AFW30 Owner's Manual v 1.1 CE ©2003 ARX®
AFW30 Owner's Manual v 1.1 CE ©2003 ARX®
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Introduction
Thank you for choosing this ARX AFW30 Anti-Feedback Workstation. It’s a great
product, and we hope you enjoy using it as much as we enjoyed creating it. As with all
ARX equipment, it has undergone extensive factory calibration and ‘burn in’ before
shipping. Since it involves a few radical departures from the normal way that we think
of equalizers, for continued trouble free use please familiarise yourself with the
contents of this manual before using the AFW30 Anti-Feedback Workstation.
About the AFW30
Tuning a live sound system, whether it’s a concert or a conference or all points in
between, is a complex procedure at the best of times! Stopping feedback is only a part
of it - you still need to adjust the actual sound of the system in the room.
In the ideal world you’d have an equalizer to set the system curve, something to
eliminate feedback, and something else to keep the system level under control.
So, we’d like to introduce you to the ARX contribution to the ideal world - the all-new
ARX AFW30 Anti Feedback Workstation. A single channel unit incorporating a 30 band
graphic equalizer, a smooth sounding peak limiter, and onboard genuine Sabine FBX
Feedback Exterminator circuitry.
The ARX AFW30 Anti Feedback Workstation has an application for every mode of live
audio: Monitors, Front of House, Church installations, TV audience monitors, Confer-
ences; in fact, anywhere there’s a live microphone, there’s a need for the AFW30.
In the next few pages you’ll discover how to set up your AFW30, where to use it, and
how to get the most out of it.
AFW30 Reference GuideAFW30 Reference Guide
AFW30 Reference GuideAFW30 Reference Guide
AFW30 Reference Guide
Let’s work our way through the operation of the AFW30, from start to finish.
The Equalizer Section
The EQ section of the AFW30 features ARX ‘Constant Q’ circuitry. Constant Q is a true
WYSIWYG (What You See Is What You Get) design concept that allows far greateraccu-
racy in EQ control.
Its 30 long throw, XR Extended Resolution sliders can be adjusted to give a maximum
of 10dB cut or boost. The Q of the filter has been specifically optimised to allow easy
combining of the filters. This enables you to set up a musical, notch free system curve.
The idea of the EQ section is to ‘tune’ the room to the system, and to ‘tweak’ the
response a little so that it sounds good. We’re not going to use it to notch out feedback
- we’ve got the Anti Feedback section for that - but to adjust the overall sound of the
system so it doesn’t sound ‘boomy’ or ‘harsh’. So, play a tape or CD that you’re very
familiar with, and adjust the sliders on the EQ section so that the system sounds ‘just
right’.
Note that a little EQ is a lot, so use each fader gently. Avoid any sudden dips or peaks -
that’s not what it’s there for. The look of the sliders should resemble a smooth curve. If
you don’t need to move it, then leave it.
Avoid too much boost at lower frequencies. Very few systems can deliver much re-
sponse below 30 Hz, so it’s pointless pushing those sliders up. However 50 to 100Hz
can often benefit from a little boost, as can 10KHz. Between those points it should be a
smooth succession of gentle curves.
Setting up the AFW30
Setting up the AFW30 correctly requires that certain steps are taken, in a particular order.
Technical people may call this the System Initializing Procedure, but we’ll just call it Setup.
1. To install the AFW30 in a sound system, connect it wherever a Graphic EQ would
go. For example, between the Mixing console and the Power amps. If you are using
multiple AFW30’s in a monitor rig, then connect one between each monitor send
and crossover/amplifier
2. Place the speakers and microphones in the positions where they will be used during
the performance. Don’t place the microphones facing into the speakers!
3. Turn on the system
4. Set the Limiter Threshold at -10dB. The process of setting up the AFW30 will induce
feedback rings, and the limiter will keep these from damaging the system
5. Check that the FBX Bypass and Status Bypass switches are not pressed IN
6. Adjust the EQ section of the AFW30 to set the system curve that you want. DO NOT
NOTCH FOR FEEDBACK. The EQ sliders should form a smooth curve
7. Set the channel levels on the console at the performance level. Reduce mixing
console master levels
8. Press and hold down the switch marked ‘PRESS AND HOLD FOR 4 SECONDS TO
RESET’ on the front of the AFW30 for 4 seconds to clear out filters set previously.
9. Place the AFW30 in the active mode by releasing the RESET switch.
10. SLOWLY bring up the console’s master sliders until feedback starts to occur. The
AFW30 will detect and quickly remove it
11. Continue slowly raising the system master volume until the system is just over the
level required for the performance. Now back off the master volume slightly so the
system is not on the brink of another feedback point
12. The AFW30 is now ready for use. It will lock these fixed filters on the feedback
frequencies, and leave a further 3 filters ‘floating’, to pull out any other feedback
during the performance if it occurs
13. Reset the Limiter at say, +3dB, or the maximum safe level of your system
14. The Clip LED may flash on transients - this is normal. But if it is lit continually, then
the level through the unit is too high and should be reduced. To do this, bring
down the master faders on the console a little, and bring up the output gain of the
AFW30 by the same amount. Perhaps you have the Limiter set too low, so it’s
continually on. You could also make sure the amplifiers are on their maximum level.
Or you may have too little system for the sound pressure level you want in too big
a room. That’s one thing we can’t fix!
Non-Volatile Memory
A complete record of the Anti Feedback filter settings is stored automatically in the
AFW30 when you power down the system. Upon power-up, the system automatically
reloads the filters and returns them to the same position and depth as they were when
the power was turned off.
Filter Reset
If the sound system’s setup has changed, such as a different venue, change of equip-
ment, significant movement of microphones or speakers, or any other change that
