Bryston Electronic Crossover 10B LR User manual

INSTRUCTIONS for 10B-STD,
10B-SUB and 10B-LR CROSSOVERS
The 10B crossover is available in three stock versions; 10B-SUB incorporating frequencies
more suitable to sub-woofer applications (40Hz to 500hz), 10B-STD which is more
applicable to speakers requiring frequency control in the mid-band and tweeter areas (70Hz
to 4500Hz) and the 10B-LR, which uses plug in resistor programming cards to set the
crossover frequency. Both the 10B-SUB and 10B-STD crossovers include a mode called
Mono Low Pass (see below) which replaces the Two Way Mono (Linkwitz-Riley) mode in
older model 10B's. The Two Way Mono mode (see below) is retained in the 10B-LR
allowing for very steep (non Linkwitz-Riley) 8th order filters.
MONO LOW PASS mode (10B-SUB and 10B-STD only):
The 10B-STD and 10B-SUB crossovers generate a summed low pass output signal by first
summing or adding together the left channel and right channel input signals to form a left
plus right (L+R) signal. If the MODE switch (located on the rear panel) is in the Mono Low
Pass position then this L+R signal is fed into both of the low pass filter sections (Left and
Right) available in the 10B. As a result, the common low pass output can be taken from
either of the two low pass (LP) outputs; either left LP out or right LP out. These outputs are
designated as Left and Right for convenience only. If the low pass output used is the one
designated as the left channel, then the crossover frequency and slope (or filter order)
switches on the left side of the unit's front panel (as viewed from the front) will control the
low pass filter parameters. Likewise, if the right channel low pass output is used, then the
right channel switches will control its filter parameters. There is no interaction between the
two sets of controls. If one of the two low pass filters is not used, then settings of its
crossover frequency and slope switches are irrelevant and will have no affect on the
performance of the other filter sections of the crossover. The two high pass filter sections
(left and right) operate independently in Mono low Pass mode.
STEREO mode:
As in the older versions of the 10B, the stereo mode provides two, two way crossovers
wherein the left input is fed into a separate low pass filter and a separate high pass filter,
both of which are independently adjustable from the front panel controls. Likewise, the right
input signal is fed into a separate low pass filter and a separate high pass filter, both of
which are independently adjustable from the front panel controls. All four filters have
separate output connectors on the rear panel. There is no interaction whatsoever between
left and right channels or between low pass and high pass filters.
THREE WAY MONO mode (10B-LR only):
Available only in the 10B-LR (Linkwitz-Riley filters), this mode is the same as in the older
model 10B. The four filter sections (two low pass and two high pass) of the 10B are
combined to form a single channel three way crossover providing one low pass, one mid or
band pass and one high pass filter. The mid (or band pass) filter is formed by combining the
left channel high pass and the right channel low pass filters into a single filter wherein the
lower end of the pass band is determined by the left channel high pass controls and the
upper end of the pass band is determined by the right channel low pass controls

