model DFR8. The rather fascinating cabinet design
redefines what is possible with a single driver in nearly every
category and represents a 6 year investment of designer Steve Deckert's
If you're considering single driver speakers, these are the most
performance in the smallest amount of space you're going to find.
They have nearly perfect bass and it's extended to the point where you
have no danger of being tempted to add a sub-woofer. They also
have no mid-range shout and all of the high frequency extension and
you could want / eliminating any desire to mess with super
tweeters. That covers
the three biggest downfalls of most single driver speaker designs.
An extremely serious audiophile speaker, the HDT should ALSO be
by audiophiles who have no intention of purchasing a single driver
design such as this... why? Because it spanks regular hi-fi
speakers with it's electrifying speed, presence, dynamics and
imaging. At 10dB louder than most hi-fi speakers on a single watt
and the ability to handle real power, these speakers can out rock even
the best of them.
HDT's are at home with 2 watts but can also handle over 100
class A tube watts making them at home on either side of the fence...
Small SET amps to large KT88 push pull monsters can be used without
distortion. This ability to work well in either camp is one of
the biggest things that separates these from other single driver
designs that are too delicate to handle real power.
Extremely honest, the HDT's are used at Decware for final voicing of
the all amplifiers because as Steve puts it; "They tell me what's wrong
faster than any other speaker we have". A great tool for
amplifier design. When the signal feeding these speakers is bad,
the sound is bad. When it's good everything sounds real and you
can no longer hear the speakers or amplifiers.
The cabinets are around 70 lbs each and consist of three primary
chambers that are cross-coupled at the top behind the driver and
passively coupled to the room to eliminate internal back wave
reflections that cloud mid-range and create distortions at higher
volumes. These 3 chambers are then tuned at the bottom to 2
different frequencies to feed an averaging chamber in the base of the
loudspeaker. This chamber feeds a transmission line that runs the
vertical length of the loudspeaker and exits at the top of the
cabinet. The energy from this line is then pre-loaded by a plate
that sits on top of the cabinet to force an omnidirectional wavefront
on a horizontal plane.
What all this accomplishes is multilevel reflex tuning across a wide
frequencies which in turn maintains better control on the cone for more
linear response. There are no large cavities inside the cabinet
and no parallel surfaces to create standing waves or box sound.
Yes, these speakers are more like quads in that they lack the typical
box coloration that we've all grown used to over the past 50 years.
The result of this design is linear response from 38Hz to 20000Hz
without inductors or networks to dumb down dynamics as illustrated by
the impulse response above - where the speaker (light blue) measured
impulse hides behind and accurately follows the test signal in
Tube amp friendly with reasonable to above average performance on our 2
watt SET amplifiers but electrifying on higher power.
ON THE SOUND
that is often hard
find in most high efficiency speakers... They accurately reflect
the recording source and amplifier. Imaging is one of these
speakers strong points and they virtually disappear with good upstream
components. Musicians will appreciate the accuracy of timbre and
harmonics making it effortless to identify specific brands and models
of instruments in the recording.
38Hz ~ 20kHz
8 ohm nominal impedance
Driver compliment - DECWARE DFR8
Crossover - none
2 ~ 100 watts
Max SPL 116dB
Size 13.5" wide, 13.5" deep, 39" high
HDT - 2003 to Present
This speaker design has remained unchanged since it's release in 2003
with the exception of a driver upgrade. The DFR8 full range
driver used in this cabinet was improved in 2005. The cone is now
white instead of black.
interesting option is called the HDT MKII.
desired. This is
accomplished with a 2-way implementation of the same cabinet using
different drivers and tuning. There are two top plates instead of
that frame the isodynamic planar ribbon tweeter. The woofer is a Silverflute wool cone driver running full range with no
Total efficiency of the MKII option is 94dB and is available in 4 or 8
have a support forum
many people who own our speakers who's experiences you may benefit
manual in pdf format.