Our Soundbar Sound Tests

Surround 5.1

While many soundbars support surround content, not all of them reproduce that content in the same way. Localization describes how the soundbar is setup to playback surround content. Depending on the localization, the soundbar may offer a more immersive listening experience, and it may be able to more accurately localize objects like voices within the soundstage.

Ideally, your soundbar comes with dedicated or discrete surround channels - this is a "true" surround setup, and it provides the most realistic representation of sound. Other soundbars on the market use a "phantom" surround sound, in which side-firing speakers on the bar bounce sound off the walls to mimic the effect of dedicated surround speakers. However, in practice, phantom setups don't sound as clear or real as a discrete setup, and surround objects won't be as accurately localized within the sound image.

It's also possible that your soundbar has to downmix surround files into stereo to play it. Naturally, the result isn't as impressive as what you get with a discrete setup. With only the left and right stereo channels available, the bar plays content intended for both the left surround and left stereo from the left stereo channel. The same phenomenon occurs with the right channels. With more content forced into fewer speakers, the bar can't mimic an accurate placement of surround objects in the soundstage. For example, on screen, you'll see a car racing past from your left. In actuality, though, the sound just seems like it's coming from a speaker placed in front of you.

When looking for a soundbar, you're more likely to come across a 5.1 setup. However, some soundbars come with two additional rear speakers designed to support 7.1 content. A 7.1 configuration helps create a more immersive listening experience through the addition of two more surround channels, which can add more depth to your sound. It's especially useful if you have a larger living room and you're looking for a soundbar that can fill the entire space with sound without any holes in the soundstage. Some content's designed for 7.1 configurations, and while they're rare, they include certain video games and movies on streaming services.

That said, a 7.1 setup isn't necessarily better than a 5.1 setup. In a smaller living room, adding extra speakers can overwhelm the front channels with the audio that's mixed onto the surround channels. As a result, some effects seem louder than others, and you struggle to hear dialogue clearly. Ultimately, the best choice for you depends on the unique characteristics of your living space.

Only a few of the soundbars we've tested offer 7.1 rears, including the Samsung HW-Q950T and the Nakamichi Shockwafe Ultra 9.2Ch.

As part of our surround 5.1 tests, we measure the frequency response of the surround channels. With the bar calibrated at 80 dB, we play a sine wave tone between 20 Hz and 20 kHz and plot its output, in dB, on a frequency response graph. From the graph, we can see how accurately the soundbar reproduces the wide range of frequencies found in audio content, from the low-bass to the high-treble.

Ultimately, the slope of the frequency response graph shows the overall tonal balance of the soundbar's sound profile. A negative slope means that the bar reproduces more bass than treble, so it sounds thumpy, punchy, and boomy. A positive slope means that there's more treble than bass, which results in a sound that's bright, sparkling, or even piercing. A slope closer to zero represents a balanced sound overall.

As with our stereo frequency response tests, we don't score the slope of the surround channels' frequency response. Your personal preferences shape which tonal balance is ideal for you. For example, a balanced sound is suitable for most audio content, while a bass-heavy sound adds more thump and punch to help you feel the rumble in bass-heavy music and action-packed movie scenes.

Standard error is a measurement that shows the average deviation of the soundbar's in-room frequency response from the in-room target response. It can help you see how accurately the soundbar can reproduce audio at different frequencies, from the low bass to the high treble. Most surround content contains a wide range of frequencies, from the thumpy bass in action-packed scenes to the dialogue in the mid-range to the higher-pitched voices in the treble range.

For our tests, we use the Harman in-room response curve as our target. The Harman curve is the result of research that found the frequency response that sounds the most pleasing to most listeners, and it adds a little extra emphasis in the bass and a little less emphasis in the treble. It's ideal to find a soundbar with a low amount of standard error since this tends to represent a cleaner, more even sound that's closer to the target curve.

The Sony HT-S100F has a standard error of 8.55 dB on its surround channels. It struggles to reproduce bass, voices are pushed towards the back of the mix, and higher frequencies are piercing and bright.

The Sonos Arc with Sub + One SL Speakers has a standard error of 2.06 dB on its surround channels, resulting in an even, neutral sound profile.

Usually, you can see which soundbars have a higher amount of standard error just by looking at the graph. If the frequency response fluctuates a lot, it probably has a higher standard error. If it's mostly flat and close to the middle, it probably has a lower amount of standard error.

Also, these fluctuations in the graph can give you a better idea of how the soundbar reproduces audio content at each frequency. For example, deviations in the bass range determine the amount of thump and punch reproduced by the soundbar, important for feeling the deep rumble in action-packed scenes. Voices reproduce in the mid-range, so fluctuations here make them sound muddy or push them to the back of the mix. Higher frequencies like S and T sounds reproduce in the treble range, so deviations here make them sound either piercing or dull.

Love to crank up the volume? This test is for you. It measures the soundbar's Sound Pressure Level @ Max Volume in decibels (dB) using a microphone array. Essentially, this measurement shows how loud the soundbar can get when you push it to its maximum volume.

In a traditional living room, a volume of 80 dB is more than enough to fill the room with sound. However, some bars get louder than that, and they're ideal for filling up large spaces with sound.

We consider a good value to be above 92 dB SPL since this gives you a lot of flexibility in selecting the volume for your audio content. While most of the bars we've tested score between 80 and 100 dB SPL, some can get even louder on their surround channels, like the Samsung HW-Q90R, which reaches 123 dB SPL on its surround channels.

 Total harmonic distortion, or THD, is a measurement that shows the number of unwanted frequencies that the soundbar reproduces alongside the intended frequencies. Essentially, it compares the audio input (the video game or movie you're listening to) with the soundbar's output to see if the audio reproduces the way it was intended by whoever mixed it.

We calibrate the soundbar to 80 dB SPL using an SPL meter, which is considered a "normal" listening volume. Basically, a soundbar set to 80 dB gets loud enough to fill an average living room space with sound. 

Then, we apply a spectrally pure sine wave and use the microphone array to measure the output. By comparing the input to the output, we can determine the amount of distortion produced by the soundbar. Our results add more weight to higher frequencies since you're more likely to perceive distortion at those frequencies. THD is difficult to hear with real-life content, so it's really only important for listeners who care about the fidelity of audio reproduction.

While 80 dB is considered a "normal" listening volume, it isn't suitable for everyone. For example, if you want to fill up a really large space with sound, you'll want a bar that lets you crank up the volume.

However, as volume increases, the amount of total harmonic distortion, or THD, tends to increase. This test is designed to see if the soundbar maintains clean and pure audio reproduction when the bar is pushed to its maximum volume. We measure the amount of THD on the surround channels at max volume. Again, we apply a spectrally pure sine wave and compare the soundbar's output with the input to determine the amount of distortion.