIYAudio ’s Multi-Way forum. I’ve seen a couple of threads on RS speakers. You may find more details there: http://www.diyaudio.com/forums/multi-way/ Best, E |