Variable smoothing: really 1/48 oct below 100 Hz? - Home Theater Forum and Systems - HomeTheaterShack.com

Old 10-13-16, 07:47 PM Thread Starter
Shackster
Andy

Join Date: Mar 2016
Posts: 24
Variable smoothing: really 1/48 oct below 100 Hz?

In connection with an earlier thread about smoothing, I was doing some experiments with REW. I took a single unsmoothed measurement and saved it twice under two different names, then using File, Open Measurement, I brought these two identical measurements into an empty project. Then I performed the following steps:
1. Select All SPL and verify that the two graphs lie atop one another with a perfect match.
2. Apply variable smoothing to measurement 1.
3. Note that the graphs now differ slightly below 100 Hz, with the dip at around 55 Hz being filled in a bit in the variable smoothing case.
4. Apply 1/48 oct smoothing to measurement 2
5. Note that the graphs are identical below 100 Hz, while the variable smoothing case is smoother than the 1/48 oct case above 100 Hz.

This suggests that variable smoothing may be 1/48 oct below 100 Hz, rather than unsmoothed. The documentation says the following:

Quote:
REW documentation wrote:
Variable smoothing applies no smoothing below 100 Hz, 1/3 octave above 10 kHz and varies between 1/48 and 1/3 octave from 100 Hz to 10 kHz, reaching 1/6 octave at 1 kHz.
I've attached the project with the two identical measurements below.
andyc56 is offline

Old 10-14-16, 01:45 PM
REW Author

John

Join Date: Apr 2006
Location: UK
Posts: 6,707
Re: Variable smoothing: really 1/48 oct below 100 Hz?

The documentation is wrong (I have updated it for the next beta), it became 1/48 below 100 Hz some while ago - June 2015 I think. The previous definition created a smoothing discontinuity at 100 Hz which could be problematic for auto EQ of some responses.
JohnM is offline

 Bookmarks

 Tags 1 or 48 , 100 , hz , oct , smoothing , variable

Message:
Options

## Register Now

Random Question
Random Question #2

User Name:
OR