I’ve never used the A1 personally, I’m sorry! It seems like it has okay reviews online…though some folks received defective units.
Sorry to hear about your experiences with your S8. I’ve never plugged any headphones into mine for long periods outside of the stock AKG earbuds, and even though I’m not a high volume listener…I agree that the sound performance is a touch underwhelming. My iPhones all had better DAC/amps inside.
Apparently Samsung is known generally to not focus on high power output for their phones. This thread on head-fi has some other folks complaining about this exact thing. https://www.head-fi.org/threads/samsung-s8-s8-sound-quality.842681/page-5
Lots of expensive headphones are harder to drive at loud volumes than those earbuds will be, yes. Sometimes a lower impedance helps…but don’t forget to look at the sensitivity as well. I’ve always found that gives a better idea of volume out of low power devices like phones.
On a computer it doesn’t matter much, as many of them have okay sound hardware inside, but on a phone even a few dB of sensitivity can make a big difference at the same/similar impedance levels.
Beyerdynamic is known for tuning their drivers to be a bit less sensitive than the average…but this is part of what gives them the clarity they’re known for, in my opinion.
Most phones these days are also tuned for in-ear headphones or bluetooth use…
I realize none of this is great news. When I bought and reviewed the 32 Ohm Beyers I was still on an iPhone 6, and I found volume levels okay…but again, I’m not much of a hardcore high volume listener.