How Much Overall DB is Lowered When Lowering EQ?

Per the recommendation of a recent YouTube video I watched, I'm lowering the EQ of my background music in the 1k to 2k frequency range so that it does not make my voiceover sound muddled (human vocal range has a large component within the 1k to 2k range, apparently).

I'm wondering if there is a way to find out how much the total db level of a particular clip has been lowered when just a portion of its frequencies (e.g., those between 1k and 2k) have been lowered. For example, if I lower a song's EQ in the 1k to 2k range by around 4 db, is there a way to know how much the total db has been lowered for that song, asides from just looking at the meters? The reason I'm wondering is because I don't want to necessarily make the background music quieter- I just want it to be less prominent in a particular frequency range, and then make up for how much the overall db has decreased by raising the overall volume for that clip. Or would raising the total volume of the song after lowering the EQ in a particular range defeat the purpose of doing so in the first place?

I'm wondering if there is a way to find out how much the total db level of a particular clip has been lowered when just a portion of its frequencies (e.g., those between 1k and 2k) have been lowered. For example, if I lower a song's EQ in the 1k to 2k range by around 4 db, is there a way to know how much the total db has been lowered for that song, asides from just looking at the meters?

Not really. The math would depend on the bandwidth and slope of the band you are adjusting and would be quite complicated to calculate.

But it's not necessary. There's an old saying in audio which has become popular in recent years; "mix with your ears, not your eyes."

The reason I'm wondering is because I don't want to necessarily make the background music quieter- I just want it to be less prominent in a particular frequency range, and then make up for how much the overall db has decreased by raising the overall volume for that clip. Or would raising the total volume of the song after lowering the EQ in a particular range defeat the purpose of doing so in the first place?

Raising the level is likely to defeat the purpose of cutting the EQ.

You really have to listen to the result. The meters are a guide to the overall level, but you can't adjust balance with meters. Of course, this becomes a problem if you don't have accurate speakers, or if you haven't trained your ears.

I see a huge number of YouTube videos where the music is massively too loud and I think to myself, "did the person editing this actually listen to it?"

One thing I suggest you look up is "ducking". This is where you use a compressor sidechain to automatically lower the music whenever there is dialog.

Thank you for that informative response! I'm being quite finnicky over the music levels, listening to how they sound both through various speakers, headphones, and earphones. The problem is that music (naturally) always sounds louder and crisper when listening through headphones/earphones, so there does not appear to be a "perfect" setting that will produce an ideal background music sound for all types of listening situations.

Hence, my goal has been to make it as loud as it should be on headphones/earphones, and if that is still not loud enough for certain speakers, well, too bad. I'd rather it be too low for those speakers than too high anywhere else.

I'm doing all the "ducking" manually with keyframes, since I don't like the quick up and down effect auto-ducking sometimes produces. That can probably be addressed in the ducking settings, I'm sure, but I've managed to get smooth results doing it manually for the time being.