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Safe hearing level on iPod

post #1 of 11
Thread Starter 
Not sure if this is the correct place to post, but this question has been burning in me since I read about the safe hearing level chart that can be found on ear-health care websites.

It has been said that the louder the decibels of your music, the shorter the period of time you have to listen to it play, and that "you should know what a safe listening volume is".

I was just wondering--how many db is a quarter volume on an iPod 5th gen ( i think its the same for all iPods) with UE Superfi.5 Pro? I guess there is some calculations about subtracting the ohms (or something to that effect;not sure about that)

Can anyone over hear (pun intended) help me on this? I would firstly like to know the decibels of what a quarter of the iPod vol level is, and the equation to find out the exact db with the specific output earphone.

Thanks a lot.
post #2 of 11
When I listen, I first put it at a fun level, then back off little by little with each additional track. It's amazing how low you can set it, once you settle into your music.
post #3 of 11
Thread Starter 
Quote:
Originally Posted by Bilavideo View Post
When I listen, I first put it at a fun level, then back off little by little with each additional track. It's amazing how low you can set it, once you settle into your music.
"Fun level" eh? Haha. But I can agree with you that once you settle in on your music you wont really notice that its actually quite soft. Once while listening to a comfortable level of hearing, I pulled my IEMs out to talk to my friend, and when I put it back in after a few minutes, I got quite a shock that it was so loud but I guess your ears get accustomed to that after half a minute
post #4 of 11
First, you need to know a table and/or graph of the actual output (in AC mA) of ipod and impedance.

....which is very hard to get, and only one source I know of is here, and it only has data for ipod touch G2. Maybe assume amplifier section are same/similar for all ipod?

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Korean site, but no worries. look for " Vol_DB_091202.xls" click it to download and see the excel file.

Second, you need to know the sound pressure level, a.k.a input sensitivity. For your case, it's 119dB/mW for your IEM.

Now you need two equations.

dB = 10log(p1/p2), p1=1 for our case.
and
W = (V^2)/R,

So, usual safe hear level is 85db, but lower is better. Let's say you are aiming for 80db. So based on your IEM spec we subtract 119-85 = 34db. So there needs to be 34db difference....

Now using first equation, we can get the target output level of ipod...

34 = 10log(1/p2), and p2 is the one you need to get. Get your TI-89 (or other scientific calculator you can use) and find the value of p2.

Now, substitute p2 that you calculated into first equation as W, thus it becomes...

p2 = (V^2)/R, R is for your IEM's impedance, which is 21 ohm...

p2 = (V^2)/21, now get the value of V. That's the desirable player output for getting 80db from your IEM.

Now, using the excel chart to estimate the position of volume wheel... it's been divided into 16 positions, which you can predict by yourself.



To be honest, this is not even accurate anyway because the spec from companies are sometimes... not accurate at all. If you were asking for headphones, a Radioshack sound measure meter modded with cardboard works like a charm, but it does not work on IEM....
post #5 of 11
Thread Starter 
I dont quite get it. I aimed for 50db. So after calculation I got V=~1.0247^(10X-3).

Lets say I want to get a quarter of the click wheel volume. So that will be 4. Under the Apple column in the excel chart I get 4.77

Now where do I go from here?

Thanks
post #6 of 11
NO, you should not getting such lame number like "1.0247^(10X-3)."

Be careful with substitution. the number you get from 119dB/mW is milliwatt, while W = (V^2)/R uses just watt.

That means, after you got p2, you need to multiply this number by 100 to match, and then you proceed as usual.

So, more accurate equation will be p2*100 = (V^2)/21 Try again and see if you get sane (i.e numbers between 1 to 400 something.) number for V. There may be some mistakes since my brain is getting bad.
post #7 of 11
50 db doesnt work considering a normal conversation btw 2 people would be ~70 db...
post #8 of 11
I just put it on whatever depending on my mood and what type of song it is. If I feel like banging my head or something on hardcore/alternative/rap music it's going up. If it's something like classical it will be a little lower.
post #9 of 11
According to my rough approximations, you'll get to 80 dB at roughly half volume with a 118db/mw iem through an iPhone 3GS. Those were by finding measured levels with headphones and adjusting +X dB for the difference in sensitivity. It's not exact, obviously, and since some songs are louder than others, you're better off staying a bet below half volume.
post #10 of 11
Thread Starter 
Quote:
Originally Posted by Young Spade View Post
I just put it on whatever depending on my mood and what type of song it is. If I feel like banging my head or something on hardcore/alternative/rap music it's going up. If it's something like classical it will be a little lower.
Hmm i thought if it was classical you ramp the volume up...
post #11 of 11
Quote:
Originally Posted by thepredestrian View Post
Hmm i thought if it was classical you ramp the volume up...
Haha yea I raise and lower the volume.. but I was saying that based on my mood ya know? If I'm listening to classical I'm mostly in a laid back, relaxed mood so I'm going to have the volume low.
But yea if I want to feel the bass or really get into my classical music, I'll definitely turn it up
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