MUSE HiFi M4 Portable Bluetooth

Disclaimer: This review reflects my personal, subjective preferences and is solely based on my experiences with the product. It's important to note that HiFiGo does not influence this review, and I have not received any compensation. As always, I highly recommend testing the product yourself before purchasing. I want to thank HiFiGo for organising this review tour and allowing me to share my thoughts on the product.

Product link: Get yours from here!

Technical features:

• Flagship-Grade Portable Bluetooth USB DAC/AMP.
• Stable Bluetooth Connectivity With Latest Qualcomm QCC5125 Chipset.
• 3.5mm+4.4mm+2.5mm Headphone Sockets.
• Independent HiFi Architecture With ES9038Q2M DAC Chipset.
• It can be used as a USB DAC.
• SCC Intelligent Switching.
• Independent Charging & USB Data Input.
• Automatic USB Mode Configuration.
• Clear and crisp Performance With High-Quality Internals.
• Seven Digital Filters For Sound Adjustment.
• Elegant Design With a Transparent Front and metallic Chassis.
• NFC Support.
• Two-Level Gain Adjustment.
• Strong Output Power(Up to 320mW).
• Compact and lightweight Design with up to 8 Hours of Battery Life.

Prelude: The MuseHiFi M4 is a new high-end portable Bluetooth and USB DAC/AMP with an elegant design. It features the latest-generation Qualcomm Bluetooth chipset for smooth and stable high-resolution Bluetooth connectivity and supports various high-definition codes such as LDAC, AptX HD, and more. It also has an independent HiFi USB DAC functionality, equipped with a high-performance USB receiver and a premium ES9038Q2M DAC chipset that offers crystal precise, high-resolution sound signal decoding. The M4 has a transparent shell design, seven digital filters, and three headphone output ports. Overall, it delivers exceptional sound quality, an easy setup process, and intuitive controls.


Smooth and Stable High-Resolution Bluetooth Connectivity:
The Muse HiFi M4 offers excellent wireless Bluetooth connectivity with the help of Qualcomm's latest Bluetooth chipset. It is stable and has low-latency connectivity, providing smooth, lag-free, high-definition Bluetooth connectivity. The M4 supports high-resolution wireless transmission protocols, including LDAC, AptX HD, SBC, AAC, and more.

Independent HiFi USB DAC Functionality:
MuseHiFi designed the M4 as a dedicated USB DAC as well. It features a high-performance USB receiver and a premium ES9038Q2M DAC chipset, offering crystal-clear, high-resolution sound signal decoding. The M4 supports Hi-Res PCM (32-bit/384kHz) and Native signal decoding.

SSC Intelligent Automatic Switching:
MuseHiFi equipped the M4 with SCC Intelligent Smart Switching architecture. It controls the independent DAC decoding, USB Signal, Power management, and independent headphone output. It ensures everything works as intended and offers clear and crisp sound, restoring Wireless output to match the performance of wired ones.


Dual Independent USB Ports, Automatic USB Mode:
Muse HiFi M4 houses dual independent USB ports. One port is for charging the device, while the other is for use as a USB DAC. It automatically switches to USB DAC mode whenever a smartphone is connected to the USB data input port. It still uses its battery for 80%, ensuring stable and healthy power of the source smartphone.

Elegant, Transparent Shell Design:
MuseHiFi M4 has an elegant build structure. The DAC/AMP has an entirely transparent front panel, where you can see the neat internal circuitry and a smoothly textured metallic chassis. It has independent volume keys with 60-level volume adjustment on the device.

Seven Digital Filters to Play Around:
MuseHiFi M4 features seven digital filters that help you play around with the output and adjust it to your liking. These filters bring small but noticeable changes. You can choose between various options, including Rapid Roll-Off, Slow Roll-Off, Linear phase fast Roll-off, minimum phase roll-off, etc.

Connect Your Favorite Headphones with Your Choice of Termination:
MuseHiFi M4 houses three headphone output ports, including a 4.4mm, 2.5mm balanced, and a 3.5mm single-ended plug. Connect your headphones without worry, as with a dedicated amp section; the M4 provides strong output through these ports to ensure easy driving of different IEMs and Headphones.

