Real Equalizer
==============

This Equalizer is a THE real thing.  A full fledged FIR designed with
the window method using RDFT and a Hamming window.  This
equalizer can also be used with any decoders contrarily to the MPEG
audio decoder!  Also since it's a real EQ, it uses juice. I mean major
juice.

The convolution is implemented by FFT convolution which is the fastest
possible way. It is strongly recommended to use FFT convolution, because it
is far superior to any other method. Maybe future versions of realeq will
no longer give you a coice. Using the maximum FIR kernel length and FFT
plansize should be fine.

To come back on the filter order for the casual user, this is the number of
samples processed (in addition to the current sample) to obtain a new
sample. What does this means?  Ok say you are playing at 44100Hz, this
means there are 44100 samples passing per second in the filter also, right?
Ok, so say you'd like to catch 20Hz and filter that decently.  This means
you will need a filter order of at least 3*44100/20 = 6612!  With values
in this range, you can make your stereo EQ jealous.
But be aware of the the following: to get 4Hz resolution at 20Hz to separate
the lowest two sliders you need a filter order of at least 33000! That high
filter orders are not supported by the current realeq version because of
design flaws of the PM123 filter plugin interface.
So even with the maximum FIR order it is a good advise to set adjected low
frequency sliders to similar values.

The 32 middle octave bands are calculated by step of 1/3 octave as
defined by the ISO standard and are as follow in Hz:

16.0	(15.85)
20.0	(19.95)
25.0	(25.12)
31.5	(31.62)
40.0	(39.81)
50.0	(50.12)
63.0	(63.10)
80.0	(79.43)
100	(100.0)
125	(125.9)
160	(158.5)
200	(199.5)
250	(251.2)
315	(316.2)
400	(398.1)
500	(501.2)
630	(631.0)
800	(794.3)
1000	(1000)
1250	(1259)
1600	(1585)
2000	(1995)
2500	(2512)
3150	(3162)
4000	(3981)
5000	(5012)
6300	(6310)
8000	(7943)
10000	(10000)
12500	(12590)
16000	(15850)
20000	(19950)

The FIR order needs to be a multiple of 2 (or 16 because of MMX). The
plansize is for the internal FFT and therefore should be a power of 2.
Just leave it at 16384 or 8192, that's fine.
The plansize MUST always be larger the the FIR order!

WARNING!! If you do not "Use FFT convolution" and not "Use MMX", the FPU
will be used and you might not be able to get away with 512 coeficients
with the FPU.  So change the FIR order to some more reasonable values such
as 64 before trying it.

With FFT convolution, it can play realtime with 12288 coeficients on a K6/400
This is pretty much as good as most professional EQs...!!
