{"product_id":"sky-high-car-audio-fxb-800-4-4-channel-amplifier","title":"Sky High Car Audio FXB 800.4 4-Channel Amplifier","description":"\u003ch1\u003eSky High Car Audio FXB 800.4 4-Channel Amplifier\u003c\/h1\u003e\n\n\u003cp\u003e\u003cstrong\u003eSold by AudioSellerz.com\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThe Sky High Car Audio FXB 800.4 is an ultra-compact Class D full-range amplifier that delivers useful four-channel speaker power from a chassis measuring barely over 5 inches long. It produces up to 225 watts RMS per channel at 2 ohms while fitting into spaces where many conventional amplifiers will not.\u003c\/p\u003e\n\n\u003cp\u003eThis makes the FXB 800.4 a practical choice for amplified door speakers, component systems, coaxial speakers, midrange drivers, custom doors, motorcycles, powersports vehicles, factory-system upgrades and other installations where space is limited.\u003c\/p\u003e\n\n\u003cp\u003eBrowse more \u003ca href=\"https:\/\/audiosellerz.com\/collections\/sky-high-car-audio\" style=\"color:#0066cc;text-decoration:underline;\"\u003eSky High Car Audio products\u003c\/a\u003e, compare our complete selection of \u003ca href=\"https:\/\/audiosellerz.com\/collections\/4-channel-amplifiers\" style=\"color:#0066cc;text-decoration:underline;\"\u003e4-channel amplifiers\u003c\/a\u003e or view \u003ca href=\"https:\/\/audiosellerz.com\/collections\/amplifiers\" style=\"color:#0066cc;text-decoration:underline;\"\u003eall car audio amplifiers\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eReal Four-Channel Power in an Extremely Small Amplifier\u003c\/h2\u003e\n\n\u003cp\u003eAt 14.4 volts, the FXB 800.4 produces 130 watts RMS per channel at 4 ohms or 225 watts RMS per channel at 2 ohms. That gives customers enough clean power for many upgraded daily-driver speaker systems, higher-output coaxial speakers, component sets, midrange drivers and compact pro-audio installations.\u003c\/p\u003e\n\n\u003cp\u003eThe FXB 800.4 is not limited to four-channel operation. It can also be bridged to produce up to 400 watts RMS across two channels at 4 ohms, giving installers more flexibility when the system needs fewer channels with additional power.\u003c\/p\u003e\n\n\u003cp\u003eCustomers building a complete Sky High speaker system can compare \u003ca href=\"https:\/\/audiosellerz.com\/collections\/sky-high-car-audio-speakers\" style=\"color:#0066cc;text-decoration:underline;\"\u003eSky High full-range speakers\u003c\/a\u003e, \u003ca href=\"https:\/\/audiosellerz.com\/collections\/sky-high-mid-range-speakers\" style=\"color:#0066cc;text-decoration:underline;\"\u003eSky High midrange speakers\u003c\/a\u003e, \u003ca href=\"https:\/\/audiosellerz.com\/collections\/sky-high-car-audio-midbass-speakers\" style=\"color:#0066cc;text-decoration:underline;\"\u003eSky High midbass speakers\u003c\/a\u003e and \u003ca href=\"https:\/\/audiosellerz.com\/collections\/sky-high-car-audio-tweeters\" style=\"color:#0066cc;text-decoration:underline;\"\u003eSky High tweeters\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eRMS Power Ratings at 14.4 Volts\u003c\/h2\u003e\n\n\u003ch3\u003eFour-Channel Mode\u003c\/h3\u003e\n\n\u003cul\u003e\n  \u003cli\u003e225 watts RMS × 4 at 2 ohms\u003c\/li\u003e\n  \u003cli\u003e130 watts RMS × 4 at 4 ohms\u003c\/li\u003e\n  \u003cli\u003e900 watts RMS combined at 2 ohms\u003c\/li\u003e\n  \u003cli\u003eMinimum stereo impedance: 2 ohms per channel\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTwo-Channel Bridged Mode\u003c\/h3\u003e\n\n\u003cul\u003e\n  \u003cli\u003e400 watts RMS × 2 at 4 ohms\u003c\/li\u003e\n  \u003cli\u003e260 watts RMS × 2 at 8 ohms\u003c\/li\u003e\n  \u003cli\u003eMinimum bridged impedance: 4 ohms\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003e\u003cstrong\u003eImportant impedance notice:\u003c\/strong\u003e The FXB 800.4 must not be operated below 2 ohms per channel in four-channel mode or below 4 ohms when bridged. Calculate the completed impedance of every channel before connecting the speakers.