My Experience

• With AK Odyssey IEMs

The audio performance of the device was truly exceptional. It retained the tuning of the Odyssey, a highly revered and respected audio benchmark, without any noticeable deviations or distortions. The sound quality was clear, crisp, and balanced, with impressive detail and depth. However, what truly stood out to me were the digital filters. These filters provided an incredibly accurate and precise sound and allowed for various customization options. They could accurately reproduce the original sound intended to be heard and added clarity and definition that genuinely elevated the listening experience. In addition to the impressive sound quality, the device boasted an almost non-existent background noise floor. This meant no unwanted noise or interference, allowing for an enjoyable audio experience. Overall, the device was an exceptional piece of audio equipment that genuinely exceeded my expectations.

• With Senneheiser HD660S2

Although it could drive the IEMs without issues, the device struggled to produce optimal sound quality with the 660S2 headphones. It was clear that an external amplifier was necessary to fully utilize the potential of the headphones. However, the sound quality produced without any external amplifier was impressive and practical, given the device's small form factor. The audio was vibrant, clear and had good separation, allowing for a delightful listening experience. The bass was tight and punchy, while the high frequencies were crisp and detailed, highlighting the subtleties of the music. The mid-range was also well-balanced, providing a good foundation for vocals and acoustic instruments. Overall, the device was practical and suitable for casual listening, but audiophiles seeking a more immersive sound experience would need to invest in an external amplifier.


Conclusion:
The performance of the product is impressive. Its sleek and transparent or see-through design, which effectively complements any IEM used in conjunction, is a notable feature much appreciated. The design is aesthetically pleasing and flawlessly complements any IEM used in conjunction, rendering it an excellent choice for those who value both form and function. The ease of the setup process and the intuitive controls make for a user-friendly experience, enabling effortless navigation through the settings. Furthermore, as promised, the product boasts a decent battery life when used with IEMs.

Review Of The Muse HiFi M4​

Introduction​

This is the third product I have purchased from MuseHifi, a Chinese company that was established earlier this year. I discovered later that the company also released a planar IEM, but their initial focus was on sources like dac/amp. Despite being perceived as a distinct company, none of their products did particularly well in terms of sales or popularity. They have since developed the MuseHifi M4, a new dac/amp with more features at a reasonable price. Prior to proceeding, I would like to address a few points.

Disclaimer​

*Since this unit tour was organised by Joe Bloggs, I am very grateful for this opportunity. And as I've said in all of my evaluations, the same is true for this one: all of the concepts I've expressed below are entirely my own, original ideas that haven't been influenced by anyone else. If interested, go to this link.
*I am not associated with the connection, and I receive no financial assistance from anyone.
*For the remainder of the review, I will refer to the DAP as “M4.”
*I am using various IEMs and sources for better judgement and versatility.
*Finally, I will only evaluate the M4. based on their performance, even though I will explain how it feels and seems physically and aesthetically.

Specification​

One ESS Sabre ES9038Q2M chip for DAC and one ES9603Q chip for amp is housed in the M4. The device has a Qualcomm QCC5125 that supports SBC, AAC, APTX, APTX Adaptive, APTX LL, APTX HD, and LDAC. The USB DAC is a SA9137. Under the power/play/pause button, there is a sliding side switch that allows you to access the M4's high and low gain. The volume rockers, the next and before buttons, and a reset port are located on the right side. It features two Type-C ports below (one for charging and the other for data transfer), and three output ports (2.5mm, 4.4mm, and 3.5mm) on top. Additionally, the has a 1100mah battery, which I was able to drive for roughly during my testing. Additionally, there is an all-around microphone for recording and making calls. It also has a NFC pairing. Below are additional technical details:


The DAP comes with a USB C data cable

Design And Aesthetics​

The M4 is a cuboidal device that measures roughly 41.8 x 84 x 15 mm and has curved edges. It is comfortable to hold in the hand and carry in the pocket. Because of the aluminum chassis and the glass on the front and rear of the body, the weight is not as much as I had anticipated. A transparent section on the front gives the user a view of the board. By no means does the body's design feel rough, uneven, or unfinished. Though I would have preferred the entire front panel to be transparent, the placement of the bluetooth light in the front detracts from the device's premium feel, otherwise I think it looks great.

Usage ​

I listened to M4 both with and without a wire, but I believe I used the bluetooth most of the time. Nevertheless, I had convenience in my pocket whether I used it wirelessly or connected. However, some people may find that its larger size interferes with their daily routine. Generally speaking, I like things that are portable. overall use, with a reliable battery backup and quality control for minor deterioration. It is excellent in my opinion as a wireless source. I think wired use has its benefits, but because of my routine, I rarely sit down and take my time, so I mostly use wireless.

