With the Signa S4, Polk adds the immersive Dolby Atmos format to the supported formats of its "small" soundbars belonging to the Signa series. The S4 is a soundbar with truly affordable 3.1.2 channels. It is accompanied, of course, by its own wireless subwoofer and an elegant remote control. Dolby Atmos comes in lossless and lossy format through the HDMI (eARC) port. The Signa S4 features 7 drivers (2 tweeters, 2 mid-woofers, 1 full range driver in the center, and 2 mid-woofers on top) and a wireless 5.9" subwoofer. It is designed as a 3.1.2 system, meaning that the drivers are positioned to deliver the following discrete channels: Front Left, Center, Front Right, Front Left Atmos enabled, Front Right Atmos enabled, plus the LFE channel (Subwoofer). Unfortunately, it is not upgradable to 5.1.2 with the addition of surround speakers, as is the case with Polk's larger soundbars (MagniFi, React). It has one HDMI with eARC/ARC, but does not have a full HDMI input. It also has the "classic" inputs for older TV models, Optical In & AUX In. Bluetooth connectivity is also available for wireless streaming from our mobile or TV. Through the HDMI eARC connection, the Signa S4 can reproduce all Dolby standards (Dolby Digital, Dolby Digital Plus, Dolby TrueHD, Dolby TrueHD Atmos, Dolby Digital Plus Atmos), while it does not support any DTS standards. Finally, the optical connection allows us to receive only Dolby Digital (AC-3) and simple stereo signals. However, what is missing in the Signa S4? For some, the first two omissions will be relatively important, while for others they will not. Initially, instead of the dots indicating the level (Volume) or mode, we would prefer to have an LCD/OLED screen with a few characters at least. The second omission that could easily be present is an Android/iOS application for controlling the soundbar. The third omission is the absence of an HDMI input, which is almost insignificant thanks to the presence of the eARC port. A minor detail is the remote control, which we would naturally prefer to be Bluetooth instead of InfraRed, so that we don't have to aim and shoot. For the testing of the Signa S4, we used our HTPC, our carefully designed testing space, our measuring equipment, as well as a second space with a 55" Q70R Samsung TV and an NVIDIA Shield TV Pro. Based on its characteristics, we conducted our measurements and tests at a distance of 1m, but also at 2.8m, which is a "typical distance" for a TV in our living room in our country. Ideally, the maximum distance from the viewing position to this soundbar, in combination with a 55-65" TV, is between 1.67m and 2.2m. This way, we will have the correct "viewing angle" for the size of our TV, and "high" levels from our soundbar without having to strain and result in noticeable distortion. The small-sized subwoofer of the Signa S4 delivers good bass, but from 45Hz and above, we lose a significant range between 20Hz - 45Hz that gives "life" to our action movies. It is certainly more... friendly for those who live in apartment buildings and do not want to disturb their neighbors. The "effects" in movies with Dolby Atmos soundtracks are not intense enough. As with all soundbars with upfiring drivers, their performance depends heavily on the position of the soundbar, the listening position, and the height of our ceiling. With proper placement, the feeling that sounds are coming from above in our space is achieved, of course not at a comparable level with discrete ceiling speakers.
• The absence of surround speakers is evident. The feeling that sound was coming from the sides and behind us was not achieved in any of the scenes we tested.
Despite its weaknesses and shortcomings, it remains a very good choice (if not the top base of capabilities and performance) for the money it asks for.