Comparison Denon DHT-S218 vs Denon DHT-S217

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).

HDMI interface version supported by the soundbar.

See the interface itself for more details (“HDMI input”, “HDMI output”), and its versions differ primarily in bandwidth. Here are the current options:

— v 1.4. The earliest of the widespread versions, which, nevertheless, has quite decent features: in particular, it supports 4096x2160 video at 24 fps, and in Full HD the frame rate can reach 120 fps, which already allows you to work with 3D. It has two modifications — v.1.4a and v.1.4b — differing from the original mainly in slightly advanced capabilities for working with three-dimensional content.

-v 2.0. The version introduced back in 2013. The increased bandwidth allowed support for 4K video at frame rates up to 60 fps, as well as up to 32 channels of audio and up to 4 audio streams simultaneously. This version also has two extensions: HDR support was added in the v.2.0a update, and this feature was improved and expanded in v.2.0b.

— v 2.1. An update to the HDMI standard released in 2017. Of the main innovations, support for 8K and 10K video at speeds up to 120 fps has been added, and HDR capabilities have been improved. However it is worth considering that all these features are available only when using special HDMI Ultra High Speed cables.

The diameter of the tweeters ("tweeters") installed in the sound projector. The larger the speaker diameter, the higher its power can be, but the lower the operating range. Therefore, tweeters, usually, are small in size, and the required power can be provided by their total number (see above).

The diameter of the midrange drivers installed in the sound projector. An increase in the diameter of the speaker has a positive effect on its power (due to an increase in the usable area) and reduces the operating frequency range. Therefore, midrange heads can be noticeably larger than tweeters (see above). More detailed data on the diameter of the speakers can be found in special sources.

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.

The ability to control the soundbar, in addition to the standard push-button from the device case, also includes control from the remote control, the TV remote control to which the acoustics are connected, through the application from a smartphone or tablet, and in some cases using a voice assistant. More details about each of them:

— Remote control. The presence in the configuration of the classic remote control on IR sensors, like those used in TVs. It can contain much more settings functions than the controls on the body of the device and, of course, makes it easier to control the soundbar.

— TV remote control (HDMI-CEC). Connecting the soundbar via the HDMI port allows you to control it via the HDMI-CEC protocol via the TV remote control. This solution will reduce the number of remotes in the room and facilitate the comfort of the settings. However, the functionality of the "non-native" remote control may be limited. In this case, the compatibility of the TV and the soundbar can be achieved using other protocols (not necessarily HDMI-CEC).

— Smartphone control. The ability to control the soundbar through the application. This makes it easier to “search” for the remote control, because the phone is always at hand. The application also has extensive settings and such control is highly likely to be supported by t...he TV, which allows you to execute absolutely any commands from your smartphone for a comfortable pastime on the TV.

— Voice assistant. This is not about the assistant built into the soundbar itself, but about compatibility with external devices that have this function (for example, with a smartphone or tablet). But even such compatibility allows you to give commands to the voice projector by voice — this is often more convenient than more traditional control methods. The specific set of supported commands and languages may vary depending on the voice assistant and its specific version. And among the most popular at the moment are Google Assistant, Apple Siri, Amazon Alexa.

Soundbars made in a curved case.

From the point of view of acoustics, this shape does not provide any noticeable advantages over the traditional straight line. Therefore, it is mainly used in soundbars designed for curved TVs — so that the TV and the sound projector are optimally compatible with each other in shape. And since the diagonal and curvature of the screen can be different, devices in curved cases are often designed for a specific line of TVs or even for strictly defined models. So before buying a similar model, you need to pay special attention to compatibility.