Shopping for a RetroSound radio? Start with the motor, not just the faceplate. The face, knobs and bezel decide how the radio looks and fits your dash. The Motor is the electronic unit behind it, and it sets power, inputs, outputs and features. On most RetroSound listings at Vintage Car Radio, you choose Motor 1B, Motor 2B or Motor 4HD from a menu. Here's how they differ, based on Retro Manufacturing's published feature lists.
What every RetroSound motor has in common
Before the differences, here is what you get no matter which motor you choose:
- Built-in Bluetooth 5.0 for music streaming and hands-free calling, with a microphone included
- AM/FM RDS tuner with 30 presets and selectable USA/EUR/AUS/JAP/RUS tuner frequencies
- A built-in MOSFET amplifier (the power rating depends on the motor)
- Non-volatile memory for presets and settings
- A modular design, so the motor pairs with the face made for your car. Assembly is required.
So the real question is how much power, connectivity and expandability your system needs.
Motor 1B: essential Bluetooth
Motor 1B is the foundation of the RetroSound lineup. RetroSound designed it for simple systems and classic vehicles using factory or lightly upgraded speakers.
Key features:
- Built-in 275-watt peak amplifier, 18 watts RMS x 4 channels (TrueRating)
- Single rear auxiliary input for a portable device
- White display illumination only
- No USB port, no RCA pre-outs and no subwoofer output
- 1-year manufacturer warranty
Who it suits: You want Bluetooth, hands-free calls and clean AM/FM with stock-style speakers, and you don't plan to add an amp or subwoofer.
Motor 2B: the most popular choice
RetroSound calls Motor 2B its most popular motor and the right fit for most classic car and truck builds. It's also the default selection on most RetroSound radio pages at Vintage Car Radio.
What it adds over Motor 1B:
- More power: 300-watt peak amplifier, 25 watts RMS x 4 channels (TrueRating)
- A rear USB port for flash drives and other devices, with 2.1-amp charging
- Dual RCA pre-outs for external amplifiers
- A dedicated subwoofer output
- An adjustable color display (32,000 colors) you can match to your gauge lighting
- 1-year manufacturer warranty
Who it suits: You're running upgraded speakers, want louder and cleaner sound without an external amp, or might add an amp or subwoofer later. If you're unsure, Motor 2B is the safe middle ground for most street-driven classics.
Motor 4HD: the flagship
Motor 4HD is RetroSound's flagship digital motor and its most advanced platform. It keeps the 2B's power and outputs and adds digital features on top.
What it adds over Motor 2B:
- HD Radio technology
- SiriusXM-Ready (the SiriusXM SXV300V1 tuner is sold separately)
- RetroSound Radio App compatibility, so you can control and customize the radio from your smartphone. RetroSound says Motor 4HD is the only one of these three motors that works with the app.
- Two USB ports for media playback and 2.1-amp charging
- The same 300-watt peak / 25 watts RMS x 4 amplifier, dual RCA pre-outs, subwoofer output and adjustable color display as Motor 2B
- 2-year manufacturer warranty, double the 1B and 2B
Who it suits: You want satellite radio, HD Radio, phone-app control or two USB devices, or simply every option for a full audio build.
Already own a 4HD? App control only works on the current app-enabled version. RetroSound says to check for "MOT4H1" on the motor label or "MOTOR 4HD-1" on the box. The older version is marked "MOT4H" or "MOTOR 4HD".
Quick comparison
| Feature | Motor 1B | Motor 2B | Motor 4HD |
|---|---|---|---|
| Bluetooth streaming + hands-free | Yes | Yes | Yes |
| Built-in amp (RMS x 4) | 18 W | 25 W | 25 W |
| Peak power | 275 W | 300 W | 300 W |
| USB ports | None | 1 | 2 |
| RCA pre-outs + subwoofer output | No | Yes | Yes |
| Display | White only | Adjustable color | Adjustable color |
| HD Radio | No | No | Yes |
| SiriusXM-Ready | No | No | Yes (tuner sold separately) |
| RetroSound Radio App | No | No | Yes |
| Manufacturer warranty | 1 year | 1 year | 2 years |
Fitment notes before you order
The face, not the motor, decides whether a radio fits your car.
- Pick the face first. Vehicle-specific RetroRadio faces are made for particular dashes, like the 1964-66 Ford Mustang RetroRadio, the 1967-68 Chevrolet Camaro RetroRadio, the 1957 Chevrolet Bel Air RetroRadio and the 1967-72 Chevrolet C/K Series Truck RetroRadio. If your dash has a DIN opening, look at a DIN-style face like the RetroSound Liberty Single DIN Radio.
- Then choose the motor from the Motor menu on that product page.
- Motor choices can vary by radio model. For example, the Motor menu on the 1954 Chevrolet Truck Apache Radio lists Motor 1B and Motor 2B only. Always check the menu on the listing you're buying.
- 12-volt, negative-ground systems only. Check shaft spacing and the dash opening before cutting anything, and read the Specs, Manuals and FAQ tabs on each listing.
- Plan your speakers at the same time. A stronger motor won't help one worn-out dash speaker. See our Classic Car Dash Speaker Buyers Guide, Speakers & Wiring Basics and RetroSound speakers. Prefer to buy it all at once? A matched package like the 1957 Chevrolet Bel Air RetroSound Stereo Package with Amp bundles the parts together.
Vintage Car Radio is an authorized RetroSound dealer. We don't install radios, so plan on doing it yourself or using a local installer.
Which motor should you choose?
- Stock speakers, simple setup, Bluetooth is the goal: Motor 1B
- Upgraded speakers, more volume, maybe an amp or sub later: Motor 2B
- SiriusXM, HD Radio, app control or two USB ports: Motor 4HD
Still deciding between a look-alike, hideaway or DIN radio? Start with How to Choose a Classic Car Radio. If you want Bluetooth without changing your dash, read How to Add Bluetooth to a Classic Car Without Cutting the Dash. For a side-by-side reference, see our RetroSound Motor 1B vs 2B vs 4HD buyers guide.
FAQ
Do all RetroSound motors have Bluetooth? Yes. All three include Bluetooth 5.0 for streaming and hands-free calling, with a microphone.
Which RetroSound motor has USB? Motor 2B has one USB port and Motor 4HD has two, both with 2.1-amp charging. Motor 1B uses an auxiliary input instead.
Can I add an amplifier or subwoofer? Yes, with Motor 2B or 4HD. Both have dual RCA pre-outs and a dedicated subwoofer output. Motor 1B doesn't have pre-outs.
Does Motor 4HD include a SiriusXM tuner? No. Motor 4HD is SiriusXM-Ready, but the SXV300V1 tuner is sold separately.
Get fitment help
Not sure which face or motor fits your car? Call Vintage Car Radio at 844-802-4499 and we'll help you match the radio to your year, make and model. Every RetroSound radio ships free within the continental US. See Shipping & Returns for Alaska, Hawaii and international rates.