The q-series line array, 1 number of cabinets required, 2 subwoofer setup – d&b TI 385 d&b Line array design User Manual

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5. The Q-Series line array
The Q1 is a compact and lightweight line array cabinet

providing a 75° constant directivity coverage in the

horizontal plane down to 400 Hz. The system can be used

from very small configurations of two cabinets per array up

to a maximum of twenty cabinets per array for larger

venues.
Q1 cabinets have a very low height of only 30 cm (1 ft)

and when combined in arrays its accurate wavefront covers

up to 14° vertically per cabinet, and couples coherently up

to 12 kHz when configured in a straight (0° splay) long

throw section. The Q1 covers the frequency range from

60 Hz to 17 kHz.
The Q7 and Q10 cabinets are mechanically and

acoustically compatible loudspeakers with 75° x 40° and

110° x 40° spherical dispersion patterns which can be

used as a downfill (Q7) or nearfill extension with Q1

arrays.
Smaller configurations of Q1 cabinets can also be used

ground stacked, supported by Q-SUB cabinets. The most

even energy distribution in the audience area will however

be achieved with a flown array.
The TI assumes that all Q-Series cabinets are driven by d&b

D6 or D12 amplifiers. E-PAC amplifiers do not provide HFC

and CSA settings.

5.1 Number of cabinets required
The number of Q1 cabinets to be used in an application

depends on the desired level, the distances and the

directivity requirements in the particular venue. Using the

d&b ArrayCalc calculator will prove whether the system is

able to fulfill the requirements.
Depending on the program material and the desired level

additional Q-SUB subwoofer systems will be necessary to

extend the system bandwidth and headroom. The number

of Q-SUBs needed per Q1 cabinet for serious full-range

program will decrease with the size of the system. For small

setups a 1:1 ratio is recommended, for example four

Q-SUBs to four Q1s, while larger systems will work with a

2:3 ratio, for example eight Q-SUBs to twelve Q1s. Please

note that CSA setups require a multiple of three Q-SUB

cabinets.
As an option Q1 systems can also be used with J-SUB or

J-INFRA subwoofers.

5.2 Subwoofer setup
Subwoofers are operated most efficiently when stacked on

the ground. For cleanest sound and coverage we

recommend arranging subwoofers in a CSA configuration

as described in d&b TI 330 Cardioid SUB array which is

available for download from the d&b audiotechnik website

at www.dbaudio.com.

When used with subwoofers, the Q1 systems should be

operated in CUT mode to gain maximum headroom at low

frequencies.

Q-SUB (40 – 100/130 Hz)
Q-SUB cabinets can be used ground stacked or integrated

into the flown array, either on top of a Q1 array or flown

as a separate column.
Flown Q-SUBs create a different level distribution in the

audience area than ground stacked ones. In particular the

area at the very front below the arrays has much less low

frequency energy when subwoofers are included in the

array. This can be very useful in applications that do not

require high levels of low frequency energy at the front,

however for an event with high stage level additional

ground stacked subwoofers may be necessary.
For Q1 arrays consisting of three or more cabinets we

recommend the use of the 100 Hz setting for the Q-SUB

systems. Smaller Q1 arrays providing less coupling at low

frequencies may benefit from the higher crossover

frequency of the standard mode of the Q-SUBs (130 Hz).

Q1/Q-SUB crossover setup

Compared to a standard Q-SUB configuration a CSA setup

produces slightly less level above 70 Hz, so it may be

advantageous to use the standard (130 Hz) amplifier

setting.

J-SUB (32 – 70/100 Hz)
J-SUB cabinets can be used to supplement a Q1 system in

different ways.
If the system is equipped with a sufficient number of Q-SUB

cabinets, J-SUBs can be used to extend its bandwidth to

below 32 Hz. Driven by D12 amplifiers set to INFRA mode

one J-SUB will supplement up to four Q-SUB cabinets.
This combination will achieve its maximum headroom when

the Q-SUBs are operated in the 130 Hz mode. If for audio

reasons the lower crossover frequency to the Q1s is desired

you may also reduce the gain of the Q-SUB amplifiers.

Decreasing the gain by 2.5 dB will create the same

downward shift to the upper slope as switching to the

100 Hz setting, but with less low frequency boost.

TI 385 (6.0 EN) d&b Line array design, ArrayCalc V8.x

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