Speaker Tech

Given that the low frequency response of an Echo alone probably doesn’t reproduce any useful output much lower than 100 Hz (admittedly an educated guess), the Echo Sub certainly can't hurt. But given its size and its 6-inch driver, there's no way that such a product it can be considered a subwoofer...

Subwoofer design has undergone a revolution. No, the physics of woofers, amplifiers, and enclosures haven’t changed. But new technologies have made it possible to push the bass-ic laws of nature to their limits, such that the best of today’s inexpensive subwoofers can outperform many of the top models from 15 or 20 years ago.

Affordable digital audio processing lets designers tune subwoofers in ways the engineers of the 1990s could only have imagined. High-efficiency amplifiers pound out powerful bass from boxes hardly bigger than a basketball. New speaker drivers use high-tech materials to produce sound levels that would have pushed older models way past the breaking point.

Since things are so different now, we thought this would be a great time to revisit some of the fundamentals of subwoofer design and examine how the old rules might have changed in the digital age.

S&V: What’s the most important in a subwoofer: the driver, the enclosure, or the amplifier?
CH: Being a system engineer, I believe all of it’s important. A poor-quality part in just one of the areas can mess up the whole product. For instance, no sub with a leaky enclosure is going to sound good no matter what amp or driver you use. Or if you tune the sub in an environment [room] that’s not appropriate to tune in, it’s going to sound bad regardless of the components you use.

S&V: Do you have a preference for ported, sealed, or passive-radiator subwoofers? How do the design decisions differ among those three?

S&V: What’s the most important aspect of a subwoofer: the driver, the enclosure, or the amplifier?
EM: SVS takes a holistic approach to sub design. It’s very possible to use high-quality components that don’t work well together, and the results will not be optimal. We look at the end-user application, then develop a list of components for that application. You’ve got to match enclosure size, the form factor, the amplifier power, and the driver itself...