Embedded Files
Zirconium is a 3-way monitor. This project was a Parts Express 2016 Speaker Building Design Team project. Many thanks to Parts Express for providing the parts. I've done a couple of these small 3-ways in the past and this is an attempt to take things up a notch with respect to performance and practicality without getting crazy with respect to build difficulty or budget.
To summarize some of these issues:
Hafnium: A reasonably low cost, well balanced design. Uses the finished PE 0.38 cu. ft. cabinets, which are nice but priced accordingly. These sound very open, but aren't the last word in detail. They also have shocking bass extension for their size, but can't go very loud due to the 5" sub.
Argon: Clean, tight, extended bass with the Denovo Anarchy woofer. Mids and highs are okay, but not great. Cabinet is the 0.75 cu. ft. curved MTM cabinet, which again is very nice and priced as such.
For the Zirconium, I wanted the bass capability of the Anarchy but ideally at a lower price point with a driver available at PE. For the mid and tweeter, I was looking for similar size to the Hafnium drivers, but with a little more detail resolution even if that meant they would be more difficult to work with.
Driver Selection:
Woofer: Tang Band W6-1139SIF: 11.5 mm xmax in a 6 1/2" woofer. Can manage F3 of 30Hz in the selected enclosure. About twice the displacement capability of the W5-1138SMF used in Hafnium.
Mid: Dayton PS95-8: Hasn't got as much run as the RS100 or 100P, but has a nice cast frame, shorting ring, and Kevlar/Paper cone for $23. All reports are it should be comparable with the RS100 series, maybe a little better at high frequencies, which will be important because...
Tweeter: Dayton AMT Mini-8: This is an application it should be able to handle and provide a little sparkle and air that the PS95 can't.
For this project, I wanted to offer an off-the-shelf cabinet option, but at a lower cost point and with more finish flexibility. The Denovo 0.56 cu. ft. flat pack cabinet checks all of those boxes and should allow the Tang Band sub to reach at least to 30 Hz without a ridiculously long port.
How did it come out? I have had this to my brother's house and another friends house for listening sessions. There is plenty of clean detail without harshness. The output of the Tang Band sub is impressive when there is enough amp to drive it. There will certainly be enough amp at InDIYana, which is its next stop...
From a cost perspective, drivers and crossovers wound up around $330, which is a little higher than my $300 target - but within reason. A design like this might be compared against a two way monitor that has a $50 woofer and $50 tweeter - and from that perspective, a design like this has a lot of advantages. My brother has Modula MT's that were a popular design to build 8-10 years ago and that would be in a similar price and size range. Zirconium had much more bass extension, a more refined midrange, and more detailed highs. We thought the Modulas had an advantage in the lower mids - this is a particular strength of the Dayton RS180.
For the cabinet finish, I chose white Duratex. I have spend quite a bit of time during my professional career working with Zirconia (Zirconium Oxide), which tends to be various shades of white in its polycrystalline form. I learned that white Duratex (at least my batch) takes a good solid 3 coats to approach uniform coverage, whereas I can often get away with 2 coats of black.
The frequency response is less linear than I usually design for, but that was required to get the tonal balance I prefer. Keeping the tweeter level down a little helps to compensate for its wide dispersion (less than 10 dB down 60 degrees off axis out to 14 kHz). I suspect some of the peaking in the tweeter response is due to reflections not fully gated out, but I did have to get those peaks down to the level of the midrange response or lower to get the tonal balance similar to other speakers I have designed with generally flat response.
The impedance curve shows a minimum just below 3.3 ohms at 100 Hz. That coupled with a sensitivity around 81 dB at 2.83V/1 meter means that these will need a sturdy amp for anything more than nearfield or small room use. Impedance rises to a very high 90 ohm peak above 10 kHz due to a need to aggressively filter the Mini-8 tweeter. On the 3 systems this has run on (all solid state), it hasn't been a problem. I wouldn't expect a tube amp to appreciate this type of load however.
This project has been demoed at InDIYana 2016 and Midwest Audiofest 2016.
Links:
Google Sites
Report abuse