Hidisz H2 English Review


The Little Big Bluetooth Receiver




Construction and Design




  • Very small size and weight.
  • Bluetooth codecs.
  • Connectivity capability.
  • Very simple, effective and faultless use. Great performance.
  • Surprising sound for its specifications.
  • Maximum volume reproduction free of distortion.




  • Limited power and signal-to-noise ratio


Purchase Link






The H2 is Hidizs’ answer to one of the most versatile products of the year. It is a DAC/Amp Bluetooth receiver, capable of being controlled by a APP. In this occasion the famous brand founded in 2009, breaks the deck with an unbeatable small size. Furthermore, it integrates NFC for easy pairing, microphone, 3 control buttons, a multicolor LED, Bluetooth 5.0 and the best Bluetooth codecs. It all looks very good, doesn’t it? Yes, even its pre-sale price is. What else does this small device hide? Well, we’ll see about that later.





  • Bluetooth chip: Qualcomm CSR8675.
  • Amplification chip: MAX97220.
  • Bluetooth Codecs: UAT, APTX-HD, APTX, APTX-LL, LDAC, AAC, SBC, CVC.
  • Multicolour LED.
  • Pairing via NFC One-Touch.
  • USB DAC compatible with Android, Windows, Mac OS, iPad OS.
  • USB type C.
  • Dedicated power, pairing, play and pause button.
  • Dedicated dual button for Volume + and -/Previous Track/Next Track.
  • SE 3.5mm output.
  • Handsfree / Microphone support.
  • Transmission distance: Approx. 10m (in open area). Within 4m for UAT & LDAC.
  • Battery capacity 160mAh.
  • Battery life 7h.
  • Charging time 1.5h.
  • Nominal output power 8mW+8mW@32Ω.
  • Frequency response 20Hz-90Khz.
  • Total harmonic distortion + Noise 0.008% (1kHz).
  • Signal to noise ratio 92dB.
  • Crosstalk: 68dB (@32Ω).
  • Recommended headphone resistance range 8-60Ω.
  • Net weight 12G.



Packaging, Content, Construction and Design


The Hidizs H2 comes in a smooth, matt, black cardboard box, measuring 108x108x52mm. It is covered with protective transparent cellophane. On the top, the H2 is drawn with its outlines, in a darker engraving. In the corners there is the brand, model and other logos, in silver holographic ink. On the back, the features are specified, in Chinese and English, with the same silver ink. It does not look like the box of something so small and after removing it, the surprise is consumed. The H2 comes packed in cellophane and a cloth band allows it to be unwrapped from the protective mould. Under it, a cardboard cover that, after being lifted, shows the rest of the accessories. In short:


  • H2.
  • USB type-C to USB cable.
  • Translucent plastic case with rear clip.
  • User’s manual.
  • Warranty card.
  • USB Type-C to Type-C cable


A cloth bag is missing to protect it from scratches or blows. Although the content is correct. The protective casing with clip is suitable and very useful for using the H2 as a hands-free device. The type-C to type-C USB cable is somewhat rigid and when bent has taken on that shape.

The body material is made of Makrolon resin from Germany. It is available in black or white. The device feels hard and compact, without creaking or gaps, very solid. Its weight is derisory, only 12g, as are its dimensions: 32x32x10mm. On the main side there is the brand logo, its name and the model. Below, the description of the device and, finally, the full name of the brand. On the back side, only the NFC logo, at the bottom. On the upper edge, on the left, is the 3.5mm SE output. In the centre, a hole in which the microphone is supposed to be located. These are two Qualcomm cVc microphones of the eighth generation in noise cancellation technology. It has a wide bandwidth to provide high quality voice calls in HD. At the left edge, in the centre, there is a round, multi-function button (On/Off). Underneath it, the multicoloured LED. On the right-hand edge there is a double button (+ and -), with a bulge on top, to identify the positive side. On the lower side, near the left corner, is the USB type C port.

The casing is adapted to the main face, held by clips to the rear face, leaving all controls free. It includes the hole to release the microphone. It has a spring clip and its colour is translucent, but somewhat cloudy. This component performs its function properly, it holds firmly and the clip is strong. None of the connectors are gold-plated.

The design is simple, ultra functional, not without appeal, durable and extremely compact.

