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How to Build The Minimus 7 PZ-2.1 Crossover

Okay so from memory I believe that a few people have tried this crossover in the M-77 with good
results. Does anyone remember if there are measurements with the PZ-2.1 in the M-77 anywhere?
Also, I believe that the used the PZ-2.1 as designed - no changes required.
Edit: Here's one use of PZ-2.1 in the M-77:

Minimus 7 Loudspeakers - Measurements

Thank you sir, nice and tidy. My kid is a 1st year EE student, I think this will be a fun Christmas break project.
audiokarma.org

Here are the measurements of the mod in the M-77, I believe that lukidog has a web page also:

Minimus 7 Loudspeakers - Measurements

Thank you sir, nice and tidy. My kid is a 1st year EE student, I think this will be a fun Christmas break project.
audiokarma.org

Next question is if anyone knows if the Optimus Pro 110 speakers are the same or nearly the
same as the M-77. I have no experience with the Pro 110.
Anyone?

@BigscreenBob Are you able to measure the DC resistance of the drivers, this is a start? And tell us
the model numbers for the drivers.
 
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This should probably all go in a new thread.
All I can say is try it and tell us what you think since I know nothing about this speaker.
If the original woofer had foam, I'd stay with foam, rubber will not be right.

It would be great if a moderator could move posts #42 on to a new thread:
"PZ-2.1 in Optimus Pro 110"
 
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Pete B said:
This should probably all go in a new thread.
All I can say is try it and tell us what you think since I know nothing about this speaker.
If the original woofer had foam, I'd stay with foam, rubber will not be right.
Click to expand...
Roger that.

Thanks for the warning about the rubber surround not playing nice with the woofer cone. I’m glad you saved me from making a rookie mistake!
 
I'd like to say, "thank you" to @Pete B and to those who added details to this thread as well. I have a set of Minimus 77's that recently got stuffed with M11 woofers due to foam rot on the originals, and will also be getting a set of these crossovers and a paint job (white to black) to serve surround duty in my HT setup. They sound pretty good currently, but I'm looking forward to hearing the "after." PE is backordered on a couple of parts until the first of November, but this will be a good cold-weather project.
 
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omehsa said:
I'd like to say, "thank you" to @Pete B and to those who added details to this thread as well. I have a set of Minimus 77's that recently got stuffed with M11 woofers due to foam rot on the originals, and will also be getting a set of these crossovers and a paint job (white to black) to serve surround duty in my HT setup. They sound pretty good currently, but I'm looking forward to hearing the "after." PE is backordered on a couple of parts until the first of November, but this will be a good cold-weather project.
Click to expand...
Welcome to AK!!
 
Wow. Fitting these components on to a 3.25" x 5" square is quite a challenge. But I believe I have the inductors positioned correctly to reduce interaction. I'll add speaker connections in the center opening somewhere...

20250114_215018B.jpg
 
bhjazz said:
Wow. Fitting these components on to a 3.25" x 5" square is quite a challenge. But I believe I have the inductors positioned correctly to reduce interaction. I'll add speaker connections in the center opening somewhere...
Click to expand...

I had no trouble when I followed the examples posted (See my pic in the post above). This layout makes for pretty easy connections, too. BTW, It looks like you're missing a resitor?
 
Hey there! I am working with a Minimus 7, not the 77, so I need the smaller board to fit through the woofer cutout. There is one resistor on the left, two on the right!
 
omehsa said:
The "Minimus 77 Project" is complete and I couldn't have done it without this thread. Pics included to show my x-over assemblies and mounting location in the cabinet. (Wire colors are reversed woof to tweet, though.)
Click to expand...
Beautiful, organized wiring by the way. Looks great!
 
If you want an upgrade, replace the laminated inductor with an air core, it'll be bigger and will need thick wire to match the dcr.
 
Pete B said:
I'm posting this because people are often asking how to build this crossover. I've reposted
Zilch's diagrams in the long Minimus 7 thread but new posts keep pushing them back down.
Link to the original thread for those who want to read the long history:
https://audiokarma.org/forums/index.php?threads/minimus-7-loudspeakers-measurements.199790/

I'd like to ask people to please make posts here just about how to build the crossover and do the modification.

My PZ-2.2 revision that adds a tweeter control:
I strongly suggest using Stuart's L-Pad if you choose this:
https://audiokarma.org/forums/index...2-mod-diy-circuit-board-by-pete-basel.750334/

Continue below to build the PZ-2.1 version if you do NOT need a tweeter level control:

This is an older how to build it thread with a more step by step guide:
https://audiokarma.org/forums/index.php?threads/minimus-7-pz2-1-installation-guide-review.900518/

Zilch used the ERSE 1.0 mH but now there is a nearly exact copy under the Parts Express (PE)
brand for much lower cost. Edit: Both 1.0 mH are out of stock at PE I will look for an alternate.
Edit: The Dayton steel laminate 1.0 mH is back in stock as of 9-24-2023, they go in and out of stock.
The schematic was finalized in post #121 at the top of page 7:
https://www.audiokarma.org/forums/i...mus-7-loudspeakers-measurements.199790/page-7

Schematic:
index.php


Note that this is an old BOM but at least you get the idea:
BOM: Note that you may use cheaper NPE caps to reduce cost.
index.php


Layout Sketch:
index.php


Picture of Zilch's Layout:
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Picture of Installed Mod:
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Before/After Frequency Response:
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Another Excellent Build by Stuart:
https://audiokarma.org/forums/index...kers-measurements.199790/page-15#post-2726526

Another Build Diagram Found on Ebay:
index.php
Click to expand...
Has anyone ever tried the PZ-2.1 ON THE Optimus PRO X44AV, which is the ported version of the Minimus 7.
 
Thanks Pete!!! I just bought a pair for my grandson's bedroom system. They really do need the new crossovers. They can be pretty harsh on the ears without it.
 
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