Panasonic RP-HT21 vs Audio-Technica ATH A500: Which Headphones?

Quick answer

Choose the Panasonic RP-HT21 if you want the lightest possible on-ear pair for casual listening and don't mind an open-box item. Choose the Audio-Technica ATH A500 if you need closed-back isolation and a more controlled, higher-impedance sound for focused listening at home.

Weight and fit: 1.2 ounces vs 10 ounces

The Panasonic RP-HT21 is built for all-day wear without pressure: its open-air on-ear design weighs just 1.2 ounces without the cable, and the wide headband with foam-cushioned earcups spreads that weight evenly. The Audio-Technica ATH A500 is a full-size closed-back headphone at 10 ounces, using a 3D Wing Support Housing and ear-fitting pads to hold it in place. Neither is inherently better; the Panasonic suits light, portable use, while the A500's mass and support structure are meant for stationary sessions where stability matters more than featherweight comfort.

Sound and isolation: XBS bass vs closed-back accuracy

The RP-HT21 uses 30mm neodymium drivers and an XBS port to magnify low frequencies, giving it a fuller, more bass-forward character than its size suggests. The ATH A500 takes a different route: 53mm drivers with neodymium magnets and CCAW voice coils, a 5–30,000Hz frequency response, 100dB sensitivity, and 64-ohm impedance, all in a closed-back cup that reduces sound leaking in and out. If you listen in a noisy room or need to keep your music private, the A500's closed design has the clear advantage. If you want a lively, bass-heavy sound for podcasts or casual video, the Panasonic's XBS tuning is the more direct match.

Power and price: what 64 ohms and open-box mean

The A500's 64-ohm impedance and 500mW maximum input power mean it can handle more power, but it may need a stronger source than a basic phone headphone jack to reach its full volume and control. The RP-HT21's impedance isn't listed, so we can't say how easy it is to drive, but its lightweight on-ear design suggests it's intended for simple, low-power sources. Price is the other trade-off: the Panasonic is an open-box item at a much lower catalog price, while the Audio-Technica is a new closed-back model at a higher price. Open-box buying can save money, but you should confirm the condition and return policy before ordering.

Key trade-offs

• Weight vs isolation: The RP-HT21 is far lighter at 1.2 ounces, but its open-air design leaks sound and lets noise in. The A500 is heavier at 10 ounces but its closed-back cups block more noise. Decide whether comfort or quiet matters more for where you'll listen.
• Bass boost vs balanced accuracy: The RP-HT21's XBS port emphasizes low frequencies for a fuller, more energetic sound. The A500 is tuned for accurate reproduction with a 53mm driver and 64-ohm impedance. If you want bass punch, pick Panasonic; if you want neutrality, pick Audio-Technica.
• Source power and price: The A500's 64-ohm impedance may need a better source to sound its best, while the RP-HT21 is likely easier to drive from basic devices. The Panasonic is open-box and much cheaper; the A500 is new and costs more. Check your source and whether you're comfortable with open-box condition before buying.

Product facts

• Audio-Technica ATH A500 - Headphones: Closed-back, dynamic headphones with 53mm drivers and a 5–30,000Hz frequency response. The closed cups and wide frequency range suit focused listening where you want to hear detail without disturbing others.

  

• Panasonic RP-HT21 Headphones On-Ear Lightweight with XBS - Open box: Open-air on-ear design weighs 1.2 ounces without cable and uses XBS port for bass. That low weight and bass emphasis make it a comfortable, lively choice for casual, portable listening.

  

Which should you choose?

Best for

• Listeners who prioritize light weight and comfort for hours of casual use
• Buyers who want a bass-forward sound at a low price and are open to open-box items

Not for

• Listeners who need noise isolation in loud environments
• Buyers who want a closed-back, higher-impedance headphone for critical listening