Most factory stereos, even premium systems, protect speakers by reducing bass output when the volume is turned up. That's OK in a stock system, but this limitation will hamper low-frequency performance if you want to upgrade your factory stereo with amplifiers and subwoofers.

The MTX re-Q senses the input level from the factory stereo, adding more bass at high volume levels, while keeping bass response balanced when the volume is low. Now you can keep your factory stereo and its steering wheel controls while truly improving the sound.

The re-Q wires up to the speaker outputs of your factory stereo, and its stereo and subwoofer preamp outputs connect to your amplifiers. You'll find individual gain controls for the right, left, and sub outputs, plus low-pass and subsonic filters for maximizing your sub's performance. A bass enhancement switch lets you kick in a little more bump if you desire.

Product Highlights:

  • signal processor restores bass when adding amps to a factory system
  • right, left, and subwoofer preamp outputs
  • low-pass and subsonic filters
  • Bass Enhance switch
  • 8-1/8"W x 1-1/16"H x 3-3/4"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

MTX re-Q Reviews

Average Customer Review:

14 reviews
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Way better than a Line Converter

Written By Bad Robot, San Diego, Ca. on Thursday, April 21, 2011

My advice to those who want to keep their OEM radio is to by this now! Maybe you
want stealth or to just keep the clean factory look of the dash as it was
intended but this little beauty will deliver great sound. I used it in a 2005
Jeep liberty with only the factory CD player (it won't even play MP3's) and a
Scosche aux in adapter. I have an iPhone and use it for all my in car
entertainment. Since this is my "spare vehicle" and sits on the street most of
the time, I wanted to minimize its break in appeal. I am only running a Legacy
(cheap) mono amp and an old 12" MTX thunder 6000 with the original stock
speakers. The bass sounds GREAT and really improves the over all listening
experience. I am going to add one to my new 2011 Dodge Nitro (keeping the Mygig)
as well.

Works great on an 09 GMC with navigation

Written By Colorblind83, Houston Texas on Sunday, December 19, 2010

Wired up a Clarion Monoblock to a 2 ohm CVR Shallow Kicker under the rear seat.
I used the handy little device and spliced into the factory left rear speaker
wire for a signal and it WORKS PERFECTLY! All i had to adjust was the crossover
portion, AWESOME PRODUCT!!! If you have a factory radio and don't want to change
it out, its too complicated, too expensive, or you just love your factory radio,
BUY THIS NOW! You won't regret it!
The only con is that the instructions are really brief, so they don't explain
all the settings clearly, but I'm sure Crutchfield would be happy to assist
anyone who buys this from them :)

Firs time purchasing a product like this

Written By KCBrian, Kansas City, MO on Friday, October 22, 2010

Crutchfield Customer Review (What's this?)

This is the firs time I 've installed a product like this. It makes the stock Infinity sound system
sound so much better. Tony in sales and Ely in tech support were so patient and great to
work with. I will be using Crutchfield again!

MTX re-Q

Written By BC, Jax, FL on Saturday, October 09, 2010

I used this to replace a cheap Scosche line out converter I used to add a sub to my Ford Shaker 500 factory system. All I can say is buy this - it was amazing to hear how much more bass I got compared to the line out converter. I mounted it to the back of my sub box for easy access to the adjustments when my back seat is flipped down. For some reason, I couldn't get the remote turn on to work, but the smart sense works, so as long as it keeps running I'll be happy.

Its soooo easy.

Written By Robert, Haughton, LA. on Wednesday, December 09, 2009

Crutchfield Customer Review (What's this?)

Well this little gizmo made my amp install soooo easy. You just run it to the rear speakers and a power source. I didnt even have to splice any wires. I'm glad I called Crutchfield for advice, thanks Dean.

FINALLY!!!! My Music is BACK!!!

Written By John, Evansville, IN on Friday, February 06, 2009

Crutchfield Customer Review (What's this?)

Once I got the unit installed properly (much love to Crutchfield Support!!) and fine tuned the controls, I was once again in audio heaven. This unit does an excellent job of restoring high and low frequencies robbed by factory installed sound processors.

Only been using it for a couple of months so I will have to wait and comment on the lifespan on the unit, so till then...... ROCK ON!!!

Pro's and Con's

Written By Thomas, Arizona on Monday, December 01, 2008

Bought this to add a subwoofer to a 2009 Mazda 3 with the factory radio.

The pro's to this product is that it did seem to do a decent job of processing/handling the bass after I got it dialed in.

There were several cons, however. First, there is no mounting hardware provided. This wouldn't be a big deal if it weren't for the fact that the unit is pretty thick and the holes that run though the silver-colored insets in the corners are very narrow - too narrow for a #8 screw and I couldn't find a #6 locally that was long enough. If you're mounting is unorthodox, MTX should provide a few screws.

Second, the "Smart Engage" feature did not work for me. This is probably 95% of the reason I purchased this unit. "Smart Engage" is supposed to
sense input and turn the unit on *and* provide a remote turn-on for your amp. This unit turned itself and my amp on as soon as the car was on. Whether the radio was on or off had no effect. This could be something odd about the Mazda audio system and how the RE-Q senses input...but it
was very disappointing that this did not work as advertised.

Would I recommend the RE-Q? Overall, probably not. If you are buying this just for the Smart Engage feature, don't - it may not even work for
you. The lack of any type of mounting hardware is inexcusable in a product at this price - I think they can supply a nickel's worth of screws. And the
directions are poor, at best.

Great idea, poor implementation.

MTX re-Q

Written By pedro, Okeechobee,FL on Sunday, October 19, 2008

Crutchfield Customer Review (What's this?)

This product sounds great. It really enhances bass output. But that is where it's praise ends. After about 4 months it shorted out internally causing it to blow fuses. Mtx replaced it under warranty a couple of months ago. Today the new one started doing the samething. So if you are considering buying this product think twice.

Perfect for Toyota w/ JBL

Written By Mark, Naperville IL on Sunday, October 12, 2008

This adds a huge performance boost to my 2008 Tundra w/ the JBL audio system. All connections can be made at the factory amp under passenger seat. I connected it to the woofer outputs from the amp, along with the WFR front signal outputs based on Toyota's wiring diagrams. No need to run ignition lead; it auto senses and provides a handy remote turn on lead for your amp.

Go For It

Written By Jay, Seattle-Tacoma,WA. on Friday, August 01, 2008

Crutchfield Customer Review (What's this?)

I brought this product because of Leased Car
MTX Has always made good products that are AFFORDABLE.
Like mentioned,It Q's your bass and works AWESOME.
Keep ur Sealth Look but amaze your friends and Family with your stock/factory deck with aftermarket sound. The unit is small too,for additional adjustments. under seat,under dash
Remember -Out Of Sight ,Out Of Thief

Works great for 12 months...

Written By Ariel, Buffalo, NY on Wednesday, June 18, 2008

Crutchfield Customer Review (What's this?)


I bought the MTX
Re-Q because its
ability to turn on
amps without the
need of a remote
signal from the
radio. Well it
worked great at
first, but after 12
months of use it
died on me. Maybe
it knew that the
warranty had

It's frustrating to
waste $150.00, yes
it is. But at least
I can share my
experience so that
people can make a
better choice.

MTX re-Q

Written By Lpfont, Louisiana on Sunday, December 30, 2007

Crutchfield Customer Review (What's this?)

I have a 03 Tundra X-Cab with a Custom Q-Logic Box with two 8" Punch Subs in it driven by a Fosgate Punch 125 watts RMS X 2 which were all purchased from Crutchfield. Using the factory radio to keep this system totally stealth it had a really good sound. The only problem was when it was turned up above half way it seemed as though the bass should be hitting harder. The answer was installing a MTX re-Q, which took care of this problem and then some. With all of the adjustments on this unit you can really add a lot of Great Clean Thunderous BASS to your system. This unit even gave me more BASS at low volume levels too. I didn't expect this much performance to come out of this product ! I had no idea that two 8" subs could produce this much BASS ! Thanks MTX for making this product and Thanks Crutchfield for telling me about it !

MTX re-Q

Written By Chris, Boston, Ma on Tuesday, June 26, 2007

This is a good product. I seen it in a MTX's Chevy Colbalt and it had it thumping 8 10" Thunger7500 right off the factory HU. Good product

Great Product

Written By Casey, outside of Memphis, TN on Monday, May 21, 2007

Crutchfield Customer Review (What's this?)

This is a really great product. It was easy to install, and it made my 10" fosgate punch and fosgate amp thump harder than ever before. Including running it off a basic after market stereo. I suggest buying this pre-amp if your running your amp off of the high output (speaker wires) jack on your amp.

Hands-on research

What's in the box?

Download owner's manual

  • Re-Q module
  • 12" Input harness
  • In-line fuse holder with 8" wire
  • Instructions

Product Research


Overview: The re-Q restores and enhances bass response intentionally removed from a factory stereo system.

Balanced Bass: Rather than just turning up the bass linearly, the re-Q senses the factory radio output and adjusts its boost level to balance the sound.

Smart Engage: An input signal sensing circuit turns the re-Q on automatically. There is also a remote turn-on input if you prefer not to use the Smart Engage feature.

Speaker Level Input: There are speaker level inputs for left, right, and subwoofer channels. The compatible input range is 250 mV to 30 V. If your factory system has no sub, the re-Q's sub output is taken from the left and right inputs.

Line Level Output: The line outputs for left, right, and sub are individually adjustable. The maximum output is 2.5 volts for the full range channels and 8 volts for the sub.

Crossover: The subwoofer crossover is continuously adjustable from 40 Hz to 200 Hz.

Subsonic Filter: The subsonic filter is continuously adjustable from 10 Hz to 40 Hz.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team. They verify what’s in the box, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.