Inside is the Qualcomm CSR8675 Bluetooth 5.0 chip, capable of supporting the latest codecs. It is specially paired with the MAX97220 amplifier chip, which has high compatibility, low distortion and noise. In my opinion, very little juice (power) is taken from this chip. Perhaps it’s all due to a battery consumption issue: more power = more consumption. I don’t think there are any problems with heat dissipation. I think a small size has been prioritized over a larger power. But this is just a personal assessment that may differ from reality.

And speaking of the battery, its capacity is 160mAh, which gives it a duration of 7h. Its full charge takes 1.5h and a 5V DC and 2A charger is recommended.

During the time that I have used it, the duration of the battery has been a little less, although it is true that I have made it work at maximum volume, using IEMS of 16/32Ω.

The H2 also offers the NFC for Bluetooth pairing, by a simple touch, with those compatible devices.

In short, the presentation is remarkable, the content is good, the construction is very good and the design seems quite logical, simple, but effective.





The H2 can be used as a Bluetooth receiver and as a USB DAC via cable. Via Bluetooth it supports the UAT, APTX-HD, APTX, APTX-LL, LDAC, AAC, SBC and CVC codecs. Of particular note is the compatibility with the UAT (Ultra Audio Transmission) codec developed by HiBy, which is capable of supporting 192kHz and the highest bandwidth (1.2Mbps). Furthermore, under this protocol, the different HiBy APPs can communicate with the device, exchange information and improve the user experience (alternative volume control to the Smartphone, firmware update via OTA, equalisation, etc.) Connected to my PC with the old Windows 7 is recognised without problems, without the need for additional drivers, although it does not have ASIO drivers. It should be noted that the buttons on the H2, work in this connection mode. Both the volume, and play or stop, can be operated from H2. While connected to a PC, H2 can also be charged.

It can also be connected by cable, to compatible DAPS, such as the Tempotec V1-A and HiBy R3 Pro, although its reduced power makes it unsuitable. A connection via Bluetooth would make much more sense in these cases.

Cable connection, such as USB DAC, is extended to Android, Windows, Mac OS, iPad OS devices.

Connected to my Xiaomi Redmi Note 8 Pro, the default codec is LDAC. Of course, from the developer options, you can choose different codec and BitRate. From the APP HiBy Music you can choose the UAT codec, being able to unlink the volume of the H2 from the volume of the Smartphone, among other features. At the moment, APP HiBy Blue does not allow many other functions. I suppose that in the future this will improve.



The transmission distance is approximately 10m (in open area). About 4m for UAT & LDAC.

Two Bluetooth devices can be connected at the same time, maintaining a stable and trouble-free connection. It can also be connected as a DAC to the PC and via Bluetooth simultaneously, with Bluetooth playback preference over use as a DAC.

The connections, both wired and Bluetooth, are certified as Hi-Res Audio and Hi-Re Audio Wireless, capable of reaching and reproducing a resolution of up to 24 bits/96kHz.

According to the web, it can also be connected to the car’s auxiliary input, a TV, a desktop speaker, etc. It is understood that when connected in this way, the output acts as a line output. But I have not found a selector switch between headphone output and line output. The output impedance and behaviour are not the same. But if the manufacturer advertises it, it will be possible to use it, without the device suffering any deterioration.

In summary, the H2 is a very versatile device in the connectivity section, capable of offering multiple forms of connection, as well as excellent ease of use. As a DAC, no additional driver is required and the best codecs are supported via Bluetooth. Excellent.





The use of H2 is very simple. I recommend connecting the headphones before turning it on, because this way we will hear the voice assistant, which will report the status of the device itself. I have to emphasize that the voice of the assistant is very clear and intelligible, unlike many other voices, as well as having a very adequate volume. By pressing the round button for a long time, the device will switch on and enter pairing mode. A short press will pause/resume playback. A long press will turn the device off.

With the double volume button, short presses can be used to vary the volume. Long presses on these buttons will allow you to switch between songs, next or previous, depending on the button pressed.