Sound Impressions ​

IEMs​

Thieaudio Monarch MKII

Monarch MKII is the foundation from where I start recognising other IEMs. For me the Monarch MKII has the perfect treble, mid range and bass. I may prefer more punchy bass though, but all in all close to what I find in an IEM. The treble is extensive and exceptionally smooth for my taste. The mid range is centric and very expressive and the bass goes deep and rumbles beautifully. The bass feels lacking slam but it is there, but I love the way it is. In my opinion, these are technical monster, as the stage is expansive and realistic with great depth and acting dimensions. The imaging may have been more edgy and sharp but it is enough to sound clean and crisp. The separation is really how distant and distinctive every element should be. The attack and decay resolves at a pace I find natural and real. All in all I find it to sound perfect with superb tonality and excellent technicalities. Monarch MKII still surprises me how both technical and tonal performances blend and compliments each other. A peaceful and relaxed play. No other sources were able to alter or change the sound of this IEM except for the mid range which either became subdued or very revealing, the sound felt the same except for warm sources or very transparent ones like the WM1A and Questyle M15.

Because of the M4, Monarch MKII sounds more engaging and expressive. It also allows the bass to have more authority and boosts the vocals. I think the reaction is felt almost exactly as I experienced the pairing of HYPE2. However, I thought that the bass was mixed in much too much, which detracted from the stage, separation, and imaging that the Monarch MKII is praised for. Though it's not worse, I wasn't quite fond of it. Tracks with emphasized higher frequencies and light bass notes, however, sounded blissful. Every minute of the vocal presentation was amazing.

Thieaudio Hype2

The hype2 is an IEM with a natural sound that completely outperforms IEMs in this price range in terms of tonality, sound imaging, separation, and resolution. The sound is fuller and richer, and the imaging and separation make it easy to listen to vocals, particularly female vocals. It is hypnotic to listen to because it is easy to distinguish between the various vocalists or the vocal layering. The Hype2 is a very capable IEM because I never noticed any changes in tone or quality missing from the response from any of my sources, including the Sony WM1A, Tempotec V6, or other sources I had the chance to listen to like the RU7, BTR7, or Astell & Kern Khan Max. It is only when the vocals are slightly provoked or subdued using sources that there is a slight difference, but that is mostly what I heard while listening. The Hype2 is one of the top IEMs in this price range in my opinion, and it can layer and image just as well as the Monarch MKII.

Although it sounds like a mild-shape tuning, the Hype's more vocal-forward sound allows for a more open sounding. When paired with the M4, the more vocal-forward sound brought about a balanced sound, but at the expense of filling the space and making the sound seem less spacious. By all means, the tone remained the same, but the mids and bass had more energy. I noticed a more aggressive approach where the response seemed to be a blended mix of overjoyed notes with a strong vocal presence, and the details felt better. I should also mention that the bass spreads out and becomes more noticeable.

Thor Mjolnir MKII

Mjolnir is a very bassy set which has a lot of sub bass emphasis. The treble and upper mid range is also very forward in the mix. The upper treble has great extension as well. The bass is very punchy and boomy while acting fast. Mjolnir is a great V-shape sounding IEM with a different approach to explosive bass that has better technicalities, especially in this price range. The stage is great with nice surround stage and depth where the separation of each element sounding distant enough them to procure space to breathe and distinct themselves. The attack and decay of the driver capability is really quick and performs great. The vocals may feel lean and sparkly, the warmth or the fuller experience is something that these lack. Th bass response does vary from sources to sources whether I listen to a warm source or a neutral one, the bass becomes either overwhelming or authoritative or both.

M4 somewhat tames the energy in the upper mid range and lower treble and brings about a more expansive stage, which helps it sound balanced yet forward with mid range and relaxed in the lower treble, even though the Mjolnir MKII is a spacious sounding IEM. While the response seems to have been through a filter, as evidenced by the off-key backgrounds, I find that the response also provokes vocals while maintaining a realistic timbre, which is why I find it to be somewhat likeable.

