Hidizs MP145 IEM Review

[Blorg]

Do we have more data points for confirming a change in tuning? If yes, by much of a change is it from the initially released units?

He graphed it himself in the video:

 

[InfiniteJester]

I have finally casted my vote for these IEMs, let me share my experience:

The fit for the tips is terrible. The width of the nozzles is too much for the custom tips to endure. Changing them is a real hassle and I'm sure that you can break them even when changing them with considerable caution. I started with the balanced tips, but wanted to compare them against the bass ones. After suffering due to how difficult it was to change them, I decided to stay with the bass ones permanently. For that reason, my impressions steam mainly for the combination of pink filters and bass tips. They have three kind of filters and three kind of tips, but you are not encouraged to experiment with them at all.

The cable is mediocre. It is thin, it tangles and you feel like it will also break or get damaged, even when you just careful slide the ring they have to adjust the length of the bifurcation they have before going to your ears. They are also strongly microphonic. You can experience the auditory experience of an earthquake if you slide their metallic ring.

The point in which the cables insert into the monitors doesn't rotate, so you can't make them perfectly fit to the sides of your head, like you can do with the FH9s.

I was unable to detect any flex problem, but that has been reported a number of times.

Having said that, this is the best IEM I have ever tried, it is even better than most of my headphones. I know that many people believe that frequency response and distortion is everything; but, either the commonly used preference target is not for me, or there is more to this whole deal that we aren't measuring yet. Comparing these IEMs to something like the Zero:2s is a joke. The MP145s sound spacious, natural, refined... Whereas the Zero:2s sound too close and congested.

Until I tried these IEMs, I thought that having your hears fatigued after listening to an album was normal. I now think that I may have been listening music wrong for years, maybe for chasing targets that weren't fitting for me. These IEMs are incredibly laid-back without sacrificing any sparkle or detail. Hidizs has threaded the needle in a way that I thought wasn't possible. Even though they are detailed, they are more laid-back than detailed. I believe that we are surprised at first with more intense tunings, only to get fatigued hearing after a while. These were made for long sessions. You may think that they lack punch during the first ten seconds, but you will be filled with bliss after half an hour.

For my personal taste, which may not extrapolate, they are a masterpiece of tuning. After playing for hours with different EQs and surround DSPs, I have concluded that everything that I can do to them only worsen their sound. Dolby Atmos, which is essential to squeeze some soundstage out of the Zero:2s, diminishes the outstanding soundstage of the MP145s.

I like their tuning so much, that I have started to tune my headphones to more closely resemble the experience the MP145s offer.

Despite the troubles with the tips and the cable, they are extremely comfortable, both physically and acoustically. I believe that these IEMs are a masterpiece and everything that I have been waiting to have. They put the much more expensive FH9s and their 7 drivers per monitor to shame, and I have a hard time believing that you can get a better auditory experience than the one these IEMs offer. They, of course, also put the much cheaper Zero:2s to shame, to the point of making me skeptical of the reductionist point of view.

The MP145s are perfect to me. I understand that people expecting more punch and a less ethereal sound may hate them, because they are very distinct compared to other ones I tried. But if you are after a huge soundstage and a laid-back presentation, these are exactly that. They are also very big, but I'm big myself and they fit me like a glove. If you are on the smaller side, they may be too much for you.

I'm quite infatuated with them and they have gained my unconditional "Great" despite the several annoyances they present.

Customary proof of ownership:

 

[imnotarobot]

He graphed it himself in the video:
View attachment 354075

I know and I did watch the video about this. It's still one example. They probably have sold hundreds of these. I do think the chances we get clarity on this is slim due to the pace of the hobby.

 

[InfiniteJester]

Listening to these I reach two conclusions:

Everything we thought we knew about soundstage should be bullshit: angled pads, huge drivers, interaction with the pinna, complete lack of isolation, acoustic space excitation... How it is possible that these things can project things out of your head better than many over-ears?

