SEAS W15CY001 + HIQUPHON OWI
Copyright 2006 © Troels Gravesen
This construction was made before I started my diy-loudspeaker website, and I never found the time to write anything about it. The drivers here are among my few favourites and the W15CY001 drivers were acquired for the Point75 dipole speaker and the HIQUPHON OWI was bought only because I wanted to own a pair of these - probably - best ever made 19 mm domes, thanks to Oscar Vroending at HIQUPHON.
The Point75s were sold
to fund the Acapella adventure and it was only
recently I bought another pair of the W15CY001
midbass drivers. A shop in Copenhagen had a
sell-out of SEAS drivers.
So, time to heat up the soldering iron and take a second look at this construction. The W15 and OWI were placed in my 7.5 litre test cabs and the OWI had a lot of Gaffa tape to cover a wider routing from other constructions. Test cabs are still 19 x 30 cm and driver placement is as seen on construction details below.
First of all I wanted to see if the original crossover (V1, not shown) could be modified by simple means so that replacing expensive crossover components could be avoided. By adding a resistor (R2021) in series with the 6.8 uF capacitor in the low-pass section, the 1-3 kHz range can be attenuated 1-1½ dB, having an immediate impact on the forwardness of the sound. Tweeter obviously needed some further attenuation, thus the 8R2 (R1011) is replaced by 10R and a 3R3 (R1061) is added in series with the tweeter.
Overall the crossover topology is very close to LR4 and given the tweeter's placement some 25 mm ahead of the W15's acoustic centre, both amplitude and phase fall nicely into place. Using LR2 would require 20-25 mm recession of tweeter (stepped baffle) and the Hiquphon is not easy modelling for this setup.
Download Kit Sales Presentations here. (pdf file)
The Jantzen kit comes with a 35 mm x 120
mm tube. Used as-is, this will make a vent tuning of 53