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RE Audio BT900.4

480W RMS 4-Channel BT Series Class AB Bluetooth Car Amplifier

List price $499.99

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$257.99

with warranty

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FREE 8 Gauge Amp Kit with Select Amplifiers Purchase!

You will need an amp kit to install your amp, and the TruConnex TC4KIT-84B by Metra is the perfect kit for this amp. For a limited time, when you click "Add Both to Cart", you'll receive the amp kit for FREE. This offer cannot be combined with any other coupons or offers.

29.99

88218

1214

RE Audio BT900.4

$257.99

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TruConnex TC4KIT-84B by Metra

$29.99

Special Price $0 ($29.99 if purchased separately)

TruConnex TC4KIT-84B by Metra

• 8 Gauge Power Amplifier Installation Kit
• Ideal for Systems Up to 275 Watts
• Premium Power and Ground Wire Provides Optimal Power Transfer
• 4-Channel Twisted RCA Cables

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$257.99

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RE Audio Store

Bluetooth Sound without the Headunit

Have you ever wanted to add Bluetooth functionality to your car without opening up your dash and installing a costly new headunit? The new RE Audio BT900.4 Bluetooth amplifier allows you to do just that. This innovative 4-channel 480 watt RMS amp has integrated Bluetooth so you can stream your favorite music straight to your sound system, no headunit required. The Bluetooth has outstanding range, allowing you to stream your music from across a parking lot if you ever want to show off. An RCA input also allows the BT900.4 to be used as a traditional amplifier with your headunit. With on-board overload, short circuit, over heat and under voltage system protection, this amp will be a perfect, long term addition to your sound system. Being unable or unwilling to install a new headunit in your car is no longer an excuse to not have Bluetooth!




Sonic Electronix Power Certified Amplifier

RE Audio's BT900.4 4-channel amplifier is a Sonic Electronix Certified Amplifier. This amp's power output has been professionally tested with our SMD Amplifier Dyno, bringing you it's true power ratings. Learn more about this amp's Sonic Electronix Certified Power Here!

Impedance
Claimed Output
Certified Results
Dynamic Results
4 Ω
80 @ 14.4v
145W @ 14.77v
277W @ 14.83v
2 Ω
120W @ 14.4v
155W @ 14.83v
167W @ 14.85v
1 Ω
230W @ 14.4v
95W @ 14.87v
97W @ 14.90v



General Features:

  • BT Series 4-Channel Bluetooth Class AB Car Amplifier
  • RMS Power Rating:
    • 4 ohms: 80 watts x 4 chan.
    • 2 ohms: 120 watts x 4 chan.
    • Bridged, 4 ohms: 230 watts x 2 chan.
  • Sonic Electronix Certified Power Rating*:
    • 4 ohms: 145 watts x 4 chan.
    • 2 ohms: 155 watts x 4 chan.
    • 1 ohms: 95 watts x 4 chan.
  • Built-in Bluetooth allows you to bypass connecting with your headunit
    • Works with most Bluetooth enabled devices
    • Bluetooth Range: Up to 30 feet (10m)
    • Intelligent switching between Bluetooth® and RCA signal
    • Automatic Bluetooth® on and off
    • Bluetooth antenna included
  • Accepts Bluetooth audio signal and RCA input
  • Intelligent switching between Bluetooth and RCA signal
  • Bluetooth audio and remote turn on signals can be passed to other amplifiers
  • 4 or 2 channel operation
  • SMD dedicated audio chip device
  • Full MOSFET DC-DC PWM power supply
  • ROHS compliant production technique
  • Variable high-pass filter: 50 - 500 Hz
  • Variable low-pass filter: 50 - 500 Hz
  • Input Level : 0.2 V ~ 5 V
  • Frequency Response: 10 - 3,500 Hz
  • Sampling Frequency: 44.1 KHz
  • Radio Frequency: 2.4GHz
  • Total Harmonic Distortion: < 0.1%
  • Signal to Noise Ratio: > 90dB
  • Channel Separation: > 60dB
  • Bluetooth Receiver Sensitivity: < -80dBm
  • Overload, short circuit, overheat and under voltage protection
  • 8 gauge power and ground wiring is required for installation
    • Contact us for information regarding a discount on select amplifier kits from our website when purchased together with this amplifier
  • Dimensions: 7.4"W x 12.6"L x 2.2"H
  • Marinised version available: RE Audio BT900.4M
  • Authorized Internet Dealer
  • 1-year Manufacturer's Warranty

*The Sonic Electronix Certified Power Ratings listed are based on a test of a specific sample amplifier. Actual power ratings may slightly vary between amps.

