① The double 15 speakers are two 15-inch woofers. If it is a dual 15 full-range speaker, it is two 15-inch woofers+1 tweeters with an impedance of 4 ohms.

② A single 15 full-range loudspeaker is a 15-inch woofer+1 tweeter with an impedance of 8 ohms. There is also a single 15 subwoofer. Of course, it goes without saying that this is a 15 inch bass. So the impedance of double ten 15 is different from that of single document 15.

Extended data

Audio refers to an audio system in which electrical devices are combined to produce sound.

A sound system usually includes:

1, audio equipment: (listed as: DVD, CD, MP3, MP4, computer, mobile phone, microphone and other audio output equipment)

2. Audio signal dynamic processing equipment (voltage limiter, effector, mixer, audio processor, equalizer and other audio signal processing equipment).

3. Audio signal amplification equipment (analog power amplifier and pre-stage power amplifier, post-stage power amplifier, digital power amplifier and other equipment).

4. Sound reproduction equipment (full range speakers, ceiling speakers, pillars, linear array speakers, array speakers, tweeters, subwoofers, etc.). The development history of technology can be divided into four stages: electron tube, transistor, integrated circuit and field effect tube.

References:

Baidu encyclopedia? sound