EarAcoustic SPA-Hi End Series IEM – Redefining High-End Audiophile Listening

Discover the EarAcoustic SPA-Hi End Series, a pinnacle of innovation and acoustic engineering built for audiophiles who demand the very best. This high-end in-ear monitor series includes four premium models—SPA-Hi End, SPA-Hi End Ultra, SPA-Hi End MAX, and the SPA-Limited Edition—each designed to deliver a rich, immersive soundstage, low distortion, and remarkable detail retrieval.
Engineered with low impedance and high sensitivity, these IEMs are easy to drive while offering extraordinary sonic performance. The Ultra and MAX models elevate sound reproduction with higher thrust, while the Limited Edition model delivers intricate detail, exceptional warmth, and elite-grade durability.

At the heart of the SPA-Hi End Series lies an advanced dual magnetic Tesla coil design powered by a high-flux N52 magnet exceeding 10,000GS. This setup provides enhanced dynamic range, pinpoint accuracy, and a full-bodied listening experience, outperforming traditional driver configurations.
Featuring a Titanium Gold Ball Top diaphragm and double-sided vapor-deposition silicon crystal hanging edge, these IEMs deliver smooth frequency response with ultra-low distortion. With a Titanium vibration modulus of 105–110 GPa, they respond swiftly to audio signals, ensuring rich layers, precise imaging, and exceptional detail across genres.
Flagship-Level Acoustic Tuning
Crafted through hundreds of acoustic simulations, the SPA-Hi End Series is tuned to a flagship-grade target frequency response, offering a wideband range from 5Hz to 40,000Hz. This translates to expansive sound fields, engaging warmth, and realistic spatial imaging—perfect for critical listening and emotional musical connection.
Total Harmonic Distortion (THD): < 0.5% for pure, clean audio
Intermodulation Distortion: < 0.05% for sonic clarity
Sensitivity: > 109dB/mW for effortless driving
Transient Response Time: < 3ms for rapid signal delivery
Low-Frequency Rebound: ≈ 40ms for rich, textured bass
Signal Attenuation: < 0.5dB for undistorted high-fidelity sound
Every model is ergonomically designed and built with precision:
SPA-Hi End: 3D resin printing with matte silver finish
SPA-Hi End Ultra: CNC-machined zinc alloy with mirror silver electroplating
SPA-Hi End MAX: Aerospace aluminum alloy via five-axis CNC and mirror plating
Shell Design: Uses 7075 ultra-strong alloy, diamond-cut textures, and resin coating
SR Blue Label: Clearly marks the left ear for ease of use

Bundled with a high-definition coaxial audio cable, made of oxygen-free copper and silver-plated cores, the SPA series ensures minimal signal loss and interference. With a 0.78mm dual-pin design and 408 core strands, this cable offers crystal-clear transmission and unmatched durability.

