Comparison Yamaha YAS-108 vs LG SJ3

The projector supports the virtual surround function.

The purpose of this feature is that due to special sound settings and the reflection of sound beams from the walls of the room, the listener hears more channels than are actually available in the projector (see "Audio Format"). For example, a 3.1 system with virtual surround sound can produce sound similar to 5.1 surround sound. This allows you to achieve the effect of "immersion" in sound without increasing the number of channels and the cost of the projector. On the other hand, the reliability of such sound is usually noticeably worse than that of real surround sound, and the overall quality is highly dependent on the characteristics of a particular room.

Note that the virtual surround function is specified for 2.0, 2.1, 3.0, 3.1 format systems. In more advanced multi-channel systems, there are a priori additional channels for reproducing surround sound.

The ability of the projector to output a video signal in 3D format — that is, a "volumetric" image that has three full dimensions (including depth). Since 3D uses the division of the “picture” of the image into two parts (for the left and right eyes), the format of such a signal differs from the usual two-dimensional one, and not every model is able to work with it. You also need to consider that in order to view 3D content, you need not only a projector, but also a TV (or other playback device) with the appropriate screen capabilities.

This feature requires the projector to have at least one HDMI output (see below). In this case, the video signal source can be either an external device or the projector itself, operating in the format of a media centre (for example, a model with direct playback from USB media).

The ability of the projector to output a video signal in Ultra HD (4K) resolution — 3840x2160. This is the highest resolution used in modern consumer video equipment — 4 times higher than Full HD. However, note that this feature significantly affects the price of the projector, and to view such a video signal, you will need an appropriate screen. Therefore, it makes sense to specifically look for an UltraHD device only if you initially plan to connect it to a screen of the appropriate resolution.

This feature requires the projector to have at least one HDMI output (see below). In this case, the video signal source can be either an external device or the projector itself, operating in the format of a media centre (for example, a model with direct playback from USB media).

The total power rating of the sound projector speakers (including subwoofer, if present).

This parameter is often used to estimate the overall sound volume of the device, but this is not entirely true. The fact is that the actual sound volume is determined mainly by the power of the main speakers of the sound projector, and the total power is the sum of this power and the power of the subwoofer. Therefore, models with the same power rating can vary markedly in actual volume: for example, a 150-watt soundbar with a 50-watt subwoofer will be louder than a 100-watt projector with a subwoofer of the same power, although in both cases the rated power will be equal to 200 watts.

Summing up, we can say that it is possible to evaluate the volume by rated power only if the sound projector is not equipped with a subwoofer — in such models, the rated power is equal to the power of the main speakers. In other cases, it is worth focus on the power of the soundbar and the power of the subwoofer directly stated in the characteristics (see below for both).

The nominal power of the speakers installed directly in the soundbar, excluding the subwoofer (in models with a built-in subwoofer, respectively, only the power of the main speakers is taken into account).

This indicator directly determines the overall volume of the sound projector; It is worth choosing according to this parameter taking into account the specifics of the room in which the projector is planned to be installed: the larger the room and the greater the distance to the viewer, the higher the power should be, otherwise the soundbar will not be able to effectively sound the scene. Detailed recommendations on the optimal power for different situations can be found in special sources.

The audio frequency range supported by the projector's speakers.

When evaluating this parameter, it is worth remembering that the audibility range of the human ear is about 16 – 22,000 Hz (and narrows with age). If the projector's frequency range is narrower, this can result in "cutting" low or high frequencies (however, with a slight narrowing, this effect is almost imperceptible). There are models in which the frequency limit is much wider — however, this is a kind of "side effect" of high-quality acoustics and has no meaning other than advertising.

Also note that a wide frequency range in itself does not guarantee high-quality sound — a lot depends on other parameters of the projector.

Impedance is the projector's resistance to alternating current, or more precisely, to the analog audio signal input from an external power amplifier. Actually, this parameter is of practical importance precisely if the device is planned to be used with an external amplifier. Ideally, the projector's impedance should match the impedance for which the amplifier is designed - otherwise, the volume may either decrease (if the impedance is too high), or distortion, overload, and even damage to the acoustics (if the impedance is too low) may occur.

Higher impedance is also thought to reduce the likelihood of interference. However, modern speakers (including sound projectors) have standard impedance values of 4, 6 or 8 ohms - the difference is not so great that the differences in sound quality are noticeable.

The presence of a built-in subwoofer in the design of the sound projector.

Any subwoofer enhances the bass response, delivering rich bass. Models with a built-in subwoofer are more convenient to install and take up less space, because. no need to look for a separate place for the woofer. On the other hand, the dimensions of this speaker are usually smaller than those of a separate subwoofer (this is due to the limited space in the projector cabinet) — accordingly, the bass is less powerful and richer.

The presence of a wireless subwoofer in the design of the sound projector.

Any subwoofer enhances the bass response, delivering rich bass. The advantage of a wireless subwoofer is the ability to install it almost anywhere in the room without the hassle of laying wires — this makes it easier to adjust the sound to specific conditions. In addition, such subwoofers can have a fairly solid speaker size — 200 mm or more (see below for more details). However note that wireless acoustics require their own power source and significantly affect the cost of the projector.