(Aren't sure why you need a subwoofer in the first place? Please check our subwoofer theory page.)

All PSB subwoofers are designed to give you a maximum of the virtues we describe in our segment on subwoofer theory (linked above). They can move large amounts of air with very low distortion, and both their drivers and the power amplifiers built into them are carefully designed to match well both with our (and other people's) main speakers and — critically — with your amplifier or receiver. In the latter regard, there are lots of opportunities for problems from the separate amplifier of a sub. We go to great lengths to avoid them and achieve a seamless interaction with your equipment.

Because the single most expensive commodity in speaker design is extended low-frequency response at high volume levels, we supply subs at four performance levels that allow listeners to choose just how deeply and powerfully they want to go into subterranean bass. Our least ambitious model is perfect for compact systems and small rooms. The next may serve you beautifully even with some very ambitious main speakers, and the two steps up from it in performance are designed to leave successively fewer stones unturned.

All of our subwoofers have what may be the most valuable commodity these days in subwoofers: tremendously sophisticated, interface circuitry for dealing with the all-too-frequent overload conditions in Home Theater bass. Here is how it works.

Subwoofers face two very different kinds of stress. One is the sudden and sometimes tremendous peak 'slam' of one kind or another, one of those jolts that come both in music and movies. The other is a primarily movie phenomenon — the ominous, sustained sounds that sometimes underlie a movie soundtrack. They're the ones meant to build up reactions from awe to nervousness and fear, and they can go on for minutes at a time. Subwoofers that deal well with one of these demands may not do as well with the other, and some have trouble with both.

The circuitry we have developed for all our present subwoofers is as close to ideal for these conditions as we can imagine. It has very fast-acting limiting to supply all the dynamic headroom needed for short-term demands of music and sound-track transients of all kinds — moments that can make many subwoofers stutter very audibly and even drop out. And it combines that limiting with equally fast-to-come, fast-to-go compression that handles the longer-term stresses of subterranean Home Theater effects without any sign of strain. Put one of our subwoofers up against a typical sub that takes a clearly audible part of a second to recover from overload, or quits altogether in some situations until the coast is clear again, and we think you will hear an major difference that you will not want to give up. The difference is not at all hard to hear in head-to-head comparisons. In some subs, sudden peaks are audibly cut off, or audibly clip the beginning of the sound following them. And others simply drop out on sustained passages. If you are not making a direct comparison, a deficiency may pass by your consciousness, since you probably don't have a reference for what a passage should sound like. But when you listen comparatively, what our subwoofers do on these passages makes a really dramatic and lasting impression. You hear things you didn't hear before, and you don't hear any stutters, hiccups, or drop-outs.

Some philosophy
PSB subwoofers are designed to provide the flattest possible frequency response, full bass extension, low distortion and high output. Frankly, these are characteristics that most manufacturers would strive for. Our years of experience and our sophisticated design and measurement tools allow us to achieve ideal subwoofer performance. Beyond these characteristics there a few other parameters that we uniquely feel are very important in the design of a subwoofer. First and foremost it is important to us that a PSB subwoofer be musical. In this era of home theater this might at first seem out of step, but we believe that a musical subwoofer will also sound the most natural when playing movie soundtracks. Furthermore, an ideal subwoofer should have the ability to play musically even under conditions of overload or stress. No subwoofer is so large with its limits so great that it can never be overloaded, especially with modern movie soundtracks. For this reason PSB subwoofers incorporate very intelligently applied limiting circuitry to prevent audible overload.

The limiting circuitry of all PSB subwoofers is a combination of peak limiting circuits that hold amplifier signal swing to the point just short of the amplifiers clipping, and compression circuitry that will come in under conditions of long term overload and reduce the amplifiers gain. The trick is to apply these circuits in such a way that they don’t squeeze the life out of the music or movie soundtrack, to allow the dynamics to get through while preventing gross distortion. We do this by being mindful of the dynamics of music and carefully tailoring the time constants of the circuits to that of music. For example, it is known that most music is performed with a beat of 80 to 140 beats per minute. Our test signals are configured to follow this timing and allow maximum transient effect without distorting on sustained tones.

We go to great lengths to reduce any mechanical noises our subwoofers may make. Woofers are designed never to bottom harshly. Ports have large radius end flares to reduce noise from turbulence. Cabinets and amplifiers are designed so that no air leaks (which can contribute minute amounts of noise) are possible. All of our designs are exhaustively tested. A subwoofers design isn’t complete until the sub’s amp and woofer can survive a 15 hour test of being driven continuously to maximum output.

Here is the rundown on our subs:

Alpha SubSonic 1
Century SubSonic 2i
Stratus SubSonic 3i