Input Sensitivity: 98 dB @ 1 kHz
Efficiency: 112 dB @ 1 kHz, 1mW
Frequency Response: 5 Hz to 20,000 Hz
Impedance: 21 ohms @ 1 kHz
 
^^^ is my IEM
 
DIR(Digital Input Receiver)
192kHz sampling frequency support
Low jitter recovery mechanism for a very low jitter clock recovery
Very high sensitivity differential input circuit
External noise reduction circuit for minimizing transmission errors
ASRC(24Bit/192kHz upsampling D/A conversion)
Upsampling up to 192kHz
THD: 133dB
Dynamic range: 142dB
DAC(D/A converter)
THD: 0.0004%
Dynamic range: 132dB
 
^^^ is my HPA / DAC combo ~ Eximus DP1
[size=x-small]If I have the dial on the headphone amp @ 2 clicks, what is the db listening level according to the specs posted on my IEM?[/size]
 
I have the HPA volume setting @ 7-8 o clock what would be my listening level? ~ DB

[size=small]>>If I have the dial on the headphone amp @ 2 clicks<<[/size]
 
[size=small]"clicks"  has no meaning.   You have to measure the sound coming out of the IEM using a Sound Pressure Level meter.[/size]
 
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=390-722

The manufacturer specs say nothing about how a particular setting of the volume control maps to the actual output level, so it is impossible to tell, you need to measure it. Also, the specs are often overly optimistic or even made up (I doubt your DAC really has a dynamic range of 132 dB, for example).