Drop-in replacement woofer for Minimus 7?

[camerakid]

Hi! I got my first ever pair of Minimus 7's from the thrift store about a week ago, and after I took the grills off I noticed the woofers were moldy, and the surrounds are just absolutely gross; they have black powder on them that won't come off. And the grills are rusty, and I like them better without the grills on.

So, my question is; what would be a good drop-in replacement driver that doesn't require new screw holes to be drilled? I can maybe file down some edges and solder the wires onto the terminals, but I am not able to drill holes due to our vintage drill that just died.

I've been looking at a couple of woofers on Parts Express, like the HiVi M4N and B4N, Dayton DA-115-8, GRS 4PF-8 and the "WP-4008" buyout woofers. The 4 inch MCM woofer is out of stock and won't be available for 117 days, which is a HUGE bummer.

And also, these only cost $5 for the working pair, so I can spend more on replacement parts, but nothing over $40 for the pair of drivers.

Thanks in advance!

 

[camerakid]

And also, what is a "pincushion" woofer? I couldn't find any information on what it is.

 

[N8Nagel]

well, I'd disregard the condition of the surrounds. Do you think you can save the cones on the original woofers if you bleach them? If so refoaming would be a better option than replacing.

 

[WBCN]

I was just looking into this myself, and it looks like the MCM 55-1856 is the best choice, but as you pointed out they are back ordered til like forever... The 55-1853 looks like it might work, and should be available sooner. Other than that, it's the Goldwood GW-204/8, which is available at PE (Part # 290-372), but it doesn't look as good as either of the MCM options...

"Pincushion" just refers to the shape - kind of a rounded-off square.

 

[camerakid]

I was just looking into this myself, and it looks like the MCM 55-1856 is the best choice, but as you pointed out they are back ordered til like forever... The 55-1853 looks like it might work, and should be available sooner. Other than that, it's the Goldwood GW-204/8, which is available at PE (Part # 290-372), but it doesn't look as good as either of the MCM options...

"Pincushion" just refers to the shape - kind of a rounded-off square.

The 55-1853 looks the same as the 55-1856, just shielded, so that is a possibility... in fact, all the specs look the same also.

 

[WBCN]

The 55-1853 looks the same as the 55-1856, just shielded, so that is a possibility... in fact, all the specs look the same also).

The specs are a bit different - the 55-1856 can handle more power, but that's probably not a big factor for Minimus 7s.

I plugged the specs for the 3 drivers I listed into WinISD, and now it looks like the 55-1853 is best suited to the Minimus 7 box (which I have as approximately 0.07 cu ft). The 55-1856 is second best, and the GW-204/8 really doesn't look like it will work well in that box. Though the difference in the two MCM drivers probably wouldn't be very perceptible - they're both down 10dB at about 65Hz.. The 1853 has a little more output between 65 and 500Hz, but really they're within about 1dB of each other so you probably wouldn't hear it.


I think I would be inclined to try the 55-1853 and rework the crossover. I may even get around to it one of these days (months)...

 

[cubby01]

The best drop in replacement would be to rob them from another pair of Minimus-7s. Or better yet, sounds like yours might have sat in water, just pick up another pair.

To clarify these are butyl surrounds right? They don't generally go bad or break down like foam. Those surrounds should wipe down easily enough with warm soapy water. If you've got powdery crud all over them, I can't imagine where it's coming from.

Maybe pics would help.

 

[camerakid]

The best drop in replacement would be to rob them from another pair of Minimus-7s. Or better yet, sounds like yours might have sat in water, just pick up another pair.

To clarify these are butyl surrounds right? They don't generally go bad or break down like foam. Those surrounds should wipe down easily enough with warm soapy water. If you've got powdery crud all over them, I can't imagine where it's coming from.

Maybe pics would help.

I tried soapy water, wipes and even a wet toothbrush on them. Nothing helped. Here's some pics:

I rubbed my finger on the surround...

And yes, I have confirmed that's mold considering the driver smells like mildew, and also because I have had lots of experiences with mold (California weather). It's not dust, that's for sure. And also, the driver is VERY sun faded, that's for sure. It's faded from light grey to white...

 

[xero-D-hero]

A while back someone on the auction site had a blow-out on some NOS carbon-fiber woofers for the optimus LX4 and that's what I was gonna try purely as an experiment of sorts,unfortunately I have'nt got around to doing so just yet,though upon a cursory examination I did notice that the terminals were different between the two woofers (wide blade vs. narrow blade),so at the minimum that would need to be addressed,but other than that they look to drop/bolt right in as far as I could tell.

Also the wires for the woofers on mine seem unecessarily short for some reason as well.

Also not sure if I'm gonna like the look of that either,as I have the walnut cabinet Min7's ?

Not about to mess with my Optimus Pro7av,those are my test bench system speakers,and I like those just as they are.

But I digress.

Bret P.

 

[mikeybc]

There's a couple pairs of Minimus 7 woofers and some singles up on eBay right now, I'd get those and be done.

 

[Kingshead]

The black dust is dry rot. These were most likely being used outside as patio speakers hence the rust, mold, and dry rot.

 

[CKDC]

There is somebody on eBay (litekeys) that is currently selling an upgraded crossover and woofer kit.

At $80.00, it might be out of your budget but might be worth looking at.

 

[Copa1934]

Woofers turn up regularly on eBay. No sense making something else fit. If they were unobtanium that would be a different matter. You will want to try to get as close as you can as these speakers did get revised multiple times and I'm not sure the woofers were exactly the same between revisions. Have a set on my computer and love them. Powered by a RS 150 amp. Works fine for near field listening.

 

[tjohnusa]

Mask off the surrounds and spray paint them black.....clean the surrounds with alcohol and that should do you for a while.

 

[camerakid]

I now think it's really time to replace the woofers and the insulation inside... just took out one of the woofers that's in the better cabinet, and the terminal plate is almost rusted off; and the fiberglass (or whatever it is) has white powder (I sure hope it isn't drugs...) coming off of it. Grossssssss.... at least I have some leftover fiberglass.