Another design flavour of the Porta Pro series of driver, this brings together a refinement of the KPH30i that might be described as a modern Porta Pro.
Wide soundstage - though the KSC75 and KPH30i may be wider in stock forms - and good imaging, excellent warm tonal balance and timbre. Detail retrieval and resolution isn't out of this world, so maybe look at IEMs in this price range if that's your thing, but the rest of what this offers is so good you just use them as a portable set or lying about when you want a relaxed listen.
Treble and bass are more refined than the KPH30i, but it also comes with another 2dB in that 5-6kHz peak, but there's a lift in the midbass to compensate. Bass and treble extension go further, but audible roll off from neutral bass will be there at around 35Hz. Overall this will sound less mid-forward than the KPH30i - maybe even making it slightly v-shaped - perhaps reflecting a better clamp/seal/conduction between the user and the driver.
This is a good lightweight option for listening to music, casual gaming, and even has very solid imaging for competitive gaming… just lacking on detail retrieval if the audio mix gets super busy. Scales with an amp due to varied impedance curve, so bass may sound less controlled from weaker sources (phone, onboard audio).
Build quality wise it is absolutely a step up from the KPH30i, with a stronger, lighter frame and a detachable base to the cable (2.5mm). Official USB-C and lightning adaptors are available, but are priced ridiculously. Adaptors are now showing as an additional $16 (inc delivery) with code.
For the headphone itself, this is an all-time low, the previous being $60 on Amazon. Enjoy!
EDIT: 25% mark down has ended, now cheaper again with 30% off through code 'CYBER30' (credit to @cornbeef).
i missed this deal
https://www.ozbargain.com.au/node/489107
my 1st pair ksc75 lasted 5 years before the rubber sleeve disintegrated and cable snapped.
2nd pair ksc75 developed problem of 1 side no sound within a year,
looking for my 3rd pair.