Hello Spantini,
I appreciate the conversion calculator on provided website link.
In establishing a rudimentary knowledge base (in this rather specialized area), over the last few days I reviewed material on dB applications and terms, which I understood of basic concepts. However, I am not confident I correctly applied that information to the conversion calculator.
If convenient of your time, would you double check my results on two basic calculations?
If you may further assist, here is the conversion calculator I used: “How to Calculate Decibels?” selection at the bottom of page you provided. To save you time, I used this page:
dB calculate - decibel calculation dB calculator voltage power ratio sound pressure level matching dBA SPL sound pressure intensity ratios converter thd percent % audio engineering impedance matching bridging - sengpielaudio Sengpiel Berlin.
Then I used the section titled:
The formulas for voltage and power and the level calculation.
With the 2 operations I did (briefly outlined below), I included my steps (underlined), as I applied terms/values entered into the conversion calculator.
1) In wanting to determine the line-level dBV input (that the manufacturer used in testing the stated response of a woofer), the only figure I had to work with was 0.1V input (as the limited information I could obtain from the manufacturer). I arrived at approximately (rounded) -20dBV input using the conversion calculator.
Conversion operation steps: I went straight from entering the voltage of 0.1V to dBV conversion.
That seemed an unusually low dBV testing level. However, if correct it may possibly be why the manufacturer’s website does not show it used to arrive at their stated Hz response . . . or I may be wrong in conversion.
2) My Tascam DP24SD unit has a monitor jack rated at -2dBu output. I need to convert dBu output to dBV output, so I know what dBV line-level I am sending to sub/monitors. By using the conversion calculator for the -2dBu figure, I arrived at approximately (rounded) -4.2 dBV.
Conversion operation steps: I first entered the -2 dBu to get the audio voltage. Then I entered that voltage figure into the box for voltage to dBV conversion.
If I’ve got the conversion calculator right on this second operation (for -2dBu), then I’ll be confident to convert other dBu values to dBV for a common output term (dBV) sent from my Tascam to monitors—doing this for myself in the future with various applications using different dBV line levels.
At your convenience, if not imposing, I’d appreciate your double checking both of these operations for me. Again, in light of my brief familiarity of terms, I may have selected the wrong terms in steps of conversion.
I’ll be making purchase decisions in a couple months based on such information, so I appreciate your experience extended further if your time allows.
Most gratefully for what you've done thus far and any further help, JeffF.