Loudspeaker Management Systems
incorporating WHISEWORKS – NTM filters
Touring Sound • Studio Monitoring Systems
Club Sound Systems • Zone Control (EQ and delay)
OMNIDRIVE systems have been responsible for raising the
standards in sound system control for ten years, and now
reach new heights with the
with WHISEWORKS – NTM filters.
Determined to provide leading edge products, BSS have incorporated not only the latest
technology advances in digital audio, but have provided genuinely useful facilities for
the engineer to ensure better performances, time after time.
• 3 analogue Inputs and 6 Outputs for maximum
flexibility in one rack space
• Alignment Assistant takes care of your driver
delay settings, automatically
• New version 2 firmware incorporating Australia’s
WHISEWORKS Neville Thiele Method™ filter
technology for even better system performance
• Stereo Digital Input (44.1/48/88.2/96kHz AES)
• Latest 24-bit input and output converters give
a dynamic range in excess of 112dB,117dB when
AES inputs used.
• Dynamic Equalisation on every input and output
• Freely assignable EQ filters – put EQ where you
need it
• Contact closure program recall
• 96kHz Sample rate
• Output transformer options
• New DSP algorithms for absolute phase matching
• RS-232, RS-485 and MIDI control options
3 Inputs, 6 Outputs
Now offering the maximum flexibility in one rack space, the FDS-366T
can be used in multiple applications:
Stereo 3-way; mono 4, 5 and 6-way (units can be slaved for large stereo
systems), triple bi-amp or even dual tri-amp for stage monitors; zoning with EQ and delay to 6 zones; LCR studio monitoring,
each channel giving a 2-way output; and more.
This means standard inventory and less redundancy as one model can be used for either FOH or monitor racks.
96kHz Sample Rate
High Specification Converters
Using a sample rate of 96kHz not only prepares the
With technology continually advancing in
FDS-366T for use with digital sources, but means that
the digital domain, we use high specification
we can give you a wider, more open sound thanks to
A/D and D/A converters, giving the 366T a
an extended bandwidth. The use of a higher Nyquist
dynamic range of greater than 112dB,
frequency means we have been able to design more
possibly the best performance for such a
accurate filter sets and so enhance the performance.
processor currently available.
A New Filter Design for Outstanding Performance
“The biggest step forward in digital crossover technology since
Linkwitz-Riley. Significantly lower distortion artifacts, increased
clarity, greater projection coupled with a closer, tighter sound
are among the benefits of using these new filters.”
Jerry Wing, Britannia Row, UK
The new Version 2.0 firmware includes new filter designs in the shape of the WHISEWORKS – NTM* topology.
This new design, developed by Neville Thiele and patented by Australia’s Precision Audio, provides the fastest roll-off slopes
outside of the pass band in modern IIR filter designs, while maintaining zero phase difference between adjacent bands throughout
the crossover region, preventing beam-tilting. Listening tests have shown
a marked and noticeable enhancement in performance over traditional
Linkwitz-Riley 48dB filters. The new filters are kinder on the ear, and like
the L-R design also maintain a flat frequency response throughout the
crossover region.
“In my opinion they are
the cleanest and clearest
filters I’ve heard to date.”
Andy Dockerty,
Adlib Audio, UK
Our WHISEWORKS – NTM filters are designed around 4th order and 8th order topologies. Since WHISEWORKS – NTM filters
have a very fast roll-off this can often be used in place of an 8th order Linkwitz-Riley filter with a much improved group
delay characteristic. These new filters use a notching characteristic to 'speed-up' the roll-off slope. This notching action
causes the slope to change continuously, actually nearing infinity dB/Octave close to the notch, which is one octave away from
the crossover frequency (in each direction).
Existing users can upgrade their FDS-366 to include
WHISEWORKS – NTM filters by registering their unit on
the BSS Audio website at www.bss.co.uk/366/thiele.htm,
where you can also find a white paper describing in
detail the advantages of this new design.
“The new filters allow me to put more power to the devices without fear of overload or
over-excursion. Once adjusted, sounds better than standard filters. The system seemed
louder and clearer. We were setting off alarms in the car park!”
Ferrit, Enterprise Live, Las Vegas, Nevada, USA
New Algorithms for Enhanced Precision and Performance
Our DSP code just gets better and better. We’ve developed new algorithms which maximise the dynamic range of crossover
and EQ filters and makes them more accurate, and algorithms that optimise the phase responses at crossover band edges.
The benefits are reduced noise and distortion, better resolution and greater accuracy.
New Limiter Design
A new limiter design offers user-adjustable attack and release, with an adaptive attack algorithm that helps to preserve sonic
transparency for light overshoots, but acts more aggressively if the signal strays too far. An adaptive release system prevents
short-term overshoots reducing the average power output while keeping distortion low on sustained overshoots. Finally, an
adjustable brickwall overshoot limiter contains signals which overshoot during the attack phase.
*The words “WHISEWORKS”, “Neville Thiele Method” and NTM logotype are trademarks of Precision Audio Pty. Ltd.
