Amped Up Hemi

I recently upgraded my salad bowl hemispherical speaker with a new amp board, and I’m loving the sound. I get more volume with less distortion.


This 6-channel board (Sure Electronics TDA7498) is significantly more powerful and easier to install than my previous configuration of 3 stereo amps. I had to use a router to make room for the cooling fan, but otherwise the installation was straightforward.

Here’s everything hooked up before I stuffed the innards back in place and fastened the bottom plate.

The DIY orchestra of the future – hemi speakers

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.

Hemi Power

I wrote earlier about problems with the amps on my hemispherical speaker cutting out. After a little diagnostic work I realized the solution was simple–the amps weren’t getting enough juice. So I sprang for a heftier power supply (12 volt dc putting out 6 amps) and now everything runs hunky-dory. Can’t wait to take this puppy out to my next show! I’ve also been working out the kinks on some spatialization routines. More on that later…