Tiny TiMMs: Small 2.5-way
by , 12-03-2009 at 04:39 PM (4762 Views)
Previous projects were vented 2-ways, so this one brings me into new territory: a sealed 2.5-way. I tried them out with 3 different amps: NAD C325BEE, LM1875-based gainclone and Dayton T-amp. They did fine with all three. The T-amp is their intended mate, with a Bose Wave CD player/radio as the source, bypassing its equalized amp and mediocre speakers (using analog line-outs...there is a decent DAC in that thing!).
Objective
Small speaker project intended for desktop/office or kitchen.
Drivers
Midwoofer and .5 Woofer: Dayton RS100S-8 - known for its low harmonic distortion
Tweeter: Vifa DQ25SC16-04 - low cost/high value titanium dome tweeter
Crossover
The XO point is at 2kHz. Several other DIY projects around have demonstrated that the DQ25 can go this low. jkim did the crossover modeling (Thanks again Jay!) and my voicing concentrated on finding the right tweeter padding values, ending up with 4.7 Ohms and 2 Ohms on the series and parallel resistors, respectively.
Cabinet
F3 is 77Hz in a .32 cu. ft. sealed enclosure. The small footprint of the mid-woofers and the tweeter faceplate allow for a fairly narrow baffle and high WAF. These cabinets are intended to sit on a desk or countertop.
They are stuffed with polyfill only, roughly 2.6 oz each speaker. Another way to put it: take a 16 oz bag from Walmart or crafts store, use a third of that and divide it equally between the two speakers.
Impressions
Soundstage is bigger than you might expect from such small speakers. They are also very vivid and precise sounding. During one voicing session listening to Coltrane's, "A Love Supreme" on SACD, it was as if the philosopher-poet himself was in the room with me. The Tiny TiMMs do quite well off axis horizontally and vertically.
I've previously built the Microbe with Seas 22TAF/G tweeter. Since the Tiny TiMMs and Microbes are both small speakers based on RS drivers and metal dome tweeters, they lend themselves to comparison.
The tonal quality of both speakers is quite similar, however, there are some differences. Microbe is warmer in tone and has more depth; not surprising as even with a smaller box volume, F3 is 50Hz in a ported cabinet. But the Tiny TiMMs were more detailed and offered more subtle nuances in sound; they generally have more punch, sound tighter, and I find them to be slightly more accurate, but still not harsh or sterile. However, with an F3 of only 77Hz and sealed alignment, they can be mated with a sub for critical listening.
![$vboptions[bbtitle]](images/techTalkHeader-leftGray2.jpg)
![$vboptions[bbtitle]](images/techTalkHeaderRepeatGray3.jpg)


Email Blog Entry



