If one wanted to experience Planar Magnetic for the first time, what would you recommend?
I’ve always wanted to add a Planar to my (tiny) headphone collection.
I’m curious, I’ve never heard one.
4xx? Sundara? Aeon Flow RT? Ether CX? Something else?
Has to be available new.
How deep do I need to reach into my pockets to get something that will impress me? 
Sundara for the win.
Agreed. The 4xx can impress with planar qualities but the longevity you’ll get by comparison with the Sundara is worth the extra money.
I think the 4xx is limited. its a cheaper planar imo. Where the Sundara punches above its price. what headphones do you already have? you could put that in your profile and people can see and know how to advise
4xx is my first planar and with some EQ (especially to the low end) it sounds awesome to me. I do want to try the Sundara next though.
What aspect of planar are you hoping to explore? If “planar speed” is your goal, the Sundara will do just fine. If “planar slam” is your goal, look a tier up at a LCD-2C or an Edition XX.
Thanks 
Would you say that I’d be doing myself a disservice If I tried the 4xx first? Or should I go for the Sundara directly?
That’s a good point, I added a list of what I’m currently using.
Mmmm. I don’t have a good answer. Both? My gut is telling me I want to explore the slam, but since I haven’t heard them before, I might discover something else I didn’t expect I’d like. When I first got the 6XX I didn’t really have expectations, and I actually didn’t like them very much, but now they’re my main headphones. They could use a tad more bass, but still.
Sundara.
It is worth just getting those. If you end up liking the 4XX, you’d probably end up getting the Sundara anyway. If you don’t like the 4XX, you’d still probably want to try the Sundara.
I love my 4XX. But if you want something that will impress, the 4XX probably won’t cut it
And if you want cheap, the Fostex T40/50/60 is an in
The Fostex TXRP series are indeed planar. They’re not often associated with the “planar sound” though. I think mostly that’s because their drivers are no bigger than most dynamic drivers.
Ok. I have no firsthand knowledge but it does sound like the Sundara responds decently to low end EQ. Community, please correct if that’s wrong. Since this is your first planar it’s probably better to drop $350 here than $600+ on the others I mentioned.
BTW, what dac and amp are you going to use with them?
+1 to the sundara
I have a Schiit Hel, which seems to have enough power to drive most things. I use it with the 6XX now.
I also have a BTR5.
Are these the same as these?
The listing doesn’t mention planar. Some websites do, some don’t. It’s so confusing.
What about the Dekoni Blue Fostex @ Drop? Anybody heard these? https://drop.com/buy/dekoni-fostex-blue-planar-magnetic-headphones
I have the Dekoni blues, and they are among my least favorite headphones, but I don’t like any of the TX0RP headphones I’ve listened to, the Bass to mid transition to me is something i can’t get past.
But some people seem to like them so YMMV.
Can’t remember what’s so special bout those T60rps other than the design is different and it’s practically already partially modded. As for the rest of the series. T20rp is the open back version with a lot more bass, T40rp is your closed back, and T50rp is what is considered the best sounding and is semi open back meanwhile dekoni blue is something of a bright or V signature sounding headphone and it’s already modified. The headphone is practically designed to be modded.
If you want to go in on the cheap, a forum member is selling a 4XX - Buy/Sell Thread
:edit: price drop to $105.
Yes, by TXRP I meant the X to mean 20, 50, or 60. That series has small (50mm maybe?) planar magnetic drivers. Your Schiit Hel may actually struggle to drive that series of headphones. They are power hungry and when underpowered, it’s the bass that get most affected. They become boomy and sloppy in the low end.
Yes, that’s the set of T50 mods that I own. @Polygonhell is right that they can be a bit much in the mid-bass to bass transition region. Pad swapping helps quite a bit, IMO. I put Shure 1540 pads on mine and they sound pretty good. TBH, though, they don’t sound ‘planar’ to me. In fact, they sound like a slightly less refined and detailed version of the Massdrop - Fostex TR-X00 Purplehearts. They have a very similar V shaped signature. But the X00’s are biodynamic drivers. That’s one reason I say the T50RP based headphones don’t sound ‘planar’. The planar drivers by HiFiMan and Audeze are HUGE. The sound wave that hits your ears covers more area. That creates a bit different sound than a dynamic driver based headphone. IMO, the T50 mods lack that “big planar” sound characteristic.
This is not to say one should avoid T50-based headphones. I think the T50 line is an assett in the <$500 category. They take really well to modding and pad rolling so there’s a lot one can learn from playing around with them. When tinkered-with well, their sound is pretty good too.
Carl? Is that you?