SEAS W15CY001/HIQUPHON OWI, built by J. Eekels, Holland
Copyright 2010 Troels Gravesen

Hello Troels,
Here another response from John Eekels from Holland. First of all I want to thank you for you’re great project on the Super-Mini-Monitor! I’ve built this design recently. All pics and comments (In Dutch) here:
Nieuwe pagina 1. I must say, you did a great job on this! The overall balance and sound stage are amazingly well balanced. On my SE 300B tube amp, they sound impressive, even though this is not a HES speaker… Now I started a new project from you’re site, I have some questions on you. I build a pair of mini cabinet’s from scratch wood, (cherry,wood etc.) on you’re W11XT design. Instead of using a wooden port on the back side of the cabinets, I want to use a PVC pipe. When i calculate the air mass of you’re design i come to: 1,2 x 17,9 x 11,4 = 245 cm3 of air volume. When I want to use a pipe, is it correct to use the math formule: x 3,14 x D2 x L to calculate the equivalent of a similar pipe volume to the rectangular wooden pipe? Thus:245 = 0,785 x D2 X L. Lets say I will use a ID pipe dimension of 40mm L will be 245/16 makes appr.15,3 cm???? And one other question: Can you tell me where I can buy the SEAS W11CY001 units? They are obsolete I think…. Thank you for you’re great DIY site, and sharing your designs with us. Regards John Eekels

Hi John,
Thanks for your mail and response to the W15/OWI construction. I'm pleased you like them - - and I can't believe how beautiful they are!
I still have some hard wood on the shelf for the final cabs. Some day....
Unfortunately the W11CY001 drivers are no longer available. I've tried modelling the W12CY001 + OWI and it looks promising. Maybe it's time to replace the
the W11 with a new construction. There really isn't any substitute for the W11CY001, having a lightly coated paper cone.
Port dimensions (same length):
The W11 port area is 12 x 114 mm = 13.68 cm^2. A tube will have a radius of (13.68/pi/3.14) = 2.1 cm for the same area.
The actual port tuning of the W11 is close to 56 Hz, somewhat lower than the intended 65 Hz. I guess I was expecting the Fs to lower at bit over time. A 40 mm (ID) vent should be 16 cm long to keep current port tuning. I would possibly try 12 cm to get port tuning up to 65 Hz. Best regards, Troels