A review of the Kitsound Boombar (KSBOO30) for listening to shortwave recordings

Hei,

Today I will be looking at and reviewing the Kitsound Boombar Bluetooth speaker and analysing how it performs for playing back shortwave recordings … Spoiler: It’s terrible!

Look and Feel

The Kitsound Boombar has a modern slick look to it with a well moulded metal speaker grill, rubberised top buttons with little holes for the indicator lights and a solid plastic back where the USB C charging port and bass reflector reside.

Internals

After disassembling the speaker with great effort I was pleased to find that the battery and speakers use a socketed design. This makes servicing and repairs easier to perform!

The chips I could identify used in this speaker are the Bluetooth chip, a JL AS20BP03007-55F4, The Battery chip, a TP4056 and the amplifier chip a HT8699R.

Performance

And this is where all the good parts to this speaker fall apart. As you can see from the images between the input and speaker output, there is a high level of audio distortion coming from these speakers! Notice how loud the distortion is at about 7-10KHz, an area where hearing is very sensitive at most ages. Please ignore the ~12Khz tone, it’s a bug!

After doing some research I found that the HT8699R has a THD of up to 10% which is crazy. No wonder it’s so distorted!

To try and combat this unpleasant sound, I wired the speakers directly to my USB powered TDA7297 amplifier and the noise did greatly reduce.
However, compared to my main Pioneer speakers connected to the exact same amplifier setup powered from the same laptop USB socket, you’ll instantly see that the distortion remains on the Kitsound speakers indicating that the speakers themselves are responsible for some of the distortion!

On a positive note, the battery performs great as does the Bluetooth connection.

Sound

We now know that this speaker creates lots of distortion and in controlled experimental tests it sounds terrible but what about the real world? Are these issues really noticeable when listening to music or just a technical imperfection?

Here is a side by side demo of raw audio files and what the speaker outputs:

While the distortions is acceptable for most songs, but not all songs, while listening to something that is more narrow band, such as AM radio, this speaker has unacceptable levels of distortion and is useless and unpleasant to listen to.

The general sound quality is bright but also a bit dull and there is also a lack of bass which can be heard on the clips.
_{The microphone for this clip is a Razer Sieren X and it seems to have reduced the highs the Kitsound outputs.}

Final Thoughts

This speaker has good build quality, USB C charging, good battery life and Bluetooth but is sadly heavily let down by the high levels of distortion the speakers are producing. I can’t recommend this speaker to anyone who wants to listen to any narrowband content on it.

Rating:

• Look and Feel (10% weight): 4/5 – It looks good and feels sturdy.
• Internals (10% weight): 5/5 – The speakers and battery are socketed to the main board for easy modification and repair.
• Performance (20% weight): 1/5 – The high levels of distortion from the speaker unit and amplifier chip combining is unredeemable.
• Sound (60% weight): 2/5 – High levels of distortion emphasised at 7-10KHz which are noticeable on some tracks and all AM reception recordings combined with a lack of bass and a dull sound lead to an unpleasant mediocre sound experience

Overall: 46% – Good construction, connectivity and battery are let down by the lacking sound quality.