Been some time since I have touched on the minimus/ optimus 7 and 77 speakers but getting back into them again. I have a set of the Optimus 7 speakers (I stuffed the ports with Dacron Fibre for their length to kill the obnoxious chuffing since the ports dont help at all) I bought new back in 1990. They were used in my my parents Suzuki Samurai that lacked anything resembling a reasonable sound system along with a portable CD player. Cabin gain provided reasonable bass and I was happy with the sound, blissfully ignorant of the generally horrible midrange thanks to the listening environment. The eventually went back in original bags and foam packaging in boxes where they sat untouched for the better part of 25 years unused. Then I happened across the discussion of the work done by Zilch and figured I would give that a go. Worked up a PE order, with cheap but more than good Dayton film caps and inductors per the Zilch 2.1 design. Parts arrived shortly there after and before the mod i took a half hour to refamiliarize myself with them. Frankly I was not very impressed with they way they sounded or imaged. So I did the needful on one of them and had another listen. The side by side A/B was breathtaking. I immediately did the second speaker and was very rewarded for the modest cost and effort. Literally night and day. I use them now for our portable theater setup when we go to friends backyard movie night parties and at the cabin we rent each year in the mountains. A friend that is into sound and music like I am was blown away by them. Now the drivers will run run out of steam pretty fast and they dont dig deep if pushed. But generally from around 125Hz and up they are a pretty darn good speaker for general listening. BBC LS3/5 speakers they are not though.
My latest project are a pair of the Optimus 77 speakers. Stock they are the same tweeters and crossovers as the minimus and Optimus 7's with a larger enclosure and a 5" woofer. Same generally piss poor sound and imaging due to the woofer being left to do its thing without control. I bought one set, supposedly in good working order off fleebay and the seller did some of the worst packing I have ever seen. The handling by the USPS, of course, was nothing short of criminal brutality and resulted in one od the enclosures being bent and broken. That and both woofers were cooked. The seller apologized and refunded me the full amount and told me to keep them or dispose of them. So I set those aside for eventual repair and ordered a second set. They were also supposed to be in perfect working order, LOL. The woofers foam surround was disinterested so the search for replacements began. I eventually happened across the FaitalPro 5RE120 and ordered a pair as their specs suggested that they would be a good replacement and a serious upgrade as well. Sadly they need modification to fit and the bolt hole circle is about 5mm smaller than the stock drivers and the basket edges are turned up where stock are flat. But after molding the drivers and installing them the results we're pretty stunning. BUT, there was a difference between the two pairs I had! One set had the exact same crossover as the Optimus7's I have and this pair have an additional inductor in the woofer of .8mH so it has a 6dB/octive low pass filter. It tamed the midrange and the difference was night and day. I then had a look at the tweeter since the woofer was so much of an improvement and ordered up a pair of Wavecor TW030WA14 drivers. They have a much higher power rating and a back chamber as well. They will of course require an adapter plate too but I expect that they will compliment the FaitalPro woofer. Also gonna dampen the interior of the metal enclosure and remove the crossover to an exterior box to allow for experimenting and consistent enclosure volume.
