When it comes to stereos, acoustic jazz fans have it easy. The deepest tones in traditional jazz come from the double bass, which in most cases goes down as low as 41 Hz, and the kick drum, which usually has a fundamental tone around 50 or 60 Hz. These notes aren’t deep enough to challenge most speakers. Fans of R&B, rock, and hip-hop need bigger speakers—or subwoofers—to reproduce the deep tones of instruments such as five- and six-string electric bass guitars (which play down to 31 Hz) or synthesizer bass and electronic percussion ( both of which can get down to 20 Hz and below). Reproducing midrange and treble is easy for most speakers, but once the notes get below the range of electric guitar, the demands increase exponentially. The deeper the bass you want to reproduce, the larger and beefier the woofers have to be, and the more powerful an amplifier you’ll need.
Now many contemporary jazz artists are adding elements of hip-and electronic music to their becoming their artist albums that bottom fans for jazz start thinking about bringing more end into their systems. But the audio industry doesn’t make it easy.
Do You Need Deep Bass?
If your tastes focus on traditional acoustic jazz—whether big-band, bebop, hard bop, or avant-garde—almost any set of speakers will have enough bass. Typically, a set of bookshelf speakers with 6½-inch woofers will produce plenty of bass power for any classic jazz album; most can play fairly cleanly down to about 45 Hz. But if your listening includes jazz with electronic elements—or R&B, hip-hop, and rock—you’ll get a more realistic and involving sound if your system plays clean and loud down to 30 Hz. Or even better, 20 Hz.
The easiest way to get deeper bass is to buy larger speakers—usually tower speakers—with multiple small woofers or a single woofer measuring 8 inches or larger. However, there’s also a more affordable, practical, and better way to get deep bass: add a subwoofer.
The Challenge of Subwoofers
It’s no sweat to add a subwoofer to a home theater system, because every surround-sound receiver or processor has an output for connecting a subwoofer. Audio processing inside the receiver or processor makes sure only the low bass goes to the subwoofer, and only the upper bass, mids, and treble go to the main speakers. For this reason, some audio enthusiasts use a surround-sound receiver even if they only listen in stereo and never connect the surround speakers.
But very few stereo receivers or preamps—most notably those from Classé Audio, NAD, and Parasound—have such accommodations. If you do own one of these products, such as the $1,499 NAD C 700 integrated amplifier or the $2,999 Parasound HINT 6 integrated amplifier, you can connect the subwoofer just as you would with a surround-sound receiver.
If, like the vast majority of stereo systems, yours doesn’t have a connection for a subwoofer, the task of adding a subwoofer becomes more complicated—but still very much worthwhile. If you’re using a preamp, or your receiver has stereo preamp outputs, you can connect the preamp outputs to the stereo line-level (RCA) inputs on the subwoofer. Use Y-connectors if your preamp only has one set of outputs—connect one Y-connector from the left preamp output to the left channel of the subwoofer and the amp, and do the same with a second Y-connector for the right channel. If your system doesn’t have a preamp output somewhere, connect an extra set of speaker cables from your receiver to your subwoofer—provided the subwoofer has speaker-cable binding posts, which some subs don’t. (If your receiver doesn’t have a preamp output and your sub doesn’t have speaker-cable binding posts, or if your system has a preamp output but your sub doesn’t have stereo line inputs, you’ll have to replace the receiver or the subwoofer.)
Now that you have audio signal going to your subwoofer, you’ll have to set the subwoofer’s crossover frequency—the highest frequency at which it’ll play. Set the frequency too high, and voices will sound boomy, so Al Jarreau will start to sound more like Johnny Hartman. Set it too low, and voices won’t have enough body—so Johnny Hartman will start to sound like Al Jarreau. Start by setting this control to match the published low-frequency limit of your speakers, so if your speakers have a rated response of 50 Hz to 20 kHz, set the subwoofer crossover to 50 Hz. Tweak it back and forth by 10 Hz to get it really dialed in.
Last, you’ll need to set the subwoofer’s level control. Fortunately, this requires no technical understanding at all—just set it wherever it sounds good to you.
Will a subwoofer reveal new depths in the works of Sonny Rollins or Stan Getz? Probably not, although it won’t hurt. But if your tastes have been moving toward Thundercat or Flying Lotus, adding a subwoofer will certainly bring in a lot of notes you’ve been missing—and get your feet tapping a lot more too.
Why Bass Can Sound Bad
Some audiophiles shy away from deep bass. That’s because while midrange and treble frequencies bounce around a room, bass notes resonate, like the sound made by blowing across the mouth of a jug, which can make them boom at certain frequencies. To fix this, try moving your subwoofer closer to a corner to get more bottom end, or further from the corner to tame the boom.
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