Review: Xiaomi HIFI Hybrid Earphones (Mi Quad) – Made from Diamonds! – Headphonesty

The Xiaomi Hi-Fi Hybrid combines unusually high-quality materials and good engineering design in a small, sophisticated package with excellent Bluetooth sound quality.

the xiaomi hifi hybrid (mi quad) will appeal to those seeking strong physical features, such as zirconia, bluetooth (bt) independence, and above-average sound performance in the usd price range $200.

Reading: Xiaomi mi hifi headphone

As far as I know, these are the first headsets to provide ldac (sony) support. the bt module, a separate device, provides the best sound quality of any unit i have tested. audibly, it features sonic performance that is equal to that of a direct audio jack on older iphones equipped without ldac.

initial impressions

The packaging is impressive, it consists of a high quality black box that arrives in a sealed skin. the lid has an engraved mi quad earpiece and a nautilus-shaped lanyard that decorates the case.

When you open the lid, you will discover the detailed packaging of each component. the charging cable and the manual are located in the removable tray on the top. I found the manual to be well written, both in Chinese and English, and with good illustrations.

included in the box:

  • 1 pair of zirconia (2ba+2dd earphones)
  • 1 0.5 meter (19″) long 3.5mm audio jack cable with gold plated mmcx connectors heavy gold.integral phone control switch.
  • 1 x 1.5 meter (54″) long 3.5mm audio jack cable with heavy gold plated mmcx connectors. integral phone control switch.
  • 1 x 1.5 meter (54”) type c audio cable with dac chip and heavy gold plated mmcx connectors. integral phone control switch.
  • 1 hi-res ldac compatible bluetooth adapter
  • 4 pairs of silicone eartips plus one pair installed on earphones
  • 2 pairs of memory foam ear tips
  • 1 pair of slider over-ear hooks
  • 1 x earphone case with spring lock
  • 1 x usb to 833mm (33″) type c charging cable
  • 1 Chinese and English Illustrated User Guide

physical qualities

mi quad earphones

The headphones are solid and a bit heavy compared to others, but their weight, finish and feel demand impressive quality and confidence in longevity. eartips and connection methods are as standard as most in the industry. MMCX (microminiature coaxial) connectors are reported to be heavily gold-plated and last four times longer than comparable connectors.

I like mmcx connectors because they give you the freedom to use bluetooth cables and adapters between different products. this contributes to its usefulness for review comparisons.


I didn’t find these to be comfortable on my ears and had a hard time wearing the ear hooks. I used them for a few weeks, but never really got used to them.


The black enclosure and sound chamber are made of zirconia, a white crystalline zirconium oxide. its density can contribute to an accurate sound.

This is a very resistant material; It is four times stronger than stainless steel. and its single crystal form is cubic zirconia – synthetic diamonds. I suspect you won’t find sturdier headphone cases anywhere. they look great!

Ear tips are a common variety of materials and sizes. I’ve never gotten anything that “fits” me and I suspect it’s the physical layout of the button itself.

On the downside, this diamond-like material seems to conduct outside noise rather than absorb it. For comparison, I tested the same environment (flying a commercial airliner) with the Mi Zirconia Quads and Egger Resin Peacock P1s from a previous review. the p1s only had a slight background noise, while the mi quads had little bass, as the background noise drowned them out.

2ba+2dd element layout

These headphones feature a slightly complex design: two balanced armature (ba) units that are great for high and mid-high tones, integrated with two dynamic elements that are best for low and mid tones. Although I lack clear information, I suspect that this configuration is coaxial and similar to the proprietary technology of the mi in-ear headphones pro.

The net result is Hi-Res sound quality that meets JA (Japan Audio Association) and CEA (Consumer Electronics Association) standards, certifying that these headphones are Hi-Res.

cables and connectors

All audio cables feature silver plated oxygen free copper. the cables are smooth, small in diameter and do not tangle.

there is a large selection of cables. They provide long and short audio cables to wear with the bt adapter on your waist or around your neck. type-c is also included for with internal dac for direct connection.

none of these cables work with current iphone models. the cable has a basic push button switch for phone connection and track change. One weakness is that there is no volume control to use with the push button on the cables or the bt adapter.

See also: How To Replace A Headphone Jack – The Correct Easy Way [SOLVED] – How To Fix Headphones

xiaomi offers a nice carrying bag with spring closure and fleece lining. the bag has a nice textured external finish and is the perfect size. I prefer this instead of a box to put in my pocket.

