4-Channel Class D Full-Range Amplifier, 100 W x 4 @ 2 Ω / 75 W x 4 @ 4 Ω - 14.4V
Utilizing our exclusive NexD™ high-speed switching technologies, the ultra-compact RD400/4 amplifier is engineered to deliver loads of audio output power, with incredible efficiency and low distortion. Don’t let its modern styling and small size fool you though, this little powerhouse churns out 100 watts of crystal-clear audio from each of its four channels into 2 ohms (14.4V, 1% THD) and is fully bridgeable, so it can be used as a 3-channel amplifier, or as a 2-channel amplifier producing a whopping 200W x 2 into 4 ohms.
For your convenience, the RD400/4’s controls can be found on top of the amplifier, beneath a protective cover, with all connections located along one side of its chassis. Studio-grade signal processing features include high or low-pass 12 dB / octave filters (defeatable) for each channel pair, with continuously variable frequency selection from 50-500 Hz, and dual-range, differential-balanced inputs capable of accepting most input voltage levels. Automatic turn-on capability (via signal sensing or DC-offset sensing) is standard equipment, along with all-new input type switches for bridging of stereo output channels without needing to use Y-adaptors.
Onboard LED-clipping indicators are also included with your RD400/4. This all-new, innovative feature lets you easily set your amplifier’s input sensitivity settings, quickly and accurately, with no special equipment needed. You’ll also find a set of preamp outputs on-hand, so you can pass signals to another amplifier, almost effortlessly. The RD400/4 features a durable, black powder-coated finish and a top-mounted, dual-color LED light strip that reports the overall status and condition.
Rated Continuous (RMS) Power @ 14.4 V
- @ 4 Ω 75 W RMS x 4
- @ 2 Ω 100 W RMS x 4
- Bridged @ 4Ω 200 W RMS x 2
Rated Continuous (RMS) Power @ 12.5 V
- @ 4 Ω 60 W RMS x 4
- @ 2 Ω 90 W RMS x 4
- Bridged @ 4Ω 180 W RMS x 2
- Frequency Response 12 Hz - 22 kHz (+0, -1dB)
- S/N Ratio, referred to highest rated power >104 dB below rated power (A-weighted, 20 Hz - 20 kHz noise bandwidth)
- S/N Ratio, referred to 1 W >84 dB (A-weighted, 20 Hz - 20 kHz noise bandwidth)
- Damping Factor @ 4 Ω >150 / 50 Hz
- Damping Factor @ 2 Ω >75 / 50 Hz
- THD+N @ Rated Power <1% @ 2 Ω per Ch.
- Input Voltage Range @ RCA Inputs Switchable from 200 mV - 2 V RMS (Low) to 800 mV - 8 V RMS (High)
- Min.Copper Power / Ground Wire Gauge 4 AWG wire
- Fuse Rating 40 A (AFS, AGU or MaxiFuse™)
- Filter Mode(s) Low-Pass or High-Pass
- Filter Slope(s) 12 dB/octave
- Filter Frequency Range 50 Hz - 500 Hz
- Filter Defeat Function
- Channel Input Mode Switch (2/4 ch.)
- Pass-Through Preamp Output Buffered
How will you send my item?
We ship to addresses within the UK using Royal Mail and DPD couriers.
How much does delivery cost?
- Royal Mail Standard - 2-3 Day non-tracked service - £3.99.
- Royal Mail Tracked - 2-3 Day tracked service - £4.99.
- DPD 2-3 Day - 2-3 Day tracked service - £7.99 .
- DPD Next Day - Next working day tracked service - £11.99.
- DPD Delivery - Non specific DPD service for larger/bulkier orders - £15.
- Saturday/Sunday Service - Tracked service specified for Saturday/Sunday - £22.99.
For orders to UK Non-mainland and International destinations, there will be an additional charge at checkout. Please see below for more information.
How long does delivery take?
Depending on the delivery service you choose, delivery usually takes between 1-3 working days to mainland UK from the moment we despatch your order. Orders to UK non-mainland and international destinations can take longer.
When will you despatch my order?
Orders placed before 3pm are processed and despatched the same day (excluding bank holidays and weekends). Orders placed on weekends will be processed and despatched the following working day.
*Please note that international orders may require extra checks before we are able to despatch your order so timescales may vary.
Can I track my delivery?
Yes - Order tracking is offered as standard on all items, whether they are shipped via DPD or Royal Mail. You will receive your tracking information via email once we have despatched your order.
UK Non-mainland and International destinations.
Due to the UK leaving the EU, some of our delivery partners have changed the way we ship to international and offshore destinations. This means that for the time being we are unable to ship items to these locations.
We are still accepting orders to these destinations however delivery times and prices are not final. We will confirm via email once we know more from our delivery partner.
Shipping for all items to UK Non-Mainland and International destinations will incur a charge at checkout. This charge is not final and we may need to charge for additional postage if required.
Shipping to international destinations may require further security checks and I.D. may need to be provided by the cardholder. We reserve the right to cancel any orders where you are do not pass our security checks or do not pay for appropriate postage.
Please note that we are unable to ship some items outside the UK. To avoid any disapointment please contact us before making your order.
What do you class as UK Non-mainland?
Rep. Ireland, N. Ireland, Channel Islands, Jersey, Guernsey, Isle of Wight, Isle of Man and Scottish Highlands. If you are unsure whether your address is classed as UK Non-mainland please feel free to contact us and an advisor will be happy to help.
For any further enquiries with regards to your delivery please contact us on 020 8561 9845 and one of our adviser's will be happy to help.
If you're not happy with your item or you've changed your mind.
Even though we're sure you'll be happy with your purchase, it's important that you are aware of how we deal with returns in the event that you need to send something back.
We understand how inconvenient it can be when you buy a product and aren't 100% satisfied with it. For this reason we have designed our returns policy to prevent any further inconvenience to you in these instances.
Under 14 days
- You can return your goods for a full refund or exchange as long as you inform us of your intention to return the goods within 14 days of receipt, starting from the day after you receive your goods (Exclusions apply, see below.)
- All return costs are down to the buyer and it is recommended that you return your items using a trackable method with appropriate insurance (if required).
- Once we have approved your return, please ensure that you return the item within 14 days.
- If a returns number is provided then please ensure that the parcel has this clearly marked.
- Items need to be returned in "as new" condition in their original packaging. We don't mind if you open the product to check it, however any used or damaged products will be subject to a 25% handling fee so please take care when opening your items
After 14 days
- We will not offer a refund after 14 days of you receiving your delivery unless your product is faulty.
Exclusions from our returns policy
As we're sure you'll understand, there are some products that we can't offer returns on due to their nature. These include:
- Special order items (these items will be clearly identifiable).
- Custom cut items.
- Clothing due to health and hygiene reasons.
- Products that include software which require activation.
Please note that these exclusions do not apply to items that become faulty.
If your product becomes faulty
We endeavour to get your items to you in fully working order, however in the event that your items do become faulty, please read below on what you should do next.
In a lot of cases with some products, faults can be fixed by performing some basic troubleshooting, so to prevent any further inconvenience to you we advise that you contact our Customer Service team who can guide you through some basic troubleshooting before sending items back.
Under 30 days
- If your items become faulty within 30 days of delivery you are entitled to a full refund or exchange. Please contact our customer service centre who will provide necessary returns details.
- Please send the items back with a cover note including a description of the fault and your original order number.
- Once we have fully tested the item and confirmed the fault, we will process the refund or exchange including cost of carriage back to us (within reason).
- If during our testing we cannot find a fault, no refund will be given and you will be charged for delivery of the item back to you.
After 30 days
- After 30 days you will still be able to get your faulty items repaired or replaced within the manufacturers warranty and we will be happy to assist you with this. Please contact our customer service team to find out the best way to get your items repaired or replaced. Please be aware that after 30 days we will not cover you for any carriage costs.
Air Lift Warranty information
Click here for Air Lift warranty information.
PLEASE NOTE: ALL RETURNS NEED TO BE ACCOMPANIED BY A COMPLETED RETURNS FORM: DOWNLOAD
DONT HAVE A PRINTER? Just ensure you include the relevant information required on a note inside the return so that we can process your request.
I want to return an item
- Unwanted Goods: In accordance with The Consumer Contracts Regulations (2015), you have a 14 working day 'cooling off period' in which you have the right to cancel your purchase and receive a full refund. The cooling off period starts on the day after the day on which you received the goods (does not include weekends). You are responsible for the cost of returning the item to us. For your own protection, we recommend that you send the parcel using a delivery service that insures you for the value of the goods.
- Providing that unwanted goods are received back by us in "as new" condition, we will refund payment for the goods. We don't mind if you open the product to check it, however any used or damaged products will be subject to a 25% handling fee so please take care when opening your item. These refunds will be made within 30 days of return of goods. Should you wish to cancel your purchase within the 14 working days 'cooling off' period, please e-mail us at [email protected]
- Please tell us your name and address, how your order was placed and any payment reference (ie Paypal) and the order number.
- Should you cancel your purchase with this 14 working day 'cooling off' period, we will refund your payment in full via the method of payment. There will be no charges for cancellation within this 14 working day 'cooling off period'.
- You are advised to wrap the product carefully to avoid damage. You are also advised to return goods by recorded delivery, registered post, or by courier. Proof of postage will not be accepted as proof of delivery. Please remember to include with the return your name and address, and a copy of your purchase receipt.
- Manufacturer's warranty: Beyond this 14 working day period, you are covered under the manufacturer's warranty which is typically 1 year. If your product becomes faulty during this period, you should contact our eSupport department, via the website, direct email or phone for a returns number. We will then arrange for your item to be repaired (or replaced, if appropriate with a new product) or provide details of the manufacturers local service centre.
- PLEASE NOTE: ALL RETURNS MUST BE ACCOMPANIED BY A COMPLETED RETURNS FORM: DOWNLOAD
Christmas Returns Policy
- Any product purchased between 25/11/22 and 24/12/22 will qualify for our extended returns policy.
- If your purchase is made within this time you have until 01/01/2023 to inform us of your intention to return your items.
- All orders placed within this time which are outside of the standard 14 day policy can only be returned for a credit. All credits need to be used within 90 days of issue.
- Please ensure you inform our Customer Service team in writing or via email ([email protected]).
- Any items being returned need be in brand new, unopened and unused condition.
- All products must be returned to us within 14 calendar days after our Customer Service team have authorised a return.
- Any promotional items received FREE at the time of purchase must also be returned, unused and unopened, otherwise the value of the promotional item will be deducted from the credit.
Please note: Our normal returns policy still applies on all orders if you are within the 14 day returns period.
Airlift Warranty Managments:
- Limited Lifetime Warranty for Air Lift Performance 3HTM, 3PTM or 3STM Air Management/Control system and Accessories purchased before 09/03/2021
- 2-Year Limited Warranty for Air Lift Performance 3HTM, 3PTM or 3STM Air Management/Control system and Accessories purchased individually on or after 09/03/202
- 4-Year Limited Warranty for Air Lift Performance 3HTM, 3PTM or 3STM Air Management/Control system and Accessories purchased with an Air Lift Performance front and rear suspension kit or four (4) Air Lift Performance Dominator Air Springs (purchased within 45 days of each other) on or after 09/03/2021
Airlift Warranty Bolt-on Suspenion:
- 1-Year Limited Warranty for Air Lift Performance bolt-on Performance Series and Slam Series suspension kits purchased individually before 09/03/2021
- 2-Year Limited Warranty for Air Lift Performance bolt-on Performance Series and Slam Series suspension kits purchased with a 3HTM, 3PTM or 3STM Air Management/Control System on or after 09/03/2021.
Airlift Warranty Compressors:
- 1-Year Limited Warranty for Air Lift Performance compressors purchased before 09/03/2021
- 90-Day Limited Warranty for Air Lift Performance compressors purchased on or after 09/03/2021