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4" Road Thunder Extreme Series Bullet Car Tweeter

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List price $69.95

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Get 25% off Sound Dampening Speaker Kit with Purchase!

For a limited time, get 25% off of the NVX SDSK2 Speaker Kit with a qualifying pair of speakers! Sound dampening will eliminate rattles, insulate against heat, and also improve the sound and output of your speakers!







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Special Price $11.24 ($14.99 if purchased separately)


• Eliminates Road Noise
• Quiets Vibrations
• Stops Annoying Rattles
• Increases SPL
• Reduces Heat
• Simple To Install
• Peel and Stick Installation
• Two 10" x 10" Pieces

(Offer 1 of 1)

Combined Total Price


You Save $3.75

General Features:

  • 4" Road Thunder Extreme Series Car Tweeters
  • Power Handling:
    • Peak: 400 watts each
    • RMS: 200 watts each
  • 8 ohms impedance
  • Designed to provide maximum levels of SPL
  • Built-in crossover capacitor filter for smooth roll off of lower frequencies
  • Flush mountable basket design
  • Sensitivity: 97dB
  • Frequency response: 2,700-22,300 Hz
  • Top-mount depth: 2"
  • Replacement Diaphragm: RTX4BTRD
  • Authorized Internet Dealer
  • 1-year Manufacturer's Warranty

Priced Individually

Tweeter Specifications

Tweeter Size
Refers to the size of the tweeter. Typically, smaller tweeters produces less output with higher frequency response.
Tweeter Design
Designs such as cone, dome, semi-dome, balanced dome, and whizzer are most popular. Cone tweeters are simple, efficient and typically are the most reasonably priced. Dome tweeters are used in most home speakers, and provide a smoother and more accurate sound. Semi-dome design is one with a dome placed inside a cone. A Balanced dome driver is a semi-dome with equal reproduction area given the cone and dome portions of the driver. A whizzer tweeter is a separate tweeter cone driven by the voice coil of the woofer.
Tweeter Composition
Materials such as polypropylene, silk, cloth, and paper are the most common, where as many more recent tweeters are now manufactured with composites such as Aluminum, Titanium, Mylar, and other materials.

PEI is an acronym for "Polyetherimide" which is an amorphous, amber transparent, high-performance thermoplastic.

Not Specified by Manufacturer
Flush Mount
If the speaker or tweeter is flush mountable, then it can be installed flush to the mounting surface.

When installing a flush mount tweeter, make sure that there is enough room behind the mounting surface for the tweeter and magnet. Check the mounting depth with your specific vehicle.

Surface Mount
If the speaker or tweeter is surface mountable, then it can be installed to be raised above the mounting area.

When installing a surface mountable tweeters, make sure that there are no obstructions that will prevent the tweeter from being installed correctly.

Angled Mount
If the speaker or tweeter is able to be angle mounted, then the installed tweeter can be positioned at an angle. An angle mounted tweeter can improve the audible sound quality of your system.

When installing a angle mountable tweeters, make sure that there are no obstructions that will prevent the tweeter from being installed correctly.

Peak Power Handling
Peak power handling refers to the amount of power a speaker can handle during a brief musical burst. The RMS power range figure is a much more reliable rating for determining the speaker's power requirements. The Peak power handling specification is typically rated per speaker unless otherwise noted.
400 watts
RMS Power Handling
The RMS power is the amount of power the speaker requires to operate safely and properly. RMS Power Handling refers to the amount of power a speaker can handle on a continuous basis. We recommend powering your speakers or subwoofer with 80%-120% of its recommended RMS rating. The RMS power handling specification is typically rated per speaker unless otherwise noted.
200 watts
An efficiency or sensitivity rating tells you how effectively a speaker converts power into sound. The higher the number, the more efficient the speaker and the louder it will play with the same input power. An efficient speaker helps you maximize your available power. Most sensitivity ratings measure the speaker's output with 1 watt of input, 1 meter from the speaker. Some speakers' sensitivity is measured with 2.83 volts of input, instead of 1 watt.
Efficiency (1w/1m) is not an accurate indicator of a subwoofer's output capability and should not be used as a comparison to other speakers or subwoofers to determine which one is "louder".
97 dB
Frequency Response
The range of frequencies the speaker will reproduce (lowest frequency to the highest). Bigger is better, meaning the wider the range, the better. The optimal range is 20 - 20,000 Hz (which is the range of human hearing).
2700 - 22300 Hz
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.

