[earfonia]

I've ordered 2x PM4, and so far only received 1 unit. I'm not really sure if my unit is in good condition, because of my impressions so far, and also some of my friends' impressions that have tried my unit, are not very positive and quite different from the review that I've read.
 
I have no issue with the tonality, more bass or less bass, and treble, they are tunable with filters. But my main concern is the fuzziness in the midrange. The midrange sounds fuzzy, with rather average or below average instrument separation. Beside poor instrument separation, the soundstage is rather congested as well, smaller imaging than what I use to experience with my other IEMs. Doesn't matter which filter I use, which I've tried all, the fuzziness is still there. My friends (@thatonenoob, @audio123, and others) also heard the fuzziness in the midrange.
 
Anyway, I will hold my judgment for now, until I hear more units of PM4 in Singapore. Hopefully, it is only my 1st PM4 unit that has a fuzzy midrange, and others would sound fine.

 

[esm87]

I've ordered 2x PM4, and so far only received 1 unit. I'm not really sure if my unit is in good condition, because of my impressions so far, and also some of my friends' impressions that have tried my unit, are not very positive and quite different from the review that I've read.

I have no issue with the tonality, more bass or less bass, and treble, they are tunable with filters. But my main concern is the fuzziness in the midrange. The midrange sounds fuzzy, with rather average or below average instrument separation. Beside poor instrument separation, the soundstage is rather congested as well, smaller imaging than what I use to experience with my other IEMs. Doesn't matter which filter I use, which I've tried all, the fuzziness is still there. My friends (@thatonenoob
, @audio123
, and others) also heard the fuzziness in the midrange.

Anyway, I will hold my judgment for now, until I hear more units of PM4 in Singapore. Hopefully, it is only my 1st PM4 unit that has a fuzzy midrange, and others would sound fine.

that is not what I hear, to my ears, pm4 is spacious and clear sounding with really deep low hitting bass, fairly vibrant midrange, nice clear vocals and clear highs.

I find this to be on either gold undampened or silver undampened. Silver just gives you more deep bass, its addictive.

I listen with either my mojo or sabre android hifime dac with cayin c5

To my ears, I think they represent really great value, thoroughly loving them

 

[dbdynsty25]

I'm kind of in the "fuzziness in the midrange" camp as well.  If not powered properly, they def sound a little fuzzy and unclear in the mids.  But if powered properly, that clears up quite a bit.
 
I shelved my Atlas when I received the PM4, thinking it would be far superior.  I'm not sure that's true.  At least not to my untrained ears.  I've tried every combination imaginable in both headphones.  I actually think I prefer the sound of the Atlas overall.  Obviously it's easier to drive w/ a portable (phone in my case, OnePlus 3T) because it only has 2 drivers vs. 4...so I almost need to max out my phone when at the gym to get the experience I want when working out.  With the Atlas I'm at about 75%.  The Atlas also fits me better...nestles in my ear better because it's smaller.  Yet somehow the sound seems bigger out of a phone.
 
Yes, when I stick them on my Micca Origen coming out of my PC, I can get closer because they are being powered properly, but 90% of my use case of IEMs is from my phone, without an amp.
 
So don't get me wrong here, the PM4 is probably a better headphone overall (and I'm sure most of the audio guys on here would crush me for even suggesting the Atlas can compete), but from my use perspective I think I prefer the Atlas.  Guess I should take my ad off of the Marketplace.  Anyone want a PM4?  LOL.

 

[cleg]

I've made a video with my initial impressions on PM4. Made it on Thursday, but published only today.

[VIDEO]https://www.youtube.com/watch?v=m19oUuAGClM[/VIDEO]

Disclaimer: 1. My strong accent is still here. 2. It's just an initial impressions, not a final review

 

[FUYU]

I've ordered 2x PM4, and so far only received 1 unit. I'm not really sure if my unit is in good condition, because of my impressions so far, and also some of my friends' impressions that have tried my unit, are not very positive and quite different from the review that I've read.

I have no issue with the tonality, more bass or less bass, and treble, they are tunable with filters. But my main concern is the fuzziness in the midrange. The midrange sounds fuzzy, with rather average or below average instrument separation. Beside poor instrument separation, the soundstage is rather congested as well, smaller imaging than what I use to experience with my other IEMs. Doesn't matter which filter I use, which I've tried all, the fuzziness is still there. My friends (@thatonenoob
, @audio123
, and others) also heard the fuzziness in the midrange.

Anyway, I will hold my judgment for now, until I hear more units of PM4 in Singapore. Hopefully, it is only my 1st PM4 unit that has a fuzzy midrange, and others would sound fine.

