Soundbar buying guide- specs explained (wattage, channels, frequency range…)

When buying a soundbar to improve your TV’s sound, it’s essential to balance between cost and performance.

However, this can be difficult considering how many features most soundbars are crammed with today.

Some specs may also be misleading to the average consumer, hence the need to better understand the features on soundbar spec sheets to better inform our buying decisions.

Some of these features include;

  • Wattage (sensitivity)
  • Frequency range
  • Number of channels (2.1, 5.1, 7.1, etc)
  • Supported video and audio formats (4k passthrough, DTS-X, Atmos, etc)
  • Connectivity (Bluetooth, HDMI, etc)
  • Dimensions

Soundbar wattage

A soundbar’s wattage is the measure of how much power the soundbar’s in-built amp can supply which in turn affects how loud we perceive a soundbar to be (SPL or sound pressure level).

SPL is a complex topic that is discussed in depth in this guide. But on a basic level, is the measure of sound pressure level (“loudness”) on a logarithmic scale and denoted in Db (decibel).

For some soundbars, it can be difficult if not impossible to find the correct power ratings (wattage) that should preferably be in RMS watts.

When measured correctly, RMS ratings give us a more accurate picture of what a soundbar is capable of.

Granted, the soundbar will have a power rating that should be the number of watts that the drivers can continuously draw from the built-in amplifier without distortion.

Unfortunately, some soundbars have inflated power figures that don’t equate to real-world performance or superior sound quality. This should not be a problem for most listeners but at higher levels (higher volume) the soundbar’s performance may be underwhelming, especially struggling with bass output.

As a general rule of thumb, a surround soundbar with a total power of around 400 watts RMS should properly fill most average-sized rooms with sound.

A more powerful soundbar such as the Nakamichi Shockwave 9.2.4 soundbar will be required for a larger room. Soundbars that can output a total of 200 watts RMS should be great for small rooms.

Consequently, avoid soundbars with PMPO or unclear power ratings.

Do more research on the soundbar’s capabilities and read reviews to see other people’s experiences with the product. Be aware of fake reviews too.

Note: Not all soundbars have built-in amps and those without are known as Passive soundbars. A soundbar with a built-in amp is known as an Active soundbar. Passive soundbars require external amplification for sound reproduction.

This brings me to my next topic “soundbar sensitivity” which is another way to predict how loud a soundbar can get.

What is soundbar sensitivity?

Sensitivity is the measure of how loud (SPL) a soundbar gets with 1 watt of power at 1 meter from the soundbar and is denoted in dB/W/M.

Each time you increase your soundbar’s volume, the wattage is increased increasing the decibel level. However, keep in mind that an SPL increase of 3db will require a doubling of the power output from the amp.

A higher sensitivity rating does not necessarily equate to good sound quality. With that in mind, I would recommend a soundbar with a sensitivity rating of between 85-88dB for a medium-sized room.

Sensitivity rating85 dB/W/M91 dB/W/M
Number of wattsLoudness in decibelsLoudness in decibels
18591
28894
49197
894100
1697103
32100106
64103109
128106112
256109115
512112118
If you are after high listening levels, get a soundbar with a sensitivity rating of 85 decibels or above.

How loud is a soundbar at 85 decibels?

To get an idea of how loud a soundbar is at 85 dB, let’s compare different decibel levels to some real-world examples.

Decibel levelLoudness level (real-world examples)
10dBNormal breathing or rustling leaves
30dBWhisper
40dBLight rain or refrigerator hum
50dBQuiet office
60dBNormal conversation
70dBToilet flushing or dishwasher
80dBA leaf blower or heavy traffic
90dBWelder
100dBHandheld drill
120dBSiren
130dBLive rock band
140dBFireworks
160dBShotgun blast
180dBRocker blast
Decibel levels vs real-world examples

Frequency range

A soundbar’s frequency range is a measure of how wide a soundbar can play on the frequency spectrum.

Ideally, a soundbar should have a frequency range of between 20 Hz and 20 kHz (20,000 Hz) which is within the range of human hearing. However, this would require a dedicated subwoofer capable of reaching as low as 20 Hz.

  • 20 Hertz to 80 Hertz represents the sub-bass frequencies usually reproduced by a sub-woofer.
  • 80 Hertz to 200 Hertz represents the upper-bass frequencies usually reproduced by a woofer
  • 200 Hertz to 2,000 Hertz (2kHz) represents the mid-range frequencies (mids). Reproduced by mid-range speakers or woofers.
  • 2,000 Hertz (2kHz) to 20,000 Hertz (20kHz) represents the high frequencies (highs/treble). Reproduced by the tweeters.

Most soundbars will have mid-sized woofers plus a subwoofer to play the full audible frequency range. Some may also have tweeters or small woofers for the highs/trebles.

Other soundbars such as the Sennheiser Ambeo may not come with a dedicated sub but have an LFE output that allows you to add your sub for additional “Oomph” to your sound.

Soundbar channels

Contrary to popular belief, channels are not the number of “speakers” (drivers) in a soundbar. In actuality, a channel is an independent audio signal path (circuitry) that can be reproduced by one or multiple soundbar drivers (“speakers“).