Not Specified by Manufacturer
Impedance (Per Voice Coil)
The load value (in ohms) that the speakers present to the amplifier per voice coil - the amount of resistance to the current flow. This is a key specification as subs wired in parallel or low impedances can create problems with your amplifier and potentially void all warranties. We encourage you to ask our support department prior to purchase if you do not understand which impedance level will suit your application best.
8 ohms
Top-Mount Depth
The depth when installed on top of the mounting surface. Measured from the bottom of the speaker's magnet to the bottom of the mounting holes on the rim of the speaker.
Cutout Dimensions
Refers to the dimensions of the hole, measured in inches or millimeters, required to contain the speaker.
3-9/16" x 3-9/16" 

Specials with this Item

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Warranty and Return Policy

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

Summary of Customer Ratings & Reviews

Rating Distribution

5 Star
4 Star
3 Star
2 Star
1 Star

Average Attribution Rating


Chula Vista, CA

Turn it up till the knob break off

September 17, 2013

Highs so crisp, clear and most importantly loud.
This is for people that can't hear over the bass and speaker can't hack it. Screw the "cheap1" tweeters one off these and your straight.
Ima lil crazy and have two 4" and two 2" roadthunders and am not disappointed.
Like I said these are LOUD like a concert in the car and have ringing ears when you shut it off.
Being right in front of the screaming tweeters feels like a slap to the face! Buy 'em while they got em.
Ps. these last a long time just don't run them with out the bass blockers or you'll pop the voice coil (15$) but lasted a week of abuse only popped on max volume. And a lil acetone to rub the red paint and it'll show the nice metal finish.

14 of 26 found this helpful

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Las Vegas, NV

Great Speaker

April 1, 2015

Crisp High's! Loud too! I would recommend these! Perfect addition to our stereo!

10 of 19 found this helpful

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Ocala, FL

very nice tweeters

September 18, 2014

Great super tweeters. Sound great an very good quality for cheaper price. I also recommend the mtx 12" midrange speakers to go with some of these.

11 of 22 found this helpful

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Mexico Beach, FL

Verified Purchase
Need Power - But they SCREAM

June 28, 2015

I put these in my Z3 (that I was giving to my daughter).
Right behind the seats so the back of the seat was at best two inches from the speaker.

But they look REAL cool shining out from the back wall.

Ran 150w RMS through them and I telling you these babies make the high-hat sing when cruising down the road with the top down.

Sound a bit tinny when pumping lower juice through them but the deadening of the seat back worked that out.

Great horn for the price - make note they are 8-ohm...
Knocked them down slightly for sucking up so much juice.

Update - after nearly three years I rode in the car with my daughter today and they are still cranking crystal clear making the top down cruise so much more enjoyable.

2 of 5 found this helpful

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Yuba City, CA

pro build

September 30, 2013

I purchase 2 of these MTX tweeters built a center pod under my dash with a 6 1/2 wire it to the amp and they bring pure bliss into my system I have a set of the MTX high end components in my doors and 2 hidden MTX 10s in a center seat in my 74 Chevy truck and my system sounds amazing..its tuff fitting good sound in a truck ...I will be building a blazer soon so I stocking up with stereo stuff these tweeters now don't hesitate ....

11 of 23 found this helpful

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kotzebue, alaska

great value plus amazing sound

April 9, 2015

if you want to hear your music and not just the bass, buy these they sound amazing for the price. you will hear sounds you never heard before with very good sound quality.

4 of 10 found this helpful

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Accessory Tools and Products

Accessories added

25 ft. of 12 Gauge MTX Streetwires Speaker Cable

High quality speaker wire with twisted pair construction, and ultra flex jacket, and Streetwire's Zero-grip insulation for easy installations!

Your Price $44.95

50 ft. of 14 AWG StreetWires Speaker Cable

Streetwires Super Cable provides a zero-grip insulation for a smooth install as well as true gauge twisted wire construction.

Your Price $37.95

Dynamat 10007 Rubber Roller

Install your Dynamat with ease! This heavy duty rubber roller is designed specifically to install your Dynamat!

Your Price $19.99

Dynamat Xtreme Wedge Pak

Just enough Dynamat to install around tweeters and speakers.

Your Price $29.95

Universal Window Handle Remover

Remove your manual windows and door panels with this simple and convenient tool.

Your Price $9.99

Universal Wire Puller & Grabber

Running wires has never been easier! This wire puller allows you to run wires through those hard to reach places!

Your Price $6.99

Car Stereo and Speaker Installation Tool Kit

Includes Test Light, Crimp/Splice Tool, Multi-bit Screwdriver and more.

Your Price $16.99

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Browse 2 questions and 4 answers
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Why did you choose this?
Sonic Electronix Store
Have two up front in our boat! Love them! Going to install two more in the back!
Paul T on Feb 24, 2015
quality & price
Daniel M on Aug 24, 2014
Extra quality highs at a good price
bolingo b on Dec 19, 2014
do these have a built in crossover or will i need to get one myself?
A shopper on Aug 24, 2014
Best Answer: Hello,

The MTX RTX4BT has a Built-in crossover capacitor filter, which - in theory - will roll off at/before ~2,700Hz. Even so, we always recommend properly setting your external crossover properly (whether its on the amp or on a passive/active crossover).
Reply · Report · Customer SStaff on Aug 24, 2014
· Add Answer · I Have This Question Too (0)

Product Summary


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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: MTX RTX4BT