I admit I cringed a little when I saw “50USB” in the name of this product, followed by “reference monitors.” The mental wince came from the idea this Behringer product was a USB-powered speaker system claiming reference monitor status. USB-powered speakers are a wonderful convenience, to be sure, bringing audible audio to places where no further power supply is on hand. However, the low voltage available through a USB bus preempts the possibility of a serious reference monitor.
With relief, I noted that the Behringer Studio 50USB reference monitor adds a USB port to its roster of audio inputs. Otherwise, the system — sold in pairs — delivers 150 watts through a 5-inch rear-ported woofer at a very reasonable street price under $200. This is a very attractive price point for a 5-inch reference monitor, provided the speaker can deliver the goods.
On record, I’ve expressed my preference for front-firing ports, where ports exist at all. It’s harder and harder to find sealed cabinets, particularly in the affordable, active speaker category. The reason for that is likely due to the consumer attitude that louder equals better. Speakers generate sound by moving back and forth in their mounts, driven by a coil of wire responding to changes in a magnetic field surrounding the coil. By design, a speaker moves forward and backward, pushing and pulling on air, both in front and behind the speaker cone.
Sealed speakers utilize only the movement in front of the cone. The back is enclosed within an airtight cabinet, usually well-padded with insulation to dissipate the sound energy within. A ported enclosure permits that rear-facing energy to escape, usually through a tuned port that minimizes several inherent problems with the sound coming from the rear of the speaker cone.
The two biggies here are phase and time alignment. A speaker essentially makes two copies of the audio signal as it moves, although one copy starts with positive pressure (in front) and the other with negative pressure (behind) as the speaker pumps back and forth. On their own, each copy would sound fine. As a listener, starting positive or negative is not really a big deal. However, when you combine these, they interfere with each other, the effect known as phase cancellation. In extreme cases, these signals eliminate each other to the listener. This principle makes devices such as noise-cancelling headphones possible. As an accident of sound, though, it’s not a desirable effect.
Since these copies are also created at the same instant, the extra distance the rear-facing wave travels to get to the listener’s ear is potentially troublesome. While breaking up the time of the waves is good from a phase perspective, sound waves still partially interfere with each other. This is where speaker engineers earn their stripes, deciding on the length, direction and resonant frequencies of the ports. Not simply a hole in the face of the cabinet, a port is usually a tube of certain size and shape to accomplish what the engineer wants in terms of time and frequency enhancement. Properly tuned, a port adds volume and frequency emphasis to the speaker’s output.
What this all comes down to for the 50USB is that its design ports to the rear. I find a certain vagueness to the sound of this design in most cases. The dispersion of lower frequencies prevents a little punch to my ears, and frequently there’s a poorer sense of stereo imaging, since the output of the port is intended to disperse and reflect. These effects vary by speaker location, since a nearby wall means more reflection than a more distant wall. Keeping these points in mind, let’s look at the 50USB.
As mentioned, the 50USB is a stereo pair of monitors. All the business is on the right speaker. A special four-conductor connector runs between left and right. This is good news, which we will get to momentarily. All inputs are on the right cabinet. These include XLR and ¼-inch for both channels as well as a Type B USB connector for digital audio sources.
A nice touch here — all inputs can be used simultaneously. With the routing possibilities available with computer audio, interfaces and mixers, having three inputs available without physically re-routing or switching sources means you can listen to the signal you want, when you want. True, you’ll end up playing two signals that have nothing to do with each other and momentarily experience a WTH? Moment, but after a few of those you’ll be accustomed to directing signals.
At first glance, the sound modification choices on the 50USB may seem odd, and, compared with most reference monitors, they are. These include a center-detent Input Trim and four-position high frequency response switch. Most reference monitors feature a low frequency response switch, if there’s only one frequency modifier. Speaker placement, as we saw above, affects low frequency response by reflecting more sound when placed closer to a wall. The effect is even more pronounced when corners come into play. Because of the efficiency with which low frequency sound waves move, bass response is boosted the most.
It makes sense, then, to adjust the bass frequencies. Behringer has chosen, with the 50USB, to alter the highs instead. This is potentially a valid move, but the settings they’ve chosen don’t make sense to me. Here’s why: seasoned engineers know that cutting frequencies around the frequency they wish to enhance is a noise-friendly alternative to boosting the enhanced frequency. That actually brings sense to the high frequency adjust switch. What any of these controls do is alter the relationship between high and low frequencies.
As a speaker moves closer to the wall, physics makes the bass increase due to reflections. So, cutting the bass or boosting the treble restores the relationship. So far, so good.
However, the 50USB features four options: 0, +2, -2 and -4 dB. Assuming 0 dB is the setting for a speaker in an open field, no walls nearby, then +2 dB may counteract the wall effect. With the 50USB set into a corner, however, there’s no additional high frequency boost to compensate. The -2 and -4 dB settings then don’t really have a logical place here. Unless, that is, the 50USB is inherently a bright monitor. On we go to the sound.
Keeping in mind this is a monitor system that comes in around $150, some expectations should be tempered. My first impression of the 50USB was not that of a particularly bright monitor, but rather of a set that was light in the bottom end.
Fortunately, I’d read about the speaker before checking it out, so I was already curious about that high frequency switch. Immediately, I set it to -4 dB, not to attenuate the highs as much as to reduce their relationship with the lows. Voila, now the output had a better balance between highs and lows. It’s still not a bass-heavy monitor, but it’s natural and neutral with good midrange clarity. Using -4 dB as the base setting, then the 50USB has three treble boost settings for wall/corner adjustment. Far more sensible than the suggestion that 0dB is the base. However, after adjusting the position of the monitors in relation to walls and corners, the rear port issues noted above are in evidence.
And volume. Did I mention volume? Holy smokes, these are loud. That in itself should guarantee some positive user feedback for those who don’t know any better.
That four-conductor connection cable indicates that both speakers in the left cabinet receive their own signal which means bi-amping. Yay! Bi-amping is good. Both the tweeters and woofers have an amp dedicated to their needs, not a single amp that offers a compromise to one or both frequency ranges. This is good news.
The cabinets aren’t small, measuring 8 inches by 10 inches, with 7 inches of depth. Nor are they light, at 14 lbs. These are, however, good qualities for monitors, if you’re not cramped for space. All connectors and controls feel solid, on par with monitors three times the price.
Users reviewing on music store sites are extremely happy with the 50USB, commenting on — you guessed it — the volume. There are equally raves for both sound and value. Users from retail sites are less happy. There are actually negative comments about the loud output. I don’t think I’ve ever read that before. I don’t really get it, as there are too many places in most signal chains to adjust output, including the input trim on the 50USB itself. However, you can be assured this will not be the quietest monitor you’ll ever encounter.
Personally, I’d like a little more going on in the bottom end from the Behringer Studio 50USB. A front-firing port might have done it, speaking from the what-if position of an equipment reviewer. However, it’s not a monitor deficiency as much as it’s my personal taste. Therefore I have no hesitation recommending that you add the 50USB to your shopping list, particularly those who are starting from scratch and on a budget. These monitors score Very High on the cost-to-performance scale, definitely worth a look.