onyx studio 4 wireless portable speaker

Harman Kardon Onyx Studio 4 Review

Nowadays, the convenience brought by wireless technology makes many consumers prefer products with wireless transmission technology when making purchasing decisions. Especially wireless speakers have the convenience and easy-to-handle features, making more and more people abandon the traditional wired speaker system and choose it. And Harman Kardon Onyx Studio 4 is one of the wireless choices.

Harman Kardon has designed many classic products in the past that have attracted the attention of consumers when it comes to wireless speakers. Harman Kardon Onyx Studio 4 is introduced this time. It is an upgrade from Harman Kardon’s classic ONYX studio product lines.

You can find reviews on Onyx Studio 5, Onyx Studio 6, and Onyx Studio 7 here.

Harman Kardon Onyx Studio 4 Wireless Bluetooth Speaker

Audiophiles who usually pay attention to Harman Kardon speakers should not be unfamiliar with its ONYX STUDIO series of Bluetooth speakers. ONYX STUDIO Bluetooth speakers have a unique spherical appearance design, excellent acoustic structure, and surging bass sound effects.


Harman Kardon Onyx Studio 4 continues the design of previous generations of products. At first glance, it looks almost indistinguishable from the previous models. However, the new generation of ONYX STUDIO 4 has brought improvements and upgrades in terms of functions, battery life, and Bluetooth features.

onyx studio 4 speaker

Main Features of ONYX STUDIO 4

  • Bluetooth 4.2 protocol;
  • 8 hours battery life;
  • Voice integration (one-click quick access to Siri or Google Now);60W output power;
  • Wireless Bluetooth streaming, two smart devices can be connected at the same time;
  • Noise and echo cancellation function to achieve extremely clear calls;

The unique shape of ONYX STUDIO 4 reminds me of the universe and the planets at first glance. Although the two small stands on the speaker’s back support the speakers, the visual effects make ONYX STUDIO 4 looks more like a UFO, in my personal opinion.

onyx studio 4 bluetooth speaker

The box of ONYX STUDIO 4 has a certain angle of inclination, which facilitates the spread of sound. In addition, the speaker also uses rubber at the bottom of the feet to improve the overall shock-absorbing ability.

The speaker’s front does not have too many decorative elements, only the Harman/Kardon Logo in the center, which looks very simple and generous.

In terms of color, Harman Kardon ONYX STUDIO 4 has three finishes, black, white, and blue, for consumers to choose from.

harman kardon onyx studio 4

The front of this speaker is covered by a fabric grille, which can prevent dust and dirt. At the same time, the smooth and delicate fabric material is also easy to clean.

If the speaker’s surface is dirty, you can just wipe it with a wet tissue. Harman Kardon Onyx Studio 4 is equipped with six buttons made of soft plastic material on the speaker’s top. In fact, the edge of the speaker is also made of soft plastic material. The buttons are on/off, one-touch call, volume +, volume -, HK series, and Bluetooth pairing key. And the buttons are soft and flexible, making the operation feel excellent.

At the center of the back of the speaker is a passive radiator. The vibration of this passive woofer can be seen when music is playing, and it also indicates the intense bass of this speaker.

harman kardon onyx studio 4 wireless portable speaker

There is also a groove on the back of the speaker near the bottom. That is where three interfaces land. They are the power input interface (19V/2A), AUX audio input interface (3.5mm), and a Micro USB interface for future firmware upgrades.

It is worth mentioning that ONYX STUDIO 4 also has a built-in 3000mAh lithium battery and can provide up to 8 hours of battery life at standard volume output. So this speaker can also be used outdoor.

Harman Kardon Onyx Studio 4 uses the Bluetooth 4.2 version, supporting Bluetooth wireless music streaming and up to 2 smart devices to connect at the same time to play music in turn.

harman kardon onyx studio 4 speaker

In addition, when necessary, you can also play the music through the 3.5mm AUX input with an audio cable.

Press the Bluetooth pairing button on the top of the speaker, you can hear the corresponding startup sound, and onyx studio 4 enters the pairing mode. At this time, you can search and connect the speaker via mobile phone or other Bluetooth devices.

Compared with the previous generation products, ONYX STUDIO 4 has a new function: HK Connect+. If you have two or more ONYX STUDIO 4 Bluetooth speakers, or you want to build a stereo system or multi-channel system, you can download the “HK Connect” APP to set up the speakers. For example, you can set the left and right channels for two ONYX STUDIO 4.

