Comparison Grunhelm GR-904SB vs Grunhelm GR-903SB

The audio format produced by a sound projector is actually the largest number of individual audio channels supported by the device. Note that in this case we are talking about the number of real channels, that is, channels for each of which at least one speaker is allocated; Models that support virtual surround sound can give the listener the impression of more channels than there actually are (see below for more details).

The sound format is indicated by two or three numbers separated by a dot. The first indicates the number of main channels, the second - the number of subwoofers, the third - the number of additional vertical radiators. For example, 2.1 format corresponds to stereo sound (2.0) supplemented by a subwoofer. And the conditional 3.1.2 format includes left, right and center channels, a subwoofer, left and right vertical speakers.

Sound projectors that support a more advanced sound format than 3.1 are designated in our catalog as multi-channel. The classic multichannel audio format is 5.1, but there are other options. In any case, a large number of real channels contributes to the fidelity of the reproduced sound and simplifies setup compared to virtual surround sound systems, but is also more expensive.

The most common sound formats are: 2.0, 2.1, 3.0, 3.1, 4.1, 5.1, 5.1.2, 7.1.

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.

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.

The rated power of the subwoofer included in the design or delivery of the sound projector.

The higher the power, the louder the sub can sound, the richer the bass it can provide. On the other hand, an increase in power inevitably promises an increase in the size and cost of the speaker. Therefore, an overly powerful subwoofer is just as undesirable as one that is too weak. Detailed recommendations for selecting power for the size and acoustic characteristics of a particular room can be found in special sources.

Note that the external subwoofer in soundbars should be approximately twice as powerful as the soundbar in order to prevent sound sags at maximum volume. So, if the total output power of the speaker system is 300 watts, then 100 of them should come from the soundbar alone, and 200 should go directly to the subwoofer.

— 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.

— To the subwoofer. Dedicated output for connecting an external subwoofer. This is usually a line output that only feeds bass — this eliminates the need for external frequency filters. Such a connector is designed to connect an active subwoofer — a passive one will need its own amplifier. Note that this output can be provided in models equipped with their own subwoofer (see above) — in case the capabilities of this subwoofer are not enough.

— RCA. Despite the fact that RCA connectors are used in various interfaces, the term "RCA output" is usually used only for line output with such connectors. This output is used to send an analogue audio signal to an external device; it usually uses the stereo format and consists of two RCA jacks (one for each channel). In sound projectors, the line output can be useful, for example, for connecting additional acoustics.

— 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. This output is used to connect a sound projector to a TV and work as a media centre. 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 (for example, kinescope TVs). Typically this input uses a yellow RCA plug.

— Component. An outpu...t used to send an analogue video signal to an external display. It uses three cables (usually with RCA plugs), each of which carries a different video signal 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 output. An output that allows the sound projector to be used as an external IR receiver for other devices (such as an amplifier or audio receiver). Through this output, the sound projector can transmit received commands from the control panel to the connected equipment. This allows you to install an external device anywhere, even outside the range of the remote control. In addition, this feature is especially useful for some shelf models (see "Installation type"), which, when installed, may cover the IR receiver of the TV. However note that equipment from different manufacturers may be incompatible in terms of control connectors.