Short answer: the 7Hz G1. It ranks #560 of 1291 in-ear headphones by sound quality, rated 3.8/5, at $35.14; the KZ Carol ranks #660, rated 3.7/5, and costs $35.99, which makes this an easy call rather than a real tradeoff.
Why pick the 7Hz G1: The median of 16 hobbyist measurements gives it a solid Harman preference score of 71 with a 2.00 dB spread, and its mids sit within about 1.1 dB of target, so vocals and instruments sound natural. The tradeoff: A 7.6 dB peak near 11.9 kHz can make cymbals and sibilance sound sharp.
The case for the KZ Carol: Budget true wireless earbuds with hybrid noise cancelling and Bluetooth 5.4, about 7 hours per charge and 42 hours with the case. The catch: A 2.37 dB spread from the target shows peaks and dips that better tuned sets avoid.
Buy the 7Hz G1. It is rated higher for sound quality than the KZ Carol and costs less, so only choose the other one for a particular feature it does better.
Want more options? Browse the full Headphones rankings.
The median of 16 hobbyist measurements gives it a solid Harman preference score of 71 with a 2.00 dB spread, and its mids sit within about 1.1 dB of target, so vocals and instruments sound natural.
Amazon $35.14 eBay
Budget true wireless earbuds with hybrid noise cancelling and Bluetooth 5.4, about 7 hours per charge and 42 hours with the case.
Amazon $35.99 eBayPrices on this page were last checked October 16, 2026 at 5:46 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.
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Specifications Side By Side
| 7Hz G1 | KZ Carol | |
|---|---|---|
| Price | $35.14 | $35.99 |
| Ranked | #560 of 1291 in In-Ear Headphones | #660 of 1291 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Harman Preference Score | 71 (median of 16 squig.link measurements, calibrated to AutoEQ) | 70 (median of 9 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 2.00 dB standard deviation | 2.37 dB standard deviation |
| Tonal Tilt | -0.58 (negative is warmer, positive brighter) | -0.23 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+2.5 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (-2.8 dB at 30 Hz) |
| Connection | Wired | True wireless |
| Driver Type | Dynamic | Dynamic |
| Drivers | 1 x 10mm dynamic | 1 x 10mm dynamic |
| Impedance | 18 ohms | - |
| Sensitivity | 107 dB/V | - |
| Weight | 0 lbs (8.8 g) per earbud | - |
| Frequency Response | 10Hz - 20kHz (Manufacturer specified) | - |
| Built-in Microphone | Yes | - |
| Bluetooth Version | - | 5.4 |
| Active Noise Cancelling | - | Yes |
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 7Hz G1 from atechreviews, audioamigo, bassaudio, bassyalexander, boizoff, cqtek, csi-zone, gadgetrytech, hbb, jaytiss, lumerion, silicagel, soundcheck39, soundignity, theaudiostore and treblewellxtended; the KZ Carol from aftersound, audioamigo, dhrme, flare, gadgetrytech, obodio, practiphile, pw and regancipher, all via squig.link.
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