Loudspeakers

• 3E20.10 - Loudspeakers
• 3E20.15 - Loudspeaker Resonance
• 3E20.20 - Singing Tesla Coil - Plasma Speaker
• 3E20.25 - Tooth Toons - Human Loudspeaker
• 3E20.30 - The Sound Color Organ
• 3E20.35 - High - Mid - Low Pass Filter/Crossover
• 3E20.50 - Noise Cancellation

Microphones

• 3E30.10 - Microphone Construction
• 3E30.20 - Reciprocity - Speaker as a Microphone / Microphone as a Speaker

Amplifiers

• 3E40.00 - Amplifier
• 3E50.00 - Phonograph - Turntable

Recorders

• 3E60.00 - Tape deck
• 3E70.00 - CD Boom Box

Digital Systems

• 3E80.05 - CD Reading System
• 3E80.10 - Digital Reproduction CD with Holes
• 3E80.50 - Digital Compression
• 3E80.70 / 3D50.30 - Beamz Player
• 9A20.20 - CD Player