Panasonic RP-TCM125 Review (Budget IEM)

[sejarzo]

Amir, thank you so much for bringing detailed IEM measurements to us!

So you chose the Harman preference curve again for FR target, will this affect your ratings on Etymotic Research IEMs that tries to simulate human perception of flat frequency response from an ideal studio monitor? Their curve is "bass light" and treble recessed, yet IMHO a different approach towards accurate sound reproduction.

I love my Ety ER3SEs but ONLY with EQ because there is simply no freaking way that "bass light" response sounds like real music to me, live or on a properly set up speaker rig.

There is something "pristine" about the sound of good IEMs, especially BA's like Etys, though they don't have those "perceived spatial qualities" on most pop/rock material. That is, until you listen to a properly executed binaural recording or a small ensemble using a single stereo mic rather than a multitrack mix from close-mic'ed tracks, and then those qualities seem just right.

 

[stevenswall]

This is a review and detailed measurements of the Panasonic RP-TCM-125-A in-ear monitor. I purchased this from Amazon and costs US $15.10 including prime shipping (retail $19.99). I picked this because it was used in Olive et al. research (see below). Yes, folks, we are getting into measurements of IEMs! I have a bunch which have come for review and I constantly get offers to test more. So I finally allocated a bit of time to see how my GRAS 45CA fixture can measure them and to my delight, it was dead easy, far more than any headphone I have measured! Time will tell however as I measure more whether this is typical or not.

I have a pair of Jerry Harvey Audio Lola earphones I'd be happy to send. They are quite unique... Dual opposed midrange drivers, "phase aligned" if that makes a difference, and a separate circuit for the bass.

Jerry Harvey (JH Audio) is the guy who created Ultimate Ears, and I've directly compared the Lola to flagships by UE, 64 Audio, Westone, and Shure... I'm curious if it was just impressive because it was colored, or if it truly plays well across genres. Part of me imagines I might be satisfied with an Etymotic, though my MC5 sounds flat in comparison.

Curious who the "Genelec" of IEMs is.

 

[stevenswall]

I love my Ety ER3SEs but ONLY with EQ because there is simply no freaking way that "bass light" response sounds like real music to me, live or on a properly set up speaker rig.

There is something "pristine" about the sound of good IEMs, especially BA's like Etys, though they don't have those "perceived spatial qualities" on most pop/rock material. That is, until you listen to a properly executed binaural recording or a small ensemble using a single stereo mic rather than a multitrack mix from close-mic'ed tracks, and then those qualities seem just right.

Have you tried the XR series? Those have temped me, but I do think there is something about perceived spacial qualities and "fullness" that requires multiple drivers or dynamic drivers.

 

[Harmonie]

How about pads (let’s say Alcantara). Is soapy water fine?

We were talking about silicone inserts so far.
AFAIK Alcantara's base is pet (polyester), so yes it should be fine, but beware of stains, like with all velvet type of fabrics.
Just brush it gently (no soaking of course).
Better if you look for dedicated Alcantara cleaning/maintenance recommendations.

 

[Nathan Raymond]

For measurements I had used the middle sized silicone tip that came preinstalled. They fit perfectly in the measurement fixture. On my ears though, even though they stayed put, there was no bass at all. In that regard, it didn't sound too horrible. Since I usually wear larger tips, I swapped out the larger size.

So glad to see you venture into IEM reviews!

One thing worth considering to some degree, even though it can make IEMs a bit complicated to review, is the fit and the effect of the eartips - which it's good to see you talking about to an extent already. I have quite a few IEMs and I also have about 30 different types of aftermarket eartips, the reason being that I prefer to tune each pair of IEMs with the best tips rather than use an EQ, both for fit reasons, but also because I change what devices I plug my IEMs into a lot (and change what IEM I am using pretty frequently) so try to get the best sound out of each without an EQ. The ear tip material affects fit and sound: thin silicone, thick silicone, mixed materials (pliant silicone, stiffer silicone, thermally reactive polymer, hybrid foam/silicone, dense foam, soft foam). Also the bore (diameter of the opening), shape of the opening (cylindrical, horn shaped, etc.) and depth (which can affect the resonant frequency and shift it up or down the spectrum). An IEM reviewer can't be expected to test an IEM with every possible tip, that's just not practical! But it might be worth including a couple other tips regularly as alternative reference points in reviews to try and figure out what an IEM is capable of in case the included tips just weren't that great, or to ascertain what impact the stock eartips have on the capabilities of the IEM. At the very least some commentary on what the stock tips are like to try to give the reader an idea of how well they work out of the box vs. how well they might work with aftermarket tips would be helpful I think.

