Headphones

I'm replacing my old headphone with something that I think is more on the luxurious side. What's very nice about this headphone is that it has a lot of reverb and is decent at blocking out outside noises. However, I expected a full-on sphere of sound surrounding my head. Instead, I feel like only 60% of the space is filled, and it's not as loud as I thought it would be. And by the volume, I do not mean so quiet that it's background level noise. It's just a bit under, even compared to my old headphone.

As stated in the title, I have the 250 ohm version, and I do not have an amp. The headphone is plugged straight into my PC.

I bought the 250 ohm version because people said it sounds better and is overall more professional. Today after some more research I realized that an amp is "required"? I only want a high-quality headphone that I can enjoy listening to Spotify.

Of course, I can just turn up the computer sound output volume, but I'm not sure if that's the "incorrect" way of addressing this. I'd love to get the most out of this headphone. If there are any related software or drivers, I'd be happy to download them.

Edit: Also, another weird thing I noticed is that when I download music and play them on Windows Media Player, the volume is fine (0db). The problem is if I play YouTube videos (even the same song) or Spotify with in-app volume cranked to max, it's only at about negative6db.