Bipolar Design: The Definitive Technology BP-8040ST is a 3rd
generation "SuperTower." This
bipolar speaker contains drivers on the front and rear of the cabinet. The
BP-8040ST uses a new patent-pending design called Forward Focused Bipolar Array.
By radiating sound both forward and rearward, the speaker produces sound as it
is in real life, with improved pinpoint localization of soloists, greater
placement flexibility, and superior intelligibility.
Non-Resonant Tapered Cabinet: The BP-8040ST features a
highly-engineered inert and resonance-free heavy MDF (medium-density fiberboard)
cabinet to prevent coloring the sound. The front of the enclosure is tapered to
make it appear slimmer. Wherever a driver is attached to the cabinet, a second
layer of MDF is attached to prevent the drivers from causing vibration to the
rest of the enclosure. The sealed midrange enclosures serve as braces for the
side walls, while MDF cross braces near the woofer further stiffen the cabinet.
The entire enclosure is wrapped in a cloth "grille sock", while the high-gloss
polymer composite end-cap and bottom panel add a touch of elegance.
High-Definition Drivers: The BP-8040ST
utilizes two cast-basket 3-1/2" high-definition polymer composite midrange drivers surrounding a 1" annealed
Pure Aluminum dome tweeter in a D'Appolito front array. On the rear, there is a
single identical 3-1/2" driver and the same 1" aluminum dome tweeter as used in the front array. The front and rear
arrays are housed in separately sealed MDF enclosures to isolate the midranges
from the influence of the subwoofer. The drivers feature Definitive Technology's
patented 2nd-generation Balanced Double Surround System (BDSS) that supports the
speaker cone at both the inner and outer edges, allowing longer, more linear
excursion over a wider area. A new patent-pending Linear Response Waveguide
smoothes off-axis frequency response and disperses sound over a wider area.
Built-in Powered Subwoofer: The BP-8040ST is equipped with a
long-excursion, side-firing 8" subwoofer, driven by a 300-watt Class D
amplifier with an integrated Digital Signal Processor. The subwoofer is
pressure-coupled with two 8" Low Bass Radiators. The combination of the active
subwoofer and two bass radiators gives you 30% more surface area than a single
12" woofer, but with better control, speed, and detail. The benefits of a built-in subwoofer include:
- Eliminates the need for a separate subwoofer that takes up additional
- More bass output from two subwoofers, compared to one.
- Two subwoofers reduce standing wave room resonances and dead zones for
more evenly distributed bass.
- The subwoofers are perfectly integrated and blended with the mids and
highs, eliminating the crossover and phase controls of a separate subwoofer.
Subwoofer Volume: The level of the subwoofer (relative to the other
drivers) can be adjusted using the rotary dial on the back panel of the speaker.
Once the bass level is set, the overall volume of the speaker system can be
controlled by the receiver/amplifier.
Auto Power: The BP-8040ST has a special circuit that automatically
turns on the amplifier when a signal is fed to the speaker. The LED on the back
panel will glow when a signal is sensed and the amplifier turns on. After the
signal ceases, it may take up to an hour for the amplifier to turn off. When
first powering up after being unplugged, the LED will flash for about 30 seconds
while the firmware is loading.
Stabilizer Feet: The speaker comes with four stabilizer feet which
attach to the bottom of the cabinet, two per side, with the supplied
self-tapping screws. Each foot has a threaded insert to allow you to screw in
the supplied carpet spikes or smooth floor glides, depending upon the type of
floor they're being placed upon. Four additional threaded inserts are provided
on the bottom panel (along with 4 additional carpet spikes and floor glides) in
case you decide not to use the stabilizer feet. The spikes and glides add approximately 1" to
the overall height of the speaker.
Placement: The BP-8040ST Bipolar speakers have a lot of
flexibility when it comes to placement and positioning. It is recommended that
the speakers be placed at least 4" from a back wall, and at least 6" from a side
wall. When used as left and right main speakers, you should set up the speakers
and the listening position in an equilateral triangle, with the speaker cabinets
turned slightly inward.
Binding Posts: The BP-8040ST is equipped with a pair of
gold-plated, 5-way binding posts on the back of the cabinet to attach your
receiver's speaker wire. The terminals will accept bare wire, pin connectors,
spade lugs, single and dual banana plugs. Recommended amplifier power: 20 to 300
LFE Input: For the powered subwoofer, the BP-8040ST has a single RCA LFE (low-frequency effects) input. Since you'll be using two speakers, you will
need a Y-adapter to split the LFE output from your receiver to each subwoofer.
Wiring Options/Speaker Setup: You can connect the BP-8040ST in one of
two ways, with or without the LFE connection. If you use only speaker wire, you
should set the speaker setup on the receiver to "Large" and Sub to "No." If you
connect the speaker with speaker wire and the LFE, the speaker setup should be
"Large" and "Yes."
Note: It is recommended that you do not use the receiver's
auto setup function, as it is often ineffective in setting up and adjusting
speakers with built-in subwoofers.
AC Power: The speaker has an AC power input (IEC 2-prong type) on the
back panel for plugging in the powered subwoofer. A 7' AC power cord is
- 5.6" enclosure only
- 10.5625" with stabilizer feet
- 39.0625" enclosure only
- 40.0625" with carpet spikes or floor glides
- Depth: 12.25" including binding posts
- Weight: 40 pounds