Introduction
You probably aren’t too unfamiliar with Penon, but in case you are, Penon is an online audio store, established in 2013 and has been working ever since to sell audio product at an affordable price.
Along with their online store, they also create their own audio brand in 2018 under the same name. Penon has always been known for making great sounding iem at various price ranges, configuration as well as playing with a lot of different yet still good sounding tuning.
And now, as part of the world wide tour, Penon has sent me one of their latest iem, the Penon Quattro, in exchange for my honest review.
Disclaimer: I receive no benefit from Penon from doing this other than having the experience of listening to the Quattro, as I have to send the iem for other reviewers at the end of the tour. What I said in this review is my subjective opinion only.
So what is Quattro? Quattro is an iem with a 4 dynamic drivers configuration. Out of the 4 drivers, there are 2 10mm drivers facing each other to handle the bass, an 8mm driver for the mid and a custom 6mm driver for the treble. Quattro is said to be the successor to their Serial, which is one of a rare few 3 dynamic drivers iem in the market.
Packaging
The Quattro arrived to me in the same sized package like many other Penon iem. Inside of it are a small leather pouch and a blue carrying case, which house the iem, the cable, 9 pairs of eartips at various sizes+types, a clip and a cleaning brush.
Even if you don't have other 3rd party eartips, these 9 pairs should be able to give you a decent fit to start enjoying the Quattro.
Design/Build quality/Comfort
The housing of the Quattro is made out of semi black-stransparent medical grade resin. It feels light yet sturdy in the hand.
The faceplate looks really nice too. It has many pieces of blue stabilized wood panels with some subtle, yellow-ish, white-ish wood grains inside of them. This sort of color way reminds me of the famous painting “Starry Night” by Van Gogh.
Size wise, the Quattro is on a bigger side than average. It’s not something outrageously big like the Hidizs MP145 though, so i have no problem wearing it. I can wear the Quattro for 2 hours straight without feeling pain
The cable on the other hand is an interesting choice. It’s a 2pin, 4 core graphene cable with 4.4mm connector. They have deliberately chosen this cable in this blue color to have it better matched with the theme of the faceplate. The cable feels thick and sturdy. It feels a little bit stiff when i try to wrap it to take some pictures, but it does soften up over time.
Sound Impression
- Okay, before going deeply into the sound impression, I must say something beforehand: My unit of Penon Quattro has both sides out of phase. It’s not that the left and right side are out of phase with each other. It’s just that they're in reverse phase together. How do I know this? I have an iec711 coupler and when I measure it, it shows the phase response like this. (the dotted green line).
- Now measurement wise, that is actually how an iem with the correct phase should look like. However, I know my coupler was wired incorrectly(+ wire at - and - wire at +), which is usually a characteristic of a copied coupler. So any iem that measures correctly, it would actually be out of phase irl.
Here's what would happen if i reverse the polarity of the measurement.
- Does it matter? Most of the time, no. As long as both sides have the same polarity, you probably won't recognize it, most of the time. I personally did not recognize it until I measured it. I say this in case you’re someone who are picky about it and worry it may affect the staging and such of the iem, can just rotate the 2 pin part 180 degree and the “problem” would be solved.
- If you’re wondering if it’s the cable’s fault, no it’s not. I’ve already checked the cable using the multimeter and the cable was wired correctly
That is why during the review of this iem, I've rotated the cable and listened to the iem in the correct polarity.
*Test gears:
Source: Poco F3+UAPP, Dell laptop + Foobar 2000
Dac/Amp: Chord Mojo, E1DA 9038D, Ibasso DC04 Pro, Hiby FC6
Cable: Stock
Tips: Divinus Velvet, Penon Orange + Black Liquer tips
Iem has been burn in for more than 200 hours
Tonality: Warm + bassy + colored sound.
Even without the burn in, when first listen to the Quattro, the first thing i get is how bass dominant this iem is. Not in an L-shaped tuning kind of way, but more balancing and organic sort of way, showcasing that the bass is the star of this iem
Bass: Even with a dual DD handling it, the bass does lean more towards a more musical side rather than a technical side. The subbass has good extension with a lot of air movement, but its quality was a little bit lacking to my taste, almost like it’s too diffusing.
