The Audeze Sine is a on-ear “portable” planar closed-back, and came out in 2016 but was quickly discontinued by Audeze in 2018 or 2019. It was original sold for $500 but the price dropped a lot, down to $150 before it went out of production.
The Sine isn’t very heavy compared to full-size headphones, and the build is great – lot of metal, real leather headband, solid stock cable and connector. It feels solid in the hands.
Unfortunately the comfort of the on-ear pads is not great, they are smashed against the ears and can get sweaty. The Sine is also not very sensitive and requires some power, defying its portable use. Isolation is just decent.
○ Release : 2016
○ Current status : Discontinued
○ Type : On-ear / Closed-back
○ Measured weight : 325g
○ Impedance : 20 Ohms
○ Sensitivity : ~94 dB/mW
○ Average used price : $160-220
The Sine may have the best stock frequency response in the world of sealed headphones. It measures very close to an HD650, with a better bass extension and slightly more treble. However, in real A/B listening, it’s quite far from any HD6X0. The bass extends well, but not as good as a full-size planar.
I would say the bass extension is similar to the best open dynamic headphones (like the Elex or Auteur) – very extended but rolling-off around 40hz, and the midbass is not boosted. Bass is tight but lacks the punch of an LCD-2. The midrange is very solid, pretty balanced from 200 to 4000 hz. The upper-mids sound a bit less forward than HD580 to me.
The treble is quite uneven. The low-treble (5-8 khz) is pretty recessed – great for harsh recordings, but the mid-treble and especially the region after 10 khz are definitely boosted. 11-12 khz is too crisp and sharp for my ears. Recordings with lot of “air” are difficult to listen to. It’s my only main issue with the tonality of the Sine. From 40 to 8 khz, it’s the best tone I’ve heard from a closed headphone.
For an used price sitting around $150-220, the resolution and speed are exceptional. The Sine resolves arguably a bit better than the HD6X0 line, which is a big feat considering it’s a closed on-ear planar. The timbre isn’t the most natural, as the midrange can sound a bit thin and the uneven treble is not helping. The HD6X0 have mellower mids and smoother treble, as well as slightly bigger stage.
The Sine comfort can be improved with alternative pads plus adaptative rings. Many people use Creative Aurvana Live (like I do, although they are Chinese non genuine pads), MSR7 or Brainwavz pads. They usually don’t affect too much the frequency response (less so than many headphones), and greatly improve comfort, as well as soundstage.
It’s hard to recommend the Sine as a portable or outside use headset, because the isolation is only decent, and they can’t be driven well from most DAPs or phones. I use my pair with alternative pads and the Apple USB-C dongle, and it provides enough power (but not a lot of headroom).
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