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Minimus 7 Loudspeakers - Measurements

I have been reading this and other threads for days now and still have questions. What is the crossover frequency before and after this mod? Has anyone tried a typical 2nd order crossover based on a calculator or a kit and what would be the results? The most obvious objectionable property I hear seems to be a peak around 2-3 kHz. I'm thinking about simply decreasing the tweeter capacitor to 2-3.3 µf. I'm wondering how they came up with 4.7 µf because it doesn't seem consistent with any calculator I've tried.

One other thing I thought of is using a series crossover - the type that puts the woofer and tweeter in series.
 
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The simple answer is Yes, you can do pretty much whatever you like to the crossover design.

But realise that the calculators simple academic tools only.

The more important question is will it sound ok - the simple answer then is maybe, but not likely.

Stick with the design. Enjoy the hard work of others here.

:beerchug:
 
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chris1379 said:
I have been reading this and other threads for days now and still have questions. What is the crossover frequency before and after this mod? Has anyone tried a typical 2nd order crossover based on a calculator or a kit and what would be the results? The most obvious objectionable property I hear seems to be a peak around 2-3 kHz. I'm thinking about simply decreasing the tweeter capacitor to 2-3.3 µf. I'm wondering how they came up with 4.7 µf because it doesn't seem consistent with any calculator I've tried.

One other thing I thought of is using a series crossover - the type that puts the woofer and tweeter in series.
Click to expand...
Mazza said:
The simple answer is Yes, you can do pretty much whatever you like to the crossover design.

But realise that the calculators a simple academic tools only.

The more important question is will it sound ok - the simple answer then is maybe, but not likely.

Stick with the design. Enjoy the hard work of others here.

:beerchug:
Click to expand...
I agree with Mazza - online calculators are really only a guide and are based on simplified models of drive units. Designing a good crossover requires experience and the ability to take measurements. Someone with experience has done all that for you, so what would be the point of ignoring that and using a generic crossover instead? :dunno: I suppose it could be seen as a learning experience, but what you're likely to learn is that you should have used the crossover that has been detailed in this thread.
 
Recently hooked up my 7W's in my bedroom, connected to a Realistic SA-2001 amp. I use this predominantly for background when I go to bed. After a while for "break in", since they sat for over a year dormant, I tried some classical and damn they are nice to listen to. No they don't have the range of larger, or better, speakers, but wow. I have two pair and plan to review the Zilch mods and do the upgrade on one pair and do a head to head. Look forward to the results.
 
Sorry for the newb question but; Part Express is out of stock on the 40 ohm 10w resistor. Can I use the 40 ohm 20w instead? thanks
 
I used 5 watt resistors.

My big Klipsch KG 5.5 floor stand speakers are rated for 100 watts (500 peak!) and the factory crossover uses a 5 watt resistor....:rolleyes:

:beerchug:
 
that's fine, far better than needed.
You can put two 20 or 22 ohm 5W resistors in series if you prefer
to order from one source.
 
After reading through this thread I learned a lot (and got confused a lot) about the history of the Minimus 7 speaker. I’ve always been obsessed with small speakers and have owned 7s, ADS L200s, and Lafayette Pip Speaks for many years, most bought when they were new.

I recently went on an eBay search for a pair of Realistic SD-13 tweeters. Noting happened for several months. Then all of a sudden last week 2 turned up from different sellers on consecutive days, and at reasonable prices. I quickly grabbed both. One has already arrived and the other should be here today. I installed the first one in a formerly silver (not a fan of that color), now white 40-2034 that had a SD-50 tweeter. I did an A/B with the unaltered speaker and noticed a little increase in “crispness” for lack of a better term, in the SD-13

I noticed the 13 and the 50 look very similar. I’m aware of the difference in the face plates, the 13 being aluminum and the 50 being steel, but they have very similar domes. And there’s the obvious difference in these and the later version with the plastic face plate and the silly circles. Are there any other mechanical or electrical differences in the 13s and 15s I need to know about that passed by me previously in this thread?

I’ve owned a couple of pairs of the 7Ws and have regretted moving them on. All the ones available now are going for much greater money than I paid for mine.

49466C0F-2AAC-4A2B-86AA-ADF7C2B78606.jpeg AF983E56-9EC6-42B5-AEB4-D8C989D22160.jpeg 218739C5-6364-451B-9105-15EC7F0103FB.jpeg
 
I also came across these, smaller than Minimus 7 clones, RCA 40-5000 mini speakers, identical to regular 7s except in their size. Heavy metal cabinets, 3” woofers with inverted cones, and what looks like a 3/4” polycarbonate tweeter. These examples are 99% mint and sound great except for the almost total lack of bass. I think the Realistic equivalent would be the Pro-AX33?

6A59ABAA-EF44-44EF-8DBE-24F3E2069925.jpeg ACFBEFED-E1B6-406F-9336-E968FC9959B2.jpeg
 
So, i decided to give this a go.

First I had to figure out the logistics...ie...what to mount the crossover components to and how to secure THAT to the cabinet, cleanly. I found that the PE perforated xover board fits perfectly. Then I made a wooden plate to mount the binding posts of choice to. This method is appealing as no drilling of the cabinet is required, this making this reversible. At this point i am ASSUMING that the crossover components from pz-2.1 will fit. Am i correct in my assumption or do I need to take a step back. I am at the "mock set-up" stage just to see how to best do this. Feedback is appreciated. I have not yet purchased xover components.

40-2039A, in case it is not clear in the pic.

The board is about 1/4in off of the back of the cabinet to allow clearance for zip ties, wiring, etc..

What do you think....?

20201206_133621.jpg 20201206_133645.jpg 20201206_133738.jpg
 
OK, so I am finding here and there that the earlier metal bracketed tweeter (sd51) is preferred over the plastic bracketed tweeter w/ a concentric ring. What's the scoop on this? Forgive me if this has been discussed. If it has, i just haven't digested it yet.

Plastic with ring....

1607303928101-896597004.jpg

Metal..

1607303971887-2126400448.jpg
 
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