Comparison Polk Audio Signa S2 vs Polk Audio Signa S1

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 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).

A decoder can be broadly described as a standard in which digital audio (often multi-channel) is recorded. For normal playback of such sound, it is necessary that the corresponding decoder is supported by the device. The first signs of multi-channel decoding were Dolby Digital and DTS, gradually improving and introducing new features. The final stage for 2020 is Dolby Atmos and DTS X decoders.

Dolby Atmos. A decoder that does not use a rigid distribution of sound across channels, but the processing of audio objects, due to which it can be used with almost any number of channels on a reproducing system - the sound will be divided between channels so that each audio object is heard as close as possible to its proper place. When using Dolby Atmos, in-ceiling speakers (or speakers facing the ceiling) are highly desirable. However, in extreme cases, you can do without them.

— DTS X. An analogue of the Dolby Atmos described above, when the sound is distributed not through individual channels, but through audio objects. The digital signal contains information about where (according to the director's intention) the object audible to the user should be and how it should move, and the processor of the reproducing device processes this information and determines exactly how the sound should be distributed over the available channels in order to achieve the required localization. Thanks to this, D...TS X is not tied to a specific number of audio channels - there can be as many as you like, the system will automatically divide the sound into them, achieving the desired sound. Also note that this decoder allows you to separately adjust the volume of dialogues. A separate variant of DTS X is the DTS Virtual:X decoder for providing surround sound without the use of additional upward speakers on the soundbar. You can rely on just two channels and a separate subwoofer to achieve the desired DTS Virtual:X effect. A separate variation of DTS X is the DTS Virtual:X decoder to provide surround sound without the need for additional upward-firing speakers on the soundbar. DTS Virtual:X can rely on just two channels and a separate subwoofer to achieve the desired effect.

— IMAX Enhanced. The IMAX Enhanced Mark of Conformity is awarded to equipment that meets the audio certification requirements of IMAX Corporation. Combined with DTS audio technology to deliver signature IMAX theater-like sound in the home. The most accurate reproduction of such audio is possible in systems with a large number of channels (5.1 or more). Note that for a fully immersive experience, IMAX Enhanced certification must also apply to video equipment for playing content (TV, projector, etc.).

— USB A. In this case, we mean a USB connector that allows you to connect external drives (flash drives, hard drives) to the projector and play content directly from them. At the same time, models with video outputs (see below) can often work as a media centre, outputting the video signal to a TV or other external display.

— mini-Jack (3.5 mm). By itself, the 3.5 mm plug can be used in different types of interfaces; in this case, it means a linear audio input with a mini-Jack socket. This input is mainly used to connect portable audio equipment (players, smartphones) to the sound projector.

— RCA. Technically, RCA (colloquially "tulip") is a type of connector that can be used in different interfaces. However, the term "RCA input" is used to refer only to line inputs for connecting an analogue signal in stereo format. Note that this input consists of two sockets for RCA cables, because. Only one channel of sound can be transmitted through one cable.

— Optical. Connector for digital audio signal connection via TOSLINK fibre optic cable. This interface allows for multi-channel audio transmission and is virtually immune to electrical interference; its disadvantage is the fragility of the cable.

— Coaxial S / P-DIF. A connector for connecting a digital audio signal via an elect...rical cable with an RCA connector (not to be confused with linear RCA, described above). Similar to the optical input described above, in particular, the ability to transmit multi-channel audio through a single connector. At the same time, a coaxial cable, on the one hand, is not so delicate, and on the other hand, it is sensitive to electrical interference (therefore, it is advisable to use a special shielded wire for such a connection).

— Composite. In this case, we do not mean a full-format composite interface of three connectors that allows you to transmit audio and video signals, but only one connector for working with video. And since sound projectors don't display images, the composite input is used to send video through the projector to another device, such as a TV. The composite video interface does not allow working with HD and is not of high quality; on the other hand, it is widespread and can even be used to work with frankly outdated video equipment. Typically this input uses a yellow RCA plug.

— Component. An input designed to receive an analogue video signal for further transmission to another device — a TV, video projector, etc. This connection typically uses three RCA connectors, each carrying a different video component (hence the name). Due to this, the component interface has good bandwidth and picture quality, it allows you to work with HD and is considered the most advanced modern analogue video standard.

— IR control input. Connector for connecting an external infrared remote control receiver. When properly placed, such a receiver will allow you to use the remote control even in places where the signal from the remote control cannot reach the main (built-in) sensor — for example, in another room. Note that the role of the receiver can be played not only by a specialized device, but also by another component of the audio system — for example, an amplifier with an IR control output.

The number of HDMI inputs in the design of the sound projector.

HDMI is the most popular modern interface for working with HD content, it allows you to transmit high-definition video simultaneously with multi-channel audio over a single cable. Having multiple inputs allows you to keep multiple signal sources connected to the projector at the same time and select the source from the remote without fiddling with reconnecting wires.

The diameter of the woofers (or combined woofers, in two-way systems) of the speakers installed in the sound projector. For speakers in this range, large size is especially important - it is the cones of large diameter that work best at low frequencies, while providing good power. It is believed that for a head operating in the subwoofer format, a size of at least 200 mm is desirable. But the low-frequency speakers of the general range can be relatively small.