Man, most music is terribly recorded and produced. When you get into Hi-Fi, the number of albums you enjoy gets significantly reduced. I never realized, for example, how poor Eros by Dün sounds. Are those phase cancellation issues? Dear Lord. I used to enjoy this music.

 

[NielsMayer]

I think one of the reasons for such good soundstaging is no crossover and a driver that can handle full-range audio in a single unit. Aka no phase disturbances, which audio engineers seem to ignore, since they labor under an incorrect assumption that imaginary numbers cannot be "heard" and then happily throw out half the information thinking they can reside entirely in the power domain. https://gubner.ece.wisc.edu/notes/MagnitudeAndPhaseOfComplexNumbers.pdf

That is not the case, unless you use a fancy DSP crossover in an "active speaker" configuration where different phase/frequency/rolloff tradeoffs can be made, but even with fancy DSP filters it's always a compromise. So of course the best option IMHO is to have a theoretically perfect driver that doesn't require a crossover.

https://www.audiocontrol.com/downloads/tech-papers/tech-paper-102.pdf

"Crossover Networks from A to Linkwit-Riley" (sic -- I probably shouldn't use a reference that doesn't even spell Linkwitz correctly https://en.wikipedia.org/wiki/Linkwitz–Riley_filter )

Is a planar IEM such a driver?? In many cases it is. However, I do wonder what happens as frequencies get higher, triggering vibration modes where multiple "waves" can fit within the driver's diameter: https://en.wikipedia.org/wiki/Vibrations_of_a_circular_membrane

 

[InfiniteJester]

I think one of the reasons for such good soundstaging is no crossover and a driver that can handle full-range audio in a single unit. Aka no phase disturbances, which audio engineers seem to ignore, since they labor under an incorrect assumption that imaginary numbers cannot be "heard" and then happily throw out half the information thinking they can reside entirely in the power domain. https://gubner.ece.wisc.edu/notes/MagnitudeAndPhaseOfComplexNumbers.pdf

That is not the case, unless you use a fancy DSP crossover in an "active speaker" configuration where different phase/frequency/rolloff tradeoffs can be made, but even with fancy DSP filters it's always a compromise. So of course the best option IMHO is to have a theoretically perfect driver that doesn't require a crossover.

https://www.audiocontrol.com/downloads/tech-papers/tech-paper-102.pdf

"Crossover Networks from A to Linkwit-Riley" (sic -- I probably shouldn't use a reference that doesn't even spell Linkwitz correctly https://en.wikipedia.org/wiki/Linkwitz–Riley_filter )

Is a planar IEM such a driver?? In many cases it is. However, I do wonder what happens as frequencies get higher, triggering vibration modes where multiple "waves" can fit within the driver's diameter: https://en.wikipedia.org/wiki/Vibrations_of_a_circular_membrane

I will study everything you referred to, because I have no idea about any of that.

 

[CedarX]

I think one of the reasons for such good soundstaging is no crossover and a driver that can handle full-range audio in a single unit

I don't think there is a good, simple, and objective, way to characterize the "soundstage" qualities of an IEM. If we rely on opinions, there are probably as many multi-drivers IEMs with good soundstage than single-driver with equally good soundstage. And there are single-driver IEMs with reportedly bad soundstage.

Aka no phase disturbances, which audio engineers seem to ignore,

So what is the group delay graph for? Amir includes it in every one of its reviews... I understand that many will ignore the graph and that it is not necessarily easy to interpret, but it's one of the graphs that may indicate soundstage issues. I don't think it is correct to say that audio engineers ignore anything related to phase disturbances, I think saying that phase disturbances is one of the elements affecting soundstage would be a better statement...

the best option IMHO is to have a theoretically perfect driver that doesn't require a crossover

IEM dynamic or planar drivers are perfectly capable of reproducing the entire audible spectrum. However, tuning the FR correctly is, at a minimum, non-trivial. In the IEM world, multi-drivers may be a more flexible path for the audio engineer to model the IEM FR after what marketing wants... And the marketing message is often that the more drivers the better it is!

