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Minimus 7 Loudspeakers - Measurements

Congrats, Zilch et al. When the employment situation improves this will be one of my first projects.
 
Just wanted to post that I am happy with the suggested crossover mod; though my 7W speakers now surprise my coworkers by their weight, they are lent out for audio setup testing when they are not working hard as my computer speakers.
 
DavidGoncalv said:
Just wanted to post that I am happy with the suggested crossover mod; though my 7W speakers now surprise my coworkers by their weight, they are lent out for audio setup testing when they are not working hard as my computer speakers.
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I'm pleased they worked out for you. I haven't completed my "Woodies" yet, but M7s are certainly handy little speakers.... :thmbsp:
 
Zilch said:
http://www.audiokarma.org/forums/showthread.php?p=2397327#post2397327

The build is completed in the following four pages.

Layout drawing here:

http://www.audiokarma.org/forums/showthread.php?p=2461080#post2461080

:thmbsp:
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Thanks for the hard work. I'm glad your plots of the stock unit matched mine--I guess we have the same generation of 7's. Maybe I'll give your mod a try, although as I mentioned in my write-up, they sound pretty darn good at low volume if they're placed on a table. Cheers, Dennis Murphy
 
dmurphy said:
Thanks for the hard work. I'm glad your plots of the stock unit matched mine--I guess we have the same generation of 7's. Maybe I'll give your mod a try, although as I mentioned in my write-up, they sound pretty darn good at low volume if they're placed on a table. Cheers, Dennis Murphy
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Allow me to be the first to welcome you to AudioKarma, Dennis. :thmbsp:

I hope you'll give our mod a try and report your findings both here and on your site.

[Unless you find it rather sucks, of course.... ;) ]
 
I ordered some of the $1 Alesis crossovers shown here since they have
small bar type inductors. Note that the schematic shown there has
some incorrect values:
http://apexjr.com/speakerstuff.html

There are 1.1 mH, .52, .11 mH bar type inductors, and a .12 mH
air core.
2.2 and 4.0 uF mylar type caps, and a bunch of NP electrolytics.
The 1.1 mH should be fine for the 1.0 mH, and the mylar caps should
be close enough. The 6 and 7.5 ohm resistors in parallel are close
enough to the 3 ohm. The circuit board could be reused I'm sure.

It is a budget speaker, this is a good solution to keep the cost down.
 
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I picked up a pair of RCA PRO-X44AV speakers from Radio Shack about six years ago for $30. I understand they're exactly the same as the Minimus 7s but only have a different manufacturer's name. They look the same and took the same mod kit as the 7s I brought on e-bay for $15. I have a hearing deficit and these speakers with their clarity makes listening to TV and music a pleasure and not a strain. Bass is light weight but a bass tone control adjustment fixes it. I'll never sell these guys.
 
Thanks and a question

Hi all, and thank you all for this thread. I have learned more about speakers than the sum of my previous knowledge! Admittedly a low bar, but still, it has inspired me to pick up a pair of M7s on e-bay with the intent to apply some of what I have learned here.
On to my question...
While waiting for the e-bay M7s to arrive I decided to take a look at a pair of Optimus proX5 (Cat. no. 40-2075) speakers that I used for computer speakers many years ago. One box died and I retired them. They are a bit smaller than the M7 with interior dimensions of 6.375 X 3.8" - cast AL with no port.
I took the 'bad' one apart and much to my surprise they were very different internally than anything discussed here! There does not seem to be anything that I would call a xover at all! Only a resistor or capacitor or something between the + sides of the woofer & tweeter, marked 85C, A 9505, FM(M)
Anyone familiar with these speakers? Is there an on-line source for the woofer and tweeters that provide dimensions and specs.?
current woofer - 3.2" frame with 2.5" 4 hole screw pattern marked 1020 8ohm.
current tweeter - 2.03 dia. X 2.25" screw holes (2 only, on "ears") plastic.
both marked 'Malaysia'.

Again, thanks for the thread!
Cheers!
Dave G.
PS pictures MAY be attached of these things?
 

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x-over

Thats a capacitor in there. Its purpose in life is to prevent the lower frequencies from getting to the tweeter. If its still working at its original spec (doubtfull) it may be all the crossover that the speaker will need. The next step in complexity and cost is a coil to prevent the high frequencies from going to the woofer.
 
Natal said:
I picked up a pair of RCA PRO-X44AV speakers from Radio Shack about six years ago for $30. I understand they're exactly the same as the Minimus 7s but only have a different manufacturer's name. They look the same and took the same mod kit as the 7s I brought on e-bay for $15. I have a hearing deficit and these speakers with their clarity makes listening to TV and music a pleasure and not a strain. Bass is light weight but a bass tone control adjustment fixes it. I'll never sell these guys.
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Funny you should say that...I bought these for a car I had in the 80's...used them hard and they're still fine, then gave them to my Mom when she found she couldn't hear the TV...put the Min7's right beside where she sat and voila, she could hear all that was being said...

Fast-forward 9 years later, my mother has passed on, and now I find I have a hearing loss, and so does my wife...I'm just about to put the Minimus 7's back to work upstairs, doing the same duty for us as it did for my mom! :thmbsp:

P.S. Mine are 2030C for the model #...does that have the "newer" tweeter?
 
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4Channel said:
P.S. Mine are 2030C for the model #...does that have the "newer" tweeter?
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Sorry I don't know when the newer tweeter was installed. Someone mentioned in a thread that the Centrios speaker sold by The Source in Canada is a clone of the Minimus 7 that had a newer tweeter. He felt that the newer tweeter was a bit more harsh than the old one.
 
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