Short answer: the Zuo Drum String Phanta. Both are rated 3.2/5 for sound quality (#1001 and #985 of 1369 in-ear headphones), and the Zuo Drum String Phanta costs $189 against $199 for the NF Acous NM25, with sound quality a draw, the lower price decides it.
The case for the NF Acous NM25: A single dynamic driver earphone with a bright, detailed character that suits V-shaped and neutral listeners, with a low end that stays within 6 dB of target down to 20 Hz. The tradeoff: Treble runs about 6 dB above target from 6 to 16 kHz, peaking 12.3 dB near 11.2 kHz in the median of 7 hobbyist measurements on squig.link, so cymbals, hi-hats and sibilance can sound hot and fatiguing at higher volume.
The case for the Zuo Drum String Phanta: A published AutoEQ preset corrects its response toward the Harman target, so a few minutes of EQ setup closes most of the gap. The tradeoff: An uneven response, 2.8 dB standard deviation from target.
Buy the Zuo Drum String Phanta. Both are rated the same for sound quality, and it costs $10 less than the NF Acous NM25.
Still deciding? The full Headphones rankings cover every ranked option.
A single dynamic driver earphone with a bright, detailed character that suits V-shaped and neutral listeners, with a low end that stays within 6 dB of target down to 20 Hz.
Amazon $199.00 eBay
A published AutoEQ preset corrects its response toward the Harman target, so a few minutes of EQ setup closes most of the gap.
AliExpress $189.00 eBayPrices on this page were last checked October 17, 2026 at 6:04 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
As an eBay Partner, we may be compensated if you make a purchase.
Specifications Side By Side
| NF Acous NM25 | Zuo Drum String Phanta | |
|---|---|---|
| Price | $199.00 | $189.00 |
| Ranked | #985 of 1369 in In-Ear Headphones | #1001 of 1369 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Harman Preference Score | 64 (median of 7 squig.link measurements, calibrated to AutoEQ) | 64 (median of 3 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 2.42 dB standard deviation | 2.75 dB standard deviation |
| Tonal Tilt | +0.93 (negative is warmer, positive brighter) | -0.58 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-1.5 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (-0.1 dB at 30 Hz) |
| Connection | Wired | Wired |
| Driver Type | Dynamic | Dynamic |
| Drivers | 1 x dynamic | 3 x dynamic drivers (1 x 10mm graphene full-range + 2 x 8mm coaxial dual dynamic bass) |
| Impedance | 32 ohms | 11 ohms |
| Sensitivity | 108 dB/mW | 101 dB |
| Frequency Response | - | 20Hz - 20kHz |
Frequency Response Compared
Both headphones’ measurements overlaid on the Harman target. Above the target sounds louder in that range, below it quieter. Each curve is the median of several independent measurements, shifted so its 500 Hz to 2 kHz average sits at 0 dB, so only the tuning is compared.
Measurement data: the NF Acous NM25 from cqtek, digaoreviews, faxepremium, musicafe, practiphile, pw, tonedeafmonk and treblewellxtended; the Zuo Drum String Phanta from aftersound, practiphile and tonedeafmonk, all via squig.link.
Related Headphone Comparisons
More top alternatives to NF Acous NM25: