Audeze MM-100 vs Sennheiser HD 660S2

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MM-100 compared with HD 660S2

	AudezeMM-100	SennheiserHD 660S2
Overview
Released
Released	April 2023	February 2023
Sound
Type
Type	Over-ear	Over-ear
Noise cancelling
Noise cancelling	No	No
Driver size
Driver size	90 mm	38 mm
Back
Back	Open	Open
Impedance
Impedance	18 ohms	300 ohms
Bluetooth codecs
Bluetooth codecs	None (wired)	None (wired)
Drivers
Drivers	90 mm planar magnetic; Fluxor magnet array; neodymium N50 magnets; Fazor waveguides; ultra-thin Uniforce diaphragm; 20 Hz – 25 kHz; sensitivity 98 dB/1 mW (at drum reference point); maximum SPL over 120 dB; THD < 0.1% at 100 dB SPL, 1 kHz; max power handling 5 W RMS; minimum power over 100 mW, recommended over 250 mW	Dynamic, open; 8 – 41,500 Hz; 104 dB SPL (1 kHz, 1 Vrms); THD < 0.04% (1 kHz, 100 dB); lighter voice coil than the HD 660S, with the transducer's resonant frequency lowered from 110 Hz to 70 Hz
Battery
Listening time (maker's claim)
Listening time (maker's claim)	No battery (wired)	No battery (wired)
Design
Weight
Weight	475 g	260 g (better)
Headphone cable
Headphone cable	Yes	Yes
Fit and ear tips
Fit and ear tips	Over-ear, open-back; gel-filled ear pads; adjustable suspension strap; spring steel headband; magnesium yokes and grilles	Over-ear (circumaural), open-back
Works with
Works with	2.5 m braided single-ended cable, connecting to either ear cup, with a 6.3 mm (1/4") TRS plug and a 6.3 mm to 3.5 mm adapter; Audeze's spec page gives the headphone end as both 3.5 mm TRS and TRRS	Detachable 1.8 m cables with a 6.3 mm plug and a balanced 4.4 mm plug; 6.3 mm to 3.5 mm adapter
In the box
In the box	MM-100 headphones, braided headphone cable, soft storage bag, 6.3 mm to 3.5 mm adapter, certificate of authenticity and warranty cards	HD 660S2 headphones, 1.8 m cable with 6.3 mm plug, 1.8 m cable with 4.4 mm balanced plug, 6.3 mm to 3.5 mm adapter, carry pouch