Power Specifications - Full Range Channels

RMS Power @ 4 ohms

The RMS power rating is the measure of continuous power that an amplifier can output, or a speaker can handle. It is the most accurate depiction of real, continuous power that the industry has so far.

If the final impedance of your speakers or subwoofers equals 4 ohms, this is how much power this amplifier will supply at that ohm level. The higher the RMS wattage, the more clean and loud your music will sound.

80 watts x 4 channels
RMS Power @ 2 ohms

The RMS power rating is the measure of continuous power that an amplifier can output, or a speaker can handle. It is the most accurate depiction of real, continuous power that the industry has so far.

If the final impedance of your speakers or subwoofers equals 2 ohms, this is how much power this amplifier will supply at that ohm level. The higher the RMS wattage, the more clean and loud your music will sound.

120 watts x 4 channels
Bridged RMS Power

Bridging refers to combining two channels on an amplifier to create one channel with double the voltage and an increased power output. A 2-channel amplifier will bridge down to 1-channel and a 4-channel amplifier can bridge to create 2-channels. An amplifier is most commonly bridged to drive a subwoofer.

Remember, once you bridge two channels down to one its final impedance will be 4 ohms unless otherwise specified. This rating lists the RMS power created once an amplifier is bridged.

240 watts x 2 channels

Amplifier Specifications

Amplifier Class

An amplifier increases the power of the signal being fed to it by taking energy from its power supply and matching the signal but increasing its amplitude. Amplifiers use many different methods for converting these electrical signals and have been categorized into classes.

Class A/B: Greater than 50% of the input signal is amplified while the other percentage is “off”. These amplifiers have a small amount of current flowing through the output transistors all the time which almost eliminates crossover distortion. Class A/B has great sound quality but is not as efficient as class D. These amps are most commonly used to drive speakers.

Class D: Also known as switching amplifiers, class D amps have output transistors that are completely turned “on” or “off”. This means that when the transistors are on, there is almost no voltage across them but when they are off there is significant voltage but no current flowing through it which makes these amplifiers very efficient at the cost of sound quality. These amps are most commonly used to drive subwoofers.

Other Classes: You may see classes such as GH, bD, X, FD, etc. by some manufactures. These amplifiers tend to be either class A/B, D or a hybrid of the two but with improvements to their designs that can make them more efficient or offer better sound quality.

AB
Number of Channels
Each channel on an amplifier will power one speaker using a positive and negative cable. There are various types of amplifiers, each designed to power a certain number of speakers. Monoblock amplifiers, also known as single channel, are designed to power one or more subwoofers. These amplifiers often have very high power ratings. On the other hand, multi-channel amplifiers power multiple speakers, usually at lower power ratings. 2-Channel and 4-Channel amplifiers can power car speakers or low powered subwoofers. Occasionally you might see a 5 or 6-channel amplifier that can power speakers and subwoofers at the same time. The most common setup is a monoblock amp to run subwoofers and a 4-channel amp to run door speakers. Check out our Knowledge Base for more information.
4
Total Peak Power Output
The total peak power output is measured as the wattage per channel multiplied by the number of channels, and is calculated at the lowest level of operating impedance.

It is measured during a brief musical burst, such as a sudden drum accent. Some manufacturers display peak power ratings on the face of their products to increase the appeal.

The RMS power rating is more accurate, and we recommend using it for product comparison.

480 watts
Total RMS Power Output
Total RMS power is measured by multiplying RMS power per channel by the number of channels, and is calculated at the lowest level of operating impedance.

RMS power is the amount of continuous power, measured in watts, that an amplifier produces is called RMS power. The higher the RMS figure, the louder and cleaner your music sounds.

