Empirical Labs EL-Q - Manual (Page 5)

Block Diagram
Section Details
The Input & Output
The “Line Input” section is an electronically balanced line receiver circuit. It is relatively insensitive to
all kinds of wiring, be it balanced or unbalanced. The Line Input phone jack on the back is also
balanced but will terminate (“short out” in a GOOD way) one leg of the balanced input when a non-
stereo guitar type cable is inserted.
The Instrument Input on the front panel is an unbalanced, high impedance input with 10dB of
initial gain, designed for lower level, and higher impedance signal such as electric guitar, electric
bass, and other sources that may be sensitive to input loading. It uses circuitry that was designed
for a DI box. If your instrument is low impedance and has a hot output level, plug into the rear phone
jack if any clipping occurs on the Inst In jack.
There are three outputs on the Lil FrEQ, all of which can be used at the same time. The Active
Line outputs (the two outputs other than the Class A Transformer output), are wired in parallel with
the ¼” phone jack output being unbalanced. Pin 2 of the active output XLR is directly connected to
the tip of the phone jack output. Transformer ground can be lifted with a jumper. See page 12.
Highpass Section
This is a specially shaped, digitally controlled 3rd order highpass filter. The shape has been
selected to prevent thinning out frequencies just above the corner frequency. The slope of the roll
off is 18dB per octave, and because of this steepness, the HP must be used with caution, especially
during tracking. No compromise was used in this filter, with a single active stage design, 5% caps,
1% resistors used throughout. This filter is capable of .0005% THD and over 124dB dynamic range.
High & Low Shelf Section
This is a standard, single pole, 6dB per octave shelving equalizer. It is very similar to tone controls
except the performance exceeds any known commercially available unit. The corner frequencies
are around 120Hz, and 4KHz. Maximum boost and cut is 10dB as indicated on the front panel.
Four Band Parametric EQ
These are a series of fully parametric equalizer sections, each sweepable over different frequency
ranges. All four sections are capable of cutting or boosting a band 14dB. This PEQ’s (Parametric
EQ) performance is so high, we had to buy an Audio Precision Analyzer to measure the THD, which
operates below .0006% at extremely hot levels. This is the highest audio performance parametric
equalizer we know of. Almost all frequencies are covered in two separate bands, and many of the
mid frequencies are covered in three of the four parametric sections. Each section can be by-
passed separately, without any clicking or popping during pauses. This is very important during
“Spot” EQing. The BW (bandwidth) control’s most useful range takes up 80% of the knob rotation,
with the narrowest and widest BW’s or Q’s changing rapidly in the last 30 degrees of the minimum
and maximum rotation. This is why the BW’s markings get denser towards the extremes. The
PEQ frequency knobs are hand calibrated. 11
Example Settings (Cont’d)
Vocals
- One of the worlds favorite vocalists, Frank Sinatra, became so good at” working the
mic”, moving in when he was singing soft and wanted intimate body, moving back when he belted
and needed to get the higher notes out… he became so proficient that I have heard the engineers
used very little or no EQ his voice. He got the sound at the source. As he sang soft, he would
move in a little closer to the mic, giving his voice an intimacy. He would even turn his head quickly
to the side so certain breaths wouldn’t be heard. Modern singers of every style could learn from
what Frank was doing 40 yrs ago.
Sticking my neck out, I have to say I have never heard so many nasty vocal sounds on some of
today’s (2005) hit records. There are whole albums that have become painful to listen to because of
over compressed, over brightened, and “spitty” lead vocals. I would mention engineer’s names but
some of these people are our customers! It’s a little bit frightening that people accept these sounds
as normal or actually “good”. Some of it is the result of engineers thinking it’s cool to smash every
breath, word, and syllable with +20dB of compression… and some of it from using digital “software
plug-ins” that haven’t been designed with the greatest musicality. Let’s hope this is just a phase. A
little restraint, combined with getting things right from the start can help. Here are some tips.
