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Joined 11 months ago
Cake day: September 18th, 2025
  • I’ve been running Navidrome + Symfonium for over 3 years and it replaced Spotify. The only thing they have over my setup is a near infinite number of playlists. But I do everything myself now, I’ve reconnected with my music.

    My main issue with Spotify was no lossless audio at the time, and many tracks weren’t on there, if they were they had a habit of disappearing. Now I can listen to any track, remix, bootleg, and even the 1700+ tracks my friend digitised from his vinyl collection until perpetuity.

    Symfonium, btw, is truly the best music streaming app, the customizability is beyond anything I’ve seen

  • You’re welcome! As long as the cone is in its rest position there’s no energy so no current which means (according to Ohms law) that the amplifier at this point is acting as an infinite resistor.

    Sound is then created by continuously moving between the -12v and +12v, if you connect just +12v to a speaker the cone will just stick out once and remain there, not much of a sound is it. Sound is a complicated alternating waveform.

    Sidenote: this is a physicists rabbithole, magnets moving around in coiled windings will create its own electrical signal. So if you talk into any speaker you can make it act as a microphone and record. So be careful with oversimplifications!

  • I don’t think anyone referenced audio applications yet, the concept might be easier to grasp if you visualise it with a speaker.

    Sound is just a particular way of moving the air, so a speaker at rest is just a cone sitting in the middle of an electromagnet, not protruding, just resting ready to be pushed out or pulled in according to the desired sound, this is the ‘rest’ state, or 0v.

    Amplifiers are provided with a positive voltage to be able to pull the speaker cone one way, and a negative to push out the other way, with a reference (or ‘rest’) in the middle. This voltage, often +12v 0v -12v, is provided be a transformer that has been tapped in the middle. But if you use measure accross the tranformer, you will measure +24v, because that’s the total voltage potential of the circuit.

    If you switch your measuring probes the other way around you’ll see -24v on your meter, did anything fundamentally change when you measured the other way around? No! It’s just your reference point that changed.