Harman Kardon Onyx Studio 4 Review

In the Bluetooth connection with the mobile phone, the user can also quickly wake up the voice assistant, such as Siri, Google Now, through the call button on the top of the speaker. These new features can be said to make ONYX STUDIO 4 more functionally versatile.

For the driver unit, ONYX STUDIO 4 continues the design of the previous generation of products. It is equipped with four independent speakers, 2 20mm tweeters + 2 75mm woofers, and one passive radiator on the back of the speaker.

At the same time, the speaker adopts a dual-channel power amplifier design, and its rated power can reach 60W under AC power supply and 30W under the battery power supply.

harman kardon onyx studio 4 bluetooth speaker

Sound Performance

In terms of sound quality, ONYX STUDIO 4 continues the style of the previous generation of products.
The overall feeling is very shocking, and the sound is warm and strong, which is very suitable for listening to pop, rock, hip-hop, and other styles of music.

Thanks to 2 independent tweeters and two woofers, ONYX STUDIO 4 has a good degree of separation between high, mid, and low frequencies.

The sound has a distinct sense of hierarchy. As a result, Harman Kardon Onyx Studio 4 can fully meet the listening needs of the living room and bedroom environment.

Onyx Studio 4 Wireless Bluetooth Speaker

Onyx Studio 4’s high-frequency features are mainly characterized by delicate, soft, transparent sound, and high resolution. When listening to popular music, the energy of this pair of tweeters is enough.

If you are a high-frequency loving enthusiast, remove the speaker’s grille, the treble details will be richer, the penetrating power will be more substantial.

The midrange has a thickness, and the vocals are full. The midrange performance of the 3-inch unit is satisfactory, without too many adjectives to describe it.

onyx studio 4

Besides, this pair of mid-woofers looks like a paper cone speaker at first. But if you carefully observe the basin’s surface, you can find many very tiny fiber filaments, which are more delicate than the wool basin. So it should be a new type of composite material.

The low-frequency characteristics of this speaker are powerful, sinking, and stable. Mainly due to the low-frequency radiators.

Generally speaking, a 3-inch mid-woofer speaker cannot have such an extensive dynamic range. Only through the designer’s ingenious design and the use of passive speakers in a closed box can the bass be enhanced.

onyx studio 4 bluetooth speaker

The depth of the dive creates a sense of shock. However, compared to the 4-inch 5-inch woofer, it is not inferior, and the transient response speed is also timely. Listening to Onyx Studio4, it is like it has the effect of a small subwoofer.

Pros and Cons

  • Stereo design, using two-frequency output at the same time, four sound units plus two resonators;
  • The midrange is full. The low frequency is sufficient. The high frequency is slightly not enough, not irritating. The treble will increase after removing the grille.
  • Although this speaker is positioned as a portable speaker, its quality is the same as that of desktop speakers.
  • The unique shape is decorated at home with novelty, solid structure, and long battery life.
  • I found that Onyx Studio4 has other colors, which can be purchased according to personal preference.
  • The built-in battery has a relatively large capacity.
  • The size is relatively large, and it is not convenient to go out with.
onyx studio 4 driver


As the fourth-generation product of the ONYX STUDIO series, although Harman Kardon Onyx Studio 4 does not bring much innovation in terms of design and internal structure, it has brought improvements in terms of function extension, battery life, and Bluetooth features.

onyx studio 4

The rated output power has reached a staggering 60W so that this small Bluetooth speaker can burst out surging and shocking sound effects.

If you need a Bluetooth speaker with a stylish appearance, easy-to-use functions, and powerful sound, this ONYX STUDIO 4 by Harman Kardon may be your good choice.

Harman Kardon Onyx Studio 4 Specifications

  • Support: A2DP 1.3, AVRCP 1.6, HFP 1.6
  • Transducers: Woofer 2 x 75mm, Tweeter 2 x 20mm
  • Rated Power: 4 x 15W (AC mode); 4 x 7.5W (Battery mode)
  • Frequency response: 50Hz – 20kHz (-6dB)
  • Signal to noise ratio: 80dB A-weighted
  • Weight: 2061g
  • Power supply: 19V/2A
  • Battery type: 3.7V/3000mAh Lithium-ion
  • Battery charge time: 5 hours
  • Music playtime: up to 8 hours (Varies by volume level and music content)
  • Bluetooth version: 4.2Yes
  • Bluetooth transmitter power: 0 – 9dBm
  • Bluetooth transmitter frequency range: 2402MHz – 2480MHz
  • Bluetooth transmitter modulation: GFSK, π/4 DQPSK, 8DPSK
  • Dimension (H x W x D): 260mm x 278mm x 159.5mm