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In Phase Car Audio XTB-828R 8" 300W Active Subwoofer with PassiXTB-828R
£129.99 Save £70.00  was:£199.99
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5 Stars (4)

In Phase Car Audio XTB-828R 8" 300W Active Subwoofer with Passive Radiator and Class D Amplifer

£129.99 Save £70.00 (35%)  was:£199.99
5 Stars
4 Review(s) / write a review
Quickfind Code - 45332
Quick Summary:

One of the best active subs we have ever heard...

Condition: New

Save £70.00 (35%)
rrp: £199.99
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  • Next Day Delivery available on all orders before 5pm Next Day Delivery available on all orders before 5pm

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Key Features

8" 300W Active Subwoofer with Passive Radiator and Class D Amplifer - In Phase Car Audio XTB-828R

XTB-828R is a passive radiator equipped active sealed subwoofer enclosure. Hit really low frequencies and experience true bass accuracy not normally found in bog-standard active subwoofer. Equipped with an all weather glass fibre woven cone 20cm (8') drive unit, paired with a passive radiator in sealed enclosure technology, it provides deep and controlled bass frequencies. Its built-in 300W class D amplifier offers high power handling and numerous controls.

XTB-828R has high and low level inputs that can be plugged with after market and OEM headunits.

This FOUR-in-one enclosure reduces overall dimensions while offering a great bass level. This comes complete with a wiring kit apart from RCA cables. If fitting to an aftermarket headunit, you will need RCA cables

What on Earth is a 'passive radiator'?

A Passive Radiator is a speaker with no voice coil or magnet, basically a speaker cone. This is not connected to the amp at all. The purpose of this speaker is to allow the trapped sound pressure in the sealed enclosure to excite a resonance that makes it easier for the speaker system to create the deepest pitches (e.g bassline). In short, it gives you the benefit of ported enclosures without the downsides. This leads to better sound quality, with a linear frequency response of the sealed cabinet and the higher output you get from a ported design. This is also achieved in a smaller size than the ported subwoofer. You also do not have the same issues with port noise, and instead, you end up with a smooth bass.

Class D Amplifier

A robust, compact and efficient Class D amplifier is mounted to this enclosure. This is the driving force behind the sub. Only the finest components in it's category will doOffering up to 300W peak and 200W RMS Power

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. A lot of market leaders have a generic subwoofer (from their range) then they build a box to suit. Which works to an extent, this package offers you something more unique and performance based .

Car Audio Centre Manager Comments

'Even by In Phase Standards this is unprecedented, unique and absurdly amazing. Passive Radiator technology in this application just makes sense. I am struggling to understand why the big players like Alpine, Pioneer, Kenwood, JVC, Focal or JL Audio haven't jumped on this trend'

Download image of In Phase Car Audio XTB-828R Click here for Image of In Phase Car Audio XTB-828R
Technical Specification
  • RCA Input Sensitivity 0.2-6V
  • High Level Input Sensitivity 1V
  • Comes with Remote
  • Phase Switch 0-180 Degrees
  • Bass Boost 0dB~+12dB
  • Subsonic Filter 20-Hz-50Hz
  • LPF 50-150Hz
  • T.H.D <0.38%
  • RMS Power 200W
  • Max Power 300W
  • Signal Sense
  • Soft Delay Remote Turn on
  • Protection Circuit- Thermal and Short
  • Green LED for Power
  • Red LED for Protection Mode
  • Single Voice Coil Sub
  • S/N Ratio >88dB
  • Fuse Rating 25A
  • Impedance 4 ohms
  • Dimensions 248x255x250 (MM)
  • Weight: 8kg
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Customer reviews

Very Good
Barry on 28/06/2022 5 star rating

The bass quality is unreal, I have never seen the 2 sub system before but this makes a massive difference to the bass.

phil on 14/06/2022 5 star rating

The amount of bass this pumps out for it's size is unreal

Ian on 04/05/2022 5 star rating

Replaced my faulty SWE-815 with this, was gonna go like for like. Car audio told me to try this sub. Absolutely destroys the SWE-815.

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Fitting Services

Need help with Installation?

Here at CarAudioCentre we offer a professional and reputable fitting service in all our stores. For all fitting enquiries and bookings please visit or call one of our nationwide stores. Our fitters can install your new car stereo, DAB radio, audio visual, speakers, subwoofers or amplifier. We can also help to connect your iPod or MP3 player to you existing audio unit and can offer the best advice on the right in-car entertainment for your vehicle, to further this more we also offer a total 100% custom installation service for demo and show vehicles. So if you have an idea come on in and run it past us, the possibilities are endless and we are never too busy for an enthusiastic chat about our favourite subject.

Please note:

"That our two year warranty on products is only applicable to purchases made directly from us and that have been fitted in one of our stores."

Our Stores:

120 - 122 Alfreton Road, Nottingham, Nottinghamshire, NG7 3NR
Tel: 0115 9624 986
743-745 Eastern Ave, Newbury Park, London, IG2 7RT
Tel: 0208 599 2368
835 Garratt Lane, Tooting, London, SW17 0PG
Tel: 0208 971 9181