Acoustune is a Japanese audio company founded in 2013 and they specialize in making in-ear monitors. Their iems are of a single dynamic driver configuration. I would like to thank Acoustune for the review unit of the HS1503 AL. More information can be found on Acoustune official website, Acoustune .



  • Driver Configuration: 10mm Dynamic Driver
  • Frequency Response: 10 Hz – 25 kHz
  • Sensitivity: 110 dB/mW
  • Impedance: 32 ohm

Unboxing & Accessories

The HS1503 AL comes in a black package with a black protective cover that sports the brand logo, description and image of the iem at the front. At the back of the protective cover, there are specifications and description of the model. There is metal hard case with the brand logo on top in the black package. After unlocking the case, there are the iems, cable, instruction manual, warranty card, a variety of tips [ AET02 (F), AET06 (S+/M+), AET07 (S/M/L), AET08 (S/M/L) ] and a blue leather carrying case that contains a leather cable wrap and a velcro cable tie. There is a great amount of accessories provided and there is a premium feel to them.


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IEM Build & Design

The HS1503 AL is made of aluminium CNC milling and there is solid construction, It boasts an unorthodox industrial design which helps to create a nice unique appearance. On outside of the iem, there is a circular shaped metal sticking out. There are 3 metal screws on the faceplate. On the inside of the iem, there are L & R markings on the left and right side respectively. The nozzle is slightly angled with metal mesh and there is a vent. The brand and model name are printed on the rims. The iem utilizes MMCX connectors and on the MMCX sockets, there are blue and red ring on the outer edge to differentiate between left and right. I am able to fit the iem comfortably in my ears.


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Cable Build & Design

The cable has a braided design and it is black in color. It uses MMCX connectors with a opaque black housing. On the MMCX connectors, there are L & R markings to differentiate between left and right respectively. The chin slider and y splitter are black in color. The jack is 3.5mm gold plated right angled and the housing is black in color. There is strain relief. The cable is rather flexible.


Sound Analysis


The HS1503 AL extends it sub-bass competently and it is able to deliver an impactful rumble with a moderate speed. The quantity is sufficient although it does not operate on a full-bodied bass reproduction approach. The mid-bass on HS1503 AL has a moderate amount of body and there is a consistent agile slam. Bass texture on the HS1503 AL is moderately smooth while the bass decay is quick and enhances the overall punch. Each bass note is articulated with precision and there is good tightness. There is a clean attack with great definition.


The HS1503 AL has a slight recessed midrange and it showcases great transparency. The midrange has good definition and the details retrieval is great. The cleanliness it shows is good. Although the midrange is not the thick and lush kind, there is an adequate amount of body to tackle the vocals. The lower mids has a moderate amount of body and male vocals are expressed rather nicely without sounding hollow. The upper mids has great forwardness with fair quantity and this helps to create a delightful and intimate female vocals performance. It helps to create an energetic display which helps to provide a continuous engagement.


The treble is extended well and it exhibits a fine standard of details retrieval. There is no sibilance and harshness. It has good crisp and sparkle to inject excitement into the overall. The amount of air rendered is great which results in a an airy feel at the top end. The treble has energy and it is fun to listen to. It is being portrayed brightly and it has a moderate amount of body.


The HS1503 AL has moderate naturalness and the expansion is developed nicely. The magnitude is fairly good for the width and the depth has substantial amount of space which creates an open feeling. The positioning of vocals and instruments is good and the iem has the ability to establish a great stage.



Acoustune HS1503 AL vs HiFiMAN RE800

The HS1503 AL has more sub-bass quantity than the RE800. The RE800 has the ability to extend its sub-bass slightly more. The bass agility on the RE800 is a bit quicker but the bass texture on the HS1503 AL has extra smoothness. The engagement level on the RE800 is slightly higher but the HS1503 AL is not too far off. There is more musicality from the HS1503 AL. The mid-bass on the HS1503 AL is able to deliver a more weighted slam. Each bass note on the RE800 is articulated with a greater attack and there is a clean hit. It packs agility and creates an energetic performance. The bass reproduction on the HS1503 AL is more soothing to listen to. The lower mids on the HS1503 AL has more quantity and it is capable to tackle male vocals effectively. The RE800 might sound lacking in body in comparison. The upper mids on the RE800 has extra forwardness but HS1503 AL makes up for it with more body which contributes to an organic female vocals performance. The HS1503 AL has a sweeter midrange. The treble on the RE800 is slightly more extended with extra air. The HS1503 AL has just a little more body than the RE800. The crisp is similar and the RE800 presents extra sparkle. There is no sibilance and harshness. In terms of soundstage, HS1503 AL has a more natural expansion while the magnitude for the RE800 is greater. The depth of HS1503 is slightly closed in.

Acoustune HS1503 AL vs Dita Answer

The HS1503 AL is able to extend its sub-bass better than the Answer. The sub-bass reproduction is fuller on the HS1503 AL and it is more fluid. The Answer shows some grain in it. Bass decay on HS1503 AL has the edge with more agility. Bass texture is rendered with additional finesse. There is a tighter bass reproduction from the HS1503 AL Rumble is better expressed with finer dynamics. The mid-bass has an added quantity which further increases the slam impact. The Answer does not have the refinement. Each bass note on the HS1503 AL has a clean hit and it is able to deliver an accurate articulation. The HS1503 AL has more body in the lower mids and male vocals are presented better. The upper mids on the H1503 AL brings with it more forwardness and female vocals are voiced with clarity which reinforces the sweetness of the midrange. The Answer has a shouty presentation and this showcases the control of the HS1503 AL. The treble on the HS1503 AL has more finesse and it has a fair amount of air. The Answer presents with extra sparkle. At times, the Answer may sound harsh and aggressive. The treble body on the HS1503 AL has slightly more amount but may be on the thin side for some. Lastly, for the soundstage, HS1503 AL has more width and depth which results in less congestion than the Answer. Vocals and instruments positioning is rather accurate.

Acoustune HS1503 AL vs Beyerdynamic Xelento

The HS1503 AL has more sub-bass quantity than the Xelento and it extends less than the Xelento. The Xelento is able to extend greatly and showcases its technicality well. The sub-bass reproduction has a higher engagement level with the Xelento as it is able to produce more punch. The Xelento exerts a strong authority in its bass and there is confidence. The mid-bass on the HS1503 AL has more body than the Xelento. The Xelento is able to deliver an agile slam and it is superior in its bass decay. The bass texture rendered by the HS1503 AL is smoother. The lower mids on the HS1503 AL has more body and male vocals are presented with more thickness. The upper mids on the Xelento has extra forwardness and accentuates female vocals presentation to be clear. There is good crisp on both. Both are competent at delivering a sweet vocals performance. Moving on to the treble section, Xelento is able to extend with more magnitude and it has better crisp. There is no sibilance and harshness. The amount of air rendered is slightly more on the Xelento. For soundstage, HS1503 AL is able to create a natural expansion while the Xelento excels in the width magnitude. The Xelento is able to offer greater depth.


The HS1503 AL is a v-shaped sounding iem that has good agility and boasts an airy presentation. It is able to create an energetic performance with engaging female vocals. There is an excellent intimacy. In addition, its unique industrial design gives it a striking look. The packaging has a premium feel and it is very complete with an abundance of quality accessories. The Acoustune HS1503 AL is the latest addition to the line-up and it delivers.