variant, the Azurite 25 using the Audax TM025 can be found here.
Feb 2004 Update
got back to the garage to finish these. For finishing, I chose a
quick paint job. After sanding, and running a 3/8" roundover
bit over all edges, I sealed with shellac. I used a spray can of
satin black for a base coat. Then I shot them with a coat of the
"fake rock" paint in an aqua tint. I thought they were
too blue, so I used the black to mist over the rock paint and darken
it down. A couple coats of waterbourne and they are done. My wife
actually liked them.
assembled, I got a chance to sit down with them and listen to some
CD's before turning them over to my wife. In final form, the bass
is really impressive (from a 4" driver) holding together well
into the 60 Hz region. There is a little bit of boom when near the
wall. Were I to build these again I would go to 9 liters with the
same port. (Dimensions above reflect these changes) This should
get an F3 of 62 Hz.
extended listening, I found that I needed to pad down the Audax
for my tastes. I wound up with 3.3 ohms although 4 was very listenable.
If you like it bright then 2.5. For HT, I would go 4 ohm. The TMO20J3
isn't quite as refined as the TM025, but has a definite edge in
dispersion. I found the detail I expected, it just seemed slightly
edgy at the very high end.
are very clear and smooth. Female vocals, piano and brass all have
a liquid quality that makes the Azurite sound very effortless. As
one would expect with an MTM there is a fairly narrow vertical sweet
spot. Close to the wall, the soundstage is fairly flat. Move them
out a couple feet, and the image blooms into deep soundstage that
holds up well off axis.
Azurite is fine standalone speaker for small to medium sized rooms.
Most folks would be very happy with 5 of these for HT. Better get
these drivers while they last!
swore I was going to lay off those clearance drivers at Parts Express.
Despite all the PE claims to the contrary, I never really found
the right driver for that once in a lifetime investment in a reasonably
priced line array. Until this little vifa BC-11 came around. I've
used the Vifa BC/TC drivers in other designs and I've been quite
pleased with the performance.
never been a huge fan of MTM's. Keeping impedance and box size reasonable
with two parallel drivers isn't always an easy task. The main motivation
for these came from my wife. We have a nice TV in the bedroom that
has a built in 10 watt amp for external speakers. The entertainment
center has room for a pair of 6" wide speakers. The Azurite
will fit nicely into place, provide a friendly load for cheap electronics,
and sound pretty good. [Before you ask, I cannot talk her into
a complete HT setup. She is electronically challenged and intimidated
boxes were designed for an MTM variant of my nugget monitor. They
are 8 liters, (about 485 cu in net) tuned with 1-7/8" I.D.
x 4-3/8" port (PE 269-920 ). I used 3/4" MDF for the baffles,
and 1/2" else where. Just a couple of small braces around the
middle of the box. The box is a wee bit small for the BC, but it
sounds just fine. [IMHO, people smother too much about tuning
quite a bit of time on the crossover design, as I really wanted
to push the Vifa all over the map. [I am actually planning a
line array with these!] I took both free air and ground plane
basic design is a 2nd order electrical in appearance. Crossover
is about 3850 hZ
no need for a zoebel. The 13.6 uF value is easily built with two
6.8 caps in parallel.
two 3.3 uF caps for the tweeter section. You could replace them
with a single 6.8 and feel comfortable.
4.7 uF cap provides shaping for the rising response of this tweeter.
I used 3.3 ohms for the padding resistor. A 2.5 will be on the bright
side, A 4 would be better for home theater.
a slightly pronounced midrange to help with TV dialog. After listening
to the prototypes, I was really enchanted with sound of these. The
Tangband used in the Nugget is a bit crude by comparison. Mids are
sweet and liquid. The high crossover point makes it a bit easier
to adjust padding. I am waiting for crossover coils, so I can't
really comment on imaging and placement.
bass is very tight down into the 60's. There is a definite bass
attack present. There's not quite the thump that I have in the Garnet,
but the mids in the Azurite are sweeter. Predicted impedance does
not drop below 5 ohms with a peak of about 20 ohms. I would have
no problem calling these 6 ohm (nominal) speakers.
these are as good as, (or maybe better than) my Topaz design. Certainly
the Topaz tower had better bottom end, but the mids on these are
truly silky. The better dispersion of the 3/4" Audax, and the
additional breathing room afforded by the higher crossover make
the Azurite a bit more "effortless" in reproducing music.
why build these? Great quality for cheap (<$50 each!) Nice, small
size. Exceptionally smooth sound, impeccable shielding and amp friendly
load. Both my wife and daughter said they liked the teal driver
color. Even my wife said I didn't need grills. (High SAF)
the limited availability of these Vifa's, and the Audax sale. You
might want to pick up the drivers. When I finish a pair with "real"
components I will expand this page.
6.8 cap (3)
Vifa Woofer (2)