How does the Sony MDR-7506 stack up? I've had a pair of these for many many years, although I never use them. My teenage daughter now uses them extensively as she's been through many pairs of inexpensive ear buds that break. She has worn out the ear cups and I replaced them. Headphones are still in like new condition. They seem pretty durable.
Also browsed around a bit for "decent" headphones when i bought them and they seemed to pop up frequently on recommended lists for under $100. Response above 10-12K looks...well, just not there.
I'm really surprised(not really, I suppose) about expensive well regarded headphones that don't measure up. I can't imagine dropping that kind of money on headphones without better objective data available other than marketing and subjective reviews. Or do some of them have superb test results on other sites, such as the $1500 Focals that just got tested?
If it's speech intelligibility you seek, the Sony MDR-7506 is what you want. The V-6 is essentially the same headphone. It's voiced with more bass. My guess is that their frequency response curves are designed for use in pro audio, particularly live sound. They're nearly unbreakable. Stuff like a/c line buzz is exaggerated both top and bottom. Everything is the middle is harsh and up close, you can hear every word. My understanding is these are favored monitors for the folks recording dialog for films & TV. So great for Pro Audio, sucky for music. I owned/used the V-6 for many years, a very useful tool.
Among cheap headphones, I favored the AKG K167 phones for many years. Since I got my Drop 6XX, I stopped using them. The harsh quality of the intelligibility range, peaking around 2khz, made the Tiësto unlistenable. Also, they do break too easily, kinda the opposite of the Sony 'phones. However, as a close-out item, they went for $50, were easy to drive, had a better bass balance than the Sonys, and overall sounded better. But, having experienced the breakage problems that go along with its nearly all-plastic design, no more.
I got a couple of Sennheiser 'phones discounted as returns from Blinq, around $100 a pair. Compared to the Drop 6XX, the HD 599 and HD579 are not worth it. Chalky and vague in the upper registers, bloated in the midbass and lacking deep bass. The 6XX/HD650 is also bloated in the midbass, but that's easy to EQ out. The bottom doesn't distort when jacked up with EQ, the treble is pristine. I like it better with the treble tipped up a little with EQ. It's really good as far as price/performance is concerned and appears to be really durable in construction.
Seeing how good the Philips Fidelio X2HR is for $150---it's like the Large Advent of headphones, balanced top to bottom, easy to drive, gets you 90% of the way there for not much money---I wonder how much Philips' similar but cheaper designs sound. But not enough to buy them, I'm covered for the moment.