Did you listen to the original Sabre?
There is indeed something off, however I accounted this due to the upper frequencies in my review.
"[...] sounding artificial, with various peaks in frequency-response."
I have a hunch that there are internal reflections going on or something. However these issues are not quite as drastic to my ears. Can you share a frequency response graph? I'll get a measurement set-up myself at the end of the week, maybe we can find out the error.

 

[K3cknick]

Me, Can't believe is taking so long. I'm in Colombia, South America

I can't believe, either.
I'm in Japan and waiting for almost three weeks((

 

[RedTwilight]

I can't believe, either.
I'm in Japan and waiting for almost three weeks((

 
We've been waiting since June.. 

 
 
Any moment now..

 

[earfonia]

Did you listen to the original Sabre?
There is indeed something off, however I accounted this due to the upper frequencies in my review.
"[...] sounding artificial, with various peaks in frequency-response."
I have a hunch that there are internal reflections going on or something. However, these issues are not quite as drastic to my ears. Can you share a frequency response graph? I'll get a measurement set-up myself at the end of the week, maybe we can find out the error.

 
I only have Hyperion, which is fine, just a bit too V shape. I heard Delta which I quite like.
I'm no expert in IEM design, but observing some IEM design, some designers create a dedicated acoustic tunnel for each driver in multi-driver design, so not to mix the sound from different drivers in the IEM housing, and the sound from the different driver will only mix in the ear canal. My guess, again no expert in this, but my guess is I was hearing many reflections from inside the PM4 housing. Meaning, the sound from all the 4 drivers mix in the housing and might cause some reflections in the housing that might have caused the fuzziness that I hear. I'm not sure if it can be improved by providing a dedicated acoustic tunnel for each driver up to the nozzle end, to minimize the housing reflections. But the production cost might go up significantly due to the complicated housing.
 
I actually hesitant to post this measurement due to the following reason:
1. My measurement instrument is not a standard measurement instrument for IEM, therefore might cause misinterpretation. I measured using MiniDSP UMIK-1 measurement microphone with a DIY acoustic coupler.
2. Only for the PM4 measurement, the frequency response graph doesn't match the frequency response that I perceived, as well as others that have tried my PM4. For example, the measurement below is based on the gunmetal filter. What I heard with gunmetal, the tonality is quite balanced, full bodied, warm with a tad emphasized on the mid-bass to lower-mids. No treble peaks at all like what is shown in the frequency response graph below. And the bass part should be higher than what is shown. So please take note of that. The PM4 FR graph below doesn't match the perceived FR that I heard.
 
My current reference IEM for tonality is DUNU DN-2000 which I perceive to have flat tonality, matching very well with the frequency response graph using my measurement microphone.
 
What I notice is the PM4 measurement showing high distortion around the midrange area, which is what I suspect could be related to the fuzzy midrange that I heard. The peak level of THD is quite high in comparison to DUNU DN-2000, measured by the same equipment.
 
Below is the result of the Right Channel of both PM4 and DN2000, which is similar to the Left Channel:
 

 

 
Again, as I said earlier, I need to compare with other PM4 units. I'm not sure if the PM4 unit I received is a good one and sound similar to other PM4 units. So please read it with some grains of salt 

 

[1TrickPony]

Have the dn2k myself...just waiting for the pm4 this week. The former has the right amount of vocal details for male singers (why would an audiophile want their men to sound hollow anyway lol) so I am curious as to how they measure up in my ear these pm4s!

 

[WhiteKnite]

TBH I was concerned about comb filtering and phase issues since I first heard about the Trinity multi-driver design.  Based on the description cone filtering could be the culprit and would be diagnosable by taking some measurements.  However, having also played around with a UMIK for IEM measurements you are likely to get far more issues from the measurement setup than are already present in the IEMs, so yeah that is one massive grain of salt 

  Those THD measurements are definitely something to look into though, that doesn't look right at all.
 
Without seeing the internal design it is hard to say if comb filtering could be something to worry about.  Who wants to be the first to tear apart their PM4 for the sake of science?  It still wouldn't tell us anything definite, but would be informative.  

 

[FUYU]

I only have Hyperion, which is fine, just a bit too V shape. I heard Delta which I quite like.
I'm no expert in IEM design, but observing some IEM design, some designers create a dedicated acoustic tunnel for each driver in multi-driver design, so not to mix the sound from different drivers in the IEM housing, and the sound from the different driver will only mix in the ear canal. My guess, again no expert in this, but my guess is I was hearing many reflections from inside the PM4 housing. Meaning, the sound from all the 4 drivers mix in the housing and might cause some reflections in the housing that might have caused the fuzziness that I hear. I'm not sure if it can be improved by providing a dedicated acoustic tunnel for each driver up to the nozzle end, to minimize the housing reflections. But the production cost might go up significantly due to the complicated housing.