The RMS output figure is much more accurate than the peak rating when comparing products.

320 watts
Maximum Input Gauge Size
This is the largest gauge wire that will fit into the power and ground terminals of this device. The lower the gauge number, the thicker the wire is. For example, a 4 gauge wire is thicker than an 8 gauge wire and thus has higher current carrying capacity. Always do your best to get this size wire to reduce the risk of damage to your components.
8 AWG
Minimum Impedance Unbridged
The lowest impedance the amplifier will handle when it is not bridged.
2 ohms
Minimum Impedance Bridged
The lowest impedance the amplifier will handle when it is bridged.
4 ohms
THD at Rated RMS Power
The amount of change in harmonic content of the signal as it is amplified. A lower figure indicates less change and a more accurate amp. THD below 0.10% is inaudible.
<0.1%
Speaker Level Inputs
Speaker level inputs are commonly referred to as high-level inputs and vice versa. This input type allows you to get your audio signal directly from the speaker wire in your vehicle, instead of using RCA cables. The advantage of this is factory integration, as most stock radios do not have RCA outputs to run amplifiers.
Yes
Preamp Outputs
Many amplifiers are equipped with RCA preamp outputs which pass the original music signal from the source to additional amplifiers. This is known as daisy chaining because the source connects to the first amp, and the first amp connects to the second amp, etc. The advantage to daisy chaining is you only need one 2-channel RCA cable to transfer the signal from the head-unit to the amplifier, and then one additional cable for each amp being daisy chained.
1 pair
Built-in Crossover

A crossover is a type of filtering system that permits only certain frequencies to play. A Low-Pass (LP) crossover allows only frequencies below its setting to get through which is good in the case of some subwoofers. A High-Pass(HP) filter allows frequencies above its setting to pass through, this is normally used on speakers.

When a crossover is set to FULL it means no filtering is added and the full frequency spectrum is allowed through the amplifier. Filtering is important because feeding a speaker frequencies it cannot reproduce effectively creates distortion.

Low-pass (LP)
High-pass (HP)
High-Pass Crossover Frequency
The high-pass crossover frequency can be a fixed crossover point or a variable crossover range. A variable high-pass crossover allows you to select a specific crossover point which allows frequencies above the set crossover point to pass, while making frequencies below the set point gently or harshly roll-off, depending on the steepness of the slope.

The steepness of the roll-off slope is measured in dB/octave and refers to the rate of attenuation (lowering of volume) outside their pass bands.

50 - 500 Hz
Low-Pass Crossover Frequency
The low-pass crossover frequency is typically used for subwoofers. It can be a fixed crossover point or a variable crossover range. A variable low-pass crossover allows you to select a specific crossover point which allows frequencies below the set crossover point to pass, while making frequencies above the set point gently or harshly roll-off, depending on the steepness of the slope.

The steepness of the roll-off slope is measured in dB/octave and refers to the rate of attenuation (lowering of volume) outside their pass bands.

50 - 500 Hz
Signal-to-Noise Ratio
This spec compares the strength of the signal to the level of background noise. A higher value indicates less background noise.
>90 dB
Channel Separation
Also referred to as crosstalk. The amount of interference on one stereo channel caused by the leaking of the other stereo channel. The higher the rating in decibels (dB), the better the Channel Separation.
>60 dB
Sonic Certified Amplifier
Sonic Certified amplifiers have been tested by the experts at Sonic Electronix to meet or exceed the wattage ratings provided by the manufacturer. If this is marked as Yes, then you can trust the wattage ratings. If marked as No, then we have tested the amplifier and it did not meet the advertised wattage ratings. If marked as Not Tested, then the Sonic Electronix experts have not yet been able to test the amp.
Yes
Amp Bluetooth Connectivity
This feature will tell you if the amplifier has the capability to connect to a Bluetooth device.
Yes

Warranty and Return Policy

Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider
Manufacturer

Summary of Customer Ratings & Reviews

Rating Distribution

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Accessory Tools and Products

Accessories added

NVX XBG3PK 1/0 Gauge OFC Big 3 Upgrade Kit

Comes with everything you need to upgrade your power and ground wire.