The midbass actually stands out more compared to the subbass, like it’s drawning out or masking the subbass rumble, even if the graph said other wise. Although it doesn’t have the quickest transients, a bit on a sluggish side, it does have a very addicting sense of reverb and dense texture to it.
Contrabass, kick drums, cello and saxophone in many jazz tracks sounds amazing. Even if the bass region is very dominant as a whole, each bass element in those tracks sounds very distinctive nonetheless. Taiko drums and Chinese traditional drums sounds very natural and they pack a great sensation behind each note.
On metal or fast pace rock songs though, i do feel like the Quattro’s having problem keeping up with the bass and drumming sessions.
Mids:
Since there’re a lot of bass bleed, the whole lower mids feels very warm, thick and weighty. Male vocals like Frank Sinatra, Michael Buble sounds lush and full bodied. Female vocal sounds smooth, organic and euphonic, but not in a shouty, over-energetic sort of way. The bleed introduces some huskiness feeling to some female vocals. Soprano sounds smooth with just enough vibrancy to make it pop out from the rest of the instruments in the orchestra tracks. However they do felt a bit recessed due to how forward the bass line was.
Similar thing happens for the instruments here. There’s some noticeable coloration happening for the violin, piano. They still sound velvety and natural, but they have this sort of heavy and dense sensation in the note weight.
All in all, you’d either embrace the warmth and richness goodness of the midrange, or you don’t. This coloration would not be suitable for the monitoring purposes.
Treble:
The treble as a whole sounds very smooth, non-fatiguing with soft decay to it. Compared to the bass, the treble range serves more as a supporting character rather than its own thing. It has a delicate feeling to it.
Cymbals and hihats still sound present with enough brilliant, but it’s not very crisp and airy sounding.
There’s a dip around 6khz that makes the Quattro very sibilant free, but also makes the treble have a darker edge to it. Some instruments timbre was affected because of it.
With the Quattro, i tend to have a better listen session at louder volume, which makes the treble region stands out more. If i listen to it at a lower volume, the treble got a bit masking by the bass region.
Technicalities
Soundstage wise, i think the Quattro has quite decent width, but not as great height nor depth, especially for the price of 400$. Stereo effects, spatial cues are there, just doesn’t have that “out of head” feeling to it.
Layering is also decent, but due to the large amount of bass bleed and the transients of the drivers sort of focusing on being musical rather than technical, layering feels kind blurry as a whole. Instruments separation felt a bit clumping together.
Source pairing:
I may not have heard many high end iem before, but the Quattro is the most source picky iem i’ve ever heard.
What do I mean by that? I wouldn’t say it’s picky in the sense that it’s revealing, showing the characteristics of many dac/amps like whether it’s warm or bright, but more that the Quattro behaves differently with different sources.
With the
Ibasso DC04 Pro, it can reach the sufficient listening volume just fine, however I felt like the Quattro sort of underwhelming, like the bass was not performing like it should. The bass notes sound like it got cut off in the middle of the reproduction, which granted, makes the Quattro sounds a bit more neutral.
The
E1DA 9038D on the other hand, makes it sounds brighter. The analog-ish, warmer, darker edge tonality of the Quattro with the E1DA’s more hifi-ish and brighter sound signature combo is interesting to say the least. The E1DA makes the Quattro sounds a bit less dark with more bite in the treble. The bass sounds less dense in its feeling with the E1DA
The
Hiby FC6 is an interesting pick. The FC6 in short, has an analog, warm-ish sound with quite intimate stage and a low power output of 100mW, so on paper this is a really bad pick for the Quattro, and it really is. On some occassion when my inner basshead comes out and I embrace it, i’d choose the FC6 for the Quattro, but most of the time, the FC6 just overthickens the Quattro, adding too much note weight and density into it, which throws off the balance of the Quattro and making it sounds too muffled
And last but not least, the
Chord Mojo. Out of all my sources, this dac/amp sounds the best with the Quattro, which is not too surprising since it is the best sounding and strongest dac/amp out of the bunch that i mentioned. Long story short, it’s basically Hiby FC6 but on steroid, in a sense that it has a better control over the bass driver which gives it a more effortless feel, along with a better sense of stage. Even if it does not have the brighter based sound of the E1DA 9038D dongle, i’m willing to trade it for a better bass texture and staging. That’s why Chord Mojo is my source of choice during the review of the Quattro
The Quattro definitely deserve some powerful source to truly shine, preferably a more bright leaning source. Better yet, you should try various dac/amps, be it in dongle form or deskop setup form, to see which would have the best synergy with the Quattro.
