I’ve owned a Yamaha RX-V640 AV receiver for over a year,
and for most of that time I’ve been running it with a pair
of Tannoy PBM-8 studio monitors. I also have a vintage (?)
QSC model 5.1 power amp, rated 80 watts per channel into
eight ohms, and 120 watts per channel into four ohms. The
line level subwoofer output on the Yamaha receiver feeds
both inputs of the QSC amp, and the QSC amp feeds a pair
of Rage 12” subwoofers from the subwoofers.cc division of
Audio Concepts Inc. The homebuilt sub cabinets are two
cubic feet gross internal volume, sealed, and loosely
stuffed with medium density spun polyester fiber matting.
Primary sources are the line level outputs from a Bell
ExpressVu satellite receiver, and the optical output from
a budget DVD/CD player. I hated to see 340 Watts of Japanese-engineered, Malaysian-
built power going to waste, so I decided to look into
building six identical systems to replace the two Tannoys.
There are a lot of designs out there, but I was drawn to π
Speakers for a number of reasons. I have read a lot about
speaker system design over the years, and Wayne’s
knowledge of the physics and engineering aspects strike me
as (pardon the pun) more than sound. His willingness to
share the design details of the finished systems he sells
impressed me. The greatest appeal for me was his ongoing
responsiveness and encouragement, both by email and on the
forum here.
I am no woodworker. I am fortunate to have a neighbour who
is as passionate about power tools as I am about music. My
neighbour helped me build my sub boxes, in return for a
large circle jig from Jasper Audio. This time around, I
called him and asked if he would help me again in exchange
for one of the smaller Jasper jigs. He readily agreed. His
contribution this time around was cutting rebates and
through holes for the drivers and the terminal cups, and
through holes for the port tubes. I had my local lumber
yard cut all the 5/8” MDF panels to size, and I assembled
the boxes on my kitchen counter using butt joints, #8
particle board screws, and yellow carpenter’s glue. The
boxes are caulked with silicone sealant, and lined on
three sides with 3 ½” R12 fiberglass insulation. The
baffles are removable, and sealed with 3/16” X 1 ¼” heavy
duty truck cap foam tape weatherstripping.
Immediately after we cut the holes for the port tubes, I
realized that the 2 ½” mailing tube I had purchased was 2
½” inside diameter, reinforcing the woodworker’s adage
to “Measure twice, cut once.” Determined to stick to the
proven design, I managed to find a shop in the next county
that stocked 63 mm PVC pipe. Since the internal diameter
of the PVC is roughly 2 ¼”, as opposed to the 2 3/8” in
the original design, I sought Wayne’s advice and
subsequently cut the port tubes to 3” in order to maintain
the specified tuning frequency.
As I type this, the speakers are in their places, one in
each corner of my living room, one on top of the
entertainment unit, and one on a window ledge directly
behind my spot on the couch. The corner speakers are on
27” stands, so the space between the LF and HF drivers is
at ear level. The stands were homebuilt as well, with
leftover rectangles of MDF for the bases and platforms,
and sand-filled 4” PVC tubes serving as uprights. The MDF
is coated with the same black chalkboard paint that I used
on the cabinets, and the uprights are covered with oak
grain contact paper.
As I have posted in the forum here, the best adjective I
can use to describe the one π’s is “IMPRESSIVE”. I was
comforted knowing that there was a recommended HF upgrade
from Vifa, but since my local driver source still had some
of the CTS piezos in stock, I decided to go with
them. “Spitty” has been used in the past to describe some
of the Motorola-designed piezo tweeters, but that
adjective does not apply in this case. To my ears, these
speakers are very well balanced. When I’m listening to
music, I often run just the front left and front right
speakers. The bass response is impressive, and depending
on the program material, I often choose to leave the
subwoofer amp off.
I’m entirely satisfied with my decision to build a set of
one π speakers, and I’m sure that my family and I will
enjoy them for years to come. Whether you source out the
components yourself, buy the kits from Wayne, or buy the
finished systems, which are very professionally done, I
offer my opinion that you will have no regrets. Thank you
Wayne, for sharing your wisdom and your designs!
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