Pros / The 240-watt max power output is above average.
Cons / It only has two preamp outputs.
Verdict / The Dual DC504BiM has a good amplifier that's comparable to more expensive car stereos, but it lacks many of the playback and smartphone integration features.
Editor’s Note: This product has been removed from our side-by-side comparison because it has been discontinued. You can still read our original review below, but Top Ten Reviews is no longer updating this product’s information.
With so many similar types of car stereos on the market, the Dual DC504BiM found a way to stand out with a unique motion-control feature. Instead of using the buttons on your faceplate to control the faceplate, a motion detector allows you to skip tracks, pause, play and control the volume using hand gestures. Once you get past the novelty of the motion controls, you'll find an above-average amplifier, but not great audio.
The motion-control feature is fun at first. You can turn the volume up or down, skip songs, replay songs and pause with simple hand motions. However, you'll quickly see it for what it is – a gimmick. It doesn't make the controls easier or safer to use. You have to make the hand gestures directly in front of the faceplate, which means your hand is already near the controls. Making hand motions isn't easier than using the rotary wheel and the buttons. It certainly doesn't replace the value gained with steering wheel controls.
The best feature with the Dual DC504BiM is the power amplifier's maximum output. It has a max output of 240 watts, which is 40 watts more than most car stereos. However, the continuous power output is more pedestrian at just 72 watts. In addition, the pre-out voltage is only 2 volts, which means that the output audio signal isn't as clean as those of the best car stereos, which have pre-out voltages of 4 to 5 volts.
The major downside is the lack of preamp outputs. You only have outputs for the left and right front speakers. If you want to send outputs to rear speakers or a subwoofer, you'll need an external amplifier.
The audio quality is good for the price range, but it only has five EQ presets – pop, jazz, rock, beat and classic. These presets aren't customizable. The frequency bands are set. This doesn't give you a lot of control over how you want the music to sound. The best car audio systems have up to 13 presets at various frequencies and allow you to enhance or diminish the frequencies by up to 12 dB.
The playback options are standard. It plays CDs, MP3s, WMAs and any audio streamed wirelessly from your phone via Bluetooth, which includes internet radio apps like Pandora. You can even control Pandora from the faceplate. However, it lacks HD Radio and support for SiriusXM satellite radio. It can't play WAV or AAC files from the USB drive either.
This is the only car stereo in the DC series with Bluetooth. While this allows you to stream music from your favorite internet radio apps or your phone's storage, it also allows you to take hands-free phone calls. However, the microphone lacks noise cancellation technology, so the call quality isn't very good, because your caller will struggle to hear you over the sound of the road. It also lacks the PBAP profile, which means that the caller's name won't appear on the display when you receive a call.
The Dual DC504BiM features an above-average 240-watt amplifier with 72 RMS watts of continuous power output. The audio quality is good, but it won't blow you away. With only five EQ presets and the lack of customizable frequencies, you have less control over the audio than you would with the best car sound systems. The hand motion controls are neat, but they ultimately don't add any value to the usability.