JL Audio CleanSweep OEM Audio Interface, Model CL441DSP
If you own a newer vehicle, like the ones shown here, chances are that the head unit is not easily replaced due to cosmetic or functional concerns. This doesn’t mean you have to settle for whatever audio quality your vehicle manufacturer decided was “good enough”. By accepting, processing and controlling the audio from almost any factory-installed head unit or amplifier, CleanSweep™ makes virtually any modern vehicle a candidate for high-end sound, without costly fabrication, integration or radical surgery to the dashboard (and without needing to purchase an aftermarket head unit). Think of it as freedom of choice wrapped in black sheet-metal.
- Aftermarket sound with a factory head unit? You bet...
As automakers continue to abandon the stand-alone, standard-sized head-unit in favor of integrated designs, JL Audio’s product development team felt that a need existed for a high-quality integration solution. This product would need to deliver world-class audio results while not interfering with vehicle functionality, safety or reliability. To this end, we embarked on a two-year project to develop CleanSweep™ - a patent-pending, DSP-based solution that permits almost any factory-installed audio system to serve as the source for a high-performance aftermarket sound system while also providing input for an additional source of your choice.
- Response Correction is the Key
A huge number of factory-installed sound systems incorporate non-defeatable (often radical) equalization curves aimed at correcting the response of factory speaker systems. Many also employ volume-dependent equalization effects; for example, reducing bass output at high volume and increasing it at low volume. While these characteristics might make sense within the limitations of the factory-installed speaker system, they wreak havoc on sound quality when a higher performance system is installed. Simple line level converters cannot correct for this equalization, but CleanSweep™ can! Here are some examples of factory system equalization, from a 2001 Acura® MDX with a factory-installed base system and from a 2002 Volkswagen Jetta® with a Monsoon® factory audio upgrade. In both cases, CleanSweep™ makes a huge difference in sound quality. In each example, the red line shows the factory unit's frequency response (with all tone controls set flat) and the blue line shows the frequency response after CleanSweep™ correction. Note how front and rear channels are equalized differently in the Acura® system and how CleanSweep™ is able to correct the response of each channel independently.
- What exactly does CleanSweep™ do?
1) About the size of a paperback book, CleanSweep™ accepts virtually any analog audio signal, from low-voltage line-level to high-power, amplified speaker-level, via its four differential-balanced inputs. With totally automatic level compensation, CleanSweep™ then converts the two or four connected analog signals to digital audio with 24 bit effective resolution.
2) CleanSweep™ applies the power of its state-of-the-art, 32-bit SHARC® DSP processor to automatically equalize each of the four channels with 30 bands of equalization (that’s 120 bands total), effectively correcting the response of almost any factory-equalized, full-range signal. These digital-domain corrections will range from subtle to dramatic, depending on the degree of equalization engineered into the factory audio system. To accomplish this complex feat, you simply load the supplied CleanSweep™ calibration CD into the factory-installed CD player, set its volume control between 1/2 and 3/4 volume, play the designated calibration track and then press the “Calibrate” button on the top of the CleanSweep™ processor. Approximately 20 seconds later, the CleanSweep™ is finished analyzing and equalizing the factory-installed source’s response and stores the corrections in non-volatile flash memory.
3) CleanSweep™ then converts the digitally corrected signals back to analog audio and sends them out to your aftermarket amplifiers through two pairs of low-distortion, 8 volt (RMS) line-level outputs.
4) CleanSweep™ includes an intuitive rotary user interface (a knob with stops at both ends) to control the master system volume at the outputs of the processor unit for both the OEM (factory) and auxiliary sources. The master volume eliminates the effects of any equalization that is dependent on the OEM volume control position and allows a high signal-to-noise ratio to be maintained in the system. When pressed, the master volume knob also selects between the OEM and Auxiliary source. A dash-mountable status LED changes color to indicate OEM or AUX input modes. These small controls can be easily mounted within reach of the driver.
5) CleanSweep™ can be deployed in signal-sensing mode, powering up and providing a 12-volt turn-on signal for aftermarket equipment whenever signal is detected. It can also be activated by a conventional 12-volt trigger, if the OEM system provides one.
- What does it all mean?
1) With CleanSweep™ you retain your car’s interior cosmetics and the full functionality of factory-installed vehicle functions, including navigation, OnStar®, steering wheel controls, climate controls, etc. You can also use CleanSweep's master volume knob/source selector switch instead of the factory volume control.
2) You gain the freedom to add an aftermarket source of your choice (iPod®, satellite radio tuner, DVD player, etc.) via direct line input, as opposed to inferior sounding FM-modulator approaches. Since these signals are free of equalization, CleanSweep™ will pass them without applying any correction. The master volume control knob, when pressed, selects between the factory source and the additional source unit.
3) You also gain peace of mind, because you are not messing with your car’s complex electronics. Since CleanSweep™ typically connects to the factory-installed system as if it were a speaker, the possibility of creating faults or diagnostic issues when the vehicle is serviced is virtually eliminated. A CleanSweep™ installation is fully reversible because there is no permanent modification of the factory system, and because CleanSweep™ is not a vehicle specific interface, it can be easily integrated into your next vehicle.
4) Most importantly, you gain spectacular, aftermarket sound quality!
- Add an aftermarket audio source of your choice
Today, audio enthusiasts have a huge number of choices when it comes to storing and delivering audio content… but, if your vehicle is not aftermarket-friendly, you often have to resort to low-fidelity options like FM modulator devices to add sources to your system. With CleanSweep™ installed, you can add almost any aftermarket source unit to your system through high-quality, line-level inputs… you can even add more than one with the addition of a simple source selector switch. The possibilities are endless: MP3 players, satellite radio tuners, DVD players, game consoles, cassette players, computers, even that old 8-track player in your attic... Well, let’s not get carried away
- Length: 8.24"
- Width: 4.36"
- Height: 1.45"