Onix Rocket UFW-10 Setup Manual

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UFW-10 Subwoofer Setup Guide

Written by Bossobass

AKA, Dave

Edited by PhenomeNhan

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Table of Content

PREFACE.......................................................................................................... 3

SUBWOOFER SETUP TIPS AND PROCEDURES ................ 4

TOOLS REQUIRED: .................................................................................................................................... 4

TERMS: .................................................................................................................................................... 5

STEP #1: POLARITY TEST................................................................................................................... 7

STEP #2: FIRST LEVEL ADJUSTMENT .............................................................................................. 7

STEP #3: PLACEMENT ........................................................................................................................ 8

STEP #4: LEVEL ADJUSTMENT ......................................................................................................... 9

STEP #5: RELATIVE PHASE ADJUSTMENT .................................................................................... 10

STEP #6: FINAL LEVEL ADJUSTMENT ................................ ........................................................... 11

ADVANCED SETUP SECTION ...................................................... 12

PARAMETRIC EQUALIZATION........................................................................................................ 12

DUAL SUBWOOFERS -- MONO CONFIGURATION : ........................................................ 13

Asymmetric Placement Of Dual Subwoofers: Asymmetric...Not symmetric........................................ 13

DUAL SUBWOOFERS, STEREO CONFIGURATION : ........................................................ 14

PLACEMENT ........................................................................................................................ 15

DUAL SUBWOOFERS, REBASE ROUTING CONFIGURATION : ...................................... 15

YOU MUST HAVE: ........................................................................................................................... 15

CONNECTIONS: .............................................................................................................................. 16

THIS IS WHAT HAPPENS: ............................................................................................................... 16

ADVANTAGES : .................................................................................................................... 17

FINAL THOUGHTS.............................................................................. 18

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Preface

The following has been a labor of love for me. Love of the subject (low frequency reproduction in
multi-channel audio systems in the home), and love for Mark Schifter, his vision and watching
him realize that vision from the sidelines (though anyone who meets him never feels like a mere
spectator).

I've also done this because I promised I would. Please go easy on me, as I'm not an educated
person, and I'm sure I've left out plenty. I only hope that someone who is in the shoes we all
have to walk a mile in when we're first introduced to this digital, multi-channel octopus, will
benefit in any small way by the information below.

I also would like to disclaim the facts that some of what I say is biased toward my own thoughts
and some of what I say is downright controversial. I would like for those who read this
rudimentary guide to add input, discoveries and tweaks as they are appropriate, as well as
adding to the TERMS section as people ask about ones that aren't included. I omitted many
terms for this reason.

I also have not included pictures or diagrams...maybe the graphics guys can add that input.

Good Listening, and, by all means...Listen Accurately!

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Subwoofer Setup Tips And Procedures

Tools Required:

1. Radio Shack SPL Meter. Can be obtained at Radioshack:
a. Analog version:

http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=3
3-4050

b. Digital version:

http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=3
3-2055

2. 1/12 Octave Sine Wave Test Tone CD. You can generate your own tones or download

some tones that have already been generated for you:

a. http://www.nch.com.au/tonegen/
b. http://www.snapbug.ws/sinewaves/

3. Tape Measure.

4. Frequency Response Graphing Software (optional).

5. A Tripod For Mounting Your RS Meter.

NOTE: All of the following information will assume the following:

1. A Pre/Pro or Receiver is being used to provide Bass Management.

2. All satellites set to 'Small' and subwoofer to 'Yes'.

3. A crossover point of 80 Hz is used.

4. Your subwoofer(s) is/are connected properly to your Pre/Pro or Receiver and your house

electrical system in strict accordance with the Owner's Manual that came with your
subwoofer.

5. All 5 satellite speakers are calibrated from the listening position to a reference level.

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Terms:

1. LFE: Low Frequency Effects, AKA: Low Frequency Enhancement, AKA: The .1 channel.

2. Redirected Bass: This is all information contained in all 5 satellite channels that is below

80 Hz., which is redirected to the SW (subwoofer) output of the Pre/Pro or Receiver.

3. SW Output: This is the output of the Pre/Pro or Receiver that sends a combined, single

signal comprised of the LFE channel and the Redirected Bass from all 5 satellites (or, any
satellite that's set to 'small' in the speaker setup menu) to the subwoofer(s).

