# BW Oct = BW/60?



## zilbenz (Jul 10, 2008)

Sorry for the dumb question: could Wayne or somebody please confirm that these two are indeed the same? 

I was trying to follow Wayne's "Tips for Those Who Use REW's Auto-equalizing function" wherein we're advised to drop "useless filters" such as those with "say 4/60 or less and only 2-b dB gain reduction." There Wayne also discussed the BW/60 conversion to other unit

I came up with filters whose BW Oct values are less than 1. Should I drop these? 

What if it's the only filter that REW recommend?

I think this present version 4.11 of REW automatic drops filters if less than 2 dB, correct? 

Thank you in advance. 

Chris


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## brucek (Apr 11, 2006)

> I came up with filters whose BW Oct values are less than 1. Should I drop these?


A filter with a bandwidth of 1 octave is huge (BW Oct=1). You would certainly not remove any filters that are near that size.

The easiest thing for you to do is play around with the filters in REW to get a feel for the sizes.

Start REW and select either the BFD (which offers its filters in BW/60) or the FBQ (which offers its filters in BW Oct) and then select the EQ filters button and simply enter some filters with some cut or gain and watch them on the screen while you play with the bandwidth. You'll understand it once you do this...

The advice is to not use ridiculously small filters that have no real effect.

brucek


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## zilbenz (Jul 10, 2008)

Thank you for the quick answer. 

Chris


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