In this TED Talk Ge Wang of Stanford geeks out about computer music (hooray!). He talks briefly about the hemispherical speakers used by the Stanford Laptop Orchestra. Their design (using an IKEA salad bowl) informed my hemi speaker experiments here.
I recently bought a 6-channel amplifier to upgrade the 3 2-channel amps I originally installed in the speaker. I’ll post about the new amp as soon as I drop it in.
I recently had the opportunity to help Kristin Norderval build a hemispherical speaker for use in the jill sigman/thinkdance production, Our Lady of Detritus, engagingly described as “a portable, interdisciplinary performance installation about trash and transcendence; a traveling grassroots campaign fueled by experimentation, green energy sources and community interaction.” The show is presented every weekend through mid-October at various locations around New York City. See here for details.
We used an Ikea salad bowl for the enclosure just like the SLOrk speakers.
We pulled 3 Dayton T-amps from their enclosures and mounted them on the inside of the bottom plate of the speaker cabinet.
We used 6 4″ Inifinity 4022i drivers.
Volume Pots and Connectors
The Dayton amps had combination volume and power pots, so we decided to keep them rather than source and wire up a 6-position potentiometer. A little Dremel routing magic made mounting the volume pots easier than I expected. A coaxial power jack and 6-pin Neutrik XLR jack and plug rounded out the connectors.
salad bowl – top view
salad bowl – bottom view
salad bowl – detail showing Ikea part number
salad bowl and template for marking the position of the 5 “equatorial” speakers
cutting holes for speakers
We used masking tape to prevent the jigsaw from scratching the bowl
Kristin demonstrating the dispersion pattern of the enclosure
A naked Dayton T-amp with the speaker connections on top and the volume pot on the left
A Dayton T-amp before disassembly
finished hemi – with audio and power connectors on the left
finished hemi – with 3 volume pots on the left
finished hemi – top view
The speaker sounds good–punchy and more powerful than I expected, particularly considering the 4″ drivers. I’ll be building one for myself soon.