---
product_id: 698387382
title: "In Phase USW300 Underseat Subwoofer | Car Subwoofer with Built in Amplifier"
brand: "in phase"
price: "1104.07 DT"
currency: TND
in_stock: true
reviews_count: 13
url: https://www.desertcart.tn/products/698387382-in-phase-usw300-underseat-subwoofer-car-subwoofer-with-built-in
store_origin: TN
region: Tunisia
---

# Compact 16x5x5 cm size 300W max output Die-cast aluminum chassis In Phase USW300 Underseat Subwoofer | Car Subwoofer with Built in Amplifier

**Brand:** in phase
**Price:** 1104.07 DT
**Availability:** ✅ In Stock

## Summary

> 🎶 Feel the bass, not the bulk — power your ride with the USW300!

## Quick Answers

- **What is this?** In Phase USW300 Underseat Subwoofer | Car Subwoofer with Built in Amplifier by in phase
- **How much does it cost?** 1104.07 DT with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.tn](https://www.desertcart.tn/products/698387382-in-phase-usw300-underseat-subwoofer-car-subwoofer-with-built-in)

## 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

- • **Discreet Underseat Design:** Compact form factor fits seamlessly under seats or in tight spaces—upgrade your sound without sacrificing cabin space.
- • **Trusted UK Audio Expertise:** Backed by 500+ years of combined R&D experience from In Phase, a premium brand known for quality car audio.
- • **Power-Packed Bass Performance:** 300W max output with 150W RMS delivers deep, punchy sub-bass that transforms your drive.
- • **Built to Last, Built to Perform:** Robust die-cast aluminum chassis eliminates flex and maximizes bass output under any condition.
- • **Rattle-Free Aluminium Cone Tech:** Lightweight yet ultra-stiff aluminium cone with damping materials ensures crystal-clear, distortion-free bass.

## Overview

The In Phase USW300 is a compact underseat car subwoofer featuring a built-in 300W amplifier and a durable die-cast aluminum chassis. Its lightweight aluminium cone with integrated damping delivers deep, rattle-free bass, while the discreet design fits easily under seats or in tight vehicle spaces. Engineered by a UK brand with over 500 years of combined audio R&D, this subwoofer offers professional-grade sound enhancement with a 5-year warranty, perfect for millennials seeking premium in-car audio without compromise.

## Description

The key thing about the In Phase USW 300 is the performance, the little active woofer really packs a punch, the bass response is amazing and you really do get SUB Bass from it. Its extremely responsive so the music has a completely different sound once added to the car.

## Features

- Subwoofer for Car - With a built in amplifier, max output of 300 W and 150 W RMS, the In Phase USW300 is a true pocket powerhouse of audio performance.
- Coned Aluminium Active Subwoofer Car - Aluminium Cones are light in weight and can be really stiff, but they are really robust cones that rarely go wrong. This sub has a damping material built into its cone and spider to ensure a rattle-free performance and deep bass
- Heavy duty durable construction - Die Cast Aluminium Chassis - no plastic structure here. The metal body is part of a secure and rigid structure, no flexing body when the unit is in full power, this also helps with bass output.
- Compact and discrete - Allowing to install the USW300 anywhere within vehicles boot, under seats, behind seats or in the foot well
- Trusted Brand - In Phase is a UK based brand, our team currently has over 500 years of audio research and development experience, creating quality products from premium material that our customer deserve, including, car audio speakers & subwoofers.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Age Range Description | Adult |
| Antenna Location | Car |
| Asin | B089GZ6F14 |
| Audio Driver Size | 8 Inches |
| Audio Driver Type | Dynamic Driver |
| Audio Output Mode | Stereo |
| Best Sellers Rank | 5,081 in Electronics & Photo (See Top 100 in Electronics & Photo) 1 in Car Enclosed Subwoofer Systems |
| Box Contents | Car Subwoofer Active Enclosure, Wiring Kit, Mounting Brackets, Remote Controller, Instruction Manual |
| Brand Name | In Phase |
| Colour | USW300 |
| Compatible Devices | Car |
| Compatible With Vehicle Type | Car |
| Connectivity Protocol | Auxiliary |
| Control Method | Remote |
| Controller Type | Remote Control |
| Country Of Origin | China |
| Customer Package Type | Standard packaging |
| Customer Reviews | 4.4 4.4 out of 5 stars (444) 4.4 out of 5 stars |
| Enclosure Material | Aluminum/Die Cast Aluminum |
| Eu Spare Part Availability Duration | 2 Years |
| Frequency Response | 150 Hz |
| Global Trade Identification Number | 05060047672757 |
| Input Voltage | 12 Volts |
| Is Waterproof | false |
| Item Dimensions D X W X H | 5D x 16W x 5H centimetres |
| Item Type Name | Underseat Active Subwoofer |
| Item Weight | 1.5 Kilograms |
| Manufacturer | In Phase |
| Maximum Speaker Output Power In Watts | 300 Watts |
| Model Name | USW300 |
| Model Number | USW300 |
| Mounting Type | Underseat Mount |
| Mp3 Player | No |
| Network Connectivity Technology | Auxiliary |
| Number Of Audio Channels | 2.0 |
| Number Of Items | 1 |
| Power Source | Corded Electric |
| Product Features | Built-in Amplifier, Aluminium Coned Subwoofer |
| Product Warranty | 5 year |
| Speaker Size | 28 Centimetres |
| Speaker Type | Subwoofer |
| Specific Uses For Product | Car |
| Subwoofer Connectivity Technology | Wired |
| Tweeter Diameter | 1 Inches |
| Warranty Type | Limited |
| Wireless Technology Type | No Wireless Communication Technology |
| Woofer Driver Diameter | 200 Millimetres |

