How many dB are you looking at? dB SPL/mW and dB SPL/V are the same. They are both sensitivity, but one is how much sound is produced with 1 mW and the other is with 1V.
It's a good thing you are trying to learn for yourself how to do things, but really, if you want to understand any of this, you need a background in maths and physics. Unless you are willing to put the effort into learning it, I don't think you'll be able to understand it. You can always just ask the people around here for help to confirm if a certain equipment is viable for your needs instead of trying to figure it out yourself. We won't bite don't worry.
However if you are willing to learn about it, I will link some sites that will be able to explain it better than I can and in much more detail. If you have any questions you can always post in the sound science section as I think it's getting a bit off topic now.
https://learn.sparkfun.com/tutorials/voltage-current-resistance-and-ohms-law (read this one first)
https://www.allaboutcircuits.com/textbook/semiconductors/chpt-1/from-electric-to-electronic/
http://nwavguy.blogspot.com/2011/09/more-power.html
http://nwavguy.blogspot.com/2011/02/gain-and-headphone-ampsdacs.html
for now i just want to know how to match headphone with amp. thats it
this is what i want to know:
- is this 10^((110-sensitivity) / 10) formula can be applied to all types of headphone to know how much they need power even if that spec use SPL/V? or there is other formula to convert them to SPL/V first?
- if i use db SPL/V on that calculator, for example akg k702 105db SPL/V and 62 ohm
it needs V: 1.78 Vrms I: 28.71 mA P: 51.1mW is this correct result? i mean it needs power too big (51.1 mW) compare when i use SPL/mW
then can i use these formula Vrms=(Vpp / 2) / sqrt2 then (Vrms ^ 2) / R *1000 to know how much power that an amp can produce?
for example fiio e17k has Vpp: 7.8 then the Vrms: 2.75 then i convert that to mW the result is 121.97mW at 62 ohm. is this correct? since k702 needs 51.1mW at 62 ohm, so it can drive k702 right?
- on the other thread it said fiio e17k at 67 ohm can produce P: 95 mW and V: 2.5 Vrms
but i try to calculate with the formula we discuss, at 67 ohm fiio e17k can produce 112.87mW
why is it different?
seems like what you teach to me is usefull, but in the other thread it different iam confused.
man i thank you and appreciate you for giving me those site. i will ask my friend, but for now i can't meet them since they study at different university on different city.
so for know i just want to know a simple math to determine which amp that i need. if its only simple math like i try above its very simple, but what make me confused is one says this and the others says different.
if it use like sin cos tan and the other stuff like that then i give up. and if theres varible more than what we discuss above i will giving up too. but since it only formula and i just apply the number on that formula, i think i can do it.