Royer Labs SF-12 User Manual

Royer Labs

Model SF-12

Stereo Ribbon Velocity Microphone

Operation Instructions Manual
& User Guide

Made in U.S.A.

TABLE OF CONTENTS

Model SF-12 Ribbon Microphone

Revised 2009

Introduction! 3

Description! 3

User Guide! 4

Using the SF-12 Ribbon Microphone! 4

Operation! 4

Amplification Considerations! 4

Stereo Microphones and Ground Loops! 6

Equalization and Ribbon Microphones! 6

Hum, Noise and Mic Orientation! 7

Microphone Techniques! 8

General Tips for Using the Royer SF-12! 8

Specialized Stereo Recording Techniques! 10

Classic Blumlein Technique! 10

Mid-Side (M-S) Technique! 11

Care and Maintenance! 12

Care for the Optical Black Finish! 13

Features! 13

Specifications! 14

Wiring Diagram! 15

Polar Pattern! 15

Frequency Response! 15

Warranty! 16

2

Introduction

Congratulations on your purchase of a Royer Labs model SF-12 ribbon microphone. The SF-12
is a handcrafted, precision instrument capable of delivering superior sound quality and overall
high performance.

This operator’s manual describes the SF-12, its function and method of use. It also describes the
care and maintenance required to ensure proper operation and long service life. The users guide
section of this manual offers practical information that is designed to maximize the performance
capabilities of this microphone.

Royer Labs products are manufactured to the highest industrial standards using only the finest
materials obtainable. Your model SF-12 went through extensive quality control checks before
leaving the factory. Normal care is all that is required to assure a lifetime of trouble-free service.

Please read this manual thoroughly in order to become familiar with all of the SF-12’s
capabilities. It will assist you in making the most of its superior acoustic properties. This owner’s
manual is a handy reference guide and we suggest you refer to it whenever questions arise on the
use and care of your SF-12 ribbon microphone.

Description

The SF-12 is a compact, stereophonic ribbon microphone array consisting of two matched
microphone elements that are placed one above the other. Each transducer is positioned at 45¼
to the left and right of center, or 90¼ from each other. When held vertically, connector down and
the “ROYER” logo facing the sound source, the upper microphone is the right channel and the
lower one is the left channel, from the perspective of an observer behind the mic. The
microphone elements are each bi-directional (figure-8) and may be addressed from either side
with equal sensitivity. The in-phase signals are achieved when the microphone is addressed from
the front, as indicated by the “ROYER” logo. If, however, the microphone is suspended upside
down, the connections to the preamplifier should be reversed since what was the left transducer
is now responding to signals from the right and vice versa.

Your SF-12 is equipped with a 5-pin XLR extension cable and a splitter cable that fans out to
twin 3-pin male XLR connectors. As shipped from the factory, the connectors are marked
“upper” and “lower” since referring to them as “left” and “right” could lead to confusion.

The SF-12 is reasonably tolerant of shock and vibration, but care should be taken to prevent
accidental stretching of the ribbon elements. This is covered in the Care & Maintenance section
of this manual. The performance of the microphone is unaffected by changes in temperature or
humidity.

3

User Guide

Using the SF-12 Ribbon Microphone

Operation

The SF-12 is a versatile device capable of accurate sound reproduction. There are a few
important facts about ribbon microphones that are key in understanding how to use them
intelligently.

1. The SF-12 is a side-address, bi-directional microphone and the rejection in the ‘dead’ areas is
very strong. Due to this directionality, ribbon microphones should be placed at 1.3 times the
distance normally used with omni-directional microphones, or about the same distance used
for cardioid microphones. This method is used to achieve the same ratio of direct to reflected
sound.

2. In the horizontal plane, ribbon microphones do not discriminate against the ‘highs’ off axis,
nor do they boost them on axis. Therefore, several instruments or vocalists can be placed in
front of the microphone without favoring the performer in the center of the group.

Several performers can be grouped at both the front and the back of the microphone, with
one proviso; since the outputs are out of phase at the front and back of the microphone,
cancellation can result if two tenors are placed on opposite sides at equal distances and are
singing in unison. Therefore, listen to the feed before committing to it.

3. The Royer model SF-12 requires no power supply and is safe to use on consoles with
phantom microphone powering, provided that the cabling is wired properly. It should be
noted that not all ribbon microphones are compatible with phantom-powering systems, so
check the manufacturer’s recommendations before using other ribbon microphones. Faulty
or improperly wired cables could also cause problems with your SF-12.

4. Never attempt to test the SF-12 or any ribbon microphone with an ohmmeter. A blown ribbon
could result.

5. Always provide adequate protection for your SF-12, or any ribbon microphone for that
matter. If the microphone is to remain set up on a stand when not in use, place the included
mic sock over it until it is to be used. Do not carry the microphone around without placing a
mic sock over it. Failure to follow this common-sense practice may yield a stretched ribbon
and compromised performance!

Amplification Considerations

The performance of a ribbon microphone is directly affected by the choice of microphone
preamplifier it is paired with. With so many mic preamps on the market, how do you select one
that gives the best possible performance with a ribbon microphone? Additionally, what kind of

4

performance can we expect from the preamplifiers built into our mixing desks? While most
preamplifiers will handle ribbon microphones well in most recording situations, some preamps
that work perfectly well with condenser or dynamic mics may prove to be poor performers with
ribbons.

To begin with, we must understand the fundamental differences between ribbon microphones and
other popular types, namely condenser and moving coil dynamics. A ribbon microphone is
actually a dynamic microphone that uses a flat, extremely low mass ribbon element, rather than a
coil/diaphragm assembly. For this writing, any mention of “dynamic” microphones will relate to
moving coil dynamics.

All condenser microphones have a built in preamplifier called a head amp and therefore put out a
hefty signal. Because the signal is buffered through the head amp, the output impedance is rather
low and less affected by the input impedance of the microphone preamp. Most dynamic (moving
coil) microphones generate a healthy enough electrical current to work well with a variety of
preamps, and their limited frequency response characteristics make mic loading less of a
concern.

Ribbon microphones generate a highly accurate signal, but the average ribbon mic generates
approximately 20dB less gain than that of condenser microphones. Remember, the ribbon
transducer does not have the benefit of a condenser mic’s built in head amp, so a ribbon

microphone relies solely on the microphone preamp for all its gain!

The so called ideal preamplifier is the proverbial “straight wire with gain.” This may be
considered the technological ideal and does not include “coloration” as a desirable feature.
However, coloration is often desirable and has given rise to the popularity of certain preamps and
even preamp stages in mixing desks. Neve® preamps and the famous Trident® A Range mixing
console are highly praised for their classic sound.

So what should we use with our beloved ribbon microphones?
The features that translate into top performance for a ribbon microphone are the following:

1. Lots of gain! A ribbon microphone works best with preamplifiers that have at least 60-70 dB
of maximum gain.

2. Low noise is a must! With this much gain being required for efficient operation of a ribbon
microphone, the noise characteristics of the preamp play a pivotal role in overall performance
of the captured acoustic event.

3. Load characteristics: A suitable preamplifier should have input characteristics that impose the
least amount of loading to the ribbon element. In other words, the input impedance should be
high enough that its effect on the performance of the mic is negligible. A good rule of thumb
is to have a preamplifier with input impedance at least five times the impedance of the
microphone. For example, if the mic is rated at 300 Ohms (as Royer’s are), the preamp
should have an input-impedance of at least 1500 Ohms. If the impedance of the preamp is
too low, the microphone will lose low end and body.

5