\u003c\/p\u003e\n\n\u003ch2\u003eFlexible Speaker-System Configuration\u003c\/h2\u003e\n\n\u003cp\u003eRun four independent channels for front and rear speakers, bridge one channel pair when one section of the system needs additional power or bridge both channel pairs to create a compact two-channel amplifier.\u003c\/p\u003e\n\n\u003cp\u003eThe amplifier includes selectable HPF, full-range and LP-BP crossover modes. A two-channel or four-channel input-selection switch also provides additional signal-routing flexibility for different system layouts.\u003c\/p\u003e\n\n\u003cp\u003eThese controls make the FXB 800.4 useful for daily-driver speaker upgrades, custom doors, mids-and-highs systems, motorcycle installations and modern vehicle integration. The final crossover and gain settings should always be selected around the exact speakers being powered.\u003c\/p\u003e\n\n\u003ch2\u003eFXB 800.4 Features\u003c\/h2\u003e\n\n\u003cul\u003e\n  \u003cli\u003eUltra-compact Class D full-range four-channel amplifier\u003c\/li\u003e\n  \u003cli\u003eUp to 225 watts RMS per channel at 2 ohms\u003c\/li\u003e\n  \u003cli\u003eFully bridgeable at 4 ohms\u003c\/li\u003e\n  \u003cli\u003eFull-range frequency response from 10 Hz to 25 kHz\u003c\/li\u003e\n  \u003cli\u003eOperating-voltage range from 10 to 16 volts\u003c\/li\u003e\n  \u003cli\u003eHPF, full-range and LP-BP crossover selection\u003c\/li\u003e\n  \u003cli\u003eTwo-channel or four-channel input selection\u003c\/li\u003e\n  \u003cli\u003eMetal detent crossover adjustment controls\u003c\/li\u003e\n  \u003cli\u003eTiffany-style RCA connections\u003c\/li\u003e\n  \u003cli\u003eReversible Sky High emblem for different mounting positions\u003c\/li\u003e\n  \u003cli\u003ePower, clipping and protection indicators\u003c\/li\u003e\n  \u003cli\u003eFanless design\u003c\/li\u003e\n  \u003cli\u003e85% rated efficiency at full power\u003c\/li\u003e\n  \u003cli\u003e95 dB signal-to-noise ratio\u003c\/li\u003e\n  \u003cli\u003e180 damping factor\u003c\/li\u003e\n  \u003cli\u003eLess than 0.1% total harmonic distortion\u003c\/li\u003e\n  \u003cli\u003eThermal, overload, DC-output, short-circuit and input-voltage protection\u003c\/li\u003e\n  \u003cli\u003e4-gauge power and ground terminals\u003c\/li\u003e\n  \u003cli\u003e10-gauge speaker-output terminals\u003c\/li\u003e\n  \u003cli\u003e90-amp fuse rating\u003c\/li\u003e\n  \u003cli\u003eCompatible with the SHCA modular mounting ecosystem\u003c\/li\u003e\n  \u003cli\u003eCompatible with SHCA Universal Amp Key mounting options\u003c\/li\u003e\n  \u003cli\u003ePassive-cooling and color-customization options available separately\u003c\/li\u003e\n  \u003cli\u003eOne-year manufacturer defect warranty\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eUltra-Compact Dimensions\u003c\/h2\u003e\n\n\u003cul\u003e\n  \u003cli\u003eWidth: 5.9 inches\u003c\/li\u003e\n  \u003cli\u003eLength: 5.39 inches\u003c\/li\u003e\n  \u003cli\u003eHeight: 2.1 inches\u003c\/li\u003e\n  \u003cli\u003eQuantity: One amplifier\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eMeasure the intended mounting location before ordering and leave additional room for power wire, speaker wire, RCA cables, adjustment access and ventilation. Because the amplifier uses a fanless design, it should not be sealed inside an unventilated compartment or mounted where heat cannot escape.\u003c\/p\u003e\n\n\u003cp\u003eAlthough its compact size makes it useful for motorcycle and powersports installations, the product is not identified as waterproof or marine-rated. Install it where it will remain protected from water and direct moisture.\u003c\/p\u003e\n\n\u003ch2\u003ePlan the Wiring and Electrical Support\u003c\/h2\u003e\n\n\u003cp\u003eThe FXB 800.4 uses 4-gauge power terminals and carries a 90-amp fuse rating. Power and ground wire should be selected around the conductor material, cable length, expected current demand and complete system—not terminal size alone.