Audio References • Links • Calculators • Translation dictionary • Store • WWW pro-audio search
	Professional audio Calculators
Home

Add Calculators to your Favorites/Bookmarks »» Explorer, click here. Netscape, press CTRL+D. If you wish other sound related Calculators to be added, tell us here. Do not forget to visit other useful sections in Doctor ProAudio such as Search (very powerful, search for terms within pro-audio pages of the www), audio references and the English-Spanish-English pro-audio dictionary. E-mail your friends about this page

SPL (Sound pressure level) calculator

(Fill in the first four fields on the left and click on the "Compute" button to get the theoretical SPL. The column on the right shows the partial correction relative to the reference conditions of 1 loudspeaker, 1 W and 1 m. Computation is based on the entered parameters only, and does not include others such as air propagation losses or loudspeaker power compression). You can compute air absorption with the Air absorption calculator. Resulting SPL will be RMS provided the amplifier power is RMS as well, as published by most amplifier manufacturers. For more than 1 speaker, use the "in phase" option for subwoofers located next to each other. For the remaining cases, the "random phase" option will be the closest to the actual number, and in any case we may be underestimating the SPL somewhat, so any difference will work in our favour.

SPL addition

(Fill in as many fields as required within the first four and click on the "Compute button" to get the sum. It is assumed that each source's phase is random with respect to the others)

Ceiling speaker coverage calculator

(Fill in the first three fields and click on the "Compute" button to get the resulting coverage.
If vertical and horizontal loudspeaker coverage angles are different, compute each angle separately. Ceiling speakers tend to have a -6 dB coverage angle around 100 degrees and a -10 dB angle of around 140 degrees. Often, the theoretically correct spacing for the -6 dB angle yields too many speakers. In that case you could use the -10 dB angles or multiply the -6 dB angle by a factor)

Millisecond/microsecond «» metres/feet/cm/inches calculator

(Fill in the first field, select the option and click on the "Compute" button for each term (column). You can also change the default sound speed, 343 m/s (1125 ft/s), which is shared across the two calculations (columns). Sound speed only changes slightly with humidity and temperature. To convert seconds to distance just multiply them by 1000, write the result on the first field and select "ms"

Frequency (Hz) «» wavelength calculator

(Fill in the first field, select the option if available and click on the "Compute" button for each term (column). You can also change the default sound speed, 343 m/s (1125 ft/s), which is shared across the two calculations (columns). Sound speed only changes slightly with humidity and temperature.

Air absorption calculator

(fill in the first three fields and click on the "Compute" button to calculate absorption of sound by the atmosphere. The method used here is specified on the ISO 9613-1 standard and approximates real-life values within certain value ranges. This value can be added to the loss computed at the SPL Calculator to get the total resulting level. Real-life data in graphical form

dBu «» dBV «» Volt calculator

(Fill in the first field and click on the "Compute" button for each term (column)
dBu refers to 0.775 Volts; sometimes dBv is used instead of dBu. dBu is equal to dBm assuming a 600 ohm load). dBV refers to 1 volt. 

Q «» B/W (bandwidth) calculator

(Fill in the first field and click on the "Compute" button for each term (column).
Bandwidth is in octaves. The decimal separator must be ".".
There is no standard way to convert bandwidths to Q factors and a number of formulas exist,
but the calculation above will be useful nevertheless. In tabular form

• Back to Top •

• Home •

© Copyright 2001-2009 Doctor ProAudio - All Rights Reserved. Conditions of use