Pick the right mic, the right distance and the right angle for the singer. The most expensive
mic isn’t always the best mic for a person’s voice. Moving a person a couple inches in and out from
the mic can make all the difference in the world. Putting the mic up above the person’s mouth
around their nose level can warm things up, avoid pops, and make a singer sound less nasal. When
a mic is aimed down a little towards the singer’s mouth, you will be aiming it at their body also, where
lots of low frequency resonance occurs. Conversely aiming it up can work, having the singer sing
over the top of the mic. Remember that a leading cause of “nasality” is the lack of sound and air
coming from a persons nose, so by aiming up or being level with the nose, an engineer can often
improve the basic quality of a voice. Remember to remind the singer they can move slightly in on
soft intimate parts, working the microphone ala “The Frank”.
EQing - Don’t overly brighten! One of the first things people do when they track or mix vocals
is to grab for that high end and crank it up. Of course, a certain amount of high boost is frequently
required. But, often harsh sibilant frequencies suddenly pop out making a perfectly good vocal
become this scratchy, hissy annoying squawk. UGH! Remember that pulling some woofy or pointy
lower mids can bring out the body and high frequencies without exaggerating the spit, S’es, and high
frequency resonances in a voice. Try pulling freqs from 300 to 4000 out to smooth and bring out the
low and top end. There is a danger in removing the body in the 300 – 600 range so keep your ears
alert when pulling out these freqs. A dB or two may be enough. Compression is going to bring
some of the body back up but will also bring out the honk, breaths and sibilants (sibilants are the
annoying S’es, T’s K’s that have a high frequency transient nature).
A very common technique used in pop and rock mixdowns today is applying different EQ’s to
different vocal sections. Splitting a vocal on to different channels or tracks to allow tweaking the EQ
sound is a day-to-day event for many major mixdown engineers. The engineer will mute the unused
channel(s) for different sections of a song. Sometimes different effects will also be applied to the
different sections. Even with digital editors, this is still a lot of work and takes experience to make it
sound natural and all fit together. Some of the most pleasing rock vocal sounds were achieved by
an engineer riding the EQ during mixdowns, punching an EQ section in or out or up and down during
certain sections. Again, the upper mids (3.5KHz) is a target for this kind of treatment.
The Lil FrEQ provides a dynamic equalizer in its DS section. There are some other
dynamic equalizers out there that work pretty well, but… hoping to get a great vocal sound using one
“holy grail” setting on a wildly dynamic vocal is dubious in our minds. We believe some experienced
engineers have gotten a bit lazy using some new toys and not their ears. Also, one very common
dynamic equalizer has extremely asymmetrical boost and cut, where the boost is 5 times wider than
when the same band cuts, leaving the engineer wondering why the vocal sound gyrates so widely
when compressing or expanding a frequency range. The Lil FrEQ DS section uses a crossover
method to control high frequency content and is extremely smooth and even in its response. The DS
can be moved before the EQ so that any boost in that eq, will not be undone.
On an occasional overly sibilant vocal, use the standard De-ess mode which is level insensitive.
Adjust the frequency for around 6Khz and adjust the threshold till the sibilants start sounding natural.
If lisping starts occurring, raise the frequency or raise the threshold to lower the De-essing. The De-
esser should only be working on the offending fricatives and sibilants.
4
XLRM
2 1
3
XLRM
2 1
3
XLRF
1 2
3
Input Select
Output
Gain
Shelf In/Out
HP In/Out
Parametric EQ (4 bands)
Input
Gain.
In/Out In/Out In/Out In/Out
Dynamic Section
DS
Balanced In
Instrument In
High & Low Shelf
Digitally Controlled
High Pass Filter
Active Outputs
Transformer Output
Class A
Amp
Jump
Master
Bypass
DS position
Select Relay
Unit shown with all
EQ sections "In".
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