Recording - November 2016 - 53

rooms you usually find diffusers only on
the rear wall. So for treating reflection
points, absorption is a better choice, and
that leads to our last myth: loudspeaker
directivity.
Some people believe that early reflections are less damaging if they're "neutral", coming from loudspeakers that
have a flat off-axis response. But this is
wrong-when reflections from a wall
have the same frequency content as the
direct sound, the comb filtering is most
severe. Peaks will be up to 6 dB, and
nulls can be 30 or even 40 dB deep!
If the loudspeakers have a limited offaxis response, such that the wall reflections
contain less high frequencies, the comb filtering in the important upper "clarity"
range will be less severe. In other words,
the more closely the original and delayed
sounds match in spectrum and volume, the
more severe the comb filtering. This is
basic math, and a rolled-off response at
high frequencies is the same as having
high frequency absorption on the walls.
So while a flat off-axis response is an
important goal for all loudspeakers, it
actually harms audio quality when early
reflections are allowed. In other words,
if you have good monitor speakers, it's
even more important to absorb reflections from the side walls, not less important as some people claim.
To show why this happens, I created a set
of test files and plotted their response. The
three graphs in Figure 5 show a) a pink
noise source, b) the same noise mixed with
a simulated reflection delayed 15 milliseconds to emulate a loudspeaker with a flat
off-axis response, and c) the noise mixed
with a delayed reflection having high frequencies rolled off at 6 dB per octave. You
can clearly see that the comb filtering is less
severe when the reflections have softer high
frequency content. When the source and
reflections don't match exactly, the peaks
and nulls are less pronounced.
If you're curious, you can calculate
peak and null amounts based on reflection strength using the Decibels spreadsheet on my web site
(ethanwiner.com/decibels.xls). I created
this spreadsheet for my Audio Expert
book, but I'm glad to share it publicly so
people can experiment themselves. This
is one of many tools you can use to learn
about and control the early reflections in
your listening environment and get better
sound from your monitors.
Ethan Winer (winer@recordingmag.com)
has been an audio engineer and professional musician for more than 45 years.
His Cello Rondo music video has received
nearly two million views on YouTube and
other web sites, and his book The Audio
Expert, published by Focal Press, is available at amazon.com and Ethan's own
web site, ethanwiner.com.
RECORDING NOVEMBER 2016

53


http://www.antelopeaudio.com http://www.ethanwiner.com/decibels.xls http://www.clearsonic.com http://www.amazon.com http://www.ethanwiner.com

