That seems odd.Edit... the bottom two aren't tapped and it seems folks are using those to secure the crossover board to the cabinet. Off to the machine shop, it seems.
That seems odd.
So what model M-7 do you have? Except for the very first model with round terminal cups (Cat.No. 40-2030), I thought all Realistic Minimus branded 7s in aluminium cabinets have tapped holes at either side of the terminal port at the bottom. Weren't there screws in there holding down the plastic terminal/crossover plate?
If you're referring to the cast bosses in the bottom corners, those too are tapped, but from the outside to attach optional mounting brackets. Haven't seen anyone use those for the crossover mod ...
That resistor seems to be frequently out of stock at PE. Blame the popularity of PZ-2.1 ...It looks like Parts Express is out of stock of the 10W 40ohm resistors until June. Has anyone tried a non-"audio-grade" resistor in place of the Parts Express resistors, and have you had any issues with them?
That resistor seems to be frequently out of stock at PE. Blame the popularity of PZ-2.1 ...
Pete B, who's original design is the basis for PZ-2.1, has developed an alternate version, PZ-2.2, that uses standard sand cast resistors and also offers an optional variable tweeter level control. Details can be found in his thread which demonstrates an easy method for fabricating a PCB for the crossover.
Many highly regarded loudspeaker systems use similar resistors in their crossovers without issue.
I just picked up a pair of optimus pro x7, so decided to dig out my pair of minimus 7 to compare side by side. At first glance the similarities are obvious, probably the same spring connectors, and tweeters. Possibly the same woofer. [snip]
I was searching if anyone had experimented with similar crossover upgrades on the pro x7. I'm hesitant to try the minimus 7 upgrades on them as is, they just sound too different stock.
For whatever reason, Pro-X7 never excited the market quite like Minimus-7. After Pro-X7 faded from the catalog Radio Shack still offered the Optimus (and later RCA) PRO-X44AV, a ported and magnetically shielded Minimus-7.
I've cruised this thread and I may have missed it, but which woofer is a better choice sonically, not the best because that's too subjective. I'm looking at
https://www.parts-express.com/dayton-audio-rs100-4-4-reference-full-range-driver-4-ohm--295-378
https://www.parts-express.com/dayton-audio-ds115-8-4-designer-series-woofer-speaker--295-424
https://www.parts-express.com/peerless-by-tymphany-sds-series-830855-4--woofer-8-ohm--264-1065
https://www.parts-express.com/prv-audio-4mr60-4-4-full-range-4-ohm--294-2760
Within the context of Minimus-7 modded with PZ-2.x crossovers, the aluminum coned mid-woofers from MCM will likely offer closest sonic compatibility.
Pete B. installed and measured 55-1853 and found it to be "an excellent match." Pete also references Zaph's build of a well regarded mini speaker with this mid-bass driver, while exploring optional low pass filter options for its use in PZ-2.x crossover modded Minimus-7.
Also see streckfu's posts about replacing the stock woofer with MCM's similar 55-1856. He reports "great" sound and notes a satisfying balance with "much more low end."
From your list of PE's small woofers, consider that PRV Audio 4MR60-4 boasts a relatively high 90dB sensitivity rating, which would likely overpower the stock tweeter. Doesn't look like any of these drivers will fit a stock Minimus-7 cabinet. Are you planning to build custom cabinets?