9 May
2009
9 May
'09
5:42 p.m.
Hi guys (and gals),
I plan on using the K-System [1] and Fons Adriaensens jkmeter [2] with
my monitors once they arrive but I'm unsure about the calibration of
the monitors.
Basically I want to know which kind of sound level meter is sufficient.
From what I gathered there are many standards and two categories:
1) The kind you find in bars and clubs, affordable (<100 Euro), mostly
don't comply to any standard, frequency response up to 8kHz, +-2dB,
feature the required C-weighting and slow speed.
2) The kind that complies to all kind of standards and is immensely
expensive.
It would be easy to get my hands on one of the cheap kind, but would it
be sufficient? If not, which standards should the meter comply to?
Information on the requirements (from [1]):
83 dB SPL, per channel, C-Weighted, slow speed
Improved measurement accuracy if narrow-band pink noise is used
There are many sources of inaccuracy when determining monitor gain when
using pink noise. Using wideband (20-20 kHz) pink noise and a simple
RMS meter can result in low frequency errors due to standing waves in
the room, high frequency errors due to off-axis response of the
microphone, and variations in filter characteristics of inexpensive
sound level meters. For the most accurate measurement, use narrow-band
pink noise limited 500-2kHz, whose RMS level is -20 dBFS. This noise
will read the same level on SPL meters with flat response, A weighting,
or C weighting, eliminating several variables.
For even more accuracy, a spectrum analyzer can be used to make the
critical 1/3 octave bands equal and reading ~68 dB SPL, yet totalling
the specified 83 dB SPL.
Best regards,
Philipp
9 May
9 May
6:31 p.m.
On Sat, May 09, 2009 at 09:42:08PM +0200, hollunder(a)gmx.at wrote:
I plan on using the K-System [1] and Fons Adriaensens
jkmeter [2] with
my monitors once they arrive but I'm unsure about the calibration of
the monitors.
Basically I want to know which kind of sound level meter is sufficient.
The important thing is to always use the same monitoring gain
and getting used to that. Unless you are moving between different
work locations the absolute calibration is not that critical.
Several people have reported that the reference SPL suggested by
Bob Katz is quite high anyway. This is most certainly the case if
you are in a relatively small listening room with close speakers -
there seems to be a psychological effect that makes it seem unnatural
and unpleasant to have high SPL in small enverinments.
So unless you go for scientific accuracy the cheaper meters will
probably do.
Ciao,
--
FA
Io lo dico sempre: l'Italia è troppo stretta e lunga.
From what I gathered there are many standards and
two categories:
1) The kind you find in bars and clubs, affordable (<100 Euro), mostly
don't comply to any standard, frequency response up to 8kHz, +-2dB,
feature the required C-weighting and slow speed.
2) The kind that complies to all kind of standards and is immensely
expensive.
It would be easy to get my hands on one of the cheap kind, but would it
be sufficient? If not, which standards should the meter comply to? 
6:46 p.m.
On Sunday 10 May 2009 00:22:57 Fons Adriaensen wrote:
Several people have reported that the reference SPL
suggested by
Bob Katz is quite high anyway. This is most certainly the case if
you are in a relatively small listening room with close speakers -
there seems to be a psychological effect that makes it seem unnatural
and unpleasant to have high SPL in small enverinments.
So unless you go for scientific accuracy the cheaper meters will
probably do.
Ciao,
Hi, Fons!
Will you be so kind to point me to publically available explanation of k14/k20
sense/motivation?
And is there some probability you will add a k0 type? :-)
Thanks!
Andrew Gaydenko
7:58 p.m.
On Sun, May 10, 2009 at 12:44:30AM +0400, Andrew Gaydenko wrote:
On Sunday 10 May 2009 00:22:57 Fons Adriaensen wrote:
There is a link to Bob Katz' pages in the README.
Several people have reported that the reference
SPL suggested by
Bob Katz is quite high anyway. This is most certainly the case if
you are in a relatively small listening room with close speakers -
there seems to be a psychological effect that makes it seem unnatural
and unpleasant to have high SPL in small enverinments.
So unless you go for scientific accuracy the cheaper meters will
probably do.
Ciao,
Hi, Fons!
Will you be so kind to point me to publically available explanation of k14/k20
sense/motivation? And is there some probability you will add a k0 type?
:-)
Zero, it doesn't make any sense to do that.
The K-meters indicate two values: an RMS one (the
coloured bar), and digital peak value (the white
dot). These are two independent values: the dot
is *not* the peak value of the bar as it is with
most meters. They will indicate the same value
for a continuous sine wave.
For typical music signals the peak indication will
be higher than the RMS one, and that is why the dB
scale (which applies to the RMS indication) is offset.
The only difference between the k20 and k14 meters is
this offset of the scale, they are the same meter
otherwise.
The k14 is used for music that is compressed, so it
can have a lower peak/RMS ratio, and thus a higher
average RMS level.
Ciao,
--
FA
Io lo dico sempre: l'Italia è troppo stretta e lunga.
8:28 p.m.
On Sunday 10 May 2009 01:50:19 Fons Adriaensen wrote:
The page itself hasn't any level-related refs. I have tried to register, but
was not lucky. Nevertheless...
Hi, Fons!
Will you be so kind to point me to publically available explanation of
k14/k20 sense/motivation?
There is a link to Bob Katz' pages in the README. The K-meters indicate two values: an RMS one (the
coloured bar), and digital peak value (the white
dot). These are two independent values: the dot
is *not* the peak value of the bar as it is with
most meters. They will indicate the same value
for a continuous sine wave.
For typical music signals the peak indication will
be higher than the RMS one, and that is why the dB
scale (which applies to the RMS indication) is offset.
The only difference between the k20 and k14 meters is
this offset of the scale, they are the same meter
otherwise.
The k14 is used for music that is compressed, so it
can have a lower peak/RMS ratio, and thus a higher
average RMS level.
...your explanation is sufficient for me now. Fons, thanks!
Andrew
8 p.m.
On Sunday 10 May 2009 00:22:57 Fons Adriaensen wrote:
> The important thing is to always use the same monitoring gain
> and getting used to that. Unless you are moving between different
> work locations the absolute calibration is not that critical.
>
> Several people have reported that the reference SPL suggested by
> Bob Katz is quite high anyway. This is most certainly the case if
> you are in a relatively small listening room with close speakers -
> there seems to be a psychological effect that makes it seem
> unnatural and unpleasant to have high SPL in small enverinments.
>
> So unless you go for scientific accuracy the cheaper meters will
> probably do.
>
> Ciao,
Thanks Fons,
so I'll be borrowing a cheap one from a bar.
My listening space is indeed very small and I'll probably place the
monitors closely (<1,5m), so I'll likely use a lower SPL, just don't
know yet how much lower and if I'll have to read the meters the same.
I'll definitely try get into the topic some more and am looking forward
to trying it.
Hi, Fons!
Will you be so kind to point me to publically available explanation
of k14/k20 sense/motivation?
And is there some probability you will add a k0 type? :-)
Thanks!
Andrew Gaydenko
As far as I understood it K0 would make no sense.
I tried to remember to not forget the links but naturally forgot them..
[1] This explains the K-System:
http://www.digido.com/level-practices-part-2-includes-the-k-system.html
[2] jkmeter download, tarball contains brief explanation:
http://www.kokkinizita.net/linuxaudio/downloads/index.html
Best regards,
Philipp
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5 comments
3 participants
participants (3)
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Andrew Gaydenko -
Fons Adriaensen -
hollunder＠gmx.at