Design Goals / Driver Selection
Curt: For those who lusted for the Statements, but for one reason or
another, couldn't squeeze them in their listening space or budget, or for
those who wanted a smaller version for surround duties, Jim came up with a
nice looking design that combines 95% of the excitement in 50% of the
volume, and shaves about $200/pr. from the Statements budget. To
accomplish this, Jim chose a TMWW topology and utilized a single Tang
Band W4-1337SA, the Fountek NeoCd3.0 ribbon, and a pair of Dayton
RS180S-8's to hold down the low end.
The big question everyone seems to have is: "How do these sound
compared to the Statements?" Well, they sound... smaller. The RS225's
push a lot more air than the 180's, and the tactile feel of the larger drivers
is substantially reduced here. That said, they have that same spacious
sound stage as their larger siblings, and nearly the same low end
extension. Wayne and I went to a lot of effort to obtain the same voicing as
the Statements, and I think we came pretty darn close. The midrange and
highs give nothing up to their big brother, even though a single W4 is doing
the lion's share of the work. For smaller venues, this is the one to choose.
Jim: The Statements design is one of those speakers that simply exceeded
our expectations. When I formulate an idea for a speaker project, I establish
the design goals I want to achieve and then start to research drivers to see
if I can find ones that meet the criteria. I then get a crossover professional
(Curt) involved examining my idea and tearing it apart looking for flaws. If it
makes it past that stage, chances are, it will be a nice speaker. The
Statements came out so much better than just a nice speaker, the Mini
concept started to materialize.
The Mini Statements were a result of feedback after the Statements design
was completed. A center had been planned from the start, so when people
started making comments that they really liked the Statements but they
were simply too big, the Mini project started to take shape. Curt made the
comment that once we published the center design, inevitably someone
would build three and stand two of them on end for mains. That is when the
Mini's officially came to life.
The goals we wanted to achieve for both the center and the Mini's were to
retain the Statements open, spacious mid range, the sparkling top end and
still have good solid bass down into the upper 30's but in a much smaller
cabinet. Using a W/W/M/T configuration for the Mini's with the RS180's
woofers, W4-1337SA midrange and Fountek NeoCD3.0 ribbon seemed like
the perfect combination and an extension of the center so they could be
used as either mains or surrounds. The cabinet is based on a 50 liter
ported enclosure for the (2) RS180's sitting on top of a 3" tall base.
However, the RS180's are quite flexible and a cabinet size as small as 30
liters can be used. Theoretically, they can be constructed as monitors as
well as floor standing speakers with appropriate adjustments on ports size
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Statement Designs and the new RS
drivers: Winds of change or status quo?
(posted 10/08/2010 on the HTGuide.com)
It would make sense that shielded drivers
would eventually be replaced now that there is
no need for them. Remember all those old
threads asking how to shield a driver? -What
was a CRT, anyway? I forgot...
The eventual supply exhaustion of shielded
RS drivers used in the Statements,
MiniStatements, and StatementCC designs,
beg the question: Do I stock up now, or will the
replacement drivers be drop in replacements?
Here is the "new guard":
Looking at the new 8-ohm, non-shielded driver
specs, they are going to be close, but will they
be close enough?
With a little back of the envelope calculating,
and comparing the published specs, it
appears that the new unshielded RS drivers
T/S parameters suggest slightly smaller
enclosures, slightly higher f3’s and (very)
slightly lower sensitivities. The good news is
that I was told by an undisclosed source that
the new drivers were Klippel optimized.
RS225 Shielded vs. Non in the Statements
The enclosure size is fine and if the tuning is
raised 3 Hz, will come very close to the
transfer function of the shielded woofer. The
maximum modeled difference in dB is less than
.5 dB, and the f3 drops by 4 Hz for the non
shielded version model. In addition, the
enclosure size could be reduced by 20%, to
80 liters, with no increase in f3 over the
original design. The ‘new’ driver sports a
slightly smaller Sd than the ‘old’ driver (which
obviously didn’t change) which is used to
calculate the SPL, so the SPL differences may
be even smaller than modeled.
RS180 Shielded vs. Non-Shielded
MiniStatements and Statement CC Initial
The ‘new’ driver will exhibit the same f3 and
f10 with the original enclosure and tuning, but
has a more of a shelving response, so will
have up to 1 dB less output for the 1/2 octave
either side of 80 Hz. A 20% to 25% reduction
in enclosure volume along with a 4 Hz higher
tuning results in a modeled response that
closely emulates the original response and
only loses about 3 Hz of extension over the
shielded driver. This may be good news for
those who think the present enclosures need
to be more svelte...
Plug and play? Well sort of… We won’t know
for sure until we do, but based on the present
data, they may very well work acceptably well
with no crossover modifications at all.
The RS180S-8 drivers are
NLA, but the RS180-8, the
non shielded version have been
deemed a suitable
replacement. See the excerpt
from my forum post to the right: