Penon PAC English Review


Priceless Warmth




Construction and Design




  • Improved classic sound.
  • Construction.
  • Ergonomics.
  • Magnetic absorption.
  • MMCX connection.




  • The treble is soft, which for some may be a virtue, for others a defect.


Purchase Link


Link to the Store




Sometimes, the world of portable audio brings juicy and very affordable surprises. Like, for example, the earbuds I’m going to review today. These are the Penon PAC, headphones that cost $50 or nothing. 50$ is the price stated on the purchase website. But, in fact, you can get them for free if you buy from Penon Audio, any of the cables or IEMS listed on the website. There are more than 30 products that can come with these exclusive earbuds, which feature a 15.4mm dynamic driver with a titanium PET composite diaphragm. As standard, they have an MMCX connection and no cable. So it’s only natural that they come with a cable, isn’t it? Let’s see what these attractive and inexpensive earbuds can do.





  • Driver Type: 15.4mm dynamic with PET composite titanium diaphragm
  • Frequency Response: 20Hz-20kHz
  • Sensitivity: 106dB
  • Impedance: 40Ω
  • Cartridge Connection Type: MMCX





Penon PACs are not sold on their own, but are available by purchasing a cable or IEMS. In this way, they accompany another product and have no packaging as such.
In my particular case, they came in a small velvety cloth bag, with the Penon logo in the middle. When I took them out of the bag, I saw that they were doubly protected by a little plastic zip bag. Nothing else. No additional accessories, no cables, no foams. You would think that the presentation and the non-existent content is very poor. But it’s free, what more do you want?



Construction and Design


The Penon PAC has a very nice design. It is true that it is not new and there are very similar shapes on the market. But there is no doubt that the PACs have a winning construction. Each capsule is a cut-out cone, the slope of which is rounded. The back is flat and can be said to be regular in shape. Only the gold-plated MMCX connector breaks the harmony of the design. The MMCX connector is a gold-plated cylinder that protrudes out of the cone skirt, very close to the rear face of the earbuds. They are completely black and metallic. The back face has a concentric circular engraving, while the cone has a smooth and shiny surface. The rim is cleanly coloured and the metallic nature of the earbuds is visible. The emitter face is made of plastic very similar to that of the classic MX500 earbuds. On each capsule is a white capital letter, indicating the channel.
The outer faces are magnetised, allowing the two to stick together by magnetic absorption.
The MMCX connection appears to be of very high quality and the connection with the cables confirms this, as the fit is tight, durable and strong.
The diameter of the capsule is approximately 16.8mm.
The weight is very low, despite the metal construction.
Stellar, simple construction and design for a minimal price.



Adjustment and Ergonomics


A simple, conical, gently rounded design, although relatively large in diameter, has a very simple fit. The plastic inner face makes it easy to grip and the conical shape greatly aids the fit in the pinna. Not new, but very effective, PAC earbuds are comfortable and allow free ergonomics: they can be worn with the cable downwards, or with the cable upwards, as they could be worn if the cable used had over-ear guides. This may not be the most normal way, but it is always an option.
The diameter is common, on the conventional side, but large. No bigger than the classic MX500 capsule. All in all, it’s a step or two beyond simple earbuds, which means a higher degree of satisfaction in terms of fit and ergonomics.
Last but not least, even though they are metal, the weight of the earbuds is not noticeable, because they are quite light.







The Penon PACs have a warm tendency, with a good presence and energy in the low end, which mellows out as the frequencies rise. There is a controlled rise in the early treble, something that provides a certain V-note. But I stand by my idea that the most dominance is in the low end, but with a good balance and transition between the three bands.
I have used donut foams to amplify clarity and improve detail perception, without detracting from the bass presence.
Although I have tested several cables with the PACs, both copper and silver-plated, I would like to point out that pairing them with the latter is more beneficial. Among several silver-plated cables that I own, one of the winning combinations has been the pairing with the Penon Orbit, a 4-strand cable, with 154 cores each, for a total of 616 cores. Coincidentally, when you buy this cable, PACs come as a free gift, so your link is a pretty clear choice. The Orbit cable elevates the clarity and technicalities of the PACs, gaining in transparency, separation and resolution. The treble is more evident, but still maintains the characteristic smoothness. It is not an added emphasis, but a sharper perception.




Thanks to the good fit, the bass presence is really full, both in amplitude and extension. The bass in the earbuds doesn’t usually seem the fastest or quickest, when there is a good level of emphasis. But, you could say that the PAC bass has a fairly appreciable and tight punch, which gives it a good degree of dryness and precision. Both the sense of depth and the breadth of the bass help to accentuate the warm character of its profile. The colour of the range is quite dark, which also contributes to the perception of this warmth, as well as to the overall smoothness of the sound, which is based on a perceptible and physical sub-bass. There is a slight colouring in the pure LFO reproduction, but the tones from 40Hz onwards become realistic and punchy, with a completely pleasant physical-visceral point, with a natural tendency. In this sense, the PACs pass this test on a high note, offering one of their best sides. I don’t want to claim that the PACs are only bass-heads earbuds, because I consider that they have more virtues. But there is no doubt that their lower range is quite remarkable, both in quantity and performance. And I think it can be easy for earbuds to offer a wide, but not extended low end towards the sub-bass, with power, depth and punch, without losing resolution or precision. And that’s what the PACs achieve, bass with character, power, control and definition, able to generate layers and a good level of stratification, enriching the lower range, without ever dissipating it, or showing it bloated, to the point of masking the details. Very good work.





The mid-range starts off with warmth. But I perceive a kind of U-tuning, which avoids excessive body or emphasis in the first half, managing to keep away any muddy, undesirable sensations. The male voices come across as full, but on the soft side of their presence. They are very harmonious, silky, grounded on a very solid bass base, which gives them a broad, full-bodied positioning, but without monopolising the scene, or appearing too close or intimate. Undoubtedly, in acoustic pieces, the protagonism of the male voices is powerful, but the PACs generate a lot of space for the instrumentation, something that enhances the scene, as expected from good earbuds. The sparkle of the early treble helps to finish off the vocals with a good amount of detail, enriching their velvety surface with delicate nuances.
On the other hand, the female voices feel slightly withdrawn, compared to their male counterparts. Their drawing is not as full, nor is their base as rich or broad. One could say that their birth is situated at the deepest part of the frequency response. But the subsequent growth helps them to boast clarity, detail and a good level of transparency. But that doesn’t detract from the fact that they can be perceived as somewhat muffled overall. And this feeling is not unique to female voices. The combination of warmth, softness and bass presence give the midrange as a whole a less vivid character. I miss a higher level of sparkle, energy and brightness, helping the mids to emancipate and soar. However, the midrange remains in that soft and less luminous performance, which is usual for warm earbuds. The advantage is still the good level of detail, separation, definition and scene width achieved in this range. A differential virtue that increases its value compared to other earbuds with good bass.




The upper zone begins with the typical restrained initial flare and its subsequent control zone. The treble is smooth and contained in its extension. The impact on the sound is noticeable in the details and nuances of the mid-range, which makes the two bands blend very well together. But this fact also allows for a more homogeneous and continuist sound, without big flashes in this upper range.
The treble is not the protagonist and its role is complementary, beyond the initial phase. I would have liked a little more notoriety in their presence, with the intention of offering a sound with more energy and sparkle. But, on the contrary, the PACs are more contained and homogeneous in this sense.
The result is a fairly thin treble, without much emphasis and, as I said, with a restrained extension, something that cuts out a more elongated projection and a higher level of harmonics.



Soundstage, Separation


The scene is moderately wide. There is no congestion, despite the good bass presence and warmth of the sound. The male voices are closer together, which adds a certain intimacy in the first half of the middle range. However, the second half is more spaced out and in the middle distance, which helps to separate the range. The good level of resolution also contributes to this sense of distance between elements.
The remarkable depth helps to expand an already corporeal and well-grounded scene, albeit without much height and an average amount of air.
The three-dimensional perception is not very high, a spacious and frontal presentation persists, with good lateral presence, due to its marked width.




Yincrow RW-9


When I tried the Penon PAC for the first time, I remembered that I hadn’t used the RW-9s for a long time. So a comparison between the two was in order. It is clear that, at the construction level, one uses the classic MX500 capsule, in a bright red, with a matching braided cable. While the PACs have an aluminium construction and MMCX connection. The possibility of changing cables and the metal body, as well as the freer ergonomics of the Penon PACs, add a clear advantage in this respect.
Apart from the obvious constructional differences, both have a warm sound, with a noticeable bass base. The first difference is their sensitivity, which is higher in the Penon PACs. At equal volume, the PACs sound clearly louder. After matching volumes, I realised, to my surprise, that both have a very similar profile. The low end has a very similar presence, with a similar forcefulness and dryness. The treble is smooth on both and I think there is a little more emphasis on the PACs, but the foams could equalise the presence.
Both the tone and colour of the subwoofers, in the pure tone test, is completely analogous and I would venture to say that the differences are produced by the sonic behaviour of the capsules of each. The MX500 capsules contribute to a bass-enhancing sound, as opposed to PK-type capsules or others of particular design. In this sense, both earbuds have an equivalent loudness, with similar technical properties. I think the PACs are subtly more technical and the RW-9s have less colouring in the LFOs.
In the mid-range, the warmth in both has the same gradation. But the PACs have a little better definition and are smoother in the sibilance, where the Yincrow is a little more unresponsive, comparatively speaking. I perceive more sink in the RW-9s on female voices and a superior pronouncement on those sibilances. On the PACs it is the other way around and this is an improvement in the fullness and final result of the voices. The male voices are fuller and closer in the Penon, with a wider body, a wider base and better outlined details. The same is true of the mid-range instrumentation. The PACs have more integrity and closeness, without losing musicality. The sound is more equilibrated, with a more appropriate and better balanced tone, between its fundamental and harmonics.
The treble is again similar, but subtly softer on the RW-9s. The slight technical increase in the PACs makes the treble thinner and more delicate, while the Yincrow is rounder, giving a more restrained sparkle and the sensation of less extension. There is more air in the PACs.
The soundstage is perhaps a little deeper on the RW-9s, but the PACs’ better technicalities, more evident clarity and transparency, and more perceptible separation add a greater sense of spaciousness to the overall sonic recreation of the Penon.
You could say that the PACs are an improved RW-9, with increased midrange definition, more separation and more resolution. Their expression is more precise and concise, something that gives them a more refined and perceptible detail, with more explicit edges, offering a higher level of description, with more information. Add to this a freer, more durable metal construction, ergonomics that could be better in many ways, and the ability to use any MMCX cable, and it’s a winning combination over the Yincrow RW-9.
The tests have been carried out with the same type of donut foams.





It seems clear that the Penon PACs have a classic warm sound, but very well implemented. A winning bass base, present, deep, energetic, yet well controlled, is joined by enhanced technical characteristics, a good level of resolution, definition and smooth highs, with a hint of sparkle. To top it all off, the metal construction, the symmetrical, simple and effective design, plus an MMCX connection, elevates the value of earbuds that can be had as a gift with the purchase of many good wired models or some other headphones. What more could you ask for?



Sources Used During the Analysis


  • IFI Audio xDSD Gryphon.
  • Aune BU2.
  • S.M.S.L Sanskrit 10th MKII + iFi ZEN CAN.
  • Hidizs AP80 PRO-X.
  • Earmen Colibri.
  • xDuoo Link2 BAL.