For when you just have to have that rumble

In pretty much any setting, a 15” woofer is serious stuff. Home theatre subwoofers of this size are usually overwhelming, even in large rooms. Imagine what happens when you put one in a car, and you’ll understand why this subwoofer is not for everybody.

While the comments provided here relate to my experience with the T8154 subwoofer, they can be generalized to apply to any good 15” subwoofer, and their general performance will be within the same realm; it’s in the details that the subwoofers differentiate themselves.

First off, I should say that if you plan on installing only one subwoofer in your car, a 15” woofer such as this one is not necessarily the best way to go for a few reasons.

For one thing, it’s big, and its box requirements will be larger than that of a 10” or 12” woofer. The Thunder 8000 series is quite good in this respect however. I was able to install my 15” in a custom-made box with about 60 liters (just over 2 cubic feet) of airspace and it performs well. Some competing 15” subwoofers require as much as 6 cubic feet of airspace to function properly. The lower space requirements of the T8154 is one of the reasons that I chose the MTX. But be aware that 2 cubic feet will eat away at your trunk substantially.

Also, a 15” woofer is most suited to reproducing extremely low bass frequencies. I don’t mean the boom in rap music on the punchy bass in dance or techno. I’m talking about rumbling bass of timpani in a classical music performance, or that of an explosion or similar event. We’re talking bass that you can feel and that makes your car rattle from within. If you get the chance to listed to a THX demo (especially the Jurassic Park one) on a car equipped with a correctly-installed and powered 15” or larger woofer, you’ll understand perfectly. This characteristic of large-cone subwoofers can be a great asset or a big nuisance depending on the rest of your audio system. If you do not have any other woofers, you will be missing audio information in the upper bass frequencies, such as some bass guitar notes same drums. A large woofer is not entirely suited for reproducing such defined bass notes, as it’s moving mass is simply too large.

If however, like me, you have other woofers to cover the upper bass frequencies, the addition of a 15” subwoofer will dramatically fill the bottom end of your audio spectrum, and will make your listening experience that much more enjoyable.

Finally, large speakers like the T8154 require a lot of power to function optimally. In the case of MTX, the maximum continuous power handling is 500W. I would suggest sticking as close to that figure as possible. Virtually all MTX products are underrated, so I’d venture out to say that the T8154 would be able to handle more than 500 RMS Watts, but your mileage may vary.

Looking at the MTX specifically, we have a very heave subwoofer with a cast iron basket frame (not made of stamped steel like other subwoofers), and handy spring-loaded nickel-plated binding posts. The 15” thunder comes in two flavors: single and dual voice coil. I personally own the latter. The spring-loaded binding posts will accept wire up to 10-gauge, and makes connecting and disconnecting the subwoofer a simple task that does not require any soldering. The magnet is quite hefty at 102 ounces, and the metallized cone features ridges that increase its stiffness. Mounting is via 12 screws (rather than the 8 screws typically used on 10” and 12” woofers), and a rubber gasket is included. The NBR rubber surround is quite large, and allows for a large woofer excursion.

This translates into loud, low bass. And I’m not kidding here. Feed it close to 500W of power, and you will feel its effects as much as you hear them. It can make your interior mirror move by itself (and I don’t mean vibrating. I’m talking of having to re-adjust it after playing the system loud at a sound-off or similar event) and make your loose change rattle in the ashtray. This is not the kind of bass that the entire neighborhood will hear when you come around the corner. But it will make you notice parts of music that you never heard or felt before.

As I mentioned previously, be certain to feed this woofer enough power. MTX recommends 75 to 500 RMS Watts. My recommendation is to have at least 350 RMS Watts to get good results from the woofer. Any lower, and you will most likely be disappointed. And while you’re at it, try to use a quality amplifier. There’s no sense in using a great subwoofer with a bad amplifier. And don’t forget to set your crossover points correctly. I set my low-pass at about 50 Hz.

If you’re not looking to show off your system or compete with it, the MTX Thunder 6000 is also a very capable woofer that costs less, although it lacks certain features such as the spring-loaded binding posts and has less stiffening ridges in its cone.

Either one will perform quite well filling in the extreme low end, if you currently use one or two 10” woofers. And remember that when you want to show off how loud it can go (or how it can make your entire exhaust system rattle), you should be outside the car. Equipment like this can move serious amounts of air and damage your hearing quickly.