Thunder-KS4 I
The Thunder-KS4 I is an active subwoofer from K-Array, housing dual 18-inch neodymium magnet woofers driven by a four-channel Class D amplifier with built-in DSP. Producing up to 141 dB SPL, it is the highest-output active model in the Thunder KS range, suited to large venues and touring productions requiring powerful, self-contained low-frequency reinforcement.
Specifications
- Type: Active subwoofer
- Woofers: 2 x 18-inch neodymium magnet
- Frequency response: 30 Hz to 150 Hz / 450 Hz (-6 dB, with dedicated preset)
- Max SPL: 141 dB (crest factor 4, measured at 1 m)
- Amplifier: 4-channel Class D, 4 x 2500 W at 4 ohm (CTA-2006, single channel driven)
- Nominal impedance: 4 ohm
- Power consumption: 600 VA at 8 ohm load, pink noise, 1/8 rated power
- Crossover: DSP-controlled, low-pass at 150 Hz (preset dependent)
- DSP features: Input gain, routing matrix, delay, full parametric IIR filters (peaking, shelving, high/low pass, Butterworth), onboard preset storage, remote monitoring
- Line input: 2 x XLR female, analogue and AES3
- Line output: 2 x XLR male link, analogue and AES3
- Speaker output: 2 x SpeakON NL4
- Mains connector: powerCON TRUE1 TOP
- Networking: 1 x RJ45, 4 x USB-A
- Control: Wi-Fi mobile app, K-framework3 via wired Ethernet
- Dimensions (W x H x D): 1106 x 500 x 580 mm (includes 17 mm removable rubber feet)
- Weight: 60 kg
- Enclosure: Polyurea-coated birch plywood
- Colours: Black, White, Custom RAL
- IP rating: IP53
Applications
The Thunder-KS4 I suits large-scale live sound, touring productions, and permanent installations in large venues such as stadiums, arenas, and outdoor festivals. Its dual 18-inch configuration and 141 dB max SPL provide the headroom required for high-output system designs, while the onboard amplifier and SpeakON outputs allow passive satellite loudspeakers to be driven directly without additional amplification.
Standards and compliance
IP53 ingress protection rating (dust partial protection, water spray resistance at up to 60 degrees). For critical permanent installations such as aquatic venues and marine environments, K-Array recommends additional protective measures beyond the rated IP53 level.
Frequently asked questions
How does the Thunder-KS4 I differ from the Thunder-KS3 I?
The KS4 I uses two 18-inch woofers and achieves a maximum SPL of 141 dB, compared to the KS3 I which uses a single 21-inch woofer and reaches 139 dB. The KS4 I is also wider at 1106 mm versus 735 mm for the KS3 I.
Can the Thunder-KS4 I drive passive midrange loudspeakers directly?
Yes. Two SpeakON NL4 speaker outputs allow the four-channel Class D amplifier to deliver signal and power to K-Array passive loudspeakers in the same system.
What remote control options does the Thunder-KS4 I support?
The unit supports Wi-Fi control via a dedicated mobile app and wired network control via K-framework3 software using the onboard RJ45 Ethernet port.
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.
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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.