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Kicker Big 3 Package 1/0 Gauge Big 3 Upgrade Kit

Get all you need including wire cutters to upgrade your power and ground wire.

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Belva BBG3KT CCA 1/0 Gauge Big Three Kit

Features everything needed to upgrade factory power and ground wire.

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StreetWires FB8

8 Gauge Firewall Bushing

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Distribution Block with Two 1/0 or 4 AWG Inputs and Four 4 or 8 AWG Outputs

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NVX XIV45 4-Channel RCA Audio Interconnect Cable

5 Meters (16.4 ft.) 4-Channel RCA Audio Interconnect Cable with Dual Twisted Pair Hyper-Flex Technology

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StreetWires ZN7 RCA Interconnect Cable

16.4 ft. of 4-Channel RCA Cable with hyper twist construction, oxygen free copper, and precision machined tips.

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Kicker 4-Channel RCA Audio Interconnect Cable

4 Meters (13 ft.) 4-Channel K-Series RCA Audio Interconnect Cable

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NVX XWS1225 12 AWG Speaker Wire

25 ft. of True 12 Gauge 100% Copper EnvyFlex Speaker Cable/Wire

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NVX XWS1250 Speaker Wire

50 ft. of True 12 Gauge 100% Copper EnvyFlex Speaker Cable/Wire

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NVX XWS1625 16 AWG Speaker Wire

25 ft. of True 16 Gauge 100% Copper EnvyFlex Speaker Cable/Wire

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Belva BBSW127 12 AWG Speaker Wire

12 Gauge 7 Meter (23 Ft) Speaker Wire (CCA)

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Belva BBSW167 16 AWG Speaker Wire

16 Gauge 7 Meter (23 Ft) Speaker Wire (CCA)

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The Install Bay IB-CAP1F

True 1.0 Farad Car Audio Capacitor for up to 1000W Max

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e2 ECAP1 by Scosche - Mid-Level 1 Farad

Digital 1.0 Farad Car Audio Capacitor for up to 1000W Max

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Rockford Fosgate RFC1D - Top of the Line 1 Farad

Digital 1.0 Farad Car Audio Capacitor for up to 1000W Max

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XIX2025 Strapping RCA

0.25 Meter (0.86 ft) Hyper-Flex RCA cable w/ Serpentine-Cut Nickel Plated Connectors

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SMD DD-1 Distortion Detector

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Scosche SPL Meter SPL1000F

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Browse 2 questions and 5 answers
Hide answersShow all answers | Sort by
Why did you choose this?
Sonic Electronix Store
looking for sound system for my custom car. I can stream from my phone and not have to install a head unit.
Lonnie M on May 17, 2015
to meet the audio requirements of my classic vehicle without removing the original radio.
Thomas B on Jan 11, 2015
I have been looking for a buletooth amp for a while. I seen the one you had a the 2013 show and wanted one.
Kevin R on Mar 18, 2015
Other than using my phones built in volume control is there a way of adjusting the volume on these, like an additional knob that can be installed like the JL Audio HDRLC?
Brad G on Oct 21, 2014
Best Answer: I believe the only other way to control volume would be adjusting the gain on the amplifier manually, or doing so with a knob like the one you mentioned. That knob (if I read correctly) adjusts the gain just like if you were to do it manually, though I do not know if it will be compatible with the bt900.4
Reply · Report · Brody S on Oct 21, 2014
· Add Answer · I Have This Question Too (0)

Product Summary

Manufacturer

Model Number

BT900.4

UPC

611892980686

Weight

10.00lbs

Internal SKU

bt9004

Internal Product ID

88218

Sonic Electronix Wiring Guide

Wiring Diagram Legend

Warning: The image depicted shows the resistance change when wiring multiple subwoofer terminals. Please refer to your subwoofer's owner's manual for the proper wiring of its terminals. Sonic Electronix, Inc. is not responsible for damage caused to your audio system or vehicle due to improper installation. Please call tech support at 1-877-289-7664 if you require additional assistance.

Product Name: RE Audio BT900.4

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