Binary X Gizaudio Chopin

The bass is incredibly good with proper note weight and tends to cut off at around 200–300 Hz, which makes the lower mid range sound more cleaner but less warmer. Nevertheless, the lifted mid bass presence in the mix adds just the right amount of warmth to the overall mix. The Chopin's sound is really polished and has a great neutral response that tends to produce refined lower notes. With the exception of the notes' lack of expressiveness or detail, it probably has one of the most pleasing tones, making it sound more calming than the Moondrop Variations. The quality is still on par with other products like Variations, and it does stand a strong chance against the Truthear Nova.

When I listened to Chopin on the M4, I noticed that the bass felt natural with the same control as the treble, and the sound was forward with emphasis in the mid range where the vocals had a distinctive presentation that felt expressive but a little less natural. The mid range and the tempered placement of the instruments and vocals—all of which were stuck to the left and right stereo walls—were the most obvious, in my opinion, even though the details were notably better. Thus, the pairing wasn't my favorite.

Truthear Nova

Therefore, when I first heard Chopin, I thought it was more technically advanced than the Nova. This led me to compare the two pieces side by side and realized that while both had their own charm, I actually preferred the Nova. However, I also gained the necessary distinctions between the two so that I could determine which is better for whom. In other words, the Nova has a tighter grasp of the overall mix and is more neutral and bass linear than the Chopin, which has much more detailed and cohesive elements. Chopin seems more fluid and at ease in contrast, with a sharper treble and clearer notes that produce a more analytical sound. The vocals in the mid range are more forceful and vibrant, and the instrument sounds clear and distinct. Overall, I think this response is less calming and more lean than the Chopin.

Other than the fact that the response felt more staggering and as detailed as before, there weren't many differences in the sound response when the M4 and Nova were paired together. The bass felt more punchy and thumpy, and the vocals seemed to add some sibilance. The energy in the treble felt a little muted. I think this combination is better than V6.

7Hz x Crinacle Zero 2

In addition to sounding somewhat V-shaped and taking a more aggressive stance in the higher frequencies—which I think gives it a playful vibe—the Zero 2 is also exceptionally well-tuned, incredibly resolving, and exceptionally refined for an IEM at this price point. Whatever source I selected, it had a clear, pleasant sound with a lively response; the WM1A, in particular, gave it a more expansive, well-balanced IEM sound. When compared to other IEMs in this price range, the technical capabilities of this one are actually very impressive, to the point where I find them meaningless. With any source, I think Zero 2 generates a positive response.

With the exception of the response not being overly analytical, the Zero 2 and M4 pairing was more rich and full-sounding, with good dynamics in the lower notes and appropriate energy, allowing for a more consistent sound with the same representation as the V6. The lower mid range was a little elevated, perhaps as a result of the muted higher frequency or the push from the M4, even though I did find that the vocals were more pronounced in the mix and never had a chance to come through. This sound type appeals to me.

Tracks​

Luna Haruna - Glory days
Luna Haruna - Overfly
Rokudenashi - The Flame of Love
LMYK - 0 (zero)
ORESKABAND - Jitensya
Marina Horiuchi - Mizukagami no Sekai
RADWIMPS - Suzume
Indila - Love Story
Indila - Tourner dans le vide
Earth, Wind & Fire - September
Tom Petty - Free Fallin'
Fleetwood Mac - Everywhere
Nirvana - Smells Like Teen Spirit
Blue Oyester Cult - (Don't Fear) The Reaper
Guns 'N' Roses - Sweet Child O' Mine
The Police - Every Breath You Take
Gojira - Amazonia
TV on the radio - Wolf Like Me
Bring Me To The Horizon - Can You Feel My Heart
Bring Me To The Horizon - sTraNgeRs
Avril Lavigne - Dare To Love Me
Travis - Love Will Come Through
Gotye - Somebody That I Used To Know
DJ Shadows - Six Days (Remix) [feat. Mos Def]
Lady Gaga - Just Dance
Lil Wayne - Lollipop
Flo Rida - Low
Sebastian Lopez & Flug - Electronic Measures
Federico Mecozzi - Blue (Da Ba Dee)
Wayve - Not Enough
Kai Wachi & TeZATalks - Ghost
NGHTMRE, Zeds Dead & Tori Levett - Shady Intentions
Zeds Dead, DNMO & GG Magree - Save My Grave
Skrillex, Noisia, josh pan & Dylan Brady - Supersonic
Skrillex & Nai Barghouti - Xena
Skrillex, Missy Elliott & Mr. Oizo - RATATA
Kaifi Khalil, Eva B & Wahab Bugti - Kana Yaari
A.R. Rahman, Javed Ali & Mohit Chauhan - Kun Faya Kun

Conclusion​

In summary, M4 is a reliable and worthwhile product for the money it is being offered for. In particular, for those who continue to use 2.5mm outputs and desire both wired and wireless output. Switching between filters would have been simple if Musehifi had also created an app or eq support. But given all the features the M4 has to offer, I think it's a solid recommendation. They became much more proficient. Bravo for all of their effort.

Disclaimer:​

The Muse Hifi M4 was sent to me as a review sample from HIFIGO, for which I thank them!


I’m very grateful to have the opportunity to collaborate with this store. I must admit that they are another important contributor to my hobby. Without them, I wouldn’t be able to have all these opportunities to try out so many IEMS and DACs.


The review, as always, will be completely unbiased and uninfluenced.


I would like to remind you that I am just a person who enjoys trying out new audio products and listening to a lot of music. I am not an expert; this isn’t my work but just my hobby.


My opinions are obviously subjective.

Tech Specs:​

• Bluetooth version: Bluetooth 5.1
• Volume adjustment: The volume of the phone can be adjusted separately
• and independently
• Compatibility: AAC/SBC/aptX/aptX LL/aptX Adaptive/aptX
• HD/LDACBluetooth chip: QCC5125
• Independent chip: ES9038Q2M
• Independent amp: ES9603Q
• USB DAC: SA9137
• Independent play pause button: Yes
• Independent volume key: Yes
• Independent song before and after adjustment: Yes
• Transmission distance: 12M
• Gain setting: L/H
• Volume level: 60
• Output power: 3.5>160mW + 160mW; 2.5/4.4 > 320mW + 320mW(32Ω) SNR:3.5>118dB:25/4.4>115dB(A)
• Noise: 3.5 <3uV: 2.5/4.4 <5.5uV
• THD+N:3.5<0.00048%:25/4.4<0.00032(1KHz/6-dB@32Ω)
• Separation degree: 3.5>75dB,2.5/44 107 db or higher
• Microphone: Support Bluetooth voice call, built-in omnidirectional microphone, support CTIA headset wire control itself microphone
• NFC: Supported
• No-drive mode: Supported
• Mobile decoding: Supported
• In-car mode: Supported
• MQA Render: Supported
• Plug type: 3.5mm+4.4mm+2.5mm
• USB interface: Type-C USB 2.0 (charging) + Type-C USB 2.0 (data transfer)
• Battery capacity: 1100mAh
• Endurance: 3.5mm>8h; 2.5/4.4mm 7h
• Size:41.8mm*84mm*15mm
• Weight:≈73g
• Accessory: Type-C USB
• Color: Silver

Optional accessories:​

• 1. Type-C to Lighting
• 2. Type C to Type-C
• 3. USB plug
• 4. Real leather case

Packaging:​

The Muse Hifi M4 arrives in a discreetly well-finished and sturdy black box.


A USB-to-Type C cable and an instruction manual are found inside a separate box right away. Honestly, I would have also expected a Type C to Type C cable, but it doesn’t matter. I have many at home.


Finally, we find the Muse Hifi M4, nestled in the plastic. I must admit that the accessories included in the package are a bit limited in quantity. However, they can be purchased separately.

Build quality / First impressions:​

The design immediately reminded me of the Kmerj KM01 DAC. I really like transparent things; seeing the motherboard and the chips always has a certain charm. Here, my macro photos will probably make you better understand the beauty of the Muse Hifi M4 and also the construction quality.


The front and back appear to be tempered glass; they are cold to the touch, so I think they are glass. Along with the buttons and gain switch, there are three small holes around the aluminum frame. One of these is for the LED that indicates the charging status, and the other two are supposed to be for the omnidirectional microphones.


I have to admit that the key feedback is also very good. In the upper part, you can see that we have all the necessary outputs: 3.5mm, 4.4mm, and 2.5mm. Below we find two Type C ports, one dedicated to charging and the other to data, as it can be recharged while in use or used as a wired DAC. It’s such a versatile device that you’re spoiled for choice.


On the accessories side, we only have a good-quality cable included. As I said before, I would have had some more accessories included.

