Flatheads and IEMs are something I've wanted to try for a while now but the mass amount of them is very overwhelming to say the least lol. I believe music should be an experience and the way an earpiece, headphone, etc presents sound is just as important as tuning so with that in consideration do you recommend any?
oh there really are so many iems coming out almost on a daily bases and as i listen to those the least, i am not up to date to give a good starting point. Currently my favorite cheap set are the Kinera Celest Pandemon Planar driver iems. They are semi open and present a good open soundstage for a planar. I prefer planar drivers as i like the way they do layering. Dynamic driver iems usually have a better soundstage, but the Pandemon are comparable. They have a strong subbass tho.
A cheap but very underrrated IEM for soundstage with dynamic drivers are the Superlux H381f, they have a similar sound to the AKG k701.
You could also try the cheap Final Audio VR3000. They are marketed as gaming headset, but work fine for music too and are quite spacious for the price but are slightly V-shaped in signature.
In my experience Multi BA-driver iems have the best technicalities when done well, but you would have to invest at least 5-600 EUR for a good set, but as i said, i dont know many of the recent years, so there might be some cheaper gems. The Campfire Andromedas are a well known BA Set for soundstage if you want to invest some more money.
Or you go the open way with Audeze LCD-i3, which i use quite often at home. Another planar tho.
In the flathead realm it depends on the amount of money you would like to invest and what your prefered sound signature is. But just for testing it out i would suggest trying the Faaeal Snow Lotus you could get for about 20 EUR on Amazon. They have a strong bass but still are balanced and have a quite good out of head experience. I recommend using them with donut foams. I dont remember if they come with those, so if not, just cut a whole in the foams they come with. this way they retain the bass, but the highs will also stay airy and open. dont use flatheads without foams, as they will loose all the bass. at least when starting experimenting.
if you would like to go slightly higher in price, you cant go wrong with the original Fiio FF3 (not the FF3S!). They have some qualities in the bass and soundstage that otherwise is hard to find around 100 EUR.
Still i have to say if an AKG k701 doesnt manage to push the soundscape out of your head, you will have hard times with any kind of headphone. in this case i refer to my initial post. Only thing i could imagine would be the amp/source the k701 is driven from might have some quirks or is underpowered. Or finally the music you listen to isnt mixed with spatial cues in mind. Try to listen to some Carbon based lifeforms which do kind of ambient music, which is usually very spacious and check, if its still closed in.