Is a planar IEM such a [perfect] driver?? In many cases it is.

I have a few planar IEMs besides the MP145. Some sound pretty good as-is... others, as-is, sound like sh#$% (Audeze iSine 10, TinHifi P1). Once more, I don't think the driver technology is necessarily critical... it's mostly about the tradeoffs between marketing wants, cost constraints... and the talent of the audio engineers designing the IEM.

I do wonder what happens as frequencies get higher, triggering vibration modes where multiple "waves" can fit within the driver's diameter:

If you do the maths with a typical IEM driver size and say 20kHz as your highest frequency, there are not many vibration modes to deal with in an IEM.
I think it's more about bouncing waves in the ear canal...

 

[InfiniteJester]

I have not tried many planars, I only own the MP145s and the HE400ses, but despite how cheaper than my multi driver IEMs and my dynamic headphones they are respectively, they are probably my favorite items to listen to music. For me personally, there seems to be something about planar technology that makes audio much more enjoyable than from other sources. For me, it is like if the music is coming from nowhere or everywhere, and that really helps me with immersion.

This is purely subjective, of course. I'm very intrigued about what MEMS can do. I just don't like wireless IEMs (nor ANC), and that is why I haven't bought the Aurvanas yet.

 

[NielsMayer]

If you do the maths with a typical IEM driver size and say 20kHz as your highest frequency, there are not many vibration modes to deal with in an IEM.
I think it's more about bouncing waves in the ear canal...

I was trying to estimate the maths on this and came up confused because we don't know the speed of sound in the membrane versus air.

Trying to find some articles related to this left me even more confused:

Vibration of micromachined circular piezoelectric diaphragms

The electrically and mechanically excited resonances in micromachined circular piezoelectric diaphragms have been investigated. The diaphragm structures were piezoelectric unimorphs consisting of Pb(Zr/sub 0.52/,Ti/sub 0.48/)O/sub 3/ (PZT) films and thermally grown silicon oxide (SiO/sub 2/)...

ieeexplore.ieee.org

Vibration of micromachined circular piezoelectric diaphragms

https://www.sci-en-tech.com/ICCM2019/PDFs/4136-13520-1-PB.pdf

Resonant frequencies of a radial field piezoelectric diaphragm

Note here that for a driver (piezo not planar) of approximately the same order-of-magnitude size as the MP145's produces a resonant frequency within the audio band.

The results showed that the fundamental resonant frequency of the radial field piezoelectric diaphragm decreases from 16.43 kHz to 11.92 kHz when the diameter increases from 9.2 mm to 10.8 mm

Anybody got an estimate for the resonance modes and frequencies of those modes for a 14.5 mm driver using the kind of material used for the mp-145?

Does the "planar" method of driving not elicit these vibration modes because the electromotive force is evenly distributed across the driver?

 

[CedarX]

Anybody got an estimate for the resonance modes and frequencies of those modes for a 14.5 mm driver using the kind of material used for the mp-145?

Are you thinking about something alike cone breakup in large speaker drivers?
Even if it is a significant phenomenon for planar IEMs—and you may be absolutely correct here—wouldn’t it translate into some kind of (measurable!) distortion more than phase issues?

The MP145 distortion levels are extremely low… One could assume it’s a key to the good soundstage, but I don’t think the cause and effect relation is that simple…

 

[InfiniteJester]

Are you thinking about something alike cone breakup in large speaker drivers?
Even if it is a significant phenomenon for planar IEMs—and you may be absolutely correct here—wouldn’t it translate into some kind of (measurable!) distortion more than phase issues?

The MP145 distortion levels are extremely low… One could assume it’s a key to the good soundstage, but I don’t think the cause and effect relation is that simple…

Zero:2s have even less distortion and their soundstage is very limited.

 

[Blorg]

Zero:2s have even less distortion and their soundstage is very limited.