## Product Details

- **Audio output mode:** Stereo
- **Brand:** In Phase
- **Connectivity technology:** Auxiliary
- **Frequency response:** 150 Hz
- **Input voltage:** 12 Volts
- **Material:** Aluminum/Die Cast Aluminum
- **Model name:** USW300
- **Mounting type:** Underseat Mount
- **Speaker maximum output power:** 300 Watts
- **Speaker type:** Subwoofer

## Images

![In Phase USW300 Underseat Subwoofer | Car Subwoofer with Built in Amplifier - Image 1](https://m.media-amazon.com/images/I/81u+V61e6lL.jpg)

## Available Options

This product comes in different **Style Name** options.

## Questions & Answers

**Q: Does this require two connections? One rca from the unit to the sub out connection on headunit. And one to battery?**
A: Yes, it needs 12v power, you need the audio connection from the head unit ( RCA/sub out ) permanent live to the battery and earth to the chassis or battery, then the remote wire to the head unit which tells the sub to turn on and off, all aftermarket head units have a remote live connection for this purpose 👍

**Q: Can i use it in my home system? I have a musical fidelity amp and Linn speakers**
A: Yes, however you would need a 12V transformer with 20amps current supply.

**Q: how do you turn off if connected straight to battery?**
A: It detects the audio signal and turns itself on and off when you turn your head unit on/off. It's clever like that :-)

**Q: Can I wire to cigarette lighter for power? Says max 120w**
A: You cannot. You need to wire the active subwoofer directly for power to the battery Positive. If you are unsure how to do this, many videos on Youtube. It also explains in the instructions. However we always recommend professional installation if you are not sure.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Compact sub with a great sound
*by  on Reviewed in the United Kingdom 2 December 2025*

I was a little sceptical before ordering and was considering building something to go under the floor in my SLK.However I purchased one to try and was not disappointed. I fitted under the floor in the passenger side footwell on an SLK, some models have an amp fitted there.At the same time I replaced the headunit with a powered android type with CarPlay.Fitting was easy as the Android head had cables to connect to and a sub output.The remote was remotes to the side of the centre console, convenient for adjustments should I need to. Build quality is good, sound quality is excellent for a compact sub of its size it compliments the rest of the speaker system. It was actually worth spending the money on this product, if you can’t get a big box in anywhere this is the ideal choice and with the remote just adds to the functionality, to be fair I’ve not had the need to alter it from the initial twiddling.I’ve written this after purchasing in August 2024, just in Dec 2025 now and still enjoying the sub!

### ⭐⭐⭐⭐⭐ Fantastic value for money, easy to install.
*by  on Reviewed in the United Kingdom 17 February 2025*

+ Great Sound, Great Quality, Easy to Install, Fantastic Value.- No RCA Leads.This is a great little sub if you’re after a fuller sound for your car. I installed a set of component speakers into a Kangoo van and was disappointed with the bass, so I fitted this and it’s made a massive difference! It’s a substantial well built item and has all the sound controls on the remote instead of fiddly dials on the back of the unit which makes it great to tune while it’s situ without messing around accessing it again. It comes with all the leads you need to get it running via high level input, but you will need to but a phono lead if you want to connect it via low level RCA.

### ⭐⭐⭐⭐ Decent little sub for the price
*by  on Reviewed in the United Kingdom 6 June 2026*

Bought for my little peugeot 107 to add some bass to the pathetic little 4" speakers I have.This is a great little mini-sub, fits under the seat and was reasonably easy to fit. (Bit fiddly getting power from the engine bay and connecting the earth).Sound at normal volumes is actually pretty good, and fills out the bottom end of what the car speakers lack. For regular use it's not bad at all for the price.Now it must be said it does start to distort a little at louder volumes and is not your window shaking drum 'n bass sort of sub, but with a bit of tweaking from the controls and not raising the gain or bass-boost to silly levels you do get a good fill in low-end sound.So yeah, I'd recommend it if you're on a budget or got a small car.

## Frequently Bought Together

- In Phase USW300 300W Underseat Subwoofer - Active Car Subwoofer with Built-in Amplifier
- In Phase XTC17.2 250W 2 x 6.5 Inch Car Speakers - 17cm Car Speaker for Door or Parcel Shelf - Audio Speakers & Subwoofers

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*Product available on Desertcart Tunisia*
*Store origin: TN*
*Last updated: 2026-09-21*