Whether you're a critical listener, studio professional, or a passionate audiophile, the EarAcoustic SPA-Hi End Series IEM offers the perfect balance of cutting-edge technology, robust craftsmanship, and emotionally rich sound.
Model: SPA Hi-End
Driver Unit: 11.4mm Titanium Gold Ball Top + Silicon Edge Double-Sided Composite Diaphragm, Double Magnetic Circuit, Double Chamber Dynamic Surrounding Unit
Sensitivity: 111dB
Impedance: 23 ohms
Frequency Response Range: 5-40,000Hz
Wire Specification: 0.78mm dual-pin LiTZ coaxial bundle, oxygen-free copper and silver-plated wire mixed weave, 1.20mm
Warranty Period: 1 Year from the date of Invoice
Covered: Manufacturing Defects Only
Warranty Form: https://www.theaudiostore.in/pages/warranty-claim-form Cable: 1-month warranty only for manufacturing defects only
I am using this for my daily use. This is so good even tunable to an extent. Good quality build and audio
Best in class adapter for various IEM's. I used it with KZ caster, Fiio JD1 and KZ ZEX. All works perfectly. My choice currently is with KZ ZEX. Instead of Touch, button system to control is too good and easily fits in our ear. ANC is not too aggressive, but quite good. Transparency mode is effective. So finally it's a perfect buy for our IEM's. KZ Rockzzz.
Got this over Waner II and Bunny DSP and it was totally worth it. Loving it so far. It supports my s21 FE and Lenovo LOQ Laptop. Let's see how long it lasts.
It’s neutral and clean and slightly warm because of copper.
This cable is perceived as giving a slightly warm-toned character, with clarity and neutrality in the mix.
Superb quality. Very flexible & easy to move around. Good sound quality, it works well in practical use with their DAC/AMP chain.
It Perfectly fit my bunny's. Fixes to ear way better and Definitely heavier than the default dsp cable.
The FiiO BTR5 2021 is a well-regarded portable Bluetooth DAC/AMP known for its strong decoding ability thanks to the dual ES9219C DAC chips. It supports high-resolution audio, including MQA decoding and up to 16x MQA [Discontinued, but not completely] unfolding when paired with compatible sources. The device provides versatile connectivity options such as balanced 2.5mm and single-ended 3.5mm headphone outputs, USB-C DAC functionality, and Bluetooth 5.0 for wireless listening. It features a sleek design with an aluminum and glass build, accented by a small display that shows audio info, though the display can sometimes be unreliable in showing the exact source or codec.
Compared to the original BTR5 from 2020, the 2021 model adds MQA support, a new DAC chip for better performance and noise ratio, and an improved USB audio adapter mode that disables charging during USB DAC use. It comes with a short skin-friendly USB-C cable and a redesigned packaging.
One critical caution for the BTR5 2021 (MQA version) is with the FiiO Control app's equalizer function: using the EQ on the device firmware via this app can brick the device permanently. Users recommend applying EQ only on the phone side with apps like Wavelet instead, to avoid this issue.
In its price range, the BTR5 2021 remains competitive, especially for users prioritizing sound quality, build, and MQA support. However, some users compare it with newer or alternative models such as the FiiO BTR15 (which offers Bluetooth 5.1 and 4.4mm balanced output) or the Qudelix 5K(Gone forever), which has more extensive software EQ features but a less premium build.
Overall, the Fiio BTR5 2021 is a solid choice for audiophiles wanting a portable DAC/AMP with both wireless and wired support, especially if you avoid the Fiio app's device EQ to prevent bricking issues. It has a mature firmware, strong sound performance, and versatile connectivity suitable for IEMs and headphones.
After a lot of deliberation I bought this as my first IEM. Loved it at my first listen. Still my go to IEM. It has a slight u shape that gives a musical tone to the sound. Caters to a lot of genres. It can be driven by 60mW cheap dongle DAC and amps. Absolute value for money.
I was having a huge dilemma switching from a budget IEM to a midrange IEM and I got this masterpiece... KEFINE KLEAN provides Tank like Build ✅ "Sufficient" bass To Power up Any Tracks and Sound stage Was Better than any Other Iems at this price. As Named The Audio Was Very Clean And Smooth So There'll Be No Distortion At Any Point ...
I purchased the EarAcoustic STA Hi-End Series IEM from The Audio Store in Pune about two weeks ago, and I’m extremely happy with both the product and the overall experience.
Starting with the store — the atmosphere was excellent and very comfortable for auditioning different IEMs. The owner himself assisted me personally, and I truly appreciate the warm and professional treatment I received. Despite it being after office hours, he patiently stayed back late just to help me choose the perfect IEM according to my sound preferences — something you rarely experience nowadays.
Coming to the EarAcoustic STA Hi-End IEM, after two weeks of regular use, I can confidently say it’s a brilliant performer in its price range. The soundstage is wide and natural, with crisp highs, balanced mids, and a tight, detailed bass response. It handles every genre — from vocals to instrumental and EDM — with ease. Build quality feels premium, and comfort during long listening sessions is gets better as you use them daily. My ear adapted these according to their shape though after 2-3 hours a very little pain felt sometime.
Overall, both the product quality and the buying experience exceeded my expectations. Highly recommend The Audio Store, Pune for any serious audio enthusiast looking for genuine advice and a premium shopping experience.
Recieved before 2days of targeted shipment date.
Quality is awesome.
This is my first IEM, and coming from Sony MDR 7506 and Airpods Pro i feel this sounds more richer and detailed.
It was great purchase and I'm happy from the output of this one. And as much as i love music , i have specific demands to meet like well balanced mids and highs but also good punchy bass. I'm happy with this purchase and i love it.
This was my first purchase from The Audio Store, and I was a bit hesitant at first, but they proved me wrong! The whole process was seamless, and I even received my order earlier than expected. The IEMs are really good and totally worth the money.
If this is your pick than go for it blindly!!!👌🎧
These are a great pick if you love a balanced sound. The best thing about them is the vocals — clear, natural, and full of emotion. You can really feel the singer’s presence without any sharpness or muddiness. Everything just sounds right, especially for long listening sessions.
Audiocular packaging is premium always give a small pouch which can be very handy.Initially Right side was not working in my KZ Harman target Balanced version. Date Recd 7th Oct 2025! every thing is awesome Love Pritam for being Down to earth.I am going crazy at age 51 with this music world man
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Awesome product loved a lot 😍
I am using this for my daily use. This is so good even tunable to an extent. Good quality build and audio
It was a gift to my friend and even now it works with good clarity
Nice
Good
Amazing.Can differentiate instrument so precisely.
Very good for beginner's
Best in class adapter for various IEM's. I used it with KZ caster, Fiio JD1 and KZ ZEX. All works perfectly. My choice currently is with KZ ZEX. Instead of Touch, button system to control is too good and easily fits in our ear. ANC is not too aggressive, but quite good. Transparency mode is effective. So finally it's a perfect buy for our IEM's. KZ Rockzzz.
biggest convenience around using it is the integrated DSP
Got this over Waner II and Bunny DSP and it was totally worth it. Loving it so far. It supports my s21 FE and Lenovo LOQ Laptop. Let's see how long it lasts.