Comparison:
1/ Penon Serial
Quattro younger brother - the Serial. When it was released, it was known for its analog-ish, warm tonality with smooth treble. So now with a 100$ price jump and one DD more, how does the Quattro different from the Serial?
First, looking at the total package perspective, the cable of the Quattro looks way better than the Serial’s. It’s thicker, sturdier with better hardware, although the Penon cable feels easier to coil up.
Second, the sound. When a/b-ing the two, the Serial just sounds way more neutral than the Quattro, or conversely, the Quattro is definitely more colored than the Serial.
The Quattro sounds warmer, bassier and has more bass bleed than the Serial. The Quattro’s bass has more authority and body behind it, bass punch felt more velvety and denser whereas the Serial’s bass feels cleaner and lighter. The bass line felt more frontal on the Quattro.
The midrange feels clearer with more pop to it on the Serial. Male vocal sounds thinner on the Serial. Female vocal sounds brighter and more energetic with less huskiness feeling on the Serial, like it felt more open and vibrant.
Treble wise, both the Serial and Quattro have that i’d considered a soft and smooth treble response with zero to none sense of sibilance. On the Serial, the treble sounds sparklier, airier, more shimmering.
While the treble of the Quattro, although with boosted in quantity, sounds darker and more gentle in its definition due to having more bass. So the Quattro sounds a bit more V (more bass+more treble) than the Serial is what i’m trying to say.
Since the intrusiveness of the bass was lessen on the Serial, the layering, to my ears, was actually better than the Quattro, like it has more breathing room between instruments depth wise, where as the Quattro sounds a bit wider compared to the Serial.
Note weight is, unsurprisingly, heavier with the Quattro. Violin and cello have way more of a bite on the Quattro.
Both sets have very natural timbre, but the heavy dose of note weight of the Quattro does make some accoustic instruments sounds more off when comparing with the Serial.
2/ Oriveti OD200
The Oriveti OD200 is only 200$, so half the price of the Quattro, so in a way, this comparison may not make much sense.
However, when I first listened to the Quattro, I couldn't help but be reminded of the OD200. And upon closer listening as well as checking the graph, i think i can see why
Both iems have a sort of warm, bassy chilling tonality. But there are a few differences.
Quattro has more subbass quantity, so at “Why So Serious” subbass drop, the Quattro feels rumblier with more air movement to it.
The midbass on the other hand, while the Quattro midbass punchs feel denser, heavier, thicker; the midbass on the OD200 was more well doned in the technical aspects, like it felt more effortless with better tactility and separation.
Midrange wise, the OD200 has more energy in the upper region, which gives female vocal a bit more pop
Treble wise, both of these sets sounds quite similar even if the graph suggest other wise. The Quattro does have a bit more bite to the cymbals and hihats in terms of the attack with slightly more micro detail, however the OD200 have a better balance due to having a steeper subbass rolloff which makes it easier to perceive the treble on the OD200.
Technicality, while the Quattro sounds a bit wider in terms of soundstage, the OD200 does have better layering capabilities and more distinct bass line.
Conclusion:
Penon Quattro is certainly an interesting and unique product coming from Penon. With the tuning of choice, how the bass was presented and how it interact with the midrange and treble, the Quattro is quite frankly a really niche product from Penon. Not bad, just niche, meaning that it’s heavily depend on the listeners’ preference and library.
If you’re someone who’d like an iem with a really rare configuration (4DD), a “soulful” tuning that has a dense, thick, rounded bass response, weighty vocal and instrument timbre along with relaxing treble, the Quattro would be the choice for you.
As for music library, I’d say the Quattro is suitable for the jazz, R&B and pop genre.
And for those who already has the Serial and are looking for its upgrade, the Quattro is NOT it. It’s more like a sidegrade to its younger brother, reasons i have already mentioned above in the comparison part.
That’s it for my review and thank you for reading.
. Please try it yourself, if possible, since we all hear things differently. If you want to purchase it, you can buy it from the official product website from the link. 
