2022 Kia Carnival EX Yearlong Review Update 4: Wow! We Make a Big Audio Upgrade

When I was a kid, I used to make my dad take me to a local junkyard, where a fancy Kingswood version of our workaday Chevy Townsman station wagon reposed. Over the course of several visits, I gradually Kingswoodified our wagon with various chrome doodads and accessories. I've undertaken a similar quest with our long-term Kia Carnival EX minivan, only this time the motivation isn't aesthetic—it's practical. The SX model with Prestige package gets all the nicest goodies, but they come bundled with seats that render the back of the van highly impractical. Surely, therefore, there must exist buyers like me, attracted by the Carnival's styling and best-in-class cargo space, who would happily part with $47,335 for the fanciest Carnival, if not for those stupid seats. So this month, we're "spending" $1,300 to $2,900 of the $7,600 price difference between an EX and SX Prestige to upgrade the audio system.

Bridging the Bose Gap

The SX Prestige trim is the only Carnival that gets the Bose 12-speaker premium audio system, which includes an external amplifier and a subwoofer. EX and SX models make do with just eight speakers, positioned in the A-pillars, doors, and D-pillars (those last two marking the "surround" upgrade from the base LX model's six-speaker setup). I'm no audiophile, but on our transcontinental trip in the Carnival, I constantly found myself diving into the equalizer settings menu trying unsuccessfully to make my favorite tracks pop when I cranked them up a bit. But they all ended up sounding tinny or muddy. So I called the folks at Harman International, who back in October 2018 undertook to teach me the tricks of the audio evaluation trade, to see if they could suggest aftermarket upgrades a savvy DIYer like me might undertake to improve our Carnie's jams.

Yes, Virginia, You CAN Upgrade Factory Audio

I've done audio swaps that involved swapping a single- or double-DIN head unit, but I assumed audio systems controlled by screens ended all that. Nope! There's still a brisk aftermarket business facilitated by websites like Crutchfield and supported by local and national car audio retailers. Crutchfield even produces how-to videos to help DIYers through the install process.

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What to Upgrade?

Base systems like ours typically lack the power to deliver full-spectrum sound at higher volumes, and many also lack the subwoofer needed to achieve the lowest frequencies. So an amplifier, speakers, and sub are a great place to start. These also represent the easiest upgrades for the shade-tree DIYer. Our install would be slightly more involved.

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Initial Benchmarking

Harman does not supply any Carnival audio systems and had yet to encounter one, so the team conducted an initial benchmarking audition using the procedures they shared with me three years ago. They were better able to articulate my general displeasure, describing the vocal color as sounding uneven with harsh or dull tones, many of which were "exaggerated." They noted uneven color swings in peaks and dips, a muddy midrange with a lot of energy focused between 100 and 200 Hz, and treble tones that were too bright and "sibilant" (harsh S and T sounds, cymbals). The system lacks "extension"—the ability to reach the highest and lowest regions of human hearing. And finally, wide imaging fails to place the vocals definitively within the soundscape (ideally they're perceived as front and center). Our problems were therefore primarily "spectral," meaning the system can't distribute sound evenly across the full frequency range, and "spatial," with dynamic shortcomings as volume increases.

The Game Plan

To broaden the system's sound spectrum, Harman proposed adding an external amp and fitting a subwoofer and higher-performing tweeters. To focus the spatial placement of vocals and instruments, it recommended a digital signal processor and adding speakers to the dash. The speaker grilles at the forward corners and center of the dash were all unused in our van, which is why the A-pillar-mounted tweeters and door-mounted speakers weren't having much luck "positioning" vocals front and center. We asked to keep the build affordable and doable for the intrepid home mechanic. The finished result also obviously had to end up looking stock—we weren't going for the Portuguese pancadão car look.

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The Components

Three new speakers per side upgraded our front soundstage, with a pair of 2-inch JBL Stadium 22S midrange units in the dash corners ($220) plus a JBL Club 605CSQ set of silk-dome tweeters for the A-pillar and 6.5-inch carbon-fiber-dome woofer for the door ($260). Each rear door got a JBL Club 625SQ 6.5-inch coaxial speaker (woofer/tweeter, $160). Much of the magic came from the JBL BassPro Nano 6 x 8-inch shallow-profile subwoofer that integrates a 100-watt amp, which was mounted under the passenger seat ($230).

The last major component was a JBL DSP4086 eight-channel digital signal processor/amp (8 x 40-watt, $430). This was trickiest to install because it required considerable disassembly of the center console area to access the factory audio head unit (the DSP itself was mounted beneath the shifter). This unit includes a remote bass volume knob and a USB cable (both mounted in the glove box).

The latter allows audiophile users (or Harman pros) to connect a laptop running free JBL software and ultra-fine-tune the sound equalization of the system as a whole. Passengers can still adjust balance, fader, and equalizer adjustments via the touchscreen. Note that our system still retains the stock D-pillar-mounted speakers. These are driven solely by the stock head unit because the DSP only controls eight speaker channels (a 10-channel or more DSP would have broken the budget). Our total so far: $1,300 in components Harman estimates a shop would charge $1,000 to install.

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There's More…

As a bonus, to further richen the in-car bass and highlight our minivan's role of facilitating family travel and adventure, the team wired in a $600 JBL BassPro Go removable speaker that clicks into a base mounted to our Kia's removable cargo floor tray. When plugged into the van it serves an additional powered subwoofer; but release its mount and unplug the cable, and it becomes a full-range portable Bluetooth speaker with an IPx5 marine rating. Want to keep it out of the vehicle? Recharge its built-in battery via USB cable. This must come out to fold the right rear seat down, but the cable reaches to plug it back in on the load floor if there's room for it.

The Result?

My tin ears were absolutely delighted with the end result, which finally allows me to crank up a favorite tune, delivering rich bass with no distortion. Also, somewhat amazingly, without vibrating any trim. That's a real testament to the Harman installers, who clearly secured every wire, speaker, and component securely. There's just a touch of rearview mirror vibration at full chat. And the volume knob for the subwoofer is a godsend. I crank it all the way down for NPR, up for Steely Dan, and mid to low for Wu Tang Clan.

Final Benchmarking

The Harman team ran it through the same rigorous benchmarking audition again to quantify the gains, which sound more modest in their frame of reference. On the spectral front, complaints about the bass extension dropped by three-quarters, complaints of midrange exaggeration and coldness/edginess disappeared almost completely, and reports of balanced treble roughly quadrupled. Spatially, the improvement was measurable but far less dramatic, as rearranging a soundstage requires more thorough reengineering.  Dynamic behavior at different volumes also improved significantly, thanks to the added amplification.

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Aftermarket Limitations

Harman's Novi, Michigan-based team does a lot of work on manufacturer base and branded audio systems and so was quick to point out the limitations of any retrofit system upgrade relative to a built-in branded audio system where they can design, program, and aim every speaker from scratch. They've never benchmarked Kia's Bose-branded Carnival setup but guess this aftermarket upgrade probably closed the gap by around 80 percent. We'll take that bargain at a price of between 17 and 38 percent of the EX-SX Prestige price gap. Before our yearlong Carnival departs, we'll be making a few more SXification upgrades, so stay tuned.

For More on our Kia Carnival

• Can the Kia Carnival Convert Its Biggest Skeptic?
• The Great 2,500-Mile Carnival Road Trip
• How Practical Is Our 2022 Carnival?
• Installing a Cargo Basket on Our Carnival