How to Read Headphone Specs Before You Buy: An Impedance, Sensitivity and Driver Guide for Audiophiles

Before you buy a pair of wired audiophile headphones, two numbers on the spec sheet—impedance and sensitivity—will tell you more about whether they'll work with your gear than any review score. A low-impedance, high-sensitivity model like the Sony MDR-MV1 can run happily from a phone or laptop; a demanding planar magnetic design like the HiFiMAN HE6 Remastered, with its 50-ohm impedance and very low 83.5 dB/mW sensitivity, needs a powerful desktop amplifier to sound as intended. Here's how to read those numbers, understand the three major driver technologies, and match a headphone to the equipment you actually own.

Understanding Headphone Impedance and Sensitivity

Impedance, measured in ohms, describes how much the headphone resists the electrical signal from your source. Soundcore's guidance on the topic draws a practical line: if you'll mostly listen on portable devices, choose low-impedance headphones that can efficiently draw power from those sources without compromising volume or sound quality; if you're investing in high-impedance headphones, make sure your amplification setup is compatible first.

Sensitivity, usually given in dB/mW, tells you how loud the headphone gets per milliwatt of power. The two specs work together, and this is where many buyers get caught out. The HiFiMAN HE6 Remastered illustrates the trap perfectly: at 50 ohms its impedance looks moderate, but its exceptionally low 83.5 dB/mW sensitivity means it still demands powerful desktop amplification, according to ecoustics' editors' choice roundup. Impedance alone never tells the whole story—always check both numbers before assuming a headphone will be easy to drive.

Matching wired audiophile headphones to audio sources by impedance and sensitivity
Headphone	Impedance	Sensitivity	Driver Type	Required Source
Sony MDR-MV1	24 ohms (low)	100 dB/mW (high)	40mm dynamic	Portable devices work; no dedicated amp needed
HiFiMAN HE6 Remastered	50 ohms (moderate)	83.5 dB/mW (very low)	Planar magnetic	Powerful desktop amplification required
General low-impedance, high-sensitivity models	Under ~50 ohms	High	Any	Smartphones, laptops and portables can drive them efficiently
General high-impedance or low-sensitivity models	50 ohms or more	Low	Any	Match with a dedicated amplifier before buying

Exploring Driver Technologies: Dynamic, Planar Magnetic, and AMT

Beyond the numbers, the driver—the component that converts the electrical signal into sound—shapes both the character of what you hear and, sometimes, how much power you need. Three technologies dominate wired audiophile headphones.

Dynamic drivers, like the 40mm units in the Sony MDR-MV1, are the common, versatile type, often providing strong bass. Campfire Audio's driver guide notes that a well-tuned dynamic driver delivers a physical, chest-thumping bass slam that other designs typically can't match.

Planar magnetic drivers, used in the HiFiMAN HE6 Remastered, carry a different signature. Campfire Audio describes their bass as "tight and well-defined, with more texture and nuance" than dynamic designs typically achieve, with an open, transparent midrange and extended treble without harshness—though they usually give up some raw sub-bass slam. They can also be more power-hungry, sometimes benefiting from a dedicated amplifier or higher-output source.

Air Motion Transformer (AMT) drivers, featured in the German-made HEDDphone TWO GT, are the rarest of the three. Bloom Audio explains that the AMT design generates sound from both sides of the driver rather than just the front, and is fast and accurate, though it doesn't have the same level of bass response as other types. Notably, AMT headphones don't require specialized amplification and have similar power requirements to planar magnetic models.