Summer means getting our rides equipped and dialed in, but with so much performance and audio equipment to choose from, it’s tough to decide what to upgrade first! The best place to start is to look at the value of your upgrade. For those of us without show cars, the audio system is used every time you drive your car, so it’s a logical choice when it comes to prioritizing your budget. When choosing the actual components, the same logic applies: look for products that can do everything you want without spending your next three months of savings!
To that end, Arc Audio tells me they have developed a series of woofers specifically for budget-minded enthusiasts. Called the XDi series, these bass-makers are built to suit a variety of applications and enclosure types.
At first glance, the Arc Audio XDi 12D2 subwoofer looks like the typical 12-inch, dual voice coil woofer. Rather than spending development dollars on bling, the designers focused on function and performance instead. Built around a heavy-gauge stamped steel basket and equipped with a powerful ferrite motor, the XDi 12D2 is available in either dual four- or dual two-ohm configurations.
When you look closer, the details that make this woofer so special become apparent.
A one-piece forged T-yoke and machined top plate encapsulate the motor assembly. The arrangement allows very close voice coil gap tolerances, thereby maximizing Bl (the magnetic energy or “force factor” applied to the voice coil) and improving driver efficiency.
Connecting the dual coils to the driver moving assembly is handled by a linear Nomex spider with integrated tinsel leads. The tinsel leads are fed electrical signals by two pairs of securely mounted nickel-plated spring loaded terminals.
One of the little things that make this woofer stand out in the crowd is the implementation of a treated paper cone. In a world of exotic materials and high dollar solutions, a paper cone is still regarded as one of the best sounding options available. It’s a simple thing, but effective when it comes to making the woofer sound good.
I notice a comment on power handling that is a pet peeve of mine. In the manual it states, “A speaker cannot reproduce DC voltage (produced when an amp clips).” This is an old industry-wide myth, probably created by someone who knew nothing about electricity. It is complete nonsense. I can prove (and have many times) that there is absolutely no DC component in the output of a clipped audio amplifier, even if it’s clipped to the point of producing pure square waves. Okay, rant complete.
For the sealed system, it suggests between 1.0 and 1.5 cubic feet, so I choose an enclosure in the middle, at 1.25 cubic feet. Because my sample woofer is equipped with two-ohm coils (and I believe a four-ohm woofer load sounds better than the alternative one ohm load) I wire the woofer coils in series and go through my normal break-in procedure before any listening. This is not necessary when buying new woofers; I do it specifically because I don’t have time to allow the woofer suspension to soften and normalize as with a typical system.
With my reference system low pass crossover set at 80 Hz at -12 dB per octave, I load up some of my favorite subwoofer test tunes and sit down to enjoy the XDi 12D2. Beginning with some serious bass thanks to Yello’s Essential Yello album, then working my way through some Billy Idol, Marc Cohn, Rush, and Pussycat Dolls, I really enjoy the sonic performance of the XDi 12D2. The bass is warm and natural; tight and clean but enough boom to satisfy the typical car audio enthusiast. This is a woofer designed to please the mainstream consumer and deliver sonic performance that might be less than optimal for the “golden ears” crowd, but the vast majority of folks will prefer it to the clinical accuracy of the best SQ woofers.
Switching to a larger 1.75-cubic-foot vented enclosure tuned to approximately 38 Hz, the entire character of the woofer changes. The focus is predominately about output and impact, but it does lose some of the natural timbre and tightness I enjoyed in the sealed enclosure. I generally prefer the XDi 12D2 in the sealed enclosure, but those who are willing to sacrifice some SQ for output might disagree.
ON THE BENCH
Measuring the Thiele-Small parameters, my data is very similar to the published specs and shows why I prefer the sealed enclosure.
The Arc Audio XDi 12D2 is a woofer that will appeal to nearly anyone. It’s well made, sounds good and can be used in vented systems where high output is king, or in a smaller SQ-oriented sealed enclosure, which I prefer. It works in a good range of enclosure sizes, and at only $139, it’s an affordable choice for virtually any budget.