MMX 300 PRO
headphones
$299
Used market: $235*
Specifications
4 of 7 values have a recorded sourceExpert Audio Engineering Commentary
Tonal Profile
A studio headphone with a microphone attached: closed back, 48 Ω, made in Heilbronn, and purely analogue — two 3.5 mm plugs, no USB and no battery anywhere in the product. The 48 Ω version exists because 250 Ω would be undrivable from a motherboard, and 32 Ω would pick up the hiss of one.
Amplification Warning
48 Ω at 96 dB/mW works out near 109 dB from one volt — comfortably loud from a laptop, but this is the one headset in the gaming half of this batch where a weak phone output is worth checking rather than assuming.
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.
«Nominal sound pressure level: 96 dB»
beyerdynamic prints 96 dB with no unit here, on the open MMX 330 PRO, and on the DT 770 PRO sheet that covers three different impedance versions. One figure standing for a closed 48 Ω gaming headset and an open one of the same impedance is possible only if both use the same transducer; nothing on either page says so. We read it as dB/mW because beyerdynamic spells the unit out on the PRO X pages — «(1mW/500Hz)» — and we note here that the same number appears on neighbouring products, so it cannot be used to tell them apart.
checked 8/5/2026* Estimated with the depreciation fallback (~79% retained value). · checked on 8/5/2026