Table of Contents for the Digital Edition of Recording - November 2016

Contents
Recording - November 2016 - Intro
Recording - November 2016 - Cover1
Recording - November 2016 - Cover2
Recording - November 2016 - 1
Recording - November 2016 - 2
Recording - November 2016 - 3
Recording - November 2016 - 4
Recording - November 2016 - 5
Recording - November 2016 - Contents
Recording - November 2016 - 7
Recording - November 2016 - 8
Recording - November 2016 - 9
Recording - November 2016 - 10
Recording - November 2016 - 11
Recording - November 2016 - 12
Recording - November 2016 - 13
Recording - November 2016 - 14
Recording - November 2016 - 15
Recording - November 2016 - 16
Recording - November 2016 - 17
Recording - November 2016 - 18
Recording - November 2016 - 19
Recording - November 2016 - 20
Recording - November 2016 - 21
Recording - November 2016 - 22
Recording - November 2016 - 23
Recording - November 2016 - 24
Recording - November 2016 - 25
Recording - November 2016 - 26
Recording - November 2016 - 27
Recording - November 2016 - 28
Recording - November 2016 - 29
Recording - November 2016 - 30
Recording - November 2016 - 31
Recording - November 2016 - 32
Recording - November 2016 - 33
Recording - November 2016 - 34
Recording - November 2016 - 35
Recording - November 2016 - 36
Recording - November 2016 - 37
Recording - November 2016 - 38
Recording - November 2016 - 39
Recording - November 2016 - 40
Recording - November 2016 - 41
Recording - November 2016 - 42
Recording - November 2016 - 43
Recording - November 2016 - 44
Recording - November 2016 - 45
Recording - November 2016 - 46
Recording - November 2016 - 47
Recording - November 2016 - 48
Recording - November 2016 - 49
Recording - November 2016 - 50
Recording - November 2016 - 51
Recording - November 2016 - 52
Recording - November 2016 - 53
Recording - November 2016 - 54
Recording - November 2016 - 55
Recording - November 2016 - 56
Recording - November 2016 - 57
Recording - November 2016 - 58
Recording - November 2016 - 59
Recording - November 2016 - 60
Recording - November 2016 - 61
Recording - November 2016 - 62
Recording - November 2016 - 63
Recording - November 2016 - 64
Recording - November 2016 - 65
Recording - November 2016 - 66
Recording - November 2016 - 67
Recording - November 2016 - 68
Recording - November 2016 - 69
Recording - November 2016 - 70
Recording - November 2016 - 71
Recording - November 2016 - 72
Recording - November 2016 - Cover3
Recording - November 2016 - Cover4
https://www.nxtbook.com/musicmaker/musicmaker/recording_202404
https://www.nxtbook.com/musicmaker/musicmaker/recording_202403
https://www.nxtbook.com/musicmaker/musicmaker/recording_202402
https://www.nxtbook.com/musicmaker/musicmaker/recording_202401
https://www.nxtbook.com/musicmaker/musicmaker/recording_202312
https://www.nxtbook.com/musicmaker/musicmaker/recording-november-2023
https://www.nxtbook.com/musicmaker/musicmaker/recording_202310
https://www.nxtbook.com/musicmaker/musicmaker/recording_202309
https://www.nxtbook.com/musicmaker/musicmaker/recording_202308
https://www.nxtbook.com/musicmaker/musicmaker/recording_202307
https://www.nxtbook.com/musicmaker/musicmaker/recording_202306
https://www.nxtbook.com/musicmaker/musicmaker/recording_202305
https://www.nxtbook.com/musicmaker/musicmaker/recording_202304
https://www.nxtbook.com/musicmaker/musicmaker/recording_202303
https://www.nxtbook.com/musicmaker/musicmaker/recording_202302
https://www.nxtbook.com/musicmaker/musicmaker/recording_202301
https://www.nxtbook.com/musicmaker/musicmaker/recording_202212
https://www.nxtbook.com/musicmaker/musicmaker/recording_202211
https://www.nxtbook.com/musicmaker/musicmaker/recording_202210
https://www.nxtbook.com/musicmaker/musicmaker/recording_202209
https://www.nxtbook.com/musicmaker/musicmaker/recording_202208
https://www.nxtbook.com/musicmaker/musicmaker/recording_202207
https://www.nxtbook.com/musicmaker/musicmaker/recording_202206
https://www.nxtbook.com/musicmaker/musicmaker/recording_202205
https://www.nxtbook.com/musicmaker/musicmaker/recording_202204
https://www.nxtbook.com/musicmaker/musicmaker/recording_202203
https://www.nxtbook.com/musicmaker/musicmaker/recording_202202
https://www.nxtbook.com/musicmaker/musicmaker/recording_202201
https://www.nxtbook.com/musicmaker/musicmaker/recording_202112
https://www.nxtbook.com/musicmaker/musicmaker/recording_202111
https://www.nxtbook.com/musicmaker/musicmaker/recording_202110
https://www.nxtbook.com/musicmaker/musicmaker/recording_202109
https://www.nxtbook.com/musicmaker/musicmaker/recording_202108
https://www.nxtbook.com/musicmaker/musicmaker/recording_202107
https://www.nxtbook.com/musicmaker/musicmaker/recording_202106
https://www.nxtbook.com/musicmaker/musicmaker/recording_202105
https://www.nxtbook.com/musicmaker/musicmaker/recording_202104
https://www.nxtbook.com/musicmaker/musicmaker/recording_202103
https://www.nxtbook.com/musicmaker/musicmaker/recording_202102
https://www.nxtbook.com/musicmaker/musicmaker/recording_202101
https://www.nxtbook.com/musicmaker/musicmaker/recording_202012
https://www.nxtbook.com/musicmaker/musicmaker/recording_202011
https://www.nxtbook.com/musicmaker/musicmaker/recording_202010
https://www.nxtbook.com/musicmaker/musicmaker/recording_202009
https://www.nxtbook.com/musicmaker/musicmaker/recording_202008
https://www.nxtbook.com/musicmaker/musicmaker/recording_202007
https://www.nxtbook.com/musicmaker/musicmaker/recording_202006
https://www.nxtbook.com/musicmaker/musicmaker/recording_20205
https://www.nxtbook.com/musicmaker/musicmaker/recording_202004
https://www.nxtbook.com/musicmaker/musicmaker/recording_202003
https://www.nxtbook.com/musicmaker/musicmaker/recording_202002
https://www.nxtbook.com/musicmaker/musicmaker/recording_202001
https://www.nxtbook.com/musicmaker/musicmaker/recording_201912
https://www.nxtbook.com/musicmaker/musicmaker/recording_201911
https://www.nxtbook.com/musicmaker/musicmaker/recording_201910
https://www.nxtbook.com/musicmaker/musicmaker/recording_201909
https://www.nxtbook.com/musicmaker/musicmaker/recording_201908
https://www.nxtbook.com/musicmaker/musicmaker/recording_201907
https://www.nxtbook.com/musicmaker/musicmaker/recording_201906
https://www.nxtbook.com/musicmaker/musicmaker/recording_201905
https://www.nxtbook.com/musicmaker/musicmaker/recording_201904
https://www.nxtbook.com/musicmaker/musicmaker/recording_201903
https://www.nxtbook.com/musicmaker/musicmaker/recording_201902
https://www.nxtbook.com/musicmaker/musicmaker/recording_201901
https://www.nxtbook.com/musicmaker/musicmaker/recording_201812
https://www.nxtbook.com/musicmaker/musicmaker/recording_201811
https://www.nxtbook.com/musicmaker/musicmaker/recording_201810
https://www.nxtbook.com/musicmaker/musicmaker/recording_201809
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201808
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201807
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201806
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201805
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201804
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201803
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201802
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201801
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201712
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201711
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201710
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201709
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201708
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201707
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201706
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201705
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201704
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201703
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201702
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201701
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201612
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201611
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201610
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201609
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201608
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201607
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201606
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201605
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201604
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201603
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201602
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201601
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201512
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201511
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201510
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201509
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201508
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201507
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201506
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201505
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201504
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201503
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201502
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201501
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201412
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201411
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201410
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201409
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201408
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201407
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201406
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201405
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201404
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201403
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201402
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201401
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201312
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201311
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201310
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201309
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201308
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201307
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201306
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201305
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201304
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201303
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201302
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201301
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201212
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201211
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201210
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201209
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201208
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201207
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201206
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201205
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201204
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201203
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201202
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201201
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201112
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201111
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201110
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201109
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201108
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201107
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201106
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201105
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201104
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201103
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201102
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201101
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201012
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201011
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201010
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201009
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201008
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201007
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201006
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201005
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201004
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201003
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201002
https://www.nxtbook.com/nxtbooks/musicmaker/recording_201001
https://www.nxtbook.com/nxtbooks/musicmaker/recording_200912
https://www.nxtbook.com/nxtbooks/musicmaker/recording_200911
https://www.nxtbook.com/nxtbooks/musicmaker/recording_200910
https://www.nxtbook.com/nxtbooks/musicmaker/nxtd
https://www.nxtbookmedia.com