From the plugs to the earphones, they’re all thick gold plated and mmcx style. efficient and quick connection and disconnection are consistent with all cables and headsets, indicating good quality machine work.

sliding over-the-ear hooks fall far short of others I’ve used that have integral wires that form a stretchy hook. its low quality will prove to be a weak point for frequent users who want an over-the-ear format.

During use, I found the earhooks moved easily and changed alignment, but never fell out. An earhook serves the function of not only relieving the load of the cable on the earphone hanging over the ear, but also keeping the earphone aligned with the ear canal. these fail in the alignment area.

A simple switch for call and track control is included on the right earphone cable. sadly, it lacks a volume control feature. at least the functions it has work exactly the same as the function button duplicated on the bt adapter.

There are no specifications or feature claims for the ipx4 sweat-resistant rating found on competitive devices. It would be nice to know where this is located. but there is a vent port and the bt adapter has clear openings with no evidence of seals.

bluetooth adapter

This is a great feature and represents one of the main strengths of this product. There are no specifications listed for the frequency response of the headphones or the bt adapter. But actual use indicates that the BT adapter meets audiophile listening standards for use with iPhones and similar devices. i found the audio quality to be the best of any bt device i have used but the transmission strength is average.

the hifi hifi is a bt 5.0 compatible device. its runtime is conservatively eight hours at 50% volume and two hours of load time. my experience seems to support these specifications after two weeks of frequent use. the status led is bright but has a narrow viewing angle and changes color for different conditions. the buttons support the same functions as the push buttons on the cables.

This module is quite heavy for its size. I suspect it is due to the size of the battery and the solid construction. One end has a standard 3.5mm audio jack and the opposite end has a Type-C charging port. on the side there is a button to turn on, connect and turn off the adapter. On the side is a studio spring clip for attaching to objects and clothing that looks and feels very solid.

received audio was excellent. talk time is estimated at about two hours of continuous use before recharging.

I recommend this product if it’s not only for the bt sound quality.

technical specifications


  • connectivity type: 3.5mm audio jack or bluetooth 5.0
  • control unit: dual balanced armature and dual dynamic elements
  • sensitivity: unknown
  • nominal impedance: 32Ω
  • response of frequency: unknown
  • wearing method: hanging ear or direct bottom
  • case material: zirconia black
  • weight: 7 g each without ear tips


  • conductor material: silver-plated copper
  • number of cores: unknown
  • core length cable : 0.5m and 1.5m
  • headset connection type: mmcx heavy gold plated
  • type source connection size: 3.5mm and type c (integrated dac)

bluetooth adapter module parameters:

  • bluetooth chip: unknown
  • bluetooth version: 5.0
  • transmission distance : 10 meters barrier-free
  • bluetooth profiles: hfp/a2dp/hsp/avrcp, ldac compatible
  • audio capability battery : unknown
  • use time: 8-10 hours
  • charging time: 2 hours
  • charging port: type c
  • input voltage: 5vdc, 1a
  • weight: 13gms
  • waterproof rating: unknown

what I would like to see physically different

  1. Improved ear fit ergonomics
  2. better microphones to improve phone performance
  3. improved earhook method integrated into cables
  4. at least ipx-6 breathability -test rating
  5. more complete specifications
  6. volume function on push button or rocker switch added

sound quality

Now we come to the most important thing to consider when purchasing items. by definition:

listening teams and criteria

this review is aimed at what i believe to be the bt iems market, which is bt for audiophiles with phone capabilities. an attempt will be made in headphone and device comparisons to emphasize warmth and listening pleasure over details.

The solid part of this review is based on the most used source devices by this market and the media source. I didn’t use any special high-performance preconditioner, preamp, dac, or comparison device.

for the evaluation, i used an iphone 11 (bt), imac 27″ 2019 (direct audio connector, bt and type c with dac) and also an iphone 6+ (direct audio connector) to be fair to users older.the team eliminates dac performance breakthroughs in the 5 year development history.all decisions made after approximately 20 hours of listening experience.

to compare to other iems i used the tin hifi t3 i bought in aug 2019. it has proven to be better than any other iems i own and meets my listening criteria. it’s also the best detailed element with great soundstage, detail and sharpness.

for my media source i used spotify set to “very high” quality (320 kbits/sec) with no equalization or other settings in both spotify settings and iphone/imac audio settings. internet feed is over 200 mbps. I didn’t have the means to test the performance of ldac, but other reviews seem to correlate that ldac below 900 kbits/sec is worse than other methods at (320 kbits/sec).

