High-Power Cardioid Subwoofer Design Pro Audio DJ Passive 3600W 21"
PA Sub boxes with high strength plywood black
Model number: INF-21
Triple 21" passive subwoofer speaker, front: 2400W RATED/9600W PEAK
POWER, Rear: 1200W RATED/ 4800W PEAK POWER.
Voice Coil of the 21” driver is 6 inches. PHT voice coil wire
inside and outside rounding and BAF voice coil bobbin, can endure
high temperature. (VC: 152.4 mm ; Mag: 330.25 mm)
The cone papers and spiders are imported from UKM.
Cardioid dispersion pattern avoids unwanted energy behind the
Greatly reduces the reverberant field at low frequencies, providing
highest accuracy in low frequency reproduction.
Selecting Hypercardioid mode in the amplifier optimizes the tuning
of front and rear channels for a maximum rejection at the left and
right sides behind the cabinet
Wooden lid for front grill is provided, as well as wheels at the rear side is
2 x 21" front + 1 x 21" rear
Maximum Peak SPL
144dB (Front); 141 dB (Rear)
2400W(Front); 1200W (Rear)
9600W(Front); 4800W (Rear)
4 ohm(Front); 8 ohm (Rear)
Dispersion Angle (-6dB)
Germany Water Paint
685 x 1180 x 1040 mm
- Large Scale indoor or outdoor concerts / Shows
- Large theaters / Auditoriums
- Large touring sound system
21" Cardioid Subwoofer
The INF-21 is a triple 21" cardioid Subwoofer for Installation
Applications, incorporating excellent patented loading principles,
designed for use in applications requiring accurate and powerful
reproduction of low frequency energy at very high levels.
It has two bass-reflex chambers containing three 21" drivers, two
facing forward in one chamber that are driven from one channel of
amplifier and one facing backwards driven by another amplifier
what applications is a cardioid subwoofer configuration appropriate
There are several situations where cardioid configurations can be
For instance, when using conventional subwoofers with a wall behind
them, the back wave will bounce back and cancellations will happen
at the front (That’s because the subwoofers radiate in all
directions). In this case, a cardioid configuration will radiate
very little pressure backward, hence minimizing that effect.
When using conventional subwoofers off the stage, the singer/
talker will be affected by the subwoofer frequencies. Cardioid
subwoofers will help the sound engineers to clean the subwoofer
frequencies and clarity will be grained on the stage.
Introduction of the company:
With 15 years experiences of manufacturing sound products,
Guangzhou Hongxiang Audio Equipment Co., Ltd, is growing up so fast
these years. Our Brand - RKB AUDIO is now well-known to everyone
domestic and overseas. We take great pride in providing clients all
over the world with the most competitive sound products and the
most excellent services. We always concentrate on designing and
manufacturing the best sound system at prices that fit everyone’s
With 30000 square meters work plant, and with 200 talented
employees and leading technology, RKB AUDIO manufactures and
supplies a wide range of professional sound system, including line
array speakers, subwoofer speakers, full range speakers, stage
monitor speakers, and professional power amplifiers. All our
products are widely used in the applications below: touring, rental
market, fixed installations, indoor or outdoor events, multimedia
halls, concerts, theaters, churches, etc.
We will not tell you how good our R&D and production team is,
and we will not tell you that how we sell our products to over 88
countries abroad, but we will sincerely invite you to try our sound
products to find out the answers. Now you've got talent, and you’ve
got the market. All you need now is the best pro audio equipment to
show your skills.
We firmly believe that, with your continuous support and our
unremitting pursuit, Germany RKB AUDIO must be always standing high
in the Reinforcement Kingdom, and we are sure that you will enjoy
our great sound and service. (OEM/ODM is welcome.)