Rainbow
Rainbow Audio Dream 0.5K Mono Class D Amplifier
SKU: 281033
Rainbow Audio Dream 0.5K Mono Class D Amplifier
Closeout, remaining stock
Rainbow Audio Dream 0.5K Mono Class D Amplifier
Compact mono subwoofer amplifier. 170W at 4 Ohm, 310W at 2 Ohm, 500W at 1 Ohm. 20Hz to 400Hz, 90dB signal to noise, THD under 0.02 percent, 155 x 55 x 165mm.
- Closeout
- Discontinued
- 1 Ohm stable
- Final sale
What You Are Buying
A single-channel Class D subwoofer amplifier in a 155 by 55 by 165mm chassis. Small enough to mount beside or behind a compact enclosure rather than needing its own real estate.
Discontinued line, remaining stock only, and we are not restocking it.
Read this before you buy
Final sale. No returns, no exchanges, no manufacturer warranty. Discontinued model with no replacement pipeline.
Reading the Power Ratings
- 170W at 4 Ohm
- 310W at 2 Ohm
- 500W at 1 Ohm
The curve is worth reading. Halving from 4 to 2 Ohms gives 1.8 times the power. Halving again to 1 Ohm gives 1.6 times. That is a supply that is working harder at each step, which is exactly what a real supply in a chassis this size does. An amplifier that claimed a clean doubling at every step would be claiming a transformer the case has no room for.
The practical consequence: pick the impedance that lands nearest the power you actually need, rather than always wiring to 1 Ohm because the number is biggest. Running a driver at 1 Ohm to get 500W into a subwoofer rated for 250W is how people destroy things.
The Rest of the Sheet
20Hz to 400Hz
Band-limited by design. This is a subwoofer amplifier, not a full-range channel with a filter switch. It will not drive door speakers.
Input sensitivity 0.25V to 5V
A wide range that covers a weak factory preout at the bottom end and a hot DSP output at the top. On an OEM integration job the 0.25V end is the one that matters.
90dB signal to noise, THD under 0.02 percent
0.02 percent is low, and it is worth noting that this is an order of magnitude tighter than what most Class D subwoofer amplifiers publish. On a subwoofer channel you are unlikely to hear the difference, but it says something about how the amplifier was measured.
Matching this to a compact ported enclosure
The Feelart SP-D622 is on the same clearance shelf and is a dual 2 Ohm driver rated 250W RMS. Wire its coils in series for a 4 Ohm load and this amplifier delivers 170W. That sits comfortably inside the driver's rating with headroom to spare, and it is a better outcome than wiring to 1 Ohm for 500W and then spending the rest of the install trying not to use it.
Who This Suits
Buy this if
- You are running a single subwoofer and need between 170 and 500W.
- Space is tight and a full-size chassis will not fit.
- Your source is a factory head unit with a low-level output.
- You accept a final sale on a discontinued product with no warranty path.
Look elsewhere if
- You need to drive full-range speakers. This stops at 400Hz.
- You need more than 500W.
- You want onboard DSP or time alignment. This is a straight amplifier with filters.
- You want warranty coverage or the option to return.
Installation
- Fuse the power wire within 18 inches of the battery, sized to the wire and not to the amplifier.
- Work out your final impedance before you wire anything, and check it against the driver's rating rather than the amplifier's maximum.
- Set the gain by ear at your normal maximum volume, then back off. Gain matches the amplifier to the source; it is not a volume control.
- Leave air around the heatsink. Class D runs cool, not cold, and a small chassis has less surface to shed heat from.
- If the enclosure is ported, engage the subsonic filter and set it below the box tuning.
Condition and sale terms
Closeout stock from a discontinued Rainbow line. Sold as a final sale with no returns, no exchanges and no manufacturer warranty. Packaging may show shelf wear from storage. Specifications are as published by Rainbow. Once remaining stock is gone this listing will be removed.
Questions on impedance, wiring or driver matching: contact us.
| Type | Mono Class D subwoofer amplifier |
|---|---|
| Condition | Closeout, discontinued |
| RMS power at 4 Ohm | 1 x 170W |
|---|---|
| RMS power at 2 Ohm | 1 x 310W |
| RMS power at 1 Ohm | 1 x 500W |
| Frequency response | 20Hz to 400Hz |
|---|---|
| Signal to noise ratio | 90 dB |
| Total harmonic distortion | Less than 0.02 percent |
| Input sensitivity | 0.25V to 5V |
| Dimensions, L x W x H | 155 x 55 x 165mm |
|---|
Power scales sub-linearly as impedance falls, which is what a real supply in a chassis this size does. Pick the impedance that lands nearest the power the driver is rated for, not the one that gives the biggest number.
