I'm interested in HE5XX and I only have Audient iD14 audio interface(the old model). So I'm curious if the headphone output of my audio interface is enough for HE5XX and other headphones like HD6XX of Sennheiser. Specification for the headphone output of Audient iD14(old model) is: MAXIMUM OUTPUT LEVEL: +12 dBu (0 dBFS digital maximum) DIGITAL REFERENCE LEVEL: +12 dBu = 0 dBFS OUTPUT IMPEDANCE: <30 Ω unbalanced VOLTAGE GAIN: +6 dB (optimised for loudness) FREQUENCY RESPONSE: ±1.0dB 10Hz to Fs/2 (load dependent) CROSSTALK: <-100 dBu @ 1kHz & 10kHz THD+N @ -1dBFS (1kHz): <0.002% (-94 dB) DYNAMIC RANGE: 108 dB un-weighted, 111 dB A-weighted MAXIMUM LEVEL into 30 Ω: +4 dBu 0.005% THD+N Power: 101mW MAXIMUM LEVEL into 60 Ω: +5 dBu 0.004% THD+N Power: 64mW MAXIMUM LEVEL into 600 Ω: +13 dBu 0.0025% THD+N Power: 39mW 1/4” TRS JACK: Tip (Left), Ring (Right) & Sleeve (Shield)