Most soundbars on the market today will have at least 2 channels (stereo) and an additional LFE channel for the sub for a 2.1 system. Other common “soundbar channel types” are 5.1, 5.1.2, and 7.1.2.

A 5.1 channel soundbar will have 3 front audio channels (left, center, and right), 2 surround channels (right and left surround), and one subwoofer channel. When you add 2 height channels to a 5.1 soundbar you end up with a 5.1.2 soundbar.

The height elements can be reproduced by height speakers or up-firing speakers mounted on the soundbar. Height elements are used to convey the feeling of a 3D sound space with formats such as Dolby Atmos and DTS-X.

Alternatively, a 7.1.2 channel soundbar will be akin to a 5.1.2 soundbar but with two extra rare channel speakers. A great example would be the Sony HT-A7000.

Some soundbar systems may also have 4 height channels for more immersion.

Soundbar audio and video formats

4k passthrough soundbar explained

Not many soundbars will be capable of processing video signals before transmission to a TV but a good number will have support for 4k passthrough over HDMI.

4k passthrough is a feature on some soundbars that allows for high-bandwidth 4k content to pass through from the source to the soundbar and reach the display unprocessed over an HDMI chain. Thus, the 4k video signals exit the soundbar as they entered.

But to stay up to date with everything tech, get a soundbar with support for 4k and HDR 10/Dolby Vision pass such as the Vizio Elevate 5.1.4 soundbar.

However, video support is not a necessity on a soundbar as you could easily connect your video sources to your TV and send the audio signals to your soundbar.

Soundbar audio formats explained

Most soundbars on the market today will have support for the following audio formats;

  • Dolby Atmos and DTS-X are object-based sound formats and are not channel-based. By being object-based formats, they enhance a sense of space and make objects feel like they are moving around us. These sound formats should be supported by soundbars with Atmos and/or DTS-X processors.
  • Dolby True HD and DTS HD and two similar lossless surround sound audio formats that will mainly be supported by some surround sound soundbars.
  • PCM and LPCM are uncompressed sound formats. However, PCM is a stereo audio format (2.1 channel) while LPCM is a surround sound format.
  • Dolby Digital (DD) and Dolby Digital Plus (DD+) are surround sound formats supported by some soundbars. DD is a 5.1 channel format while DD+ is a 7.1 channel format.

Your ideal soundbar may not have support for all these audio formats but I recommend one that supports Dolby Atmos and at least 2 other options such as PCM and DTS-X or Dolby Digital Plus and DTS-X. But to learn more about these surround sound formats visit this guide.

Connectivity

Signals to and from a soundbar can be transmitted either wirelessly or through wired connections.

Wireless connections

  • Bluetooth is mainly used to connect a soundbar to a Bluetooth source (phone, tablet, PC, etc.). What’s more, it can also be used to connect the soundbar to a supported wireless sub.
  • Wi-Fi is a wireless connection that can be used to transmit signals to a soundbar or from a soundbar to other speakers in a surround or multi-room setup.
  • Airplay– A Soundbar with support for Airplay will allow you to send audio signals from an Apple device to the soundbar.
  • Chromecast– Soundbars with Chromecast built-in will allow you to connect a source to the soundbar for audio playback.

Wired Soundbar Connections

  • HDMI– Most mid-range and high-end soundbars will have HDMI sockets as input and/or outputs. Some HDMI sockets will support ARC and eARC (Audio Return Channel and enhanced Audio Return Channel). Support for ARC/eARC will allow you to use your TV as the source for the transmission of audio signals to and from the soundbar.
  • An Optical connection will allow transmission of audio signals of up to 8 channels (7.1 surround sound) but cannot support 3D formats such as Atmos.
  • A USB connection will mainly be used for firmware updates which are increasingly being done as software updates. However, it can also be used as media playback on some soundbars.
  • Analog 3.5/Auxilliary (AUX) -This 3.5 mm analog connection, transmits analog audio signals to the soundbar from a variety of sources.

Soundbar Dimensions

The dimensions on a soundbar’s spec sheet are usually written as H*W*D (Height, width, depth). Height is how tall the soundbar is, width is its length while depth is the distance between the front and rear of the soundbar.

Soundbars come in different sizes from 12 inches long to 60 inches long. In most cases, bigger soundbars will have bigger drivers that can reach higher levels with ease but bigger is not always better.

You will need to consider placement and your Tv’s size before deciding which soundbar size is right for you.

Ideally, the soundbars should be around 2/3 the length of the TV for aesthetics. Although this is not an established rule, the soundbar should not be longer than your TV.

Also, consider where your TV’s IR receiver (remote receiver) is located to avoid buying a soundbar that will block the TV’s remote signals if it is placed on platforms such as a credenza or any other stand. This should not be a problem if your TV is mounted.

To sum up

It’s impossible to judge the quality of a soundbar based on the specs alone but it’s crucial to understand some terminologies that you may encounter.

If you are buying your soundbar from a physical store, I would recommend listening to different soundbars to judge by ear. However, if you are shopping online, read and watch different reviews to get an idea of what to expect.