KZ PRX vs Sennheiser CX 300S: which should you buy?

On aggregated review scores the KZ PRX comes out ahead with a HearWiki score of 80. The full breakdown - sub-scores, specs and what reviewers actually said - is below.

Our pick: KZ PRX - Great overall at around $55.

Wired IEMs

Score breakdown

Each axis is a 0–10 blend of what reviewers scored, not a lab measurement.

KZ PRX leads on 4 of 5 measures.

KZ PRX
Sennheiser CX 300S

HearWiki score

Sound

7.8

6.2

Calls

5.8

Value

8.6

5.6

Price (USD)

$55

$61

Generation & platform

The scores rank quality. This is the other question: is the newer one actually newer technology, or the same platform in a new shell?

Same generation

The Sennheiser CX 300S is 2 years newer, but it is the same generation of hardware: nothing in the radio, the codecs or the noise cancelling separates them. Nothing separates them on convenience features either, so the choice comes down to tuning and price.

PRX2024
CX 300S20262 yr newer

Specifications

PRXCX 300S

Type: Wired IEMs; Wired IEMs
Price (USD): $55; $61
HearWiki score: 80; 57
Released: 2024; 2026
Availability: Still sold new; Sold new
Driver: planar magnetic; dynamic
Driver type: planar; dynamic
Drivers per side: -; 1
Frequency response: -; 17 Hz - 21 kHz
Impedance: 15 Ω; 18 Ω
Sensitivity: -; 118 dB/mW
Active noise cancelling: -; No
Controls: -; buttons
Weight: -; 12 g
Detachable cable: -; No
USB-C: -; No
Connector: -; 3.5 mm
Microphones: -; 1
Microphone type: -; MEMS
Mic sensitivity: -; -44 dBV

Specification comparison of KZ PRX vs Sennheiser CX 300S
Spec	KZ PRX	Sennheiser CX 300S
Type	Wired IEMs	Wired IEMs
Price (USD)	$55	$61
HearWiki score	80 / 100 Great	57 / 100 Average
Released	2024	2026
Audio
Driver	planar magnetic	dynamic
Driver type	planar	dynamic
Drivers per side	-	1
Frequency response	-	17 Hz - 21 kHz
Impedance	15 Ω	18 Ω
Sensitivity	-	118 dB/mW
Features
Active noise cancelling	-	No
Controls	-	buttons
Design
Weight	-	12 g
Detachable cable	-	No
USB-C	-	No
Connector	-	3.5 mm
Calls
Microphones	-	1
Microphone type	-	MEMS
Mic sensitivity	-	-44 dBV

What reviewers said

KZ PRX

The KZ PRX is a budget-friendly planar magnetic IEM that offers a balanced, warm-leaning sound with strong detail retrieval and capable imaging for its price. It excels in sub-bass presence and smooth mids, though it demands proper amplification and ear tips to perform at its best. Its soundstage is decent but not exceptionally wide, and the stock cable is a noted weak point.

Pro:Excellent value for a planar IEM
Pro:Balanced, warm sound with good detail
Pro:Strong imaging and separation for the price

Con:Requires a capable source and good ear tips
Con:Stock cable limits performance
Con:Soundstage is only medium-sized

Sennheiser CX 300S

The Sennheiser CX 300S is a budget-friendly wired in-ear headphone with a dynamic driver, offering a bass-heavy yet versatile sound signature with clear vocals. It's a practical, lightweight choice for everyday music and calls via a 3.5mm connection, though it lacks advanced features like noise cancellation or a detachable cable.

Pro:Strong bass presence
Pro:Clear and distinct vocal reproduction
Pro:Lightweight and comfortable fit

Con:Microphonics (cable noise) can be noticeable
Con:Bass control and treble presence are limited
Con:Build durability is a concern

Summaries are AI-condensed and paraphrased from published reviews and specs - not original hands-on testing. More on our method.

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New comparison KZ PRX Sennheiser CX 300S