Manufactured under licence from Precision Audio Pty. Ltd. International Patents Pending.
What better way to demonstrate the
simplicity and power of the FDS-366T
than a quick run through setting it up.
Note the new key panel features such as
the Navipad and EDIT buttons.
Setting the Crossover Points
Select the band to adjust using the EDIT button for that channel. Then use
the Navipad to select the crossover screen. Using the rotary encoder, you
have control over the crossover filter type (Linkwitz-Riley, Butterworth,
Bessel or NTM™), slope (from 6 to 52dB per octave) and overlap (use the
Xover Edge mode for this,
otherwise Xover Both simply moves the crossover point). You are shown the
filter positions graphically, and the crossover frequency numerically to achieve
pinpoint accuracy.
The FDS-366T has a ‘pool’ of EQ filters which you can assign to inputs or
outputs as you need them - no fixed EQ configurations here.
To add an EQ filter, select the output with the EDIT key and move to the EQ
screen. No filter is used until you adjust its gain from 0dB. Select the mode
(EQ type (bell or shelf), slope, gain, width and frequency) and use the encoder
to adjust. To add a second filter, use the Navipad to select another filter. You will see the
number of free EQ filters is displayed in the corner of the screen.
The screen always shows the composite EQ curve for the selected channel. As you select
a filter, all its parameters are displayed numerically for reference. When EQ is used on
an input, it serves as FOH or wedge equalisation very effectively.
Context Sensitive Utilities
The FDS-366T speeds up navigation through the many features offered by taking you to
the most appropriate utility when you press the UTILS button. If you are editing the limiter
threshold parameter for example, pressing utils will take you to the limiter units utility.
You are still free to navigate around all the other utilities in the usual way.
We’ve always provided highly-accurate delay setting in all our OMNIDRIVE models.
The FDS-366T offers precision steps of 10 microseconds on each delay – all 3
inputs and 6 outputs. With a maximum delay setting of 2.6 seconds per channel
(including inputs) the FDS-366T can easily compensate for delay towers as well
as stereo image correction between stacks, and individual cabinet driver alignments.
Adjusting the delays is simply a matter of selecting the channel/band, selecting
the delay adjust screen and entering the value with the rotary encoder. Delays
can be linked and adjusted simultaneously to make correction between different
cabinets easily achievable.
The new limiter design in the FDS-366T is more protective and
comprehensive than ever. The design incorporates Adaptive Attack, where
the attack time is reduced the more over the threshold the signal strays.
This helps to preserve transparency for light overshoots, but the limiter will act more aggressively if the signal strays too far. Adaptive
Release, another new feature, prevents short-term overshoots from reducing the average power output, whilst keeping distortion
low on sustained overshoots.
Adjustable Attack and Release speeds are provided (Fast/Medium or Slow) with the speeds ganged to the high-pass crossover
frequency for optimal performance depending on the frequency range of the band.
Finally, a brick-wall overshoot limiter stage is applied, which contains signals which overshoot during the attack phase. The user
has adjustable ‘overshoot’ from 1 to 12dB (and Off).
Phase Compensation
This feature, introduced on the FDS-355, maintains the
disturb the correct phase relationship at the crossover
inter-band phase relationship true to the filter type selected
point. This can result in poor combining of adjacent
(Bessel, Butterworth, Linkwitz-Riley etc), regardless of
crossover bands, resulting in an irregular frequency
any interference from far-end crossover filtering. In 2-way
response, and non-uniform polar characteristics.
crossovers, this is not an issue since each band has only
either a high-pass or a low-pass filter. Three or more bands
The Phase Matching technique used in the FDS-366T
however cause at least one band to have both low and
eliminates this problem by compensating for these phase
high-pass filters which react with one another, and so
A+B, A+B+C
A Mono sum of the inputs is often used
for sub-bass drive. In the FDS-366T, that
sum can be of the inputs A&B, or for LCR
systems particularly, a sum of the three
inputs A, B, &C. The feed can be taken
pre or post input EQ.
Dynamic Equalisation
Pioneered by BSS in the DPR-901 and respected by engineers worldwide, dynamic equalisation means you can tame room
resonances, deal with non-linearities in drivers (such as 2” horns), and address instrument and vocal problems.
Essentially, Dynamic EQ gives you the ability to compress a given frequency only when the signal reaches a preset threshold.
You can determine how much of the program is affected using the
bandwidth setting. As an example, consider how some horn drivers can
‘bleat’ or distort at high levels - using dynamic eq you can cut the offending
frequency as the level passes that threshold.
Dynamic EQ is provided on every input and output on the FDS-366T.
AES/EBU Stereo Input
Now go straight from digital desk to crossover,
without losing a bit of performance. We include
the digital stereo input as standard, and you still
have an analogue input available in this mode.
Many top studios are moving to the FDS-366T
for digital monitoring management. Input
sample rates may be 44.1kHz, 48kHz,
88.2kHz, and 96kHz. With AES inputs, the
dynamic range is greater than 117dB.
