Sound projectors and soundbars

The idea behind sound projectors is to include a number of drivers (varying in number and type depending on the manufacturer or model) in a single device, so that it can generate virtual surround sound without the need to install a complete system in the room. Special emphasis should be placed on the concept of virtual as opposed to real. In this case, we can never think that a system of this kind will offer performance or quality equal to that of a good-quality, correctly positioned 5.1 system. That is why at CEC, following the concept used by most brands, we like to describe it as a solution, but never as one comparable to true multichannel.

ORIGINS

Yamaha has traditionally been one of the most innovative manufacturers in the field of Home Cinema. In the case of sound projectors specifically, it was also Yamaha that took the first steps. In fact, more than four years ago (an eternity in technology terms), our magazine carried out a Lab review of the YSP-800, a unit designed for 32" televisions, which housed 21 tweeters and two woofers. This first model only needed a source and a subwoofer to make up a complete system, since it included amplification. Yamaha has since continued to bet on this type of product, incorporating electronics and even DVD or Blu-ray players. At the same time, many manufacturers have entered this market, with interesting contributions both in calibration tools and in the addition of new elements, with the common aim of making installation easier. Notable among them are Marantz, Polk Audio, Loewe, B&W, Denon, Monitor Audio and even, more recently, manufacturers more focused on displays, such as Samsung, Philips and Sony.

HOW THEY WORK

Although various units include electronics and sources inside, in this section we are going to focus strictly on the acoustic aspects of these systems. Sound projectors house a variable number of drivers, normally tweeters and woofers, aimed in different directions, producing sound waves that bounce off the walls to give listeners the sensation that they are hearing a 5.1 system. This leads us to consider two aspects. The first is that a change in listening position means changes in the listener's psychoacoustic impression. This can compromise placement much more than in the case of true multichannel. This perception can be even more pronounced if several people are listening. The next factor to consider is the shape of the room, since the reflections we mentioned earlier will vary substantially depending on the space in which we place the sound projector. Some manufacturers talk about the ideal space for this type of product, looking for square or rectangular rooms and avoiding open-plan spaces, which are better suited to a 5.1 system with separate channels. Since we depend on the walls of the room, not only their shape but also the materials they are made of has an influence. By this we mean that a space with a large window will noticeably impair the sound of a sound projector, just as it would with a 5.1 system. It is a mistake to think that a room that is unsuitable for multichannel may nevertheless be suitable for a sound projector. With this type of product, the shape of the room is vital in order to exploit all its potential. However, brands are aware of this situation and normally use automatic calibration systems (simplified versions of Audyssey or similar) to make installation easier for the user. As we can imagine, consumers of this kind of device are looking for simplicity, so forcing them to carry out exhaustive fieldwork on room acoustics would be a contradiction. These devices are intended for simple rooms, usually living rooms, where having five loudspeakers and a subwoofer could be a problem. Any angle other than 90º can cause audible variations for the most demanding ears. L-shaped rooms are more complex, since the reflections are doubled. The latest models from Japan's Yamaha incorporate a simplified version of the YPAO system already included in its mid-range and high-end A/V receivers. It works in a very similar way. The microphone is placed at various points in the room where we would place the loudspeakers, and the system adjusts the various parameters. In any case, we must not forget that we are working with reflections rather than with direct sound projection. In this case, the effect that any obstacle, such as a table or a sofa, can have in a conventional installation may be doubled for this reason.

SOUNDBARS AND SOUND PROJECTORS

Although the terms are commonly associated with the same product, there are some differences that mean we can talk about different things.

We have already discussed how a sound projector works, but we have hardly mentioned soundbars, whose origin is slightly different.

As televisions have become thinner, especially thanks to LED technologies, the space devoted to loudspeakers has shrunk drastically to fit that gap. This has had an impact on sound quality for strictly physical reasons. As far as bass drivers are concerned, this thinness is a limitation that affects their performance. That is why the solution some display manufacturers have come up with is to create a soundbar as an audio complement to the TV. In this case, the drivers usually face forward and there is no attempt to generate a multichannel environment, although some models do aim for an enveloping sensation.

POSITIONING AND PLACEMENT

In an acoustic environment that is not very complicated, it should be treated much like a center channel: placed at the front at ear level. However, some manufacturers have designed their models to be placed under the TV, which complicates matters somewhat, or even with a wall bracket. An alternative solution is to angle it so that it suits the listening position. Another aspect to consider is the addition of a subwoofer. Many models include drivers of this type inside, but in many cases the presence of the lowest frequencies falls somewhat short. The approach will be exactly the same as for a traditional multichannel system. In addition, most calibration systems can also calibrate this element. Logically, sound projectors are designed for a particular type of room. We cannot expect a unit of this kind to meet the acoustic needs of a 50 m2 room. We should avoid diagonals and look for a room that is symmetrical in all its angles. It should also be said that we are working with sound beams bouncing off the walls, so the materials they are made of will have a direct effect on the final result. A bare wall is not the same as heavy drapes, which will somewhat deaden the final result. That is why the most recent models include the option of storing different custom configurations (for example, with panels over the windows or with an extra table in the room), which simplify the changes we may make in the listening room.

EXTRAS

Although they were originally conceived as a replacement for a set of multichannel loudspeakers, these devices have adapted to the rapid evolution of the market, responding to consumers' needs. Today we find HDMI connections, Dolby True HD and DTS HD MA decoders, Blu-ray players and, of course, amplification. In fact, they have become what have always been called integrated or all-in-one systems, taking those expressions to the extreme. The availability of wall brackets for these systems has also considerably increased the importance of design and aesthetics, adding to the initial audiovisual criteria. Logically, the price has also risen considerably, but this has allowed every consumer to find a product that perfectly meets their needs.

CONCLUSION

Sound projectors have evolved like a suit tailored to the consumer. At the beginning of this article we talked about a solution, and that is exactly what this type of equipment does today: it offers alternatives for everyone, with their different tastes and the different environments they have to adapt to. That is why what was undoubtedly the weakest aspect of these systems, their ability to adapt to different rooms, is the one that has evolved the most, and the best, in recent times.