Introduction
The KZ Castor Pro has become a standout choice in India, especially for those looking to buy a high-performing IEM or earphones under the ₹2,000 price bracket. What makes this IEM so popular? For starters, it brings improved bass and a Harman target-inspired variant, offering serious value at a budget price.
In today’s review, we’ll dive into the Improved Bass version of the KZ Castor Pro. This IEM features a dual dynamic driver setup along with quad-tuning switches, allowing you to choose between four unique sound profiles. With that kind of flexibility, let’s explore if this little powerhouse truly delivers on its promises.
Design and Build Quality
The KZ Castor Pro features a hybrid design—a mix of plastic and metal-painted shell. The transparent black plastic back shell lets you peek inside at the drivers and internal components, giving it a tech-inspired aesthetic. The faceplate comes with "Castor Pro" branding and a gold-accented air vent ring, adding a subtle touch of elegance.
As expected from KZ, the earphones include the brand’s typical braided-style cable, similar to what they provide with many of their other models. While the design is simple, the overall appearance is clean and functional.
The build quality is average, but it doesn't feel cheap. It’s good-looking and practical, though not the most premium in hand feel.
Comfort and Fit
The KZ Castor Pro comes equipped with Starline silicone ear tips. For my listening sessions, I used the medium-sized eartips, and I found the shell size to be medium—comfortable enough for long hours without causing fatigue.
The nozzle is sufficiently long, helping the IEM sit securely and go deeper into the ear canal, providing a snug fit with good passive isolation.
No discomfort during extended use. These are comfort-focused IEMs with a stable fit, ideal for both travel and daily listening.
KZ Castor Pro Sound Review
One of the Castor Pro's most impressive features is its quad tuning switch system, offering four different sound profiles. This kind of flexibility is rare in this price segment. You get the freedom to switch between different sound signatures such as neutral, V-shaped, bass-heavy, or relaxed—suiting everything from gaming to audiophile use.
🎵 Sound Quality Breakdown
🎧 Bass
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In UUDD and UUUU modes, the bass is powerful and punchy, with deep sub-bass rumble.
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In DDUD, the bass becomes more controlled and relaxed, suitable for longer sessions.
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The UDDD mode offers the lightest bass, giving a more neutral tone.
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Across all settings, the bass stays tight and doesn’t bleed into the mids.
🎤 Midrange
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The mids are generally clear and clean, with a slight dip between 300Hz–1kHz, ensuring no congestion.
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In DDUD and UDDD modes, vocals sound more forward and natural.
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Instruments are placed well and never feel shouty or overly emphasized.
🎶 Treble
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Treble tuning is smooth with good energy, peaking around 2.5kHz and again near 8–10kHz.
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It delivers impressive detail retrieval, especially for this price range.
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There's minimal sibilance, and UUDD and UUUU offer the airiest treble, while DDUD feels more relaxed.
🌌 Soundstage & Imaging
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Surprisingly spacious soundstage, with above-average width.
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Imaging is accurate and clear, especially in UUDD and UDDD modes.
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Layering and separation remain strong, especially in less bass-heavy configurations.
Tuning Differences Explained
| Tuning Mode | Bass | Mids | Treble | Overall Sound |
|---|---|---|---|---|
| UDDD (Blue) | Lightest bass | Slightly forward mids | Balanced, detailed treble | Most neutral; ideal for vocals and studio-style listening |
| UUDD (Green) | Stronger bass | Balanced mids | Brighter treble | Best all-rounder; dynamic and lively |
| DDUD (Red) | Warm bass | Clear mids | Softer treble | Relaxed tuning; perfect for fatigue-free sessions |
| UUUU (Dark Blue) | Most elevated bass | Smooth mids | Brightest treble | V-shaped and energetic; fun, punchy sound |
Why it Matters: These four tunings make the Castor Pro one of the most versatile IEMs in its price category, suitable for a wide variety of listeners—from neutral purists to bassheads.
Value and Competition
At under ₹2,000, the KZ Castor Pro faces stiff competition from some legendary budget IEMs. Here's how it stacks up:
🎧 KZ Castor Pro (UDDD) vs Moondrop Chu II
| Aspect | Castor Pro | Moondrop Chu II |
|---|---|---|
| Bass | Elevated sub-bass, warm & engaging | Controlled and cleaner, but less impact |
| Mids | Slightly recessed, clear | Crisp and forward upper mids |
| Treble | Smooth and safe | Bright and detailed |
| Soundstage | Decent width, slightly compressed |
Narrower stage, better imaging |
Verdict: Castor Pro offers more tuning flexibility and bass warmth. Chu II is more neutral and analytical.
🎧 KZ Castor Pro (UDDD) vs KZ ZSN Pro 2
| Aspect | Castor Pro | ZSN Pro 2 |
|---|---|---|
| Bass | Refined and controlled | Boomy and mid-heavy |
| Mids | Natural, slightly recessed | Recessed, less clarity |
| Treble | Smooth and extended | Spiky and aggressive |
| Soundstage | Good imaging and layering | Wider stage, less accurate imaging |
Verdict: Castor Pro is a clear upgrade in tuning and resolution. ZSN Pro 2 is fun but less refined.
🎧 KZ Castor Pro (UDDD) vs TangZu Wan’er SG
| Aspect | Castor Pro | Wan’er SG |
|---|---|---|
| Bass | Tight and sub-bass-focused | Warm midbass, slightly muddy |
| Mids | Clear with a slight dip | Thick, smooth, less detailed |
| Treble | Airy and clean | Rolled off, lacks sparkle |
| Soundstage | Moderate width, good separation |
The more intimate, laid-back feel |
Verdict: Castor Pro is technically superior and more versatile. Wan’er SG is smoother and warmer, ideal for laid-back listening.
Pros and Cons
| ✅ Pros | ❌ Cons |
|---|---|
| 4 tuning modes offer versatile sound | Build is average; plastic shell |
| Punchy, clean bass (especially in UUDD/UUUU) | Stock cable is basic and generic |
| Smooth and controlled treble | Tuning switches may be confusing for beginners |
| Clear mids with excellent separation | Slight dip in lower mids affects vocal warmth |
| Good imaging and soundstage | Treble might lack sparkle for some |
| Comfortable fit, secure isolation | |
| Incredible value for money |
Conclusion
The KZ Castor Pro (Improved Bass version) is a rare gem in the budget IEM world. For under ₹2,000, you get not just one sound signature, but four distinct tunings—each tailored for different musical preferences.
Its performance outshines many in its price segment, offering refined bass, clean mids, and smooth treble in a package that doesn’t compromise on technicalities. Whether you're a beginner exploring the IEM world, a gamer looking for sound precision, or a casual audiophile hunting for an affordable backup set, the Castor Pro fits the bill.
When stacked against rivals like Moondrop Chu II, TangZu Wan’er SG, and KZ ZSN Pro 2, the Castor Pro emerges as the most versatile and feature-rich option. If you want real tuning flexibility without breaking the bank, the KZ Castor Pro deserves a top spot on your list.
Final Verdict: One of the best IEMs under ₹2,000 in India—versatile, fun, and surprisingly refined.
