Can I upgrade my Minimus 7's?

[lotek]

I want to use a set of Minimus 7's that I have refurbished.
They sound okay but is there a cheap replacement for the woofer that will make them better?
I've already replaced the Capacitor with a new poly cap. The inductor is original.

I don't think there's anything on the woofer.

I see that PE sells a lot of similar drivers.
thanks!

[clydethecat]

Re: Can I upgrade my Minimus 7's?

I don't have an answer but I'll pile on in case there's a response. I have two pairs, both of which have either blown or rotten woofers. I hate to bin them, especially since one pair are 7Ws. I think there's a project for a Min 77 using a Tang Band woofer somewhere in the P-E project archives.

[Chris Roemer]

Re: Can I upgrade my Minimus 7's?

I want to use a set of Minimus 7's that I have refurbished.
They sound okay but is there a cheap replacement for the woofer that will make them better?
I've already replaced the Capacitor with a new poly cap. The inductor is original.

I don't think there's anything on the woofer.

I see that PE sells a lot of similar drivers.
thanks!

You could tell us about them (for those of us who don't own them).

How large is the woofer? 4"? How about the ND105-4?

What's the box volume? Vented? 2-way?

What up?

[Thezeek]

Re: Can I upgrade my Minimus 7's?

http://www.parts-express.com/project-gallery/speaker-projects/

One of the last pages has the project.

[bre's dad]

Re: Can I upgrade my Minimus 7's?

other than repeat the same advice others have (PE has many woofers that will work as replacements) there is a person on ebay (no association) that sells upgrade kits. You could always go that route. Or, given those are probably 20 years old you could just get the same value caps from PE and rebuild the crossovers that way. They will sing like new. I haven't done the the Minimus 7's but I rebuilt some Mach 2 XO's and it was almost a day and night difference. Very easy to do too. All you need is some basic soldering skills. Oh, and do one at a time in case you forget what part went where and also so you can compare the rebuilt with the original. That's my 2 cents worth, for what its worth.

And the project mentioned above is for a set of Minimus 77's, the slightly bigger dersion of the Minimus 7 but the concept still applies. Main difference is the 7 uses a 4" woofer and the 77 uses a 6" I think. Tweeter is the same and the crossovers, not sure about.

[johnnyrichards]

Re: Can I upgrade my Minimus 7's?

Yes you can, I got over 400,000 hits on Google using "minimus 7 upgrade" as a search term. It seems to be a strangely popular past time

FWIW, I don't think there is anything really wrong with the drivers, that speakers limitations seem to be 1/2 Bose related (too small of a cabinet) and 1/2 accounting related (minimalist crossover on drivers not suitable for that design approach).

[DDF]

Re: Can I upgrade my Minimus 7's?

I just coated my woofers, replaced tweeter and redesigned xover. Fun little boxes that sound surprising good but you need to keep SPLs very (very) low.

I heard this driver is a drop in, but never tried it:

Goldwood 204/8 (Parts-Express 290-372)

I used an Apex Jr tweeter that's not available any longer. IME, jettison the tweeter before the woofer. The woofer has a terrible break up off the hard dust cap so the xover needs some measurement equipment and xover sim to get sounding OK, IMO

[bkeane1259]

Re: Can I upgrade my Minimus 7's?

I want to use a set of Minimus 7's that I have refurbished.
They sound okay but is there a cheap replacement for the woofer that will make them better?
I've already replaced the Capacitor with a new poly cap. The inductor is original.

I don't think there's anything on the woofer.

I see that PE sells a lot of similar drivers.
thanks!

I did the Zilch xover mod on several sets, all of which were bought on ebay for dirt cheap. As long as the drivers are good, the XO mod does wonders for the sound.

On mine, I damped the woofer with a bead of silicone caulk around the magnet and also lined the stamped frame with strips of dynamat-like material. I did the same dynamat damping on the inside walls of the cabinet.

The lack of adequate XO on those was their short-coming for sure. I highly recommend looking into the Zilch XO -- Zilch was a true DIY master.

[lotek]

Re: Can I upgrade my Minimus 7's?

Hi Chris,

I got these at a garage sale for $6 and they work really well.
The woofers are 4" and have a fair hefty magnet. The tweeter is also fairly large.
It's a 2-way and the cabinet is metal. The box is sealed and the grills are also metal. When I got them the grills were black and dented in so much so that the grills were pressing into the tweeter dome.

I painted the grills, I like the look.
I also upgraded the stock capacitor with a beefier poly cap and kept the stock inductor coil. I don't believe there's anything on the woofer, the cap and coil are on the tweeter.

I'm thinking of getting a better woofer and trying a cross-over I saw on ebay, but that may not work well with a new woofer - hence my dilemma.

Thanks to all for the suggestions. I will most likely use these with my Vintage Marantz 2238B or 2230 and a sub. I have an Infinity BU-80 that has a blown amplifier. If I can figure out how to fix that then I think these will perform well for a desktop setup.

[bkeane1259]

Re: Can I upgrade my Minimus 7's?

The real problem with that speaker is the XO -- you need to rebuild them (the XO's) first before you think about scrapping a perfectly good woofer.

There is a serious hump around 3k and then again at 8k that the proper XO mod can tame. It makes all the difference in the world.

All the parts can be purchased at PE for peanuts.

Here's a link to the schematic for the Zilch project:

http://www.audiokarma.org/forums/showpost.php?p=3671070&postcount=421

P.S. If you insist on tossing those woofers, I will buy them as long as they are not blown.

[clydethecat]

Re: Can I upgrade my Minimus 7's?

P.S. If you insist on tossing those woofers, I will buy them as long as they are not blown.

Is there a reasonable replacement, for those of us who have blown ones? Do Radio Shack or Fostex offer anything suitable?

[johnastockman]

Re: Can I upgrade my Minimus 7's?

Hi Chris,

I got these at a garage sale for $6 and they work really well.
The woofers are 4" and have a fair hefty magnet. The tweeter is also fairly large.
It's a 2-way and the cabinet is metal. The box is sealed and the grills are also metal. When I got them the grills were black and dented in so much so that the grills were pressing into the tweeter dome.

I painted the grills, I like the look.
I also upgraded the stock capacitor with a beefier poly cap and kept the stock inductor coil. I don't believe there's anything on the woofer, the cap and coil are on the tweeter.

I'm thinking of getting a better woofer and trying a cross-over I saw on ebay, but that may not work well with a new woofer - hence my dilemma.

Thanks to all for the suggestions. I will most likely use these with my Vintage Marantz 2238B or 2230 and a sub. I have an Infinity BU-80 that has a blown amplifier. If I can figure out how to fix that then I think these will perform well for a desktop setup.

I had a friend who went the flea-bay XO route for his Minimus with the metal boxes...not acceptable at all. The original XO sounded better. While the stock XO was extremely minimalist, meaning it was designed for mass-production, not good SQ, anything other than that isn't an upgrade. Swapping in another woofer also leads to the same conclusion. Keep the stock drivers (if they aren't damaged) and use the Zilch XO. Much better in overall SQ. Also, he let me line the interior with Cascade Audio's peel 'n stick damping material. Noticeable improvement. Not night & day difference, but an improvement.

John A.

[johnastockman]

Re: Can I upgrade my Minimus 7's?

Is there a reasonable replacement, for those of us who have blown ones? Do Radio Shack or Fostex offer anything suitable?

I know of no exact replacement...probably only the original will work with the stock XO or the Zilch XO. Repairs can be done, PE offers a service, so do these guys:

http://www.speakerrepair.com

Trying another woofer would be trial and error, mostly error. The guys at Orange County Speaker (no relation to chopper poseurs) might even have a replacement they could suggest. Those Minimus speakers were and still are popular, so maybe someone has come up with a viable drop-in that could improve or retain the SQ. Good luck.

John A.

[michiganpat]

Re: Can I upgrade my Minimus 7's?

search the audiokarma board for minimus 7's...IIRC there's an MCM woofer that's supposed to be a very good replacement.

personally I'd try a dayton ND105-4 or maybe a hivi B4N

[ernperkins]

Re: Can I upgrade my Minimus 7's?

I think it's the MCM 55-1853 that Zaph used on his Bargain Mini project - it has the same pin cushion type frame as the RS woofer.