| General characteristics | RetroSound Redondo RS M4 | RetroSound Wonderbar 3 M4 |
| Display Color | Variable | Variable |
| EQ Bands | 3 | 3 |
| Preamp Outputs | 6-channel | 6-channel |
| Preamp Voltage | 2.85 volts | 2.85 volts |
| RMS Power Bandwidth | Not givenHz | Not givenHz |
| Screen Size | - | - |
| Steering Wheel Control Compatible | No | No |
| Sub Preamp Outputs | Yes | Yes |
| Switchable Rear Preamp Outputs | No | No |
| Video Screen | No | No |
| Power | RetroSound Redondo RS M4 | RetroSound Wonderbar 3 M4 |
| Peak Output | 45 watts | 45 watts |
| RMS Power (Manufacturer) | 25 watts | 25 watts |
| Interfaces | RetroSound Redondo RS M4 | RetroSound Wonderbar 3 M4 |
| Audio/video Input | - | - |
| AUX Input | Mini (rear) x 2 | Mini (rear) x 2 |
| Backup Camera Input | No | No |
| Memory Card Slot | USB memory | USB memory |
| Second Camera Input | No | No |
| USB Input | Rear (2) | Rear (2) |
| Compatibility | RetroSound Redondo RS M4 | RetroSound Wonderbar 3 M4 |
| Alexa Voice Control | N | N |
| Android Auto | No | No |
| Android Control | Yes | Yes |
| Bluetooth Compatible | Built-in | Built-in |
| CarPlay | No | No |
| Siri Control | No | No |
| Wireless Remote | No | No |
| Supported formats | RetroSound Redondo RS M4 | RetroSound Wonderbar 3 M4 |
| High-res Playback | N | N |
| Music File Playback | MP3, WMA, FLAC | MP3, WMA, FLAC |
| Tuner | RetroSound Redondo RS M4 | RetroSound Wonderbar 3 M4 |
| HD Radio | No | No |
| Satellite Radio Ready | SiriusXM | SiriusXM |
| European Tuning | Yes | Yes |
| FM Sensitivity | 12.5 dBf | 12.5 dBf |
| Radio Data System | Yes | Yes |
| Additional information | RetroSound Redondo RS M4 | RetroSound Wonderbar 3 M4 |
| Navigation | - | - |
| Seek/Scan | Seek | Seek |