Also consider that personal experiences with IEMs will vary more because they bypass a lot more of the external structures of the ear and ideally they compensate for that with their acoustic performance in way that works for the individual listener. Over-ear headphones include the listener's outer ear as part of the acoustic equation (bypassing just most of the head and torso), so personal experience variation tends to be less variable - though wearing glasses can significantly affect pad seal and create a big variation for over-ear. In-ear does eliminate glasses breaking the seal, but whether the tips seal well or not or whether things like any vents in the body of the IEM are pressed up against the skin of the ear so they get partially sealed (which can vary with the fit on each person, which can be affected by the tips as well as the outer structure of the ear) will change how the bass sounds in an IEM. Also there are aftermarket eartips which are designed to do things like enhance the bass (typically by making the stem out of a thicker silicone) and decrease the treble (which can be done by reducing the bore size, i.e. inner diameter, as well as other designs). Physical changes to the eartip can affect the stereo presentation and what kind of a sound field you get, which makes them more complicated than an EQ. I also think that some sub-bass experience with IEMs is tactile and that if an IEM is producing sub-bass the type of tip and seal it has can have an impact on that tactile sensation that is not just acoustic. For all those reasons I think EQ is not a 1:1 substitute for and cannot simulate all that different eartips do.

I hope some of these thoughts and observations are helpful.

 

[phoenixsong]

So glad to see you venture into IEM reviews!

One thing worth considering to some degree, even though it can make IEMs a bit complicated to review, is the fit and the effect of the eartips - which it's good to see you talking about to an extent already. I have quite a few IEMs and I also have about 30 different types of aftermarket eartips, the reason being that I prefer to tune each pair of IEMs with the best tips rather than use an EQ, both for fit reasons, but also because I change what devices I plug my IEMs into a lot (and change what IEM I am using pretty frequently) so try to get the best sound out of each without an EQ. The ear tip material affects fit and sound: thin silicone, thick silicone, mixed materials (pliant silicone, stiffer silicone, thermally reactive polymer, hybrid foam/silicone, dense foam, soft foam). Also the bore (diameter of the opening), shape of the opening (cylindrical, horn shaped, etc.) and depth (which can affect the resonant frequency and shift it up or down the spectrum). An IEM reviewer can't be expected to test an IEM with every possible tip, that's just not practical! But it might be worth including a couple other tips regularly as alternative reference points in reviews to try and figure out what an IEM is capable of in case the included tips just weren't that great, or to ascertain what impact the stock eartips have on the capabilities of the IEM. At the very least some commentary on what the stock tips are like to try to give the reader an idea of how well they work out of the box vs. how well they might work with aftermarket tips would be helpful I think.

Also consider that personal experiences with IEMs will vary more because they bypass a lot more of the external structures of the ear and ideally they compensate for that with their acoustic performance in way that works for the individual listener. Over-ear headphones include the listener's outer ear as part of the acoustic equation (bypassing just most of the head and torso), so personal experience variation tends to be less variable - though wearing glasses can significantly affect pad seal and create a big variation for over-ear. In-ear does eliminate glasses breaking the seal, but whether the tips seal well or not or whether things like any vents in the body of the IEM are pressed up against the skin of the ear so they get partially sealed (which can vary with the fit on each person, which can be affected by the tips as well as the outer structure of the ear) will change how the bass sounds in an IEM. Also there are aftermarket eartips which are designed to do things like enhance the bass (typically by making the stem out of a thicker silicone) and decrease the treble (which can be done by reducing the bore size, i.e. inner diameter, as well as other designs). Physical changes to the eartip can affect the stereo presentation and what kind of a sound field you get, which makes them more complicated than an EQ. I also think that some sub-bass experience with IEMs is tactile and that if an IEM is producing sub-bass the type of tip and seal it has can have an impact on that tactile sensation that is not just acoustic. For all those reasons I think EQ is not a 1:1 substitute for and cannot simulate all that different eartips do.

I hope some of these thoughts and observations are helpful.

I agree with your points on how tips affect sound. However, by the second half, do you mean that the sound will be more standardised as it bypasses the different shape of our ears, but in doing so, results in us perceiving a sound that we're not used to?

 

[Nathan Raymond]

After using EQ with Roon on my Sennheiser 5XX, 650 and Audeze LCD-2 Classic, there's no going back. If one of the Cinese manufacturers would make a good portable DAC/amp combo with real PEQ, I would happily go back to wired headphones when on the go.

If you're not aware of it already, you should check out the Qudelix-5K since it has a 10-band PEQ with 20 custom save slots (so you can configure up to 20 different PEQs and switch between them) and can run as a USB DAC/amp. The app to configure it runs on a mobile device and communicates with the Qudelix-5K via BlueTooth, and I don't think there is desktop software that can control it when it is running as a USB DAC/amp so you would have to switch your PEQ preset before using it in wired mode if you go that route, but otherwise it should do what you want. Also it does support LDAC so if you have an LDAC source you can do CD quality wireless sound and maintain complete control with their app while using it that way.

 

[Nathan Raymond]

I agree with your points on how tips affect sound. However, by the second half, do you mean that the sound will be more standardised as it bypasses the different shape of our ears, but in doing so, results in us perceiving a sound that we're not used to?

Crinacle does a good job of explaining this if you skip down to the "Measuring Systems" part of this article:

https://crinacle.com/2020/04/08/graphs-101-how-to-read-headphone-measurements/

I was originally going to say that IEMs are less standardized than headphones, but based on this I'm not so sure:

But simulating the whole body is only relevant when trying to find out how the human body interacts with sound in open air, as is the case with curves such as Diffuse Field and Free Field. In the case of headphone and IEM measurements, only the body parts that directly interact with the transducer are required.

For headphones, that will be:

• The flesh and bone surrounding the ear (that comes in contact with the pads)
• The outer ear structure
• The space between the outer ear and eardrum (which includes the ear canal)

Whereas in IEMs, only the last part is required for measurements since they bypass the head and pinna flange.

Anyone care to chime in?

 

[phoenixsong]

Crinacle does a good job of explaining this if you skip down to the "Measuring Systems" part of this article:

https://crinacle.com/2020/04/08/graphs-101-how-to-read-headphone-measurements/

I was originally going to say that IEMs are less standardized than headphones, but based on this I'm not so sure:



Anyone care to chime in?

I'm unable to find the answer you were referring to- maybe it's because I do not know what I'm supposed to be looking for in the first place

 

[amirm]

I am still not clear on the testing you all want on different tips. To the extent they change the fit, I don't know how relevant any testing I do is as that varies from person to person. If you mean that the fit stays the same but they are different in other ways, can you post some examples?

 

[Lunafag]

I am still not clear on the testing you all want on different tips. To the extent they change the fit, I don't know how relevant any testing I do is as that varies from person to person. If you mean that the fit stays the same but they are different in other ways, can you post some examples?

Tip's bore diameter, tip length. From my understanding they work as an acoustic resonator and can change FR quite a bit. Even simply the insertion depth can. Maybe tips from different materials than silicone, like foam tips, hybrid foam/silicone, azla xelastecs. Then there's exotic stuff like lizer lab jiju that supposedly adds reverb? All kinds of aftermarket stuff.

 

[amirm]

I can see the tip dimension making a difference but how do you control insertion depth on your own ears? And how would I do that in my fixture???

 

[Lunafag]

Crinacle says on his site

6. Expect a resonant peak. This peak exists around 7-10k and is affected by insert depth. If you are not sure what I’m talking about, don’t try to be smart. Ignore frequencies above 7k until you do.

7. Insert depth for measurements is NOT constant. I attempt to have all measurements performed with a 8000Hz resonance. However, due to the nature of certain IEMs, I may have to use deep inserts to emulate how the IEM should be used (i.e. ER4), or in other cases simply having to work with a shallower fit due to shell constraints (i.e. FitEar demos). As such, the final insert depth/resonance point of each measurement is essentially arbitrary and up to my own discretion.

I'm not trying to be smart so it's probably the best to just ask him. From my experience inserting IEMs deeper sometimes can reduce the sibilance, no experience with fixtures whatsoever.

 

[phoenixsong]

I can see the tip dimension making a difference but how do you control insertion depth on your own ears? And how would I do that in my fixture???

Some tips, like the Azla Sedna, have longer bores which extend further in than the Azla Sedna Short would, for example

 

[phoenixsong]

Crinacle says on his site

I'm not trying to be smart so it's probably the best to just ask him. From my experience inserting IEMs deeper sometimes can reduce the sibilance, no experience with fixtures whatsoever.

Oh this! It is a measured phenomenon even for the same model of tip. Apparently it shifts the frequency of the measured treble resonance spike up and reduces its amplitude with deeper insertion. Question is how to gauge the insertion depth hmm...