There isn't a conclusive determination of what might add to perception of soundstage in IEMs. I definitely think it's much more subjective and varies a lot more from person to person, than with overears. With overears there is variation in perception too but there is a general tendency to agree stuff like the HD800S or oval Hifimans have very wide soundstage and the HD600/HD650 is very narrow.

IEMs there is a lot less agreement, even IEMs that are commonly touted as having good soundstage, you'll find people saying the reverse. There is far more variety of opinion. Possibly as they bypass the pinna and so how they sound to you vs the world is going to vary more depending on your specific anatomy. Insertion depth will also move the insertion resonance you see at 8kHz in graphs, most people that will be more like 6-7kHz. It's 7.5kHz for me, for most IEMs, but I can get it up to 9 or 10 with some IEMs with a deep insertion. So how you perceive the treble is going to vary on that too.

The one obvious difference between them is that the MP145 has more treble, the Zero2 is rolled off. 711 graphs are not accurate as to the details above the insertion resonance, but they can paint a broad picture, and I'd believe the Zero 2 is more rolled off. And there is a tendency there, I think, it's more common for IEMs with higher treble to be perceived as wider. One example of an IEM often consider to have good soundstage is the Final A4000, and it combines a bit of a recess around 2kHz (which is also in over-ears known for soundstage like the Hifimans or HD800S) with a huge boost immediately after it. It does sound wider to me, but it's still an IEM. It can also get a bit tch tch fatiguing although surprisingly not as much as you might think from the graph. Not an IEM for high volume listening.

Personally, I don't find the MP145 exceptionally wide. Not narrow either, but just normal. I don't find their soundstage particularly notable though.

I think Crinacle once said something along the lines of if speaker soundstage is 100, headphones are around 15 and IEMs you are arguing over whether it's 1 or 2, they all have poor soundstage and he doesn't really factor this in a lot. I'm not sure I'd go that far, I have IEMs I'd put over the worst open backs, like the HD600/650. But it is an indication that it's personal, and I think most people do perceive IEM soundstage to be pretty limited.

 

[InfiniteJester]

There isn't a conclusive determination of what might add to perception of soundstage in IEMs. I definitely think it's much more subjective and varies a lot more from person to person, than with overears. With overears there is variation in perception too but there is a general tendency to agree stuff like the HD800S or oval Hifimans have very wide soundstage and the HD600/HD650 is very narrow.

IEMs there is a lot less agreement, even IEMs that are commonly touted as having good soundstage, you'll find people saying the reverse. There is far more variety of opinion. Possibly as they bypass the pinna and so how they sound to you vs the world is going to vary more depending on your specific anatomy. Insertion depth will also move the insertion resonance you see at 8kHz in graphs, most people that will be more like 6-7kHz. It's 7.5kHz for me, for most IEMs, but I can get it up to 9 or 10 with some IEMs with a deep insertion. So how you perceive the treble is going to vary on that too.

The one obvious difference between them is that the MP145 has more treble, the Zero2 is rolled off. 711 graphs are not accurate as to the details above the insertion resonance, but they can paint a broad picture, and I'd believe the Zero 2 is more rolled off. And there is a tendency there, I think, it's more common for IEMs with higher treble to be perceived as wider. One example of an IEM often consider to have good soundstage is the Final A4000, and it combines a bit of a recess around 2kHz (which is also in over-ears known for soundstage like the Hifimans or HD800S) with a huge boost immediately after it. It does sound wider to me, but it's still an IEM. It can also get a bit tch tch fatiguing although surprisingly not as much as you might think from the graph. Not an IEM for high volume listening.

Personally, I don't find the MP145 exceptionally wide. Not narrow either, but just normal. I don't find their soundstage particularly notable though.

I think Crinacle once said something along the lines of if speaker soundstage is 100, headphones are around 15 and IEMs you are arguing over whether it's 1 or 2, they all have poor soundstage and he doesn't really factor this in a lot. I'm not sure I'd go that far, I have IEMs I'd put over the worst closed backs, like the HD600/650. But it is an indication that it's personal, and I think most people do perceive IEM soundstage to be pretty limited.

View attachment 354765
View attachment 354766

I don't think it is only the treble, because I increased considerably them through EQ in my Zero:2s and the soundstage didn't change. This is what I was using with them:

Preamp: -5.0 dB
Filter 1: ON PK Fc 23 Hz Gain -2.0 dB Q 0.800
Filter 2: ON PK Fc 100 Hz Gain 1.5 dB Q 1.000
Filter 3: ON PK Fc 700 Hz Gain 0.9 dB Q 1.400
Filter 4: ON PK Fc 1500 Hz Gain -2.4 dB Q 1.500
Filter 5: ON PK Fc 3800 Hz Gain -0.9 dB Q 1.400
Filter 6: ON PK Fc 5900 Hz Gain 5.3 dB Q 2.000
Filter 7: ON PK Fc 11000 Hz Gain -5.4 dB Q 2.000
Filter 8: ON PK Fc 14000 Hz Gain 6.3 dB Q 2.000

I used to agree with you, but, for me personally, the MP145s have a better soundstage than many of my over-ears. Even than the HD599, which I bought because, allegedly, they had a wider soundstage than the HD600s2; which is a very, very disappointing headphone. Of course, they can't compete with the HE400se in width or with the AKG702 in accuracy, but I think that they are reasonably close, given the form factor. The thing with the AKG702s is that they are so incredible precise in their soundstage, that any other soundstage I hear, even if it is huge, sounds so diffuse and lacking definition... For me, personally, that is the biggest issue with IEMs. Still, I do get a strong out-of-my-head experience with the Hidizs.

 

[imnotarobot]

There isn't a conclusive determination of what might add to perception of soundstage in IEMs. I definitely think it's much more subjective and varies a lot more from person to person, than with overears. With overears there is variation in perception too but there is a general tendency to agree stuff like the HD800S or oval Hifimans have very wide soundstage and the HD600/HD650 is very narrow.

IEMs there is a lot less agreement, even IEMs that are commonly touted as having good soundstage, you'll find people saying the reverse. There is far more variety of opinion. Possibly as they bypass the pinna and so how they sound to you vs the world is going to vary more depending on your specific anatomy. Insertion depth will also move the insertion resonance you see at 8kHz in graphs, most people that will be more like 6-7kHz. It's 7.5kHz for me, for most IEMs, but I can get it up to 9 or 10 with some IEMs with a deep insertion. So how you perceive the treble is going to vary on that too.

The one obvious difference between them is that the MP145 has more treble, the Zero2 is rolled off. 711 graphs are not accurate as to the details above the insertion resonance, but they can paint a broad picture, and I'd believe the Zero 2 is more rolled off. And there is a tendency there, I think, it's more common for IEMs with higher treble to be perceived as wider. One example of an IEM often consider to have good soundstage is the Final A4000, and it combines a bit of a recess around 2kHz (which is also in over-ears known for soundstage like the Hifimans or HD800S) with a huge boost immediately after it. It does sound wider to me, but it's still an IEM. It can also get a bit tch tch fatiguing although surprisingly not as much as you might think from the graph. Not an IEM for high volume listening.

Personally, I don't find the MP145 exceptionally wide. Not narrow either, but just normal. I don't find their soundstage particularly notable though.

I think Crinacle once said something along the lines of if speaker soundstage is 100, headphones are around 15 and IEMs you are arguing over whether it's 1 or 2, they all have poor soundstage and he doesn't really factor this in a lot. I'm not sure I'd go that far, I have IEMs I'd put over the worst open backs, like the HD600/650. But it is an indication that it's personal, and I think most people do perceive IEM soundstage to be pretty limited.