To listen to the tracks, I mainly used my favorite test tracks from:

  1. wind machine “voices in the wind” album, first track: “voices in the wind”. for its complexity and variety of instruments with a wide dynamic range.
  2. Acoustic eidolon “barefoot” album, 4th track: “shape of a woman”. for acoustic guitar and cello depth with detailed vocals.

connection: with bluetooth and audio cable

See also: Headphones with Good Passive Noise Isolation – SoundsightR

i found there was no significant difference between iphone 1, imac and iphone 6+ with bt module which surprised me and i couldn’t find any dac spec on neither iphones nor bt adapter to compare . in any case, the iphone had a slight advantage over the imac.

I was pleasantly surprised at how excellent bt’s performance was. detail was present, including soundstage, clarity, and performance was the same as the direct 3.5mm audio connection on the iphone 6+, but much better than the imac. incredible. possibly the onboard dac was updated to support ldac specs and meet hi-res certification. the imac, however, had terrible direct audio by comparison.

I was able to compare the results with the 3.5mm tin hifi t3 audio jack using miqad bt adapter, iphone 6+ and imac.

I found the sound smooth across the spectrum. however, the comparison with tin hifi t3 indicated the following differences.

This device sounds good and has a comfortable quality with no uneven volume differences. it flows and has sweetness. has clarity, detail, no trace of sibilance.

bass range

no confusion and well balanced. these are not for bass heads. the bass is smooth at the top end and comes alive at the bottom end. I suspect the dynamic element is biased towards the low end. lack of impact with accurate playback (fast drum sequence with rapid low-to-high transition and overlap) lacks something in the handover of elements between dynamics and key signature… like crossovers on speakers.

don’t get me wrong, the transition is smooth and sounds good, but there is a lack of details that contribute to the impact due to the transfer of energy between the elements.

mid range

This is a range where I think there is a challenge. the mids are there and accurate, but they disappear to the back of the soundstage and tend to be dominated by bass on one side and treble on the other. they are not confused but seem to play a supporting role.

treble range

this range is like bass performance which surprises me as one would expect this area to be the weakest considering the emphasis is on bass performance. there is a good soundstage and presence. clarity and details are good. usually this range contributes and creates dimension. here the soundstage is flatter than in a normal iem.

what’s missing is the complex treble detail, like a brush on a snare… the hash sound is there, but not the detail of the leads sound. yes, I know it sounds fussy and imaginative but it is something that brings realism. this seems to be common on most internal devices.


the mi quad has a good soundstage to listen to. It really gives satisfaction because of the dimension of the environment that it creates and entertains you. most of the music I listen to tends to have the bass tilted to the left and the treble tilted to the right. the soundstage here is flatter with less depth than the t3 but at the same time it has a well blended sound and is comfortable without sacrificing sound quality.

multi-element design considerations

The challenge in multi-element designs is that one has different frequencies assigned to different physical elements. swept frequency sounds need to move from element to element while maintaining the same sound energy…a real challenge. the goal is to pack big sound into a small device and that’s the intent of mi quads.

You have done well and you have to listen and look for any inaccuracies in the transitions, since they are not obvious.

this is clear when listening to the reference tracks. track 1 has busy sections with complex combinations of instruments where the transition is most noticeable. track 2 leans towards slow transitions and predominant basses. this back track sounds great!

connection: type-3 with integral dac

My only means of testing this was the imac. i used 96khz 32bit float and 48khz 32bit float midi out. i found that the sound was not up to par with the other options…including bt. I suspect the integral dac is the problem. I didn’t bother to do extensive testing with this device.

why I compare it with tin t3

I choose to compare with the t3 hifi tin because I consider it to be a good standard for audiophiles in the low $65 price range. they are studio monitor quality. if you like detail, precision, flatter range of linearity, clean sound from low to high, then these are a good reference. they are for critical listening and not casual listening. they are heavy and do not allow much movement.

the tin hifi t3 is a reference that anyone can afford, but keep in mind that the bass is not as pronounced, so its use for judging in this range is limited. the t3 has a better midrange and excels in its highs. it is for critical evaluation where one concentrates on the sound and does not casually listen. if you lose focus, you may find them hard.


I think you can’t go wrong to buy xiaomi mi quad earphones because they provide such a pleasant listening experience with precise yet comfortable sound. the bt adapter is great for listening and supports audiophile listening potential and can be used with other sound devices when desired.

I want to thank hifigo for providing an evaluation unit. they are an excellent source of purchase.

See also: Denon AH-D5000 Over-ear Headphone Review – Reviewed

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