\u003c\/p\u003e\n\n\u003cp\u003eBrowse compatible \u003ca href=\"https:\/\/audiosellerz.com\/collections\/amp-kits\" style=\"color:#0066cc;text-decoration:underline;\"\u003ecar audio amplifier wiring kits\u003c\/a\u003e and \u003ca href=\"https:\/\/audiosellerz.com\/collections\/power-speaker-wire\" style=\"color:#0066cc;text-decoration:underline;\"\u003epower, ground and speaker wire\u003c\/a\u003e. Use properly sized fuse protection near the power source and keep the amplifier ground short, secure and connected to clean bare metal.\u003c\/p\u003e\n\n\u003cp\u003eIf the factory radio is staying in the vehicle, confirm whether the system needs a line-output converter, DSP or another integration solution before beginning the installation.\u003c\/p\u003e\n\n\u003ch2\u003eMatch the Amplifier to the Speakers\u003c\/h2\u003e\n\n\u003cp\u003eDo not choose speakers only by their advertised peak-power rating. Match the FXB 800.4 using the speaker RMS rating, individual impedance, number of speakers per channel, wiring configuration and amplifier output at the completed channel load.\u003c\/p\u003e\n\n\u003cp\u003eAt 4 ohms, each channel produces 130 watts RMS. At 2 ohms, each channel produces 225 watts RMS. Make sure every speaker or completed group of speakers connected to a channel can safely work with the available power.\u003c\/p\u003e\n\n\u003cp\u003eRunning several speakers on one channel changes the final impedance. Parallel wiring lowers impedance, while series wiring raises it. Never connect a speaker configuration below the amplifier’s 2-ohm-per-channel minimum.\u003c\/p\u003e\n\n\u003ch2\u003eGain and Crossover Setup\u003c\/h2\u003e\n\n\u003cp\u003eSet amplifier gain using a clean signal and treat it as an input-sensitivity adjustment—not a volume control. Use appropriate high-pass crossover protection for door speakers, coaxial speakers, mids and tweeters so they are not forced to reproduce frequencies below their intended operating range.\u003c\/p\u003e\n\n\u003cp\u003eOur \u003ca href=\"https:\/\/audiosellerz.com\/blogs\/audio-sellerz-blogs\/car-audio-speaker-tuning-guide\" style=\"color:#0066cc;text-decoration:underline;\"\u003ecar audio speaker tuning guide\u003c\/a\u003e explains amplifier gain, crossover settings and speaker-system setup in more detail.\u003c\/p\u003e\n\n\u003ch2\u003eWho Should Choose the FXB 800.4?\u003c\/h2\u003e\n\n\u003cp\u003eThe Sky High FXB 800.4 makes sense for customers who want meaningful four-channel power in the smallest possible footprint. It is a strong match for amplified daily drivers, upgraded door speakers, component systems, compact custom doors, motorcycles, powersports vehicles and factory-system integration.\u003c\/p\u003e\n\n\u003cp\u003eChoose the FXB 800.4 when 130 watts RMS per channel at 4 ohms or 225 watts RMS per channel at 2 ohms matches the speaker system. If the speakers need substantially more power, compare the larger FXB 1400.4 or FXB 2600.4 instead of operating this amplifier below its minimum impedance.\u003c\/p\u003e\n\n\u003ch2\u003eConnect With Audio Sellerz\u003c\/h2\u003e\n\n\u003cp\u003eFollow Audio Sellerz on \u003ca href=\"https:\/\/www.facebook.com\/share\/1BTSynboiR\/\" style=\"color:#0066cc;text-decoration:underline;\" rel=\"noopener\" target=\"_blank\"\u003eFacebook\u003c\/a\u003e, \u003ca href=\"https:\/\/www.instagram.com\/audiosellerz\" style=\"color:#0066cc;text-decoration:underline;\" rel=\"noopener\" target=\"_blank\"\u003eInstagram\u003c\/a\u003e, \u003ca href=\"https:\/\/www.tiktok.com\/@audiosellerz\" style=\"color:#0066cc;text-decoration:underline;\" rel=\"noopener\" target=\"_blank\"\u003eTikTok\u003c\/a\u003e and \u003ca href=\"https:\/\/youtube.com\/@audiosellerz\" style=\"color:#0066cc;text-decoration:underline;\" rel=\"noopener\" target=\"_blank\"\u003eYouTube\u003c\/a\u003e.\u003c\/p\u003e","brand":"Sky High Car Audio","offers":[{"title":"Default Title","offer_id":61865003942028,"sku":"SHCA-FXB-800-4","price":214.95,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0662\/5076\/8524\/files\/SHCA-FXB-800-4.13__18546.webp?v=1790791132","url":"https:\/\/audiosellerz.com\/products\/sky-high-car-audio-fxb-800-4-4-channel-amplifier","provider":"Audio Sellerz","version":"1.0","type":"link"}