---
product_id: 436348969
title: "In Phase Car Audio XTB-828R 8\" 400W Active Subwoofer with Passive Radiator and Class D Amplifer , Black"
brand: "in phase"
price: "₩635289"
currency: KRW
in_stock: true
category: "In Phase"
url: https://www.desertcart.kr/products/436348969-in-phase-car-audio-xtb-828r-8-400w-active-subwoofer
store_origin: KR
region: South Korea
---

# 300W peak Class D amplifier Compact desktop-sized design 8-inch glass fiber cone In Phase Car Audio XTB-828R 8" 400W Active Subwoofer with Passive Radiator and Class D Amplifer , Black

**Brand:** in phase
**Price:** ₩635289
**Availability:** ✅ In Stock

## Summary

> 🎶 Elevate your drive with bass that commands attention — compact power, colossal impact!

## Quick Answers

- **What is this?** In Phase Car Audio XTB-828R 8" 400W Active Subwoofer with Passive Radiator and Class D Amplifer , Black by in phase
- **How much does it cost?** ₩635289 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.kr](https://www.desertcart.kr/products/436348969-in-phase-car-audio-xtb-828r-8-400w-active-subwoofer)

## Best For

- in phase enthusiasts

## Why This Product

- Trusted in phase brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Space-Savvy Design:** Compact footprint fits discreetly in your car boot, maximizing bass without sacrificing cargo space.
- • **Powerful Yet Efficient:** Class D amplifier delivers up to 300W peak power without draining your car’s battery.
- • **Precision Bass Mastery:** Experience deep, controlled bass with a purpose-built glass fiber cone and passive radiator technology.
- • **Seamless Compatibility:** High and low-level inputs work effortlessly with both aftermarket and OEM head units.
- • **Plug & Play Convenience:** Comes complete with wiring kit and remote bass gain control for instant, customizable sound upgrades.

## Overview

The In Phase Car Audio XTB-828R is an 8-inch active subwoofer featuring a lightweight, durable glass fiber cone paired with a passive radiator for superior bass accuracy. Powered by a built-in 300W peak Class D amplifier, it offers deep, controlled low frequencies in a compact, desktop-sized enclosure that fits easily in your car boot. Compatible with OEM and aftermarket head units via high and low-level inputs, it includes a wiring kit and remote bass control, making it a powerful yet space-efficient upgrade for any car audio enthusiast.

## Description

In Phase Car Audio XTB-828R 8" 400W Active Subwoofer with Passive Radiator and Class D Amplifer , Black : desertcart.co.uk: Electronics & Photo

## Features

- PASSIVE RADIATOR: a speaker with no voice coil or magnet, basically a speaker cone. This is not connected to the amp at all
- COMPACT DESIGN: This sub is only the size of a small desktop computer case. This small footprint allows the user to add thumping bass without compromising space in the boot
- SUPERIOR SUBWOOFER CONE: The glass fibre subwoofer cone is purpose built for this package, it is lightweight, durable and rigid without compromising sound quality
- Power Source Type: Corded Electric

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B09ZPMVHCV |
| Antenna Location | car |
| Audio Driver Size | 8 Inches |
| Audio Driver Type | Dynamic Driver |
| Audio Output Mode | Stereo |
| Best Sellers Rank | 119,732 in Electronics & Photo ( See Top 100 in Electronics & Photo ) 77 in Car Enclosed Subwoofer Systems |
| Box Contents | All Cables Included, Remote Bass Gain |
| Brand Name | In Phase |
| Colour | Black |
| Compatible Devices | Personal Computer |
| Connectivity Protocol | RCA |
| Control Method | Voice |
| Controller Type | Remote Control |
| Customer Reviews | 4.0 4.0 out of 5 stars (38) |
| Enclosure Material | Metall/Kunststoff |
| Is Waterproof | False |
| Item Dimensions D x W x H | 5D x 16W x 5H centimetres |
| Item Type Name | Car Speakers |
| Manufacturer | In Phase |
| Maximum Speaker Output Power (in watts) | 300 Watts |
| Model Name | In Phase XTB-828R |
| Model Number | XTB-828R |
| Mounting Type | Car Mount |
| Network Connectivity Technology | RCA |
| Number of Audio Channels | 2.0 |
| Number of Items | 1 |
| Power Source | Corded Electric |
| Product Features | Passive Radiator |
| Product Warranty | 1 Year |
| Speaker Size | 8 Inches |
| Speaker Type | Subwoofer |
| Specific Uses For Product | Car Audio |
| Subwoofer Connectivity Technology | Wired |
| Tweeter Diameter | 1 Inches |
| Warranty Type | Limited |
| Water Resistance Level | Waterproof |
| Wireless Technology Type | No Wireless Communication Technology |
| Woofer Driver Diameter | 8 Inches |

## Product Details

- **Audio output mode:** Stereo
- **Brand:** In Phase
- **Connectivity technology:** RCA
- **Material:** Metall/Kunststoff
- **Model name:** In Phase XTB-828R
- **Mounting type:** Car Mount
- **Recommended uses for product:** car
- **Speaker maximum output power:** 300 Watts
- **Speaker type:** Subwoofer
- **Special feature:** Passive Radiator

## Images

![In Phase Car Audio XTB-828R 8" 400W Active Subwoofer with Passive Radiator and Class D Amplifer , Black - Image 1](https://m.media-amazon.com/images/I/91W4PNuYh1L.jpg)

## Questions & Answers

**Q: How is this wired up pls**
A: you need to buy audio cables (red and black) they go to your stereo. The blue wire also to stereo. 12v from positive battery. And 0v (ground) to negative battery

**Q: Is the wiring included lilke as advised**
A: Yes all the wires were included if ever a mistake was made I would still recommend this is very reliable strongly built and gives good bass that 10x it's size

## Frequently Bought Together

- In Phase Car Audio XTB-828R 8" 400W Active Subwoofer with Passive Radiator and Class D Amplifer , Black
- VIBE Audio Slick 1500 W System Car Wiring Kit

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**Shop now:** [https://www.desertcart.kr/products/436348969-in-phase-car-audio-xtb-828r-8-400w-active-subwoofer](https://www.desertcart.kr/products/436348969-in-phase-car-audio-xtb-828r-8-400w-active-subwoofer)

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*Product available on Desertcart South Korea*
*Store origin: KR*
*Last updated: 2026-10-15*