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The "PEPPER SHAKERS"
A neat buyout woofer from Parts Express is the 7" Infinity / Vifa TC18WG #299-493. I coupled it with a modest 1.5" Mid-Tweeter from Pioneer and ended up with a very pleasing to listen to speaker. Fairly detailed but not at all bright or brassy and nice bass response.
I was going to use the Dayton Silk Dome tweeters, but at the last minute decided to use these 1.5" Pioneer soft domes that I purchased on special from MCM Electronics for a totally different project that never got built. They are actually advertised as a midrange speaker but with an Fs of 1100Hz they really are just a tweeter that goes a bit lower than most. This woofer requires a fairly large box and these 48" tall enclosures were inspired by a similar design mentioned on the Parts Express online forum which used the same woofers. They are constructed of particle board with a single shelf brace in the center of the column. Ports are 2 1/8" dia. X 5" long. I primed them with a white PVA primer/sealer, painted them flat black then sprayed them with this interesting Black/White/Gray spatter coating called Fleck Stone. It is supposed to look like stone and is available in several colors. The resulting appearance prompted the name "Pepper Shakers".
Here is the crossover design done in Speaker Workshop My crossover target was about 3200 Hz but I always try to adjust component values in Speaker Workshop to achieve the response curve I want rather than a set frequency point. The combined, calculated frequency response
The SW model shows better response without the second dip at 4K by having the tweeter wired normal but I like the sound better with reverse polarity on the tweeter which is what is shown here. The big dips are probably due to the frequency response of the tweeter being measured by myself using only a nearfield response and resulting poor phase tracking, so everything above 2K is suspect. The woofer response was taken from the Parts Express web site. If I ever get Speaker Workshop figured out well enough to do proper acoustic measurements, I'll check what these are really doing as a finished speaker. All in all they have a mellow, laid-back sound but are in no way muffled sounding. There is still good detail and imaging without being "in your face". Great for listening to jazz. Bass response is surprising. I had been listening to music in 2-channel mode on my Yamaha surround receiver and then we put in the movie "League of Extraordinary Gentlemen". The beginning scenes have some very pronounced sub-bass, couch-shaking effects and I was disappointed that my dual 12" subwoofer didn't rattle the house. There was deep, enveloping bass but not the furniture moving type I know and expect. Also the overall sound seemed a bit lacking in the feeling of being "inside" the scene. Then I realized I had never switched to digital surround mode and my $40 speakers were alone accomplishing 70- 80 percent of what a full surround with subwoofer system did. Construction Notes The box outside dimensions are 8" X 8" X 48" using a sheet of 1/2" particle board I had leftover from another project (MDF would be preferable). Internal volume is 1.3 cu. ft. and each box was made out of the following:
The shelf had 4 ea. 2" dia. holes bored in it and placed mid-point in the enclosure. Top & bottom pieces fit inside the box ends.
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