discrete music


+4 dBu / -10 dBV

with one comment

+4 dBu / -10 dBV:  These values are typically used to represent ‘Pro’ and ‘Consumer’ audio signal levels – some gear even has a switch to scale the output, or to adjust input gain.  So what do these values mean on a common scale?

First we need to know how to get from dB to volts.  For linear measures like volts, we defined the measure in dB to be 20*log10(volts/reference).  To go backwards we’ll need volts = reference*10^(dB/20).

You’ll recall from a previous post that the reference for dBV is 1 volt, and the reference for dBu is 0.775 volts.

Let’s convert 4dBu to dBV, via volts:

0.775*10^(4/20) = 1.228V

20*log10(1.228/1) = 1.8dBV

So +4dBu=+1.8dBV, and the difference between +4dBu and -10dBV is really about 12 dB.


Written by jeffvautin

2009.06.12 at 4:00 pm

Posted in Audio/Electronics Theory

Tagged with , , ,

One Response

Subscribe to comments with RSS.

  1. […] This post was Twitted by jeffvautin – Real-url.org […]

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: