GMR-545-A-AIR
headphones
$130
Used market: $100*
Specifications
4 of 7 values have a recorded sourceExpert Audio Engineering Commentary
Tonal Profile
An open-back gaming headset built on Koss's own driver tradition rather than on a gaming-brand OEM part. Two cords ship with it: an eight-foot one with a boom microphone on separate audio and voice plugs, and a four-foot one with an in-line mic on a single TRRS plug.
Amplification Warning
35 Ω at 103 dB/mW is an easy load, but the two supplied cords are not interchangeable: the boom-mic cord splits audio and voice into two plugs and needs either two jacks or the bundled TRRS adapter. Users who plug the wrong cord into a single-jack laptop report «no microphone», which is a wiring issue and not a fault.
What the datasheet actually says
Quoted verbatim from the manufacturer’s own page, with the date we checked it. We state what is printed, not what anyone intended by it.
«Sensitivity: 103 dB SPL»
Koss writes «101 dB SPL/1mW» on the Porta Pro and KSC75 pages and drops the «/1mW» here and on the KPH30i. Since the house convention is explicit elsewhere, we read this as 103 dB/mW. The alternative reading, dB/V, would make it about 88 dB/mW — implausibly low for a 35 Ω open driver and inconsistent with the rest of the catalogue. Same figure appears on the closed GMR-540-A-ISO page.
checked 8/5/2026* Estimated with the depreciation fallback (~77% retained value). · checked on 8/5/2026