Connected to the PC as a DAC, it can be used without problems with Foobar2000 or Dopamine, but without being able to use the ASIO driver. The H2 can be configured in Windows with 16 bits and 48kHz maximum, not a very high figure, let’s say. This does not mean that it cannot play higher resolution files, as it does so without problems. It is only a limitation of the driver. Is it possible that Hidizs, in the future, can create an exclusive ASIO driver? I don’t know, but it would be the best way to get more out of the device. On the other hand, there are no clicks or pops during playback in this mode. There’s something new about this driverless device, which I like: the play/pause button works from the device, which is not the case with other products. My recommendation, when connected to a PC, is to set the volume of the H2 to the maximum and control it by the playback application. I recommend this because the volume jumps on H2 are quite large and when it is connected to the PC you have to press the volume control repeatedly to change it. The maximum is known to have been reached because there is a slight «mute» in the sound: it is suddenly lowered and then raised again, indicating that this maximum volume has been reached.

Connected to a Smartphone via Bluetooth, APP HiBy Music is recommended, but with USB Audio Performance Mode disabled. From this APP you can activate UAT mode and use APP HiBy Blue together. This APP will allow you to offer greater functionalities to the device, such as updating the firmware via OTA or through a file provided. You can also see the codec used, the battery status of the H2, allows use of equalizer and gain. Although the EQ is only effective at 44.1kHz and 48kHz sampling frequencies.



It can be seen that H2 has firmware version 0.03. It has not been possible to connect to the server to obtain an update via OTA, it is assumed that no updates are available. In this sense, there is nothing wrong with suggesting a firmware change. Although a future possibility of choosing a high gain mode, it would be very welcome and something that would greatly increase the value of H2, even though it implies a higher battery consumption.

Connecting to a Smartphone or other DAP by cable is a simple operation and on those devices that are compatible, the H2 will be recognized quickly. If not, check if the cable is upside down, turn it over and use the other C-type connector.

The different states indicated by the colour of the LED are as follows:


  • Red flashing: on charging.
  • Blue flashing: Bluetooth pairing mode.
  • Green: 44.1kHz to 48kHz.
  • Blue: 88.2kHz to 192kHz.


Please note that Hidizs recommends a DC 5V 2A power adapter.

Finally, it should be noted that the H2 has the ability to enter StandBy mode, when not in use, automatically.




The Hidizs H2 has a fairly linear frequency response, with a very slight drop in the lower zone. If it were not for the graphics and measurements, it would hardly be detectable. It is 1.5dB at 20Hz, but at 40Hz it is only 0.5dB.



This slight drop can be seen in the measurements without load, such as at 15Ω, 33Ω, 62Ω and 100Ω.

Another thing that can be seen is that at maximum volume there is no saturation or visible distortion in the pure waves.














No Load



The power calculated for each resistor that has been connected can be seen in the following image. It can be noticed that the specifications do not lie and that at 32Ω, the H2 offers almost 9mW, a little more than the 8mW declared by Hidizs for this impedance. Although, I really think that power is somewhat fair if you are going to use inefficient headphones and good old recordings, if you like high volume.





Thanks to the fact that the Hidizs H2 can be connected simultaneously by Bluetooth (UAT) and as a DAC connected to my PC, I have been able to verify that the differences in sound between both modes are practically non-existent. In this way and for ease of use, I will describe the sound offered by the H2 connected to my PC.

On the other hand, the operation of the H2 via Bluetooth has been limited to listening to music and receiving calls. In both scenarios the sound has always been fluid and without losses or lags. The sensitivity of the microphone seems adequate, although I usually talk low, I just had to place it closer to avoid problems.

I find the sound profile of the H2 neutral and clean. The first impression is that it sounds better than its numbers predict and, saving the dynamic range and power distances, the sound presentation is similar to the HD Sonata, with a little more clean and clear in the middle zone, as the sound of the Sonata is somewhat warmer and softer.

The lower zone has good expression, the texture is not too complex, but it has a good relationship between descriptive capacity and simplicity. It is true that there is a slight limitation in the lower sub-bass, but it is practically imperceptible, unless the musical genres are very explicit in this area. The result is a more than acceptable depth, a natural colour, a generous beat, but without losing naturalness.