Again, as I said earlier, I need to compare with other PM4 units. I'm not sure if the PM4 unit I received is a good one and sound similar to other PM4 units. So please read it with some grains of salt 

Big thanks.
Indeed. Usually you have an acoustic tunnel (e.g. tubing or wave-guides) for most multi-driver designs. The problem for the PM4 is possibly, the off-angle the drivers are mounted and the large outtake/nozzle. The DN2000 is a great example for this. It doesn't use any tubing as well, however it is not planted in an off-angle, but rather planar to the nozzle. I don't think that the drivers have phase issues, though. (I remember Bob saying that the PM4 has no crossover implemented)
Some people have asked me for more comparisions with my other gear. I told them my observation of that 3.5kHz peak, which looking at your graph, seems to be the error. I generally only use the undampned filters, which might even further that perception. At least this gives me some confidence in my own hearing.

Frequency graphs should be only used in A/B scenarios, but that THD+N measurement is truly something to investigate further. Luckily the DN2000 is an earphone I've heard myself.

We can only wait for you to get the second PM4 and have more comparisions pouring in. Again, much thanks.

 

[silverre]

I've ordered 2x PM4, and so far only received 1 unit. I'm not really sure if my unit is in good condition, because of my impressions so far, and also some of my friends' impressions that have tried my unit, are not very positive and quite different from the review that I've read.

I have no issue with the tonality, more bass or less bass, and treble, they are tunable with filters. But my main concern is the fuzziness in the midrange. The midrange sounds fuzzy, with rather average or below average instrument separation. Beside poor instrument separation, the soundstage is rather congested as well, smaller imaging than what I use to experience with my other IEMs. Doesn't matter which filter I use, which I've tried all, the fuzziness is still there. My friends (@thatonenoob
, @audio123
, and others) also heard the fuzziness in the midrange.

Anyway, I will hold my judgment for now, until I hear more units of PM4 in Singapore. Hopefully, it is only my 1st PM4 unit that has a fuzzy midrange, and others would sound fine.

Is this with the undampened filters? I have heard the same with my pm4 with the undampened filters. But it gets better using the dampened filters. I can lend you my pm4 to try. I live in singapore as well.

 

[WhiteKnite]

Big thanks.
Indeed. Usually you have an acoustic tunnel (e.g. tubing or wave-guides) for most multi-driver designs. The problem for the PM4 is possibly, the off-angle the drivers are mounted and the large outtake/nozzle. The DN2000 is a great example for this. It doesn't use any tubing as well, however it is not planted in an off-angle, but rather planar to the nozzle. I don't think that the drivers have phase issues, though. (I remember Bob saying that the PM4 has no crossover implemented)
Some people have asked me for more comparisions with my other gear. I told them my observation of that 3.5kHz peak, which looking at your graph, seems to be the error. I generally only use the undampned filters, which might even further that perception. At least this gives me some confidence in my own hearing.

Frequency graphs should be only used in A/B scenarios, but that THD+N measurement is truly something to investigate further. Luckily the DN2000 is an earphone I've heard myself.

We can only wait for you to get the second PM4 and have more comparisions pouring in. Again, much thanks.

 
Comb filtering is a phase issue.  This could be could be related to reflections or differences in driver distance.  Check out this video if you are curious for a great description of comb filtering. https://www.youtube.com/watch?v=w0NQwQuSMFk  We need someone with a good measurement setup to run a waterfall graph and see if that is what you guys are hearing.  

 

[earfonia]

TBH I was concerned about comb filtering and phase issues since I first heard about the Trinity multi-driver design.  Based on the description cone filtering could be the culprit and would be diagnosable by taking some measurements.  However, having also played around with a UMIK for IEM measurements you are likely to get far more issues from the measurement setup than are already present in the IEMs, so yeah that is one massive grain of salt :wink_face:   Those THD measurements are definitely something to look into though, that doesn't look right at all.

Without seeing the internal design it is hard to say if comb filtering could be something to worry about.  Who wants to be the first to tear apart their PM4 for the sake of science?  It still wouldn't tell us anything definite, but would be informative.  

Yes, due to non-standard measurement equipment, i can only use it in comparison to other IEM, and that measurement result cannot be compared with other measurement using different setup. That's the reason for showing comparison with DN-2000 measurement result.

 

[WhiteKnite]

Yes, due to non-standard measurement equipment, i can only use it in comparison to other IEM, and that measurement result cannot be compared with other measurement using different setup. That's the reason for showing comparison with DN-2000 measurement result.

Yep, and unfortunately in order to see if it is being caused by ringing or reflections we'd need a proper IEM measurement rig.  Otherwise the reflections could just as easily be coming from your setup.  Also, even one IEM to another I've found my DIY rig to be pretty inconsistent.  Just changing tips can have a MASSIVE effect on my measurements when in my ear I am hearing very minor changes.