Ellam d'

Ellam Dappo
Ellam spin-off
Copyright 2009 © Troels Gravesen

ScanSpeak 15W/8530-K00 + Vifa XT25TG-30-04

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 XT25TG-30-04 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. Period!

"Reverse Ekta" design.

Cabinets

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.

Crossover

LspCAD simulation of crossover and predicted response.