L-Acoustics - KS21
The L-Acoustics KS21 is a high-power subwoofer housing a single 21-inch neodymium cone driver in a bass-reflex enclosure. It extends reinforcement systems down to a low frequency limit of 29 Hz and reaches a peak output of 138 dB SPL, operating in standard omnidirectional or cardioid configurations for controlled low-frequency directivity on stage.
Specifications
- Configuration: Omni or cardioid subwoofer
- LF transducer: 1 x 21-inch neodymium cone driver
- Acoustical load: Bass-reflex
- Low frequency limit (-10 dB): 29 Hz
- Max SPL (peak): 138 dB at 1 m (half-space)
- Nominal impedance: 8 ohms
- Weight: 49 kg / 108 lb
- Dimensions (H x W x D): 764 mm x 571 mm x 601 mm
- IP rating: IP55
- Amplifier compatibility: LA4X, LA8, LA12X
Applications
The KS21 is deployed in touring, festival, and large-venue sound reinforcement as a ground-stacked or flown subwoofer. In cardioid configuration, front-to-back rejection reduces low-frequency energy reaching the stage, improving monitor mix isolation and audience uniformity. It pairs with KARA II, KIVA II, and other L-Acoustics line source systems.
Frequently asked questions
What does cardioid configuration mean for a subwoofer?
In cardioid mode, the KS21 is oriented and processed so that low-frequency output is directed toward the audience while output behind the cabinet is reduced. This lowers stage wash and improves low-frequency control in live sound settings.
What amplifiers are compatible with the KS21?
The KS21 is amplified by the L-Acoustics LA4X, LA8, and LA12X amplified controllers.
What is the low frequency limit of the KS21?
The KS21 has a low frequency limit of 29 Hz at -10 dB.
If you have any questions, you are always welcome to contact us. We'll get back to you as soon as possible, within 24 hours on weekdays.
-
Shipping Information
Use this text to answer questions in as much detail as possible for your customers.
-
Customer Support
Use this text to answer questions in as much detail as possible for your customers.
-
FAQ’s
Use this text to answer questions in as much detail as possible for your customers.
-
Contact Us
Use this text to answer questions in as much detail as possible for your customers.
FAQs
What is your return policy?
All refunds and returns are determined by the manufacturer's terms of sale. Change-of-mind refunds are not accepted, but all valid warranty claims will be managed by AKA Acoustics in compliance with consumer law.
How long will it take to receive my order?
Freight lead times will be provided upon order confirmation. Standard items typically ship within 4–6 weeks, while custom orders may take 6–12 weeks.
Is my payment information secure?
Yes, all payments are securely processed through Stripe and are protected under their Terms of Service. AKA Acoustics do not store any payment information ourselves.
How are freight costs calculated?
Freight costs are determined at the time of quotation to ensure accurate pricing based on your specific order. For any questions, please email sales@akaacoustics.com
How can I contact support?
For account inquiries, email accounts@akaacoustics.com. For order support, email sales@akaacoustics.com.