Re: Amplitude Decibel conversion problem

clay@[EMAIL PROTECTED]
 writes:
> [...]
> I was trying to get at the fact that we don't put an additional letter
> to denote the reference such as the case with dBm and dBw.

Hi Clay,

I don't know why you would assert such a thing. I don't agree. 

There are multiple reference levels, even within the context of
acoustics, and even within the context of acoustics for humans.

In both cases, the expression determining dB is

  dB = 20 * log_10 (p / p_ref), 

The first reference level is dB SPL, which is mentioned in other posts,
in which p_ref = 0.0002 microbar (2E-5 newton/m^2). This also
corresponds to an intensity of 10^(-12) W/m^2.

The second does not have a special acronym or identification
but it is p_ref = 1 microbar. 

I quote these from Baranek.

Baranek concludes the paragraph with the statement 

  "The reference pressure must always be stated explicitly."

Unless I'm misunderstanding you, this would seem to diametrically
contradict your assertion.

--Randy


@[EMAIL PROTECTED]
  title = "Acoustics",
  author = "{Leo L. Baranek}",
  publisher = "McGraw-Hill",
  year = "1954"}

-- 
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