Audio & Sound (6)

Julien ARNAUD

Crown CTD-8125 & iTunes clone for Linux (Sustain)

It's the little things. May 2026, I received a CTD-8125 to replace my Mini DSP 10x10 HD and the two CT8150, in parallel, I wrote a iTunes inspired Linux music player (Sustain). Two fairly small things, but huge quality of life improvement. This one allows me : One blindspot, the CTD 8125 manual said that the amps drew 2W with network, I assumed that the network would always be up, it's not. In 2W sleep mode, it turns of networking. So I had to keep an analog Dante output to…

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Julien ARNAUD

High end multi-room sound system (offline/no-cloud)

Goals of the system In plain english : It allows me to play music of my Android phone on Spotify, or play a Youtube video on my Debian laptop, or start mixing on my XDJ-XZ, or play a movie on the Chromecast 4K in the movie room and... have the sound automatically get out of each and every speakers of the house, with state of the art quality on each of them. Keys to reach the goals Components of the system Audio routing The audio routing goes as follows :…

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Julien ARNAUD

Twizy 2.2 DSP corrected sound system with 3D printed subwoofer

I designed a soundsystem for my Renault Twizy around the following elements Subwoofer The subwoofer enclosure was designed to fit in the narrow space behind the passenger seat. This gave the subwoofer a kind of rounded/organic shape. From this shape I got an internal air volume. I looked for speakers that would work in such a small volume and still produce the desired level of bass (I aimed for around 45Hz -3dB). The software popped out a 6.5" Audax with dual coils. The simulation has some compromises though, at full…

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Julien ARNAUD

Blocking hard drive I/O with sound

I replicated the results of Connor Bolton, Sara Rampazzi, Chaohao Li, Andrew Kwong, Wenyuan Xu and Kevin Fu. in "Blue Note: How intentional acoutic interference Damages availability and integrity in hard disk drives and operating systems". I set up one of my DIY Cabasse Spheres in front of a Fujitsu MJA2160BH. Doing a frequency sweep from 850Hz to 1.1Khz at around 102 to 105dB. When reaching close to 975Hz +/- 25Hz, the bitrate of the read file drops from 70MiB/s to a few KiB/s. Data was generated from /dev/random, secondary…

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Julien ARNAUD

Re-enclosed JBL SB210 Subwoofer

Unsatisfied with my JBL SB210 low frequency, I designed and built replacement enclosures. The SB210 is a dual 210mm subwoofer, using ceramic cones in a polymer enclosure. Specifications of JBL's original SB210 are My redesigned enclosure offers The first hurdle was the absence of datasheet for the speakers themselves, as they were never distributed outside of the SB210 system. After contacting JBL Professional, they were kind enough to provide me with the data. These specifications were entered in Dominique Petoin's databaseĀ and you can now find it there. As I was…

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