JVC KD-S100

Anyone who has spent time leafing through the pages of aftermarket audio magazines knows that upgrading your stock car stereo and speakers with a premium sound system is an expensive business. What if there was a way to use your existing in-car audio infrastructure to make music sound better? That is exactly what Bongiovi acoustics is aiming to do in its partnership with JVC on the KD-S100, a single-DIN stereo based on JVC's KD-SH1000. The KD-S100 looks and installs like any other standard aftermarket rig: Its wealth of audio support--standard USB and SD card playback, optional iPod connector, and satellite radio tuner--may be impressive, but the headline feature of the system is its built-in digital signal processor, designed by Bongiovi Acoustics (if the name sounds familiar, that's because the founder is the second cousin of the Jon Bon Jovi). Using a chip called the Digital Power Station, the KD-S100 scans and extends the frequency response and audio spectrum of various kinds of audio recordings.

The KD-S100 is not available as an off-the-shelf model. It can only be purchased through dealers--usually only on new cars. Bongiovi representatives say this is because each vehicle needs to be tuned individually. They map the output of the head unit to the specific factory speakers and cabin acoustic--or "profile"--of each car. The output is then tailored to the limits and design specifications of each car's speakers to maximize output. The other reason for the dealer-only distribution of the system has to do with the business model of rolling the product in with the purchase of a new car. Dealers are encouraged to sell the KD-S100 as a vehicles-specific system and to incorporate its price into customers' monthly car payments.

Design and Features
The KD-S100 is a sharp-looking head unit with a stylish black lacquer and matte silver faceplate, accented by fluorescent blue back lighting for button trim. Aside from its main volume control knob, the stereo features ten small hard buttons for browsing and selecting music and for adjusting settings. We prefer our buttons to be slightly bigger and more clearly labeled than those on the KD-S100, but we like the simplicity and economy of the design, which makes it easy to skip songs on the fly.

The system's monochrome LCD display is likewise simple and unshowy. The white-on-black characters show up well, even in bright daylight. When playing music from MP3 discs, USB drives, and iPods, the display can be configured to show an impressive number of combinations of artist, album, and song title, as well as folder and file information. Unlike many single-DIN systems, the KD-S100 is able to display a decent number of characters on its display, enabling drivers to see song titles at a glance. The source button on the top left of the faceplate provides a straightforward means of switching between different audio inputs, which also include line-in (via a rear-mounted 1/8-inch jack), satellite radio, and AM/FM radio.

The KD-S100 supports an impressive range of audio sources including iPods, which require an add-on module.

Our review model came with JVC's KS-PD100 iPod adapter module, which retails for around $50. Somewhat counterintuitively, the faceplate's Menu button has nothing to do with getting to the menu of a connected iPod. Instead, drivers have to push the Up arrow to the right of the volume dial to get to the categories in the root iPod menu (playlists, artists, albums, songs, composers), which are then scrolled through using the skip forward button. To make a selection, you have to press the down arrow below, taking you to the next submenu, which itself must be navigated with a combination of the skip button and the down arrow. This is by no means the most intuitive iPod selection interface we have seen on a single-DIN head unit from JVC--the KD-PDR30, for example, is far more easy to use. Playback of audio from SD cards is also less-than-intuitive, as users have to turn the stereo off and detach the faceplate to get the to the card slot. However, the built-in support for SD cards is definitely a positive point, and large-capacity cards will need to be changed less often, making accessibility less of an issue.

Performance
For our audio test of the KD-S100, we installed it in a car with perhaps the most basic audio system on the market: the four-speaker system in the 2007 Chevy Aveo. We had previously told Bongiovi Acoustics what our test car was, and they had loaded the specific profile for our car onto our KD-S100 review unit. This is done through the assistance of a CD, which contains information on the speaker specifications and cabin acoustics of a particular car model taken from Bongiovi's software-tuning database. To get the vehicle-specific profiles, Bongiovi plays pink noise into the vehicle cabin via the car's audio system. It then uses microphones to pick up the output and performs a "1/3-octave analysis" on each speaker, speaker enclosure, and on each of the car's listening positions. The signal is then further tweaked using frequency gain amplification and passive equalization.

It all sounds very technical, but how does it sound? To help with our test, Bongiovi had sent us a number of its own audio test discs, similar to the ones we saw at our first demonstration of the KD-S100 at CES 2008. To these sample we added a few of our discs including Buena Vista Social Club, The Long Road Out of Eden by the Eagles, an MP3 packed with an eclectic mix of bass-heavy surf tunes, and an iPod loaded up with a series of French-language podcasts. Armed with this varied assortment of formats and genres, we set about our test.