 

[deprogrammed]

+1 or soapy water, well rinsed and dried.
I would avoid alcohol and sprays that will be aggressing the silicone.

I use dawn dish soap. Let them soak in hot tap water for bit.

 

[markanini]

Crinacle says on his site

I'm not trying to be smart so it's probably the best to just ask him. From my experience inserting IEMs deeper sometimes can reduce the sibilance, no experience with fixtures whatsoever.

Hold on. That might be be true in select cases but there's a physical limit to how deep you can inset most IEMs, which are designed for shallow insertion. If your IEM passes through a canal resonance at 7kHz inserting them in a few mm depper will not be enough to shift the peak outside the audible range. Save for IEMs designed for deep insertion. If an IEM shows an excessive canal resonance it means
it's not tuned properly, and it would be disingenuous to put that on the user.

 

[dougi]

I can see the tip dimension making a difference but how do you control insertion depth on your own ears? And how would I do that in my fixture???

For my Ety er4p when using triflange tips I have to insert past what you think is ok, to get deep bass. To the point it sometimes makes you cough.

 

[Maiky76]

Note the target used in this review is an old, outdated one from 2017. Both Oratory and @jaakkopasanen of AutoEQ are now using Harman's latest 2019 in-ear target for their EQ profiles. Oratory's measurements show Samsung's (who own Harman) Galaxy Buds+, released in 2020, follow this latest target very closely:

View attachment 126363

Incidentally, the Sony MH750 shown below (or the even better sounding MH755 if you don't mind the short cable) match this target very well too (and at around $10 a pair are a far better buy than the Panasonics of this review with their awful stock response):

View attachment 126365

Here's what Oratory says about the latest 2019 target:


And on the 2017 target and why the new target is an improvement:


(My emphasis)

And here's the Listen Inc. page where you can download the new target (under the 'Get Sequence' tab, just need to fill out a quick registration form). Note under the About tab it says:


The spreadsheet is the file that contains the new target, so this confirms it comes directly from Harman's Olive, Welti and Khonsaripour.

Good spot! I have been using SC (not very user friendly and very expensive) for years but I have been playing around with Harman targets before they implemented their "Sequence" hence my use of the first published target.

Here are the revised scores.

Score no EQ: 16.7 (was 9.6)
Score with Amirm EQ: 79.6 (was 74.2)
Score Original EQ: 104.5 (was 108.5)
Score revised EQ: 108.8

Panasonic RP-TCM125-A APO EQ Score 2019 96000Hz
April272021-094135

Preamp: -7.4 dB

Filter 1: ON PK Fc 161.7 Hz Gain -9.55 dB Q 0.29
Filter 2: ON PK Fc 890.5 Hz Gain 3.25 dB Q 0.92
Filter 3: ON PK Fc 4776 Hz Gain -5.25 dB Q 3.86
Filter 4: ON PK Fc 6651 Hz Gain 8 dB Q 2.43

Original EQ with 2019 target

Revised EQ to match the 2019 target

EDIT:
Score OTT for those who can't help themselves, that includes myself:

Score OTT: 112.6 (max is 114.5)

Panasonic RP-TCM125-A APO EQ Score 2019 OTT 96000Hz
April272021-104612

Preamp: -7.5 dB

Filter 1: ON PK Fc 169.7 Hz Gain -9.58 dB Q 0.29
Filter 2: ON PK Fc 240 Hz Gain 1 dB Q 5.9
Filter 3: ON PK Fc 830 Hz Gain 3.44 dB Q 1
Filter 4: ON PK Fc 1797 Hz Gain 0.9 dB Q 2.37
Filter 5: ON PK Fc 4781 Hz Gain -5 dB Q 3.36
Filter 6: ON PK Fc 6711 Hz Gain 8 dB Q 2.43
Filter 7: ON PK Fc 7929 Hz Gain 2.46 dB Q 7.27
Filter 8: ON PK Fc 8774 Hz Gain -2.29 dB Q 7.45
Filter 9: ON PK Fc 10449 Hz Gain 3 dB Q 6.63

 

[bobbooo]

Good spot! I have been using SC (not very user friendly and very expensive) for years but I have been playing around with Harman targets before they implemented their "Sequence" hence my use of the first published target.

Here are the revised scores.

Score no EQ: 16.7 (was 9.6)

This seems more reasonable. I mean the stock response is really bad, but not 1/10 completely-and-utterly-broken bad... ~2/10 looks more sensible, and is closer to the actual rating given by listeners in the blind tests of Harman's research, which adds further support to using the updated 2019 target over the old 2017 one.