I'd straight with the bullet point. My review is based on my ears and personal experiences.
GEAR: Fiio K5 Pro -> 100W Class D Speaker Amp -> Stax Srd-7 Pro -> Can
Before EQ
Pros
- The female vocal is Amazing (Coherent and feel 3D)
- Super Details retrieval, speed, transparent
- The best bass for electrostatics (both quantity and quality)
- Very nice bass slam for e-stats
- Superb imaging like a laser
Cons
- Sound muddy due to warm/dark signature
- Stax fart
- Treble roll-off
- Intimate soundstage width
After Oratory1990 Harman Target EQ
Pros
- The detail retrieval shines and clear ( Before EQ, the details are hard to pick out, because of the warm/dark signature. But it's not missing anything)
- Very neutral sound signature
- Even better transparent and soundstage depth (Let's me explain the transparency, For example, where the instrumentals are overlapping each other, and I can clearly hear the separation between each instrument (example vocal and guitar are overlapping the middle, I can hear that the vocal is more forward than a guitar. While another track, a guitar is more forward than the vocal. So this phone can show how it is recorded or engineering.)
(Example of Soundstage depth and transparency, I can pick out anything and can tell all of it)
(1)
- Treble is very neutral, not roll-off, and not harsh.
- Bass and mid are very neutral, not too much or too less
- Still keep the bass slam
- Better soundstage width than before EQ, very neutral, but not as wide as HD800.
- Still keep the speed
- Still keep the imaging
Cons
- Losing the magic of female vocal (Before EQ, it's a bit shouty, but after EQ it's a more neutral sound, the graph also shows 1k shouty)
- Stax fart
Comparison
I currently own all of these three cans. A/B Testing with them directly
KOSS ESP 95X with Stock amp
This can is a mid-centric with mid shouty. I can't listen to it without EQ. After EQ to the Harman target and comparing with O2. It sounds harsher, with fewer details retrieval and speed. Very clearly not transparent as O2. It sounds more coherent and difficult to pick out each instrument. The bass slam is better than O2 but less bass quality (with Harman EQ) But when I boost the O2 bass with EQ, it's clearly better on O2. The only advantage is it is very lightweight(some this is cons), more comfortable than O2, and my ears can breathe better due to the seal.
HIFIMAN Ananda
I really love the Ananda tonality. The treble is one of the best I've heard to date. But after EQ, The O2 is just better over anything, except the Ananda has a taller soundstage which some may prefer. Also since it's planar, the sound has more body. Listening to some music genre (especially hard rock) will be more fun with Ananda.
The soundstage depth(or transparency as I mentioned above (1)) is not that good on Ananda comparing with ESP 95X and O2.
Audio Technica ATH-r70x
The sound has more body. The tonality before EQ is more neutral by my ears. Those are only two advantage, other it's just lose to O2 completely.
Conclusion: If you want the best of O2, Please unlock its potential by doing the EQ and you will be amazed.
GEAR: Fiio K5 Pro -> 100W Class D Speaker Amp -> Stax Srd-7 Pro -> Can
Before EQ
Pros
- The female vocal is Amazing (Coherent and feel 3D)
- Super Details retrieval, speed, transparent
- The best bass for electrostatics (both quantity and quality)
- Very nice bass slam for e-stats
- Superb imaging like a laser
Cons
- Sound muddy due to warm/dark signature
- Stax fart
- Treble roll-off
- Intimate soundstage width
After Oratory1990 Harman Target EQ
Pros
- The detail retrieval shines and clear ( Before EQ, the details are hard to pick out, because of the warm/dark signature. But it's not missing anything)
- Very neutral sound signature
- Even better transparent and soundstage depth (Let's me explain the transparency, For example, where the instrumentals are overlapping each other, and I can clearly hear the separation between each instrument (example vocal and guitar are overlapping the middle, I can hear that the vocal is more forward than a guitar. While another track, a guitar is more forward than the vocal. So this phone can show how it is recorded or engineering.)
(Example of Soundstage depth and transparency, I can pick out anything and can tell all of it)
(1)
- Treble is very neutral, not roll-off, and not harsh.
- Bass and mid are very neutral, not too much or too less
- Still keep the bass slam
- Better soundstage width than before EQ, very neutral, but not as wide as HD800.
- Still keep the speed
- Still keep the imaging
Cons
- Losing the magic of female vocal (Before EQ, it's a bit shouty, but after EQ it's a more neutral sound, the graph also shows 1k shouty)
- Stax fart
Comparison
I currently own all of these three cans. A/B Testing with them directly
KOSS ESP 95X with Stock amp
This can is a mid-centric with mid shouty. I can't listen to it without EQ. After EQ to the Harman target and comparing with O2. It sounds harsher, with fewer details retrieval and speed. Very clearly not transparent as O2. It sounds more coherent and difficult to pick out each instrument. The bass slam is better than O2 but less bass quality (with Harman EQ) But when I boost the O2 bass with EQ, it's clearly better on O2. The only advantage is it is very lightweight(some this is cons), more comfortable than O2, and my ears can breathe better due to the seal.
HIFIMAN Ananda
I really love the Ananda tonality. The treble is one of the best I've heard to date. But after EQ, The O2 is just better over anything, except the Ananda has a taller soundstage which some may prefer. Also since it's planar, the sound has more body. Listening to some music genre (especially hard rock) will be more fun with Ananda.
The soundstage depth(or transparency as I mentioned above (1)) is not that good on Ananda comparing with ESP 95X and O2.
Audio Technica ATH-r70x
The sound has more body. The tonality before EQ is more neutral by my ears. Those are only two advantage, other it's just lose to O2 completely.
Conclusion: If you want the best of O2, Please unlock its potential by doing the EQ and you will be amazed.