The middle zone is what provides the sound with its clean and neutral character, with good light. The sound in this zone is described as direct and fast, well profiled, but perhaps a little hard and strict. It is not an analytical sound, nor is it soft, but it has a digital character, something that reminds me of HiFi CD players from the late 1990s. It’s clear that a lot has happened since then and that the resolution level of digital music is much better today. But within a sound scale, which includes all the sources I own, the H2 could fit, virtually, in that position, transferred to the current era. The numbers don’t deceive, and neither does the potential limitation. In this way, the resolution and dynamics feel somewhat cut back, when the musical passages are more complex, with more instruments, where the demand for expressiveness of detail requires a greater effort. In simpler musical genres, the H2 moves well and the voices sound correct and well profiled. The instrumentation is immediate, but without an explicit micro detail. In this way, the sound is good, simple, clear, firm and present. But it does not enjoy a superior refinement that gives it greater definition, a darker background, or a very large separation. And these limitations are shown more clearly in the high zone, making the more critical highs, described in a quicker way, with less delicacy. I believe that the upper end is the area where H2 suffers most, compared to other sources. His work here is simply correct, adequate to his possibilities. The recreation is still direct but somewhat more omitted, without going into much detail, nor into a more special or higher resolution definition. The extension is on a par with this expression, but the separation and the amount of air feel more limited when the music demands it. In this way, the scene is not strictly intimate, since, thanks to the clarity and cleanliness of the sound, it has a slight expansive tendency in the middle zone. But the absence of a greater dynamic limits a greater depth in the lower zone, a better separation between notes and an amount of air that allows the scene to be more three-dimensional. The instrumental positioning is correct, homogeneous, not too agglutinated, sufficient to establish a realistic image.





Sonata HD


As I mentioned earlier, I find a similar starting point between the Sonata HD and the H2. Both possess that openly direct character, with a more energetic and sharp profile. But the greater dynamics and power of the Sonata, gives it a better capacity for definition and a greater amount of air. This translates into a sound that gains in depth, since it also does not suffer from any loss in its lower zone. The profile of the Sonata is completely flat. The better resolution results in a slightly softer and less harsh comparative reproduction, which is noticeable on long listenings. The HD Sonata provides a somewhat higher degree of resolution and more refinement. However, the sound of the H2 seems to be a little more neutral and bright. The distance between the two is not like night and day – you need trained ears, good recordings and headphones to detect these differences. In the middle zone, the voices of the H2 sound drier, while in the Sonata you can appreciate a little more smoothness, a silkier texture. The H2 is simpler in that sense, offering a cooler feel. The lower zone is quite similar in both devices, with a very similar beat, lowering the Sonata more, at the lower end, but without any greater weight in the zone. There is improved definition in the Sonata, with a little more body and packing in the bass, in addition to that point of greater depth. In the high zone is where the most differences can be seen, in favour of the HD Sonata. Its highs are more expressive, sharp and revealing than in H2. Although they have a similar sonority, in H2, they are slightly softer, offering a little less resolution and quality in the final detail.

The scene is deeper in the Sonata HD, but the H2 compensates for this by offering a cleanup that gives good separation. In the end, though, the greater dynamics of the Sonata HD makes the difference, offering a fuller, wider, higher body and image with more three-dimensional effect, because it is able to offer more air and a darker background. The H2 has a more cohesive and mixed sound, something that can be appreciated when there are many instruments or the sound is more ethereal and open in itself.

In short, the sound between the two devices has a similar approach at first, starting with a comparable staging. But, in the end, the numbers count and both the power and the dynamic range establish those differences that can be seen with the passing of the minutes and more complex musical passages.





Hidizs has created a tiny Bluetooth receiver that works flawlessly and has all the best qualities expected from a product like this: the best and most current Bluetooth codecs, 5.0 specification, fast pairing via NFC, ability to connect to 2 devices via Bluetooth, use as DAC/Amp via USB cable, integrated multipurpose buttons, status LED, internal battery and many other features. It is clear that it is the smallest product that has these properties and at the best price. If we talk about its sound, it is above its specifications. Considering its limited power and dynamic range, the H2 is recommended for headphones up to 60Ω. And, thanks to its noise-cancelling microphone, it is one of the best Bluetooth solutions for our entire IEMS collection.



Earphones and Sources Used During Analysis


  • HiBy R3 Pro
  • Xiaomi Redmi Note 8 Pro
  • Tempotec Variations V1-A
  • Ikko OH10
  • BGVP ArtMagic VG4
  • ISN H40
  • NS Audio NS5 MKII Extra Bass
  • Tin HiFi T2 Plus
  • Tin HiFi T1 Plus