Only the LEFT channel input is used in Three Way Mono mode. The left channel low pass
output provides the low pass output. The mid or band pass output is taken from the right
channel low pass output connector and the high pass is taken from the right channel high
pass connector. All filter slopes are 24dB per octave, Linkwitz-Riley alignment.
PROGRAMMING the 10B-LR crossover:
The crossover points in the 10B-LR are set by inserting small programming boards (4 per
channel) each containing 2 resistors. See illustration "10B-LINKWITZ-RILEY STEREO
CROSSOVER" and on page 7 and document "10B-FREQ-RES-TABLES.doc"
POWER AMPLIFIERS:
When power amplifiers of different power capabilities are used, the woofers will likely be
driven by the most powerful amplifier and the tweeters by the least powerful amplifier since
the woofers can generally be expected to be less efficient. When power amplifiers of
equivalent power capabilities are used in a bi-amped system, and when the power amps
employ totally separate power supplies for each channel (as all Bryston power amplifiers do)
it is desirable to place each power amplifier as close to its speaker as possible and use one
channel to drive the woofer and the other to drive the tweeter. Please note that if the power
amps being used do not employ totally separate power supplies for each channel, some
envelope distortion between channels may occur since the power drawn from the low
frequency channel driving the woofer will usually be considerably greater than from the
higher frequency channel driving the tweeter.
POWER AMPLIFIER PLACEMENT:
Where there is a considerable distance between the audio signal source and the speakers,
it is preferable to reduce the distance between the power amplifiers and the speakers at the
expense of increasing the distance between preamp and crossover or crossover and power
amplifier. The low impedance across the speaker lines is more likely to affect signal quality
with distance than is the higher impedance across the preamp to crossover, or crossover to
power amplifier cables.
BALANCED versus UNBALANCED CABLING:
If the distance between the power amplifier and crossover or crossover and preamplifier is
greater than 30 feet, it may be desirable to use balanced cables to interconnect the two
distant pieces of equipment as this may reduce noise pickup. To facilitate this, the 10B
crossover is available with balanced inputs and outputs (PRO versions) using 3 pin XLR
connectors (outputs use male connectors, inputs use female connectors). Pin 3 is the
positive (non-inverted or Hot) signal, pin 2 is the negative (inverted or neutral) signal and pin
1 is ground.
Where a long run of balanced cable is used to interconnect the preamplifier to the
crossover, and the crossover is placed within a few feet of the power amplifier there is no
advantage in using a balanced interconnection between the crossover and power amplifier.
Balanced cabling does not reduce noise; it merely reduces the ability of the cable to pickup
noise. The balanced output of a 10B Pro crossover can easily be used as an unbalanced
output by using XLR pin 3 (positive) as the HOT line and XLR pin 1 as the ground line.
Since there is no phase inversion in the 10B, the negative XLR output pins (#2) can
be used in the same way to achieve the same effect and the output will remain un-inverted
with respect to the input. In other words, any signal that enters the negative XLR input pin
(#2) will exit the negative XLR output pin (#2) un-inverted with respect to the input. Similarly

any signal that enters the positive XLR input pin (#3) will exit the positive XLR output pin
(#3) un-inverted with respect to the input. It is for this reason that the 10B has not been
changed to comply with the AES adopted XLR pin configuration for balanced signals (pin 3
negative, pin 2 positive and pin 1 ground) and retains its original XLR pin-out of pin 3
positive, pin 2 negative and pin 1 as ground.
Note, however, that Bryston's current production power amplifiers do follow the AES
convention. As the above illustrations indicate, however, the 10B PRO models do not
introduce any phase inversion and thus can be used with either pin 2 hot or pin 3 hot
balanced cable systems without changing the phase relationships of the system.
CABLES:
Bryston supplies a variety of stock audio interface cables and will supply reasonably priced
semi-custom cables (including adapter cables and cables with custom printed identification
sleeves) upon request. Bryston's balanced cables employ double insulated, 100% shielded
twisted pair cable with 24g stranded, tinned copper conductors and locking XLR connectors
with metal shells and gold plated contacts. Unbalanced cables use single conductor
shielded co-axial cable with gold plated male phono (RCA) plugs in metal shells.
BRYSTON 20 YEAR WARRANTY
Bryston products are warranted to be free from manufacturing defects for a minimum of twenty years from the original
date of manufacture. This includes parts, labour and return shipping to the first owner and all subsequent owners.
Warranty coverage is automatic and commences with the original date of manufacture which is kept on file at Bryston.
In the event or a defect of malfunction, Bryston will remedy the problem by repair or replacement, as we deem
necessary, to restore the product to full performance.
This warranty is considered void if the defect, malfunction or failure of the product was caused by damage (not
resulting from a defect or malfunction) or abuse while in the possession of the customer, tampering by persons other
than factory-authorized service personnel, or failure to comply with Bryston operating instructions.
This warranty gives you specific legal rights and you may also have other rights which may vary from province to
province and country to country.
In Canada: Bryston Service Canada, 24 Steinway Blvd., Unit 48, Etobicoke, Ontario, M9W 6T8
Tel: [phone] Fax: [phone]
In the USA: Bryston Service, 30 Coventry St., Newport, Vermont 05855
Tel: [phone] Fax: [phone]
Head office Bryston Ltd., P.O. Box 2170, Peterborough, Ontario, Canada, K9J-7Y4
and factory: Tel: [phone] Fax: [phone]