[DivineCurrent]

@Music Alchemist, thank you for your help.
@Fearless please just watch what you say next time. If you dont have anything productive to add to the conversation, don't post it.

 

[k4rstar]

Looking at your gear right now I would consider an upgrade in source equipment before new headphones, and I don't usually say that. Especially if you already like the 650 and 400i which you clearly do, they will both scale well past the O2/ODAC.
 
Just my thoughts.

 

[Fearless1]

@Music Alchemist, thank you for your help.
@Fearless please just watch what you say next time. If you dont have anything productive to add to the conversation, don't post it.

Your right. Sorry to disrupt your post. I came in as to help, I own the HE-4, 6, 400i 500 and the 560 along with some others. My intention was to offer an experienced based opinion.

 

[Hi-Fi EDU]

OP, although it's not a planar, give the Audioquest Nighthawk an honest consideration. Being a former owner of the 400i myself, I feel like the NH may fit what you're looking for, without you having to change any other part of your chain. IMO, the NH is misunderstood by some but to each their own. I'll put up more of a comparison in a few days, if interested.

 

[DivineCurrent]

  Looking at your gear right now I would consider an upgrade in source equipment before new headphones, and I don't usually say that. Especially if you already like the 650 and 400i which you clearly do, they will both scale well past the O2/ODAC.
 
Just my thoughts.

I appreciate your feedback, however I would like to stick with just the ODAC/O2. The ODAC has perfectly flat response, and I don't need any more power than the O2. I don't really understand why people spend more on DACs and amps in order to change the sound signature, when you can just as easily EQ to your liking. In fact, I probably should just EQ the HE-400i to get the sound I want. 
 
 
 

  OP, although it's not a planar, give the Audioquest Nighthawk an honest consideration. Being a former owner of the 400i myself, I feel like the NH may fit what you're looking for, without you having to change any other part of your chain. IMO, the NH is misunderstood by some but to each their own. I'll put up more of a comparison in a few days, if interested.

I was attracted to the Nighthawk when I saw all that research behind it. However, I'm still a bit skeptical of AudioQuest, as they are one of those companies who sells $1000 HDMI cables. However, I still want to get the chance to listen to them.

 

[mysticstryk]

I appreciate your feedback, however I would like to stick with just the ODAC/O2. The ODAC has perfectly flat response, and I don't need any more power than the O2. I don't really understand why people spend more on DACs and amps in order to change the sound signature, when you can just as easily EQ to your liking. In fact, I probably should just EQ the HE-400i to get the sound I want. 



I was attracted to the Nighthawk when I saw all that research behind it. However, I'm still a bit skeptical of AudioQuest, as they are one of those companies who sells $1000 HDMI cables. However, I still want to get the chance to listen to them.

Don't assume that the O2 is as good as it gets. Amps are a lot more than just the power they provide. Your hd650 and 400i would both benefit from an upgrade in your chain.

As for your questions. I would vote for the 400S with focus pads or LCD-2. But I also see your okay with EQ, in which case you could EQ some subbass for your hd650 and tame those highs on the 400i.

Also try the toilet paper mod on the 400i. Just place a single piece of toilet paper between the driver and the earpads.

 

[Vigrith]

  I was attracted to the Nighthawk when I saw all that research behind it. However, I'm still a bit skeptical of AudioQuest, as they are one of those companies who sells $1000 HDMI cables. However, I still want to get the chance to listen to them.

 
Hi. I own both the 400i and the 400S, I prefer the S model myself though it is quite a fair bit cheaper. They are just more to my preference, I like musical/smooth sounding gear myself too. I prioritize enjoyment out of my music over all else (details, sound analysis, huge soundstage, etc). The 400i are also good though, just different.
 
I have auditioned the Nighthawks and I liked the sound signature a lot, though that was at a store and off of my Hifiman DAP. I'd honestly disregard their $1000 HDMI cables when it comes to the headphones, take my opinion as you will as I know it is all subjective but one thing I can say is that Rob Watts from Chord Electronics has voiced his opinion strongly saying the Nighthawks were great headphones and his favourites right now (or at least at the time, that was recently) - I'm fairly certain he even mentioned having used them as one of his biggest points of reference when tuning the Mojo. Chord are highly regarded and very respectable so surely Audioquest must've done something right with the NHs. 

 

 

[jazzwave]

Have same situation with OP who love smooth sound, currently use HD600 , love it
I love Planar sound as well, like have speaker attached on my ear.
 
I have old HE400 (the dark blue), sold it because the treble too sharp for my ear.
..never tried 400i or 400s
 
 
I have smaller budget than OP, is Fostex TH500rp good planar?  How compare OPPO PM3
 
 
~ron~