View attachment 354765
View attachment 354766

I don't think it is only the treble, because I increased considerably them through EQ in my Zero:2s and the soundstage didn't change. This is what I was using with them:

Preamp: -5.0 dB
Filter 1: ON PK Fc 23 Hz Gain -2.0 dB Q 0.800
Filter 2: ON PK Fc 100 Hz Gain 1.5 dB Q 1.000
Filter 3: ON PK Fc 700 Hz Gain 0.9 dB Q 1.400
Filter 4: ON PK Fc 1500 Hz Gain -2.4 dB Q 1.500
Filter 5: ON PK Fc 3800 Hz Gain -0.9 dB Q 1.400
Filter 6: ON PK Fc 5900 Hz Gain 5.3 dB Q 2.000
Filter 7: ON PK Fc 11000 Hz Gain -5.4 dB Q 2.000
Filter 8: ON PK Fc 14000 Hz Gain 6.3 dB Q 2.000

I used to agree with you, but, for me personally, the MP145s have a better soundstage than many of my over-ears. Even than the HD599, which I bought because, allegedly, they had a wider soundstage than the HD600s2; which is a very, very disappointing headphone. Of course, they can't compete with the HE400se in width or with the AKG702 in accuracy, but I think that they are reasonably close, given the form factor. The thing with the AKG702s is that they are so incredible precise in their soundstage, that any other soundstage I hear, even if it is huge, sounds so diffuse and lacking definition... For me, personally, that is the biggest issue with IEMs. Still, I do get a strong out-of-my-head experience with the Hidizs.

I've switched from a longer (16mm) narrower bore (4mm) to shorter (9mm) wider bore (6mm) silicone tip for the S12. For universal iems, I perceive larger bore sizes with a more open and wider soundstage. One other thing I suspect is depth insertion but I'm not too sure on that. Maybe the soundstage shrinks the deeper you insert your iems. Etymotic iems aren't known for their wide soundstage.

 

[Blorg]

I've switched from a longer (16mm) narrower bore (4mm) to shorter (9mm) wider bore (6mm) silicone tip for the S12. For universal iems, I perceive larger bore sizes with a more open and wider soundstage.

I tend to find that as well. Tips do change the FR and between two very different types this can be significant. They can also change perceived bass levels if they create a slight leak, and there are some tips like the Tangzu Tang Sancai designed to do this (although they say to relieve pressure rather than advertising they reduce the bass). The bass usually looks the same either way in 711 graphs as the metal tube of the coupler tends to make a perfect seal with anything. This is the Tripowin Olina with CP100 (narrow long bore) vs Spring Tips (short wide bore):

 

[imnotarobot]

He graphed it himself in the video:
View attachment 354075

I suspect Michael just got a lemon. I've been looking around newer reviews and graphs of this iem and the pinna gain (@2k) and peaks are much closer to the green measurement (what we deem is OG).

 

[NielsMayer]

I just noticed that the latest wavelet update removed all the MP-145 settings previously available (w/ different EQs for the three different tips) -- all of which sounded terrible.

 

[Blorg]

I suspect Michael just got a lemon. I've been looking around newer reviews and graphs of this iem and the pinna gain (@2k) and peaks are much closer to the green measurement (what we deem is OG).

Maybe. It's unusual to get a lemon that matches left and right though, that is usually an indication that it's intentional. He also pulled it apart and noted construction differences. The other graphs are presumably just the "old" version. Would be interesting if someone else gets one and graphs similar.

 

[InfiniteJester]

I just noticed that the latest wavelet update removed all the MP-145 settings previously available (w/ different EQs for the three different tips) -- all of which sounded terrible.

All the EQ profiles out there are evidently wrong, in my opinion.

 

[Blorg]

All the EQ profiles out there are evidently wrong, in my opinion.

& @NielsMayer The AutoEQ profiles are to a bass-light version of Harman, it's the worst of all worlds. AutoEQ software is great and you can EQ to whatever target you like then, not just the one (rather weird) choice the author of AutoEQ made.