If you've been looking into a speaker upgrade, the mtx tx665c is probably a name that's popped up more than a few times on your radar. Let's face it, most factory car speakers are pretty disappointing. They're usually made of cheap paper, have tiny magnets, and start to distort the moment you turn the volume up past a conversation level. Swapping those out for a solid set of components can feel like someone finally took the earplugs out of your ears.
The MTX TX665C belongs to their "Thunder" series, which has a bit of a reputation in the car audio world for being loud and durable. But these aren't just about raw noise; since they're a component set, they're designed to actually give you a proper soundstage. If you're tired of the music sounding like it's coming from your feet, this is the kind of setup that actually makes a difference.
What Makes These Speakers Different?
When you first open the box, you'll notice that the mtx tx665c isn't just one speaker. It's a system. You've got the 6.5-inch woofers, the separate silk dome tweeters, and the external crossovers. This "component" style is a huge step up from coaxial speakers (the ones where the tweeter is stuck in the middle of the woofer).
The build quality feels substantial. MTX used a treated paper cone for the woofers. Now, some people think paper sounds "old school," but in the audio world, treated paper is often preferred because it's lightweight and very stiff. It gives you a natural sound that plastic or metal cones sometimes miss. It's backed by a pretty beefy magnet and a rubber surround, which means these things can move some air without falling apart after a few months of heavy use.
The Magic of the Silk Dome Tweeter
One of the biggest selling points for me with the mtx tx665c is the tweeter. It's a 25mm silk dome. If you've ever listened to cheap speakers and felt like the high notes were "stabbing" your ears—that's usually because of cheap plastic or hard metal tweeters. They can be really harsh and fatiguing to listen to for more than twenty minutes.
Silk domes are the opposite. They tend to be much smoother and more "musical." With this set, the highs feel airy and detailed rather than sharp and annoying. Because the tweeters are separate, you can mount them higher up on your dash or your A-pillars. This pulls the "image" of the music up to eye level, so it feels like the band is playing on your dashboard instead of down by your ankles.
Power Handling and Getting the Best Performance
Let's talk about power for a second. The mtx tx665c is rated at 90W RMS, with a peak of 360W. Now, don't get too hung up on the peak power—that's just a marketing number. The 90W RMS is what actually matters.
Can you run these off a standard factory head unit? Sure, you can. They have a decent sensitivity rating, so they'll make sound even with low power. But honestly, if you're buying these and just plugging them into a stock radio, you're leaving about 50% of their potential on the table. These speakers really wake up when you give them a dedicated amplifier.
When you feed them a clean 75 to 90 watts, the mid-bass becomes much tighter and the clarity improves across the board. If you've ever noticed your music sounding "muddy" when you turn it up, it's usually because the internal amp in your radio is clipping. Adding a small four-channel amp to these components makes a world of difference.
The Installation Process
Installing the mtx tx665c is pretty straightforward if you've done any car work before, but it does take a bit more effort than a simple drop-in coaxial. Since you have an external crossover, you have to find a place to mount that little box. Most people tuck them inside the door panels using some heavy-duty mounting tape or screws.
The crossover is the "brain" of the operation. It takes the full signal from your radio and splits it—sending the low and mid frequencies to the 6.5-inch woofer and the high frequencies to the tweeter. This ensures that neither speaker is trying to do a job it wasn't built for.
MTX includes a fair amount of mounting hardware for the tweeters, too. You can flush-mount them if you want a clean, factory look, or use the angled surface mounts if you're trying to point them directly at your ears. It's a bit of a "choose your own adventure" situation depending on how much you want to cut into your car's interior.
How Do They Actually Sound?
At the end of the day, it's all about the ears. The mtx tx665c has a very "fun" sound signature. It's not trying to be a flat, boring studio monitor. It has that classic MTX punch. The mid-bass is surprisingly strong for a 6.5-inch speaker. It's not going to replace a dedicated subwoofer, but it definitely adds some meat to the drums and bass guitars.
The mids are clear enough that vocals don't get lost in the mix. I've listened to everything from classic rock to hip-hop on these, and they handle the transitions well. If you're a fan of EDM or anything with a lot of synthesized highs, you'll really appreciate those silk tweeters—they keep the "sparkle" without making you want to turn the volume down during a crescendo.
One thing to keep in mind is that because the woofer cone is treated paper, it might take a few hours of playing time to "break in." Right out of the box, they might feel a little stiff, but after a week of commuting, the suspension loosens up and the bass gets a bit deeper and smoother.
Is It Worth the Upgrade?
If you're still rocking the speakers that came with your car from the factory, then yes, the mtx tx665c is a massive upgrade. It's a mid-range set that punches a bit above its weight class. You aren't paying the "boutique" prices of some high-end European brands, but you're getting a much more refined sound than the "budget" stuff you find at big-box stores.
The main reason to go with this specific model is the balance. MTX managed to make something that's tough enough to handle being cranked up on a highway with the windows down, but refined enough that you can actually hear the subtle details in a well-produced track.
A Few Tips for the Best Experience
To really get the most out of your mtx tx665c set, I'd highly recommend doing two things during the install. First, use some sound-deadening material on your doors. Even a little bit of butyl rubber matting around the speaker hole will stop the metal from vibrating and make the bass sound twice as punchy.
Second, make sure your phase is correct. If you wire one speaker backward (swapping positive and negative), your bass will completely disappear. It's a common mistake, but if you double-check your connections at the crossover, these speakers will reward you with a really solid, centered sound.
Final Thoughts
It's easy to get lost in the weeds with car audio specs, but the mtx tx665c keeps things pretty simple. It's a well-built, reliable component set that fixes the biggest problem most car systems have: lack of clarity and weak bass.
Whether you're just starting your audio journey or you're looking for a reliable replacement for a blown set of speakers, these are a solid bet. They bring that signature MTX energy to the table without being overly aggressive. Just give them a little bit of power, mount those tweeters correctly, and you'll probably find yourself taking the long way home just to hear a few more songs.