Outputs Power:​

Muse Hifi M4 has 3 outputs:

• 3.5mm 160+160mW 32OHM
• 4.4mm 320+320mW 32OHM
• 2.5mm 320+320mW 32OHM

The balanced connectors were initially very difficult to insert into their respective outputs; fortunately, by using them, the problem disappears.


In terms of power, I don’t think you will have any kind of problem with any IEMs.


The ES9038Q2M DAC chip is paired with the ES9603Q amp, which is the same pairing seen on the F.Audio KS01.




I tested the outputs with:

• Kefine Klanar planars on both 3.5mm and 2.5mm output with excellent results, but on the other hand, we are talking about a very efficient planar.
• Lethuer S12 Pro on 4.4mm output are slightly harder to drive than the Klanar, but only slightly.
• Kinera Celest Phoenixcall on 3.5mm and 4.4mm balanced without any efforts. There is enough power for it.
• Hidizs MP145 on 4.4mm output and is driven very well, like some desktop DACs.
• Hifiman He400Se on 4.4mm output on high gain definitely put the Muse Hifi M4 under stress. By raising the volume beyond human levels, the M4 Dongle raises the white flag, sending some distortion into the headphones. Which doesn’t happen using, for example, the EPZ TP30 and Hidizs S9 Pro Plus. With this, the Hifiman can be easily driven without worries, in my opinion. I don’t think anyone will do prolonged listening at insane volumes… except me.

Rockers and buttons:​

The Muse Hifi M4 rockers that allow volume adjustment at first glance appear to be only one, but in reality both have a volume adjustment function. By keeping the rocker pressed for a long time, where we find the symbols to send the playlist forward or backward, it is possible to roughly adjust the volume.

Fast Volume and Next/previousPrecise Volume and Mute + FiltersGain SwitchLed + Power/play/pause
While the one dedicated to volume/mute/filters allows you to precisely adjust the volume with a quick press via Bluetooth connected to the POCO M4 Pro, it does not influence the volume of the smartphone, so it is as if I had three possibilities to correct the volume. There are an infinite number of volume combinations.


Obviously, the volume rocker also allows you to mute and change the filters. On the other side, we find the switch for the gain, low-gain blue lights, and high-gain red lights.

Audio Codecs:​

The Muse Hifi M4 is equipped with the latest Qualcomm QCC5125 with dual DSP and dual-core CPU architecture, Using Bluetooth 5.1, the connection is super stable, and many codecs are available; in fact, we have AAC/SBC/aptX/aptX LL/aptX Adaptive/aptXHD/LDAC.

Wired Mode side led on
With all these formats, I don’t think you will have any problems. My POCO M4 Pro uses it in AAC or LDAC, so I did most of the testing with the best codec available. Keep in mind that if you use this codec, both the smartphone and the Bluetooth dongle will consume considerably more. In my test, you can reach up to 5 meters without problems. If you use codecs that require less important transmissions, then you can go much further.

Battery and energy management:​

Muse Hifi M4 has very intelligent energy management. The 1100 mAh internal battery maintains autonomy expectations. In addition to being able to be connected via cable, it can be recharged and used at the same time. Below, we have two Type C ports, one dedicated to charging and the other to data. If you connect it wired to your phone, the Muse M4 will only use 20% of the phone’s power, and the rest will use its built-in battery.

High Gain LDAC + Red LED while chargingFully Charged
With my iMac, I had no problem testing its charging and data functionality at the same time, but my smartphone didn’t want to accept any other cables other than its original one with a USB to Type C adapter. I’m literally full of cables to try; none of them work except for a very few. I am forced to recommend the original accessory in case you cannot find a suitable Type C cable. I only found one for a Jcally DAC, but it is so short as to be unusable even if it works with M4. Obviously, you don’t need an external power supply if you want to use it in wired mode, but a single cable in the data port.


In doubt that the issue was my smartphone, I took my old Redmi Note 7 mule, which I use as a player, but the exact same thing happened. OTG cables are needed, but not all of them are suitable.

Sound Signature:​

I keep getting more and more DACs that use these chips, and currently this is the most neutral/reference-sounding one. The low ranges are not at all emphasized in any way. The mids seem quite natural, perhaps a little more recessed, while the highs are decidedly brighter. Taking the Hidizs S9 Pro Plus, for example, it is much warmer in sound than even the EPZ Tp30. In terms of resolution, I tested it with the LDAC connection, and the quality remains very high. With careful listening, everything seems slightly more compressed. Although the data flow is very massive, using LDAC, you will not notice any instability. There aren’t huge differences in quality with a wired DAC, but when you connect it via cable, I seem to hear the sound open up. Let’s say that even its very neutral tone makes it seem a little flat.

