## Common ground
All options describe Bluetooth, wireless, or network-enabled speakers designed to play audio.
## Options at a glance
**8517.62 – Bluetooth signal receiver**
- **Defining trait:** Primary function is transmitting/receiving radio signals with paired devices (e.g., phones).
- **Typical examples:** Speaker that only streams audio via Bluetooth, no local playback.
- **Best fit when:** The speaker’s core role is wireless connectivity, not sound output.
**8518.21 – Single loudspeaker**
- **Defining trait:** Contains one speaker driver (woofer/tweeter) in a single enclosure.
- **Typical examples:** Small portable Bluetooth speaker with one driver.
- **Best fit when:** The device uses only one sound-producing unit.
**8518.22 – Multiple loudspeakers in one enclosure**
- **Defining trait:** Has two or more drivers (e.g., tweeter + woofer) in a shared housing.
- **Typical examples:** Compact stereo speaker with separate high/low-frequency units.
- **Best fit when:** The product uses multiple drivers for improved sound quality.
**8519.81 – Network speaker with media playback**
- **Defining trait:** Can read and play audio files from internal or connected storage (e.g., USB, SD card).
- **Typical examples:** Smart speaker that plays music from a local drive or network folder.
- **Best fit when:** The device can access stored audio files independently.
**8519.89 – Wireless speaker with file playback (non-traditional media)**
- **Defining trait:** Plays audio files without using magnetic, optical, or semiconductor storage (e.g., via cloud streaming).
- **Typical examples:** Speaker that streams music from apps like Spotify or Apple Music.
- **Best fit when:** Audio is played from online sources, not physical or digital media.
## Key differences
| Option | Core Function | Driver Count | Media Playback | Storage Type |
|-------|----------------|---------------|----------------|----------------|
| 8517.62 | Signal relay | N/A | No | N/A |
| 8518.21 | Single driver | 1 | No | N/A |
| 8518.22 | Multiple drivers | ≥2 | No | N/A |
| 8519.81 | Local file playback | Yes | Internal/external media | Magnetic/optical/semiconductor |
| 8519.89 | Cloud/streaming playback | Yes | Online sources | None (cloud-based) |
## How to choose
- Does it primarily transmit/receive Bluetooth signals? → 8517.62
- Is it a single speaker driver in one box? → 8518.21
- Does it have multiple drivers in one enclosure? → 8518.22
- Can it play audio files from USB/SD card? → 8519.81
- Does it stream music from apps/cloud, not stored media? → 8519.89
## Overlaps & pitfalls
- A speaker with multiple drivers (8518.22) may also play local files (8519.81), so prioritize **main function**: sound quality vs. file playback.
- Bluetooth speakers often stream from apps (8519.89), but if they also support USB playback, use 8519.81.
- 8517.62 is for devices where wireless function is the *primary* purpose—rare in standalone speakers.
- **No priority rule given**—choose based on the product’s MAIN function