Tin HiFi T4 Plus Review: The Bassier Aria

Tin HiFi T4 Plus


I’ve written numerous articles on Tin HiFi’s products in the past and today is no exception. With me is the $120 T4 Plus, their latest release to tackle the $100 segment. As noted by the Plus moniker, the T4 Plus is the sequel to the original Tin T4 released back in 2019. Back then it set the benchmark for IEMs at the $100 mark but was relatively overtaken by the MoonDrop Starfield (and its subsequent variants). The market has changed significantly since those days and is split between the single DD’s around $80 with the MoonDrop Aria/DUNU Titan S/Tin HiFi T3 Plus and the ~$150+ planar IEMs. Let’s see what Tin HiFi has done with the T4 Plus and where it stands today.

Review unit sent by Tin HiFi

What we like

  • Nice dynamic driver bass quality
  • L-shape tuning

What we don’t like

  • Pricey compared to competitors
  • Not the most ergonomic shell

What’s In the Box

  1. 3 different sets of S/M/L tips. Two of them are generic silicon. But the other is really cool - it’s a hybrid foam + silicon tip. It fits like a regular silicon tip but the foam helps improve fit and isolation. It’s the same concept as the Symbio Mandarin tips for you veterans out there. I’m surprised it took ChiFi this long to finally have these included as stock. I’ve been asking for it for years. They work pretty well though I personally still prefer regular silicon tips. No famous blue Tin foamies though.
  2. A 4-core braided 2-pin cable. It’s OK. It's similar to the one that comes with the 7Hz Dioko. Functional and that’s all I can say about it.
  3. The T4 Plus shells. They have the same overall shape and ergonomics as the infamous bullet style T2/T3/T4 shell. That is to say, the fit isn’t the best compared to modern standards. For the backplate design they went with mahogany fitted with a brass ring on the outside. It looks a little more classy to me than the previous bare metal aesthetics.
  4. A really nice carrying pouch.

As mentioned, because it uses the standard bullet shell the comfort is suboptimal. If it works for you, great. But even then it likely won’t be the most ergonomic. Do try tip rolling for optimal fit. Tin HiFi knows how to make good shells as evidenced with their other IEMs and I keep telling them to stick with those designs yet they decide to revert to the bullet style shells for whatever reason.

Source(s): Apple USB-C dongle

Sound and Frequency Response

Frequency response of the Tin HiFi T4 Plus. Measurement taken with an IEC-711 clone microphone. Comparisons can only be made relative to other measurements taken by this specific microphone. A peak at about 8 – 10 kHz is likely an artifact of the measurement rig and may not exist as depicted here. Measurements above 8 kHz are not accurate. If possible, reference multiple measurements.

Lo and behold, doesn’t the T4 Plus look very familiar? It’s got a LOT of bass and lower mids but its upper mids and treble is no different from what we’ve seen with the Aria/T3 Plus/Titan S before. I’d classify this as an L-shaped IEM despite looking like an obvious V in the midrange. Let me explain.

The first time I heard the T4 Plus, I thought to myself “Ah great, another Aria clone”. But then the bass instruments kicked in and I was really taken aback with just how hefty it is. There’s a significant amount of rumble and grunt and weight to back every note in the low end. Despite how much it bleeds into the mids as seen in the graph, I don’t find it overly bloated. It backs up the boominess with an underlying firmness, like a solid wall. There’s a sense of tact and control. That’s what makes the T4 Plus stand out to me. Too often we get bassy IEMs but the bass itself is somewhat soft or pillowy. Not enough to complain about but enough that when I hear something like the T4 Plus there’s a clear difference in the quality. The graph really doesn’t do justice to the experience.

That said, it isn’t perfect of course. There is a bluntness in the transients. While the notes themselves are controlled, note definition isn’t sharp. There is a slight one-notedness to it as well. There’s a certain character on the drums and bass guitar that is carried through from track to track. Not that it’s bad per se, just that it’s a coloration you’ll hear throughout. Yet despite my nitpicks, I do like the T4 Plus’ bass. Maybe I’m becoming a basshead over time as a reviewer but if the quality is there, even if it isn’t perfect, give me more. Mediocrity all around is never good but fun with a few blemishes is still pretty great.

There’s a lot of upper mids and lower treble to balance out the low end. The T4 Plus is thick sounding IEM and a little dark at times since its upper treble extension is only a peak and not a sustained presence. Coming off the upper mids is a good amount of lower treble in the 5 kHz region to give vocals extra clarity while the 6 - 7 kHz dip does suppress some of the crispness of the attack in the hats and cymbals. As such, like many IEMs, treble timbre has an overemphasis and de-emphasis in different parts of the note. Altogether, it makes the Tin HiFi’s top end sound like that of a balanced IEM that plays almost distinctly from its bassy low end. Hence, L-shaped sound signature.


For technical performance, the T4 Plus is adequate. Soundstage and imaging is IEM-like. Stage depth is shallow. Layering is relatively flat. Resolution and instrument separation are decent but not beyond the standard for budget IEMs nowadays. Bass dynamics is above average for the weight of its impact. The only outstanding aspect of the T4 Plus’ sonic presentation is its bass quality compared to its contemporaries. I think it’s less of a critique of the T4 Plus but rather a reflection of how good IEMs have gotten and how fiercely competitive the market is.


Here can see the graph comparison between the ever popular MoonDrop Aria and Tin HiFi T4 Plus. Tonally, the Aria has a warmer, smoother, more natural sound than the bassy, thick, L-shape sounding T4 Plus. It’s more balanced as a whole. However, the bass quality of the T4 Plus is superior to the Aria with a heavier weight and authority behind each note. Personally, I’d probably get the T4 Plus for the better bass quality. Maybe it’s recency bias or maybe I’m just burnt out with all these well-tuned, slightly warm IEMs that ChiFi is churning out now. The T4 Plus does something a little bit unique and that’s enough for me.

Should You Buy It?

Eh. I can give it a recommendation but not a strong one. I like it but the problem really is the price. At $120, it’s 50% more expensive than the Aria/Titan S/T3 Plus. While it does differentiate itself from the pack, I’m not sure it's enough. Not to mention that at this price range, the planar IEMs are just around the corner. We aren’t playing around in the “I’ll buy it and try” prices of budget ChiFi anymore. This is the “I need to make a decision I’ll can be happy with for a while” range. Here, every little bit counts in such a hyper competitive market. Case in point, the one aspect of the T4 Plus that annoys me is the shell. It works and is adequately comfortable but almost every other IEM out there nowadays is going to be more comfortable for longer periods of time. Altogether, it makes it a hard sell for the T4 Plus. But at the very least, it does have one thing going for it: it’s a rare L-shaped IEM there with commendable bass quality. I can’t remember the last time I heard one.

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