Alignment Assistant
The effects of non-identical delays between loudspeaker
drivers in cabinets, and between cabinets are well known,
but correcting for driver position in a cabinet or stereo
image can be a very hit and miss affair.
In Alignment Assistant mode, the bands/channels to be
measured are chosen. A microphone is used on input C,
The FDS-366T’s Alignment Assistant makes the calculation
and pink noise is then automatically output through every
and implementation of the correction delays quick and
band in turn. The FDS-366T will then analyse the signal
automatic, by using the sound path itself to measure and
delays, and automatically adjust the delays to compensate.
correct for the acoustic delay introduced by the positioning
Field tests have shown this to be not only highly accurate,
of the drivers and cabinets.
but the enhancement in image and sound quality is
Analyse and Equalise – using the FDS-366T with SMAART LIVE
The FDS-366T is controllable from SMAART LIVE,
SIA Software’s advanced audio analysis software
which uses an independent microphone to analyse
room responses and measure delay times, and can
then automatically correct these by itself
programming the FDS-366T. BSS Audio is an SIA
partner, and the evaluation copy can easily be
upgraded to a full purchased version.
Four Different Lock Modes
for Security from Adjustment
With Omnidrive Compact Plus, you can restrict access to certain memories, individual
parameters such as crossover points or EQ settings, and be sure that nobody can ‘tweak’
the programs. Parameters can be hidden as well as made inaccessible so that they
do not even feature on the display. Owners can also allow access only to parameters
that may need adjustment on site such as limiters and main delays. It is also possible
to lock out the whole unit.
Other facilities
• Input and output meters
• Contact Closure program select port
• Real-time edit comparisons using
• EQ and crossover filter adjustment
BACKUP and SWAP facility
• EQ gain variable in 0.2dB steps
• Gain and limiter resolution in
0.1dB steps
• Variable input and output gain
• RS232/RS485 ‘in’ and ‘out’
to 20kHz
• Control several FDS-366T units
simultaneously by slaving through
• Delay correction for temperature
• Update firmware via the RS-232 port
change by manual adjustment
(new releases always available on
• Delay units can be Feet, Metres,
BSS Audio website)
Milliseconds, or fps (24, 25, 30)
• Store/Recall programs to PC card
Input Impedance
10kOhm, electronically balanced
Maximum Input Level
Better than 50dB (30Hz-20kHz)
Input gain:
+/-15dB variable in 0.1dB steps
6, 12, 18, 24, 36, 48 or 52dB per octave
(Filter type dependant)
Frequency response:
10Hz - 20kHz, +/-0.25dB
10Hz - 40kHz, +/-2dB
Butterworth, or Linkwitz-Riley
Dynamic range
>112dB, unweighted 22Hz to 22kHz
>117dB when AES/EBU inputs used
Channel Separation
>80dB, 30Hz to 20kHz
Available on Inputs A, B, and C, and
Outputs 1, 2, 3, 4, 5, 6
Distortion (THD)
<0.005%, 20Hz - 20kHz @+10dBu
Delay Step
11 microseconds minimum
Input headroom metering:
-20dB, -12dB, -6dB, -3dB, Clip
Relative to clip point (+20dBu)
Max Delay time
2.6 seconds
Output metering:
SIG (-40dB), -20dB, -12dB, -6dB,
-3dB, 0dB, Over (+6dB)
Relative to limiter threshold setting
Input Connector
XLR-3F or equivalent
Pin 1 Floating (no connection)
Pin 2 Signal +ve (Hot)
Pin 3 Signal -ve (Cold)
Input Sample Rate:
44.1kHz, 48kHz, 88.2kHz, 96kHz
Max number of EQ filters
> 50 (depending on crossover slopes)
Output Impedance
<50 Ohms, electronically balanced
and floating
Maximum Output Level
+20dBu into 600 Ohms or greater
Output Gain
+/-21dB, variable in 0.1dB steps
Output Connector
XLR-3M or equivalent
Pin 1 Ground
Pin 2 Signal +ve (Hot)
Pin 3 Signal -ve (Cold)
Transformer Balancing optional
EQ Type
Parametric, Bell or shelving
on any filter
19” x 1.75” x 11.5”
(483mm x 45mm x 292mm)
EQ Gain
+/-15dB, variable in 0.2dB steps
8.4lbs (3.8kgs), unpacked
0.05 to 3 octaves, variable in
0.05 steps
AC Power
90V-264V AC, 50/60Hz, 30VA
EQ frequency
15Hz to 20kHz
Dynamic slope:
2:1 to 20:1 (dynamic EQs only)
Output Transformers
BSS Audio reserves the right to change specifications and features without notice.
BSS Audio
A Division of Harman International Industries Ltd.
Cranborne House, Cranborne Road, Potters Bar, Herts EN6 3JN England
Tel: +44 (0)1707 660667 • Fax: +44 (0)1707 660755
e-mail: info@bss.co.uk
8500 Balboa Blvd., Northridge, CA 91329, USA
Telephone: 818.920.3212 • Toll Free: 888.251.8351
Fax: 818.920.3208 • e-mail: BSSAudioUSA@harman.com
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