Theo Verelst EZLITE-BF533 Biamp Filter Page

Last update: june 6 2005

   I'm designing and prototyping a set of bi-amped powered speakers, which means they have a seperate amplifier for the woofer and the tweeter, and those 4 (for stereo) amplifiers are built in in one speaker, and also include an electronic seperation filter to get high quality sound.

For testing purposes I've made a digital seperation filter based on the Analog Devices Blackfin 533 EZ-LITE kit, in this case for one channel, where cutoff frequency and filter steepness can be controlled, as well as the relative volume.

Because I've made a sound synthesizer based on that board, I used that machine which I reprogrammed for the purpose.

I used the display and the control to change the cutoff frequency and the relative woofer/tweeter volume, and the high Q buffered output to drive the two amplifiers for one channel.

The filter steepness must be controlled in the software and requires recompilation of the Process_data.c source.

The speakers I'm working with I've made like this at them moment (they'll receive edge finishing and protective skay later):

The source and executables of the project are open source, but with commercial rights reserved, inform me please when you work with them:

The amplifiers are of excellent quality, and the whole sounds with the filter at about 5 kHz very good, neutral, strong, responsive, impressive enough (the woofer is 17.5 cm) and very clear and pleasant.

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