(almost) OBL-15, built by Nicholas, SA

Copyright 2020 © Troels Gravesen

Hello Troels,
 
I have completed my OB15’s with the modifications that I discussed with you in 2019, it was a fantastic project and much was learnt.
 
As you can see, the baffles are 32mm MDF but the structure of the speaker is 10mm lasercut and bent steel, engineered stone base and sides, and 10mm glass panels to provide the total width of 850mm as per your design. I made everything assembly friendly with M8, M10 and M12 fastener connections to avoid having to move the total speaker weight of 110kg as a single unit.
 
Dual Faital drivers were used which are powered by the Hypex amps, so I am able to run the mid and tweeter from my valve amplifier with a line out feeding the source to each of the Hypex amps. It took some time to set up but the cross over frequency is as per your design, with 4 different pre-set volumes on the Hypex amps to balance the bass volume for room conditions.
 
Perhaps some function was sacrificed for form, as I mounted the 15” drivers from the rear of the baffle in order to hide the flange, which is quite large on a 15” driver. With the use of an additional laser cut flange mounted to the driver flange, and additional recesses at the back of the baffle, I was able to get away with having the face of the driver only about 8 or 9mm behind the baffle face once mounted from behind. This provides for a nice clean look from the front with the illusion that the drivers are smaller than what they are in reality.
 
The Hypex plate amps accommodate many options for balancing the bass in room and I am quite enjoying the flexibility. I am getting used to the sound, which is large and wonderful, but also quite different to my Illuminators which I am still very much enjoying.
 
Many thanks for your assistance and contributions.
 
Kind regards,
Nicholas
South Africa