4. SPL: Sound Pressure Level. This is the unit of measurement used to calibrate the channel

levels of all of the 5.1 channels. SPL is measured in Decibels, which is abbreviated as dB.

5. Subsonic: This is the description used for any sound that is below the threshold of human

hearing, or below approximately 20 Hz.

6. Tight, fast, articulate, etc.: These are adjectives that describe a subwoofer that is capable of

delivering low frequencies on-time with the rest of the system, without any peaks in
response.

7. Boomy, muddy, slow, etc.: These adjectives describe a subwoofer that lacks the capabilities

of the subwoofer described in item #6, and/or is misplaced or badly calibrated, resulting in
peaky response.

8. Polarity: Better described as Absolute Phase. Usually, this adjustment is made by

comparing 0 degrees to 180 degrees. If 2 speakers are 180 degrees 'out of phase', then
there will be gross cancellation of sound waves in the region of audio information that the
2 speakers share the reproduction of. In the case of satellites and a subwoofer, this will
be at and around the crossover point.

9. Relative Phase: Phase is time. It's measured in degrees. If you can visualize a sound

wave that curves upward to it's peak and then downward to its bottom--that is one cycle
of the wave. Since degrees of angle are not curved, there are infinite degrees along this
wave. As the frequency is lowered, the phase changes. Some subwoofer designs change
more drastically than others.
Distance disparity between speakers and subwoofer also changes the time that it takes for
the shared audio information to reach your ear. Because these situations result in infinite
phase differences between speakers and subwoofer, there is no perfect phase setting that
works for all frequencies through the crossover region. This is why it's important to keep
distance to the listening position and infinite phase control in mind when setting up any

subwoofer.

10. Crossover Region: A typical multi-channel audio controller has crossover options that are

based on a Linkwitz/Riley 24 dB per octave network. This means that the subwoofer is
stopped from playing above the crossover point and the satellite is stopped from playing
below the crossover point. This stoppage of the speaker's natural response is not a brick
wall. It is a gradual braking from the crossover point and then beyond that at a rate of 24
dB per octave.
The idea is that across 2 octaves (from the crossover point to one octave below that point
the satellite has a brake applied that ends up being 24 dB lower, and from the crossover
point to one octave above that point the subwoofer has a brake applied that ends up being
24 dB lower, a total region of 2 octaves), the sum of the 2 signals at any point in the
crossover region should sum to unity, or, in other words, result in a frequency response
curve that is a flat line. This 2-octave area of overlap between the satellites and the

subwoofer is the crossover region.

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Overview:

The goal in adding a subwoofer to any multi-channel audio system is to achieve as flat a
frequency response curve as possible, in your particular room, with your particular system,
through the crossover region and to as low as your subwoofer will allow. This is not to say that
there is no room for adjustment from this point to allow for personal taste. Rather, it is the place
to start.

The steps, in order, are:

1. Polarity Test. You never want to lug the subwoofer around the room looking for the spot

where it will sound best if the polarity is reversed.

2. First Volume Calibration. During the placement exercise (pun intended) you'll listen for

bass notes of a music program that are of the same volume (no boomy notes or weak
notes). If the subwoofer isn't at least closely calibrated to begin with, that will occur at
any spot the subwoofer is placed.

3. Placement. As in real estate, location, location, location.

4. Relative Phase Adjustment. One of the more important tweaks to smooth out the frequency

response.

5. Final Volume Level Adjustment. After tweaking all of the above, a final subwoofer volume

level tweak will get you there.

NOTE: I've left out the step of tweaking the crossover slopes of the satellites and the subwoofer.
Although it's a very important tweak, it's beyond the capability of the vast majority of multi-channel
systems, and is a rather involved discussion for a more advanced setup guide than this one is intended
to be.

Calibration discs (Avia, Video Essentials, etc.)

I have little experience with these setup discs so I can't offer an opinion as to which is preferred,
or why. I have Chesky's setup disc and actually found it annoying. If you have or have interest
in any of these setup discs, search the forum and pose the questions you may have. I'm sure
you'll get the answers you're looking for and end up with an acceptable method for level
calibration.

I use the calibration tones in my Pre/Pro in conjunction with the RS SPL meter (digital version)
set up on a tripod at the listening position, at ear height (when seated). I have found this
method of level calibration to be very acceptable.

I've recently found an easy way to verify this method, and it's described as an option to try
under LEVEL ADJUSTMENT, below.