Aces High Bulletin Board

General Forums => The O' Club => Topic started by: Swoop on July 18, 2009, 02:57:57 PM

Title: sound experts....need help, dBu and r.m.s. voltages?
Post by: Swoop on July 18, 2009, 02:57:57 PM

How do I work out the r.m.s. voltage of a -52dBu microphone?

Title: Re: sound experts....need help, dBu and r.m.s. voltages?
Post by: bcadoo on July 18, 2009, 08:46:52 PM

Have you taken any readings?  Once you have use the method outlined here:

http://en.wikipedia.org/wiki/Root_mean_square

Title: Re: sound experts....need help, dBu and r.m.s. voltages?
Post by: Jenks on July 18, 2009, 09:13:29 PM

Try this link  http://www.sengpielaudio.com/calculator-db-volt.htm

Title: Re: sound experts....need help, dBu and r.m.s. voltages?
Post by: FireDrgn on July 19, 2009, 12:10:05 AM

Ok im curious........ Not sure I understand the question.

Is this what your looking for...


:"The degree of precision is up to you. You could measure the output with a multimeter that read directly in db..

Voltage ratio is antilog (dB/20)

On modern calculators antilog is 10^

If you entered -1 for the dB in that equation, the Voltage ratio is 0.8912509382 (just use the 0.891)

Now multiply that voltage ratio by the level you are working with....

0.891 x 1.228 = 1.094 volts RMS

Now multiply that by the peak to peak conversion = 1.094 x 2.8184 = 3.08 volts p-p.

+4dB is 1.228 x 2.8184 = 3.46 volts p-p"

Geoff'


If so  go here.......follow this link   http://www.auroraaudio.net/dcforum/DCForumID1/115.html (http://www.auroraaudio.net/dcforum/DCForumID1/115.html)


P.S  Im not a sound expert

Title: Re: sound experts....need help, dBu and r.m.s. voltages?
Post by: Swoop on July 19, 2009, 12:36:00 AM

Jenks, that is absolutely spot on :).

Title: Re: sound experts....need help, dBu and r.m.s. voltages?
Post by: Jenks on July 19, 2009, 10:44:50 AM

Just curious, but why do you need the conversion?

Title: Re: sound experts....need help, dBu and r.m.s. voltages?
Post by: Swoop on July 19, 2009, 10:00:57 PM

Mate of mine doing a degree in music theory, got completely lost on this bit and asked me for help.....like I know anything.

Title: Re: sound experts....need help, dBu and r.m.s. voltages?
Post by: Grayeagle on July 19, 2009, 11:23:42 PM

College teaches you how to find out stuff :)

It's working :)

-GE