DIY Speaker with Ferrofluid Display: Lava Amp

YouTuber Dakd Jung recently shared a montage of them making a Bluetooth speaker with a one-of-a-kind visualizer. In front of the speaker is a small glass case with a bit of ferrofluid in it. Inside the speaker is a device that converts part of the sound signal into electromagnetic signals, causing the blob to react to the sound in real-time.