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.
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.
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.
In default mode, the KD-S100 plays audio without assistance from the Bongiovi DPS, and we tested all of our music in standard mode first to get an impression of the output from the system's standard built-in amplifier. The first thing we noticed when playing Red Book and MP3 discs was the low volume level from the head unit. When driving along freeway speeds, the output was just audible at half volume as it competed with road and wind noise and at full volume the output was much quieter than in most other aftermarket systems.
According to Bongiovi's marketing materials, the KD-S100 is designed to be played with the Digital Power Station feature "engaged at all times," which prompts the question: Why have the ability to turn the feature on and off at all? The answer is obviously to demonstrate to yourself and others just how much the Bongiovi signal processing affects the audio output.
The first album to which we gave the Bongiovi treatment was that from the Eagles. Having played the first track for a minute or so in standard stereo mode, we pressed the "B" button on the top right corner of the faceplate to engage the Bongiovi processing. The first thing that you notice when engaging the Digital Power Station is that the output volume increases significantly: Depending on the source, the volume is boosted by anything from 5 to 10 dB. The next thing that you notice is the audio output's improvement in clarity. It is only after engaging the DPS that you realize how muffled and muddy the sound was in non-Bongiovi mode. Specifically, activation of the processor has the effect of swelling the sound into the center of the cabin and projecting audio up from the footwells where the front speakers are installed. With the Eagles, the most notable acoustic improvements came at the high end of the frequency range as acoustic guitars, snare drums, and high vocal notes took on a much crisper definition.
Next up we put in the Cuban strains of Buena Vista Social Club, starting again with the stereo in default (non-DPS-enhanced) mode. This time we were far more aware of the flat sound of the stereo in its standard mode, even after tweaking the basic EQ controls for bass and treble. With the "B" button pressed, the effect was similar to that with the Eagles, with the instruments in the high acoustic range--including the bongo drums, the maracas, and the ratchet-like guiro--coming through with particularly clear separation. The enhancement to the low-end instruments including the double bass was also noticeable, but the effect of the Bongiovi DPS is different from that of a subwoofer. While the KD-S100 does a good job of juicing up the bass, there is not the same physical vibration associated with the presence of subwoofer.
The most impressive results we found were with the French-language podcasts. With the DSP engaged, the voices became much richer and more crisply defined to the point at which we could hear breathing and the rearrangement of the speakers' mouths as they enunciated individual consonants. Across all audio sources (MP3 discs, CDs, iPod, USB drive, SD card) the effect of the DPS on audio enhancement was equally effective.
While numerous premium factory-fitted audio systems are customized to the interiors of individual cars, the KD-S100 is the first and only example of this application we have seen in a third-party aftermarket device. There is no denying the KD-S100's ability to enhance audio output relative to the standard audio of its host JVC head unit. Based on our experience, the system does a great job of maximizing the potential of stock factory speakers. Enhancing audio output through signal restoration is nothing new, but the KD-S100 does a good job of sharpening high- and midrange output while adding a reasonably convincing phantom subwoofer. But digital remastering can only go so far. The KD-S100 is not for a system for those who are expecting the kind of audio output associated with an arsenal of high-quality audio components.
Because of Bongiovi Acoustics' business model of selling the KD-S100 through car dealerships with its potential for commission, package deals, and payment plans, it is difficult to nail them down to a specific price for the product. According to JVC, the original Bongiovi system had a price tag of "$699 upwards," while Engadget reported that the total cost of the device as being somewhere between $700 and $1,000. For that kind of money, the KD-S100 puts itself up against entry-level component audio systems. For those investing in a new car who are willing to pay an extra $20 per month (albeit for an indeterminate length of time) for significantly improved audio, the JVC KD-S100 is a compelling option.