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Doing the
Ellam 9800 and Ellam XT speakers, the idea of
making a d'Appolito construction obviously came to mind.
The Ellam25, 2½-way, came first and for some time I've
had the Ellam d'Appolito on my website as an experimental
set-up.
Eventually Jesper (Ekta and Ekta Grande constructions)
came by, bringing in a finished Ellam d'Appolito, thus
the old file will be updated with new pics and measurements and a
slightly fine-tuned crossover, now for the ScanSpeak R2604/832000 tweeter.
Jesper had used an old Ekta cabinet, turning it around
and up-side down, thus a a tilted cabinet like the Ekta
with a narrow front panel. The lower one-third of the
cabinet had been sealed off to make an upper compartment
of 22 liters - and to make a long story short, I don't
think I've heard the W15 drivers better than from this
cabinet. Why? Hmm... One thing is the laminated side
panels made from 6 x 5 mm laminated plywood of various
density. Next - and this I think is the most important
thing - the depth of the cabinet. The cabs are 32 cm deep
and maybe the expansion towards rear panels has something
to do with the absorption of the energy coming from the
rear of the drivers. Whatever, it sounds great. Using two
15W drivers we're close to the membrane area of an
8" bass driver and it very much sounds so. I don't
think we can get a more powerful and deep bass from 22
liters than from these drivers.
DRIVERS
Download specs: ScanSpeak 15W/8530-K00 ScanSpeak R2604/832000 ScanSpeak D2904/980000
Speakers during crossover development.
Cabinet
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Jesper's cabs have here been transformed
into a more compact looking standmount speaker.
Suggested cabinet design.
We need 22 litres internal volume and a vent
tuning of 40-45 Hz. I advise placing the vent to
the rear and symmetrical to the two bass drivers.
The speaker needs to be lifted from the floor and
a 40 cm stand plus a 3-5° tilt will provide
proper performance from the usual listening
position.
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Crossover
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LspCAD
simulation of crossover and predicted response.
The crossover is a
4th with a 3 kHz point of crossover.
Should you want to use the 9800 for this
construction, try this for tweeter:
Purely
based on simulation, but the changes are so small I dare
publish.
Experiment with series resistor R1011 for best tweeter
balance.
Measurements
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Left: Driver SPL @ 1 meter, 2.8 volts. Right: Impedance
of drivers.
 
Left: Drivers' response driven from crossover. Right:
Response with inverted tweeter polarity (blue).
 
Left: SPL/1m/2.8V. System sensitivity = 87 dB/2.8 volts.
Right: System impedance. Minimum 3.3 ohms, not too bad!
Speaker
Kit
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Example of Superior-Z version above. More options available w/wo
drivers.
Crossover kit available from Jantzen Audio at: contact@jantzen-audio.com
Download all kit
sales presentations
here
All technical
questions to
troels.gravesen@hotmail.com
Here's the 9800
version parts' list:
CROSSOVER LAYOUT
Note STANDARD-Z caps will take up much less
space compared to Superior-Z caps but stick to distance between coils.
Speaker wiring
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