Digital Filters:​

Surprisingly, we find the same filters present on the Hidizs S9 Pro Plus. LOL.


There isn’t an RGB LED to indicate which filter you’re on, but fortunately, the gain LEDs flash as many times as the filter you choose. For example, if we choose to try filter number 4, the gain LED will flash 4 times.


There are 7 filters that can be changed:

1. Anodizing fast roll-off
2. Linear phase fast roll-off
3. Linear-phase slow roll-off
4. Minimum phase fast roll-off
5. Minimum phase slow roll-off
6. Hybrid fast roll-off
7. Linear Phase Shift Brickwall

I’m borrowing my opinion about filters from my own S9 Pro Plus review:


“The difference in filters is honestly very difficult to hear, especially if you are not used to paying critical attention to what you are hearing. If you think that switching from one filter to another will upset your life, know that you will be disappointed. The changes are extremely delicate and require almost bat-like ears. I sincerely admit to you my difficulty in hearing real changes, and therefore I would not recommend this DAC if your hope is to have 7 filters that completely change the sound.”


I honestly don’t know if, over time, I will be able to perceive even the faintest nuances of these filters.

Fast Comparison​

vs Hiby W3 Saber




Some time ago, I purchased a Hiby W3 Saber for less than 50 USD. An AK4377 with dedicated amplification is concealed in a very light and compact device.


There is a decidedly well-made app for smartphones to manage the various functions it has. Obviously, it doesn’t have monstrous power, and above all, we have a single 3.5mm output. I have to say I’ve never had any problems using it in LDAC either. The only perhaps a little sore point is that we are the complete opposite of the Muse Hifi M4. The sound timbre of the W3 is extremely warm, so much so that it almost suggests a drop in resolution and detail. Obviously, it is a cheaper product.


vs EPZ TP30 or Hidizs S9 Pro Plus


I put them together because, since they are wired DACs, comparisons can be made in terms of power and tone. Personally, I remain a big fan of wired dongles; the TP30 and S9 Pro Plus have the same chip but different amplifications compared to the Muse M4. We have greater clarity under heavy load (for example, using the He400se) without loss of definition at full scale. Both have a warmer tone than the Muse implementation, which aimed for neutrality.


vs F.audio KS01




The F.Audio KS01 is the only DAC with the same chip and amp priced under 50 USD. It is full of features and full of firmware to try, but only has a 3.5mm output with a decidedly interesting power considering the price. I have not encountered any problems, but some users have had background noises. I would like to point this out, as it is a product with a suspiciously low cost and perhaps few quality controls.

To whom would I suggest this Bluetooth DAC?​

Personally, I am very happy to have received it, as my POCO M4 Pro has some problems due to the latest updates, which do not allow me to use wired DACs as they interrupt playback randomly. Bluetooth DACs are the only solution. I already had the Hiby W3, but it has a very warm tone, and it is difficult to use it to review IEMs and headphones. This has crazy versatility in terms of outputs, more than enough power, and very good reliability. It might be a little too neutral for some. To give you an example, using the Kefine Klanar, I felt the need to reduce the low frequencies, and as a solution, I mounted Tri Clarion tips. With the Muse M4, the bass had lost so much that I had to go back to using at least Kbear 07 or Divinus velvet tips.


Personally, I needed such a neutral device, so I am extremely happy with it. The battery lasts very well, even when using it in high-gain mode. I managed to get more than 6 hours of battery life in LDAC. It’s not the smallest device on the market, but it fits in any pocket without problems. Compared to the Hiby W3, the dimensions are double, but I must say that it doesn’t change that much in terms of comfort.


As for the internal microphone, it is affected by a noticeable background noise. I think it comes from the Bluetooth module, but I’m not sure. For calls, I don’t think it’s a significant problem, while in the case of good-quality recordings, it would be quite audible.


I do not think the Muse M4 is pricey, especially when we take into account that wired DACs using the same chip can cost up to 80 USD. In fact, given its versatility, it is incredibly affordable.

Where to buy:​

MUSE HiFi M4 Portable Bluetooth 5.1 Flagship ES9038Q2M DAC Decoding Chip Headphone AMP