Review - HZSound Heart Mirror Pro

Review - TRN ST5

English | Español

Also available on YouTube in Spanish: Acho Reviews YouTube 

The TRN ST5 have been sent to me by Linsoul for me to test and share my opinions on them. As usual, Linsoul have made absolutely no requests, therefore I will do my best to be as unbiased as always in this review.

You can find the ST5 via Linsoul by following this, non-affiliate, link:


The TRN ST5 are a hybrid set of IEMs that feature a single dynamic driver for the lower ranges, 2 balanced armature drivers for the mid range, along with another 2 balanced armatures for the higher ranges. Currently priced at just under 60€, they fall outside what I would consider the ultra-budget category (the sub 50€ range that I mention often on the blog) but can still be considered an economic set of IEMs nonetheless.

I have to say that when I first listened to the ST5, I was actually surprised by what I heard and was interested in spending more time with them. There are many sets of IEMs that are tuned in a way that is impressive upon first listen but can then become tiring very quickly over longer periods of use. I have to say that, while the ST5 are by no means perfect, I have found them to be something that I can use for extended periods and enjoy them without growing tired. I will give more details in the sound section but as always, let's start off with the presentation.


While the ST5 have a no frills presentation, the contents are actually quite good, except maybe for the lack of a storage/transport case.

Arriving in a white box with an image of the product on the front and a basic diagram of the breakdown of the IEM on the back, we open it to find the IEMs, a cable with interchangeable connectors (more on that in a moment), 6 sets of silicone tips (in two different styles), a set of foam tips and various documentation.

My only complaint would be the lack of a case or at least some kind of storage bag. For me personally it is not an issue as I have plenty of cases (far too many!) available to use but I feel some kind of storage option at this price point should be expected, even if it is only a small drawstring bag to protect them from scratches etc. when placed in a pocket or bag.

Build and aesthetics…

Let's start with the bit that surprised me the most, the cable. The cable is a nicely weaved white cable with black hardware except for the two pin connectors that have a silver accent to match the IEMs. While I find the cable itself to be nice enough, without being spectacular, it is the modular connector system that surprised me.

This is obviously not the first time that I have received a modular cable system with a set of IEMs but I do think that these are the cheapest set of IEMs that have arrived with a cable featuring this. Basically the connector to the source is removable and TRN include a 3.5mm, a 4.4mm and a 2.5mm connector, allowing you to connect them to (almost) any output of your choice. The connector system is a little more rudimentary than some of the higher priced alternatives, as it uses just a simple push on/pull off system but it works well and is something that would cost almost the price of the IEMs themselves if purchased separately from other brands.

As far as the IEMs, they use the common teardrop shape that is found on many models of IEMs and has proved to work well for the vast majority of people. The IEMs are made completely of metal, in a matte silver finish. They have a small, raised, area that sports the TRN logo and have a simple design of circles around this.

I can’t say that they are beautiful IEMs (although beauty is always in the eye of the beholder) but they are not ugly or offensive in any way, to me at least.

The comfort is good for me, which is to be expected seeing that they use a shape and size that has been used many many times before.


Some months ago I reviewed the TRN TA1 Max and I found them to be fairly decent performers but with a tuning that did not fit my tastes. I find that the ST5 have a similar tuning with a few tweaks that make them far more enjoyable for me personally, even though they are still not my usual preference in tuning. 

Here is a graph of the ST5 in comparison to my preference target, alongside the TA1 Max so you can see what I am referring to:

I am not going to go into comparisons between the two, you can read my full review of the TA1 Max if you would like to know more what I felt about them, but the main differences are around a 10€ difference in price (the ST5 being more expensive) and the ST5 using 1DD+4BA rather than the 1DD+1BA of the TA1 Max. “Better” is something that is very subjective but personally I find the ST5 to perform better and be tuned more to my liking, so let’s focus on the ST5.

Starting off with the subbass, there is enough of it to do a good job with content that relies on the lowest notes. It deals with my usual “Chameleon” test pretty well and while it is not the cleanest of subbass out there, it is more than acceptable. There are times when the rumbling may be a little too much for me personally, being a little too prominent in the lowest of lows but it is a minor complaint and I do not find it unbearable. I actually feel it is more due to the fact that the drive struggles a little with excessive subbass (“Chameleon” being a good example in parts), rather than the actual elevation of the frequencies.

The midbass is a little too elevated for my tastes and I would personally prefer to tame the low end by a few dB in general but the performance is again acceptable, especially with tracks that have a little less presence in the subbass regions, allowing the driver a little more freedom to perform better.

Listening to something like “The Expert” by Yello, the bass has a bit more breathing room and the bass is a little less prominent, although the detail in the bass is still not quite as good as it could be. It is by no means terrible, as I said earlier, I have been using these IEMs and enjoying them, but it still leaves room for improvement.

I don’t know at what point the crossover between the lower ranges of the bass moves into the mids of the BA’s but I do get the feeling that the bass frequencies can sometimes “linger” and roll over a little into the lower mid ranges. It doesn’t seem to affect the lower end of vocals, it is more a case of the lower bass and guitar notes just sneaking into those lower mids and making things seem just not quite as clean as they could be.

The mids themselves are clean and articulate, with the BA’s doing a good job of keeping things coherent and while, again, they are not the most detailed of IEMs in these ranges, I do not find things to be blurred or to suffer throughout the mids.

In the higher mid range, there is a climb starting around 1kHz that peaks around 2kHz and does a decent job of giving presence to vocals and other mid centric instruments. However, I do feel that the presence could have extended just a little more to make things a little cleaner and defined. 

Where these differ vastly from the TA1 Max is in the 5kHz peak, which is not present on the ST5 at all. This is something that I am happy about, however, that does leave that 2kHz peak as the only real boost that is trying to give presence in the upper mids.

The upper ranges have good extension, obviously helped by the use of separate BA drivers for these frequencies. The sensation of air is present but… again that lack of a little extra in the upper mids doesn’t really help the treble ranges sound quite as clear as they could. 

The soundstage is about on average for a set of IEMs, although I would say that image placement is on the higher side of average. This means that, while they aren’t going to give the sensation of a huge space, they do make the most of the space they work in and make for a pleasant listen.

Isolation is not great, maybe around average for a set of IEMs for this style, but the additional sub and mid bass will do a decent job of combating external noise when listening to music.


I started off by saying that I enjoyed these IEMs and then it seems that I went on to list a whole lot of things that I feel could be better. I think that looking back on the review, it would be easy to interpret this as a negative review, yet that is not really the sensation that these IEMs give me. 

Yes, all of the things I mentioned are points that I feel could be improved upon, yet in general, these are not a bad set of IEMs by any means. I think that these can (and will) be enjoyed by many people. In fact, I am one of the people that has enjoyed them, even if they are not the set I would pick personally.

All FR measurements of IEMs can be viewed and compared on
All isolation measurements of IEMs can be found on

To comment or contact, visit any of the following social media platforms: