Hello! Thanks for reading and for the questions.
I hate to be the guy to do this to you, but those isolation numbers are actually way off. Often, when headphone companies make claims about isolation, they only do so for one specific frequency. While the M50X can reduce certain high frequencies by as much as 36 decibels…its actual overall isolation performance is significantly worse.
When you look for isolation numbers, what you want to find is a good measurement of broadband isolation. That’s an average of a headphone’s isolation performance across all frequencies. Tyll over at Innerfidelity does an exceptional job of measuring isolation. His graphs give you both a breakdown of how a headphone performs at isolating individual frequencies, and a good broadband isolation number.
So, what’s the actual isolation of the M50X? 13 dB
Tyll shows isolation in the upper right part of his charts. As you can see, the M50X has almost zero isolation effect on certain frequencies, and indeed even makes some lower frequencies louder due to resonance inside its materials.
You can find the broadband isolation average at the bottom right of his charts.
Now, 13 dB is still an okay reduction in sound, but probably not suited for really loud environments.
Now…about that DT770 M. The M indicates the “monitoring” version of the headphones. It’s a headphone specifically made for drummers, working in a studio environment, or folks running sound boards at loud concert or theater venues. Beyerdynamic has tweaked the sound and design in favor of isolation above all other things.
This means its actual sound signature is…kind of awful. It’s really only designed for drummers, or people running Front of House monitoring systems, so the sound quality is not up to Beyerdynamic’s usual output. You probably wouldn’t enjoy listening to music on them at all.
And once again, that isolation number is only its maximum performance at one frequency, not its broadband performance, which I’ve heard is closer to the 20dB range.
The regular DT770 is a much better-sounding headphone, with a broadband isolation performance around 15dB.
The ANC headphones that you’ve dismissed actually have much better broadband isolation than either of the models you’ve mentioned above. Bose’s new QC35? 28dB of Broadband Isolation.
You can easily see the dramatic difference in this isolation chart compared to the M50X chart above. In many ways, it’s not even close.
Now, the best isolation in a sound product comes from deep insertion In-Ear Monitors. So if you really need good sound quality and tons of isolation, your best bet is probably a pair of double or triple-flanged IEMs, or even IEMs with ear tips made custom for your ears. That’s what most musicians use these days to monitor their own live performances.
What sort of environment are you in where you’d need to isolate things so powerfully?
I test isolation in a loud coffee shop. I wear the headphones there for several hours and see if I can comfortably hear my music while I work. The coffee shop has a great mix of a low droning ventilation system, people talking, and coffee machine noises. So I’m not testing things the same way Tyll does…but most closed-back headphones work just fine in this environment.
The HyperX Cloud Alpha’s are probably about on par with the regular DT770 in that regard, which is pretty good. The NVX XPT100’s I tested recently have very good passive isolation, as do Sennheiser’s famous HD280 Pros.
Your notebook’s audio hardware should be able to power both headphones you’ve mentioned just fine…but again, I’m not sure they’ll isolate the way you expect them to.
Outside of hearing protection gear made for pilots and shooters, the isolation factor of most headphones is meant to work in concert with your music to isolate away the outside world. Headphones aren’t really designed to block out all outside noise. It’s just kind of the nature of physics. A hunk of plastic and metal on your ear is still susceptible to picking up vibrations in the outside world.
I’m sorry that headphone companies often market their headphones as being more isolating than they actually are. It’s why I refer to Tyll’s graphs and do my own tests in a real-world environment. If you want total silence in headphone, you’re not really going to get it without IEMs.
I hope that helps you out! Sorry it’s not better news!