In this article: I’m going to unbox and review JL Audio’s 12TW3 slim subwoofer. I’ll go through some of the core features that I think are important and what makes it a great choice for a low profile subwoofer.
JL Audio’s TW3 Slim subwoofers have been part of our list of the best slim subwoofers for a while. I’ve used these in a couple of closely spaced installations but never got around to putting together a full description. It just so happens that I recently made a custom stereo for a 2021 Ford F-150 and chose the 12TW3-D4 for the under-rear seat.
The TW3 series was announced a decade ago. crazy to think Even 10 years after their initial release, I still think they are some of the most competitive and best performing flat subs out there. The lineup consists of 10″ and 12″ subwoofers, each with a 4 ohm and an 8 ohm version.
So in this review, I’m going to unbox a 12TW3-D4 for you and walk you through some of its key features. I’ll describe some of the key components that made this subwoofer such a well-rounded, low-profile subwoofer, even after a decade on the market.
Unpack & first impression
Unboxing a TW3 isn’t really much to talk about. These subwoofers speak for themselves in terms of performance and I think JL was aware of that when designing the packaging. It’s a fairly basic package with little detail about the contents. As soon as you open it for the first time, you’re greeted with a few pamphlets, manuals, etc. and molded styrofoam to protect the sub
This particular subwoofer was purchased from Crutchfield. I always like to give Crutchfield a call and recommend them as your starting point when looking for car audio products like this subwoofer. They have experts on call and chatting if you have questions, a great fitment guide to tell you what fits and what doesn’t, and competitive prices too. If you haven’t already, take a look at this subwoofer along with all the other serious slimline subwoofers on the market Crutchfield’s subwoofer product category.
What’s in the box
Like the outside of the box, JL keeps it simple inside with the components. Here is a list of the items you will find in the box of a 12TW3 sub:
- A 12″ thin line subwoofer
- operation manual
- Voice coil connection warning
First, let me list some of the high-level specs that are pretty standard when looking for a subwoofer like this:
- It’s only 3 ½ inches deep
- It has an X-max or linear deflection of 0.6 inch in one direction
- It is designed for 125 to 400 watts RMS
- This particular model is the dual 4 ohm voice coil, but there is also a dual 8 ohm model
- It has a cast alloy frame/basket
- The frequency response is between 22-200 Hz
- Its sensitivity is 84.11 dB
Tab Ear Design
Now that the specs are out of the way, let’s talk about some of the cool and innovative features that you probably won’t find on many (if any) other low profile subwoofers on the market. If you do, you may be infringing on a JL patent!
Starting with what JL calls their “Tab Ears,” this is one of the unique features that lends itself very well to the flat, tight spaces. On the sub’s outer ring, you’ll notice four tabs and four pairs of screw holes. This differs from the traditional subwoofer outer ring, which has mounting screw holes along the entire edge.
What I like about it is that it significantly reduces the outside diameter of this sub left to right and top to bottom. This is ideal for installations that are limited in terms of the length and width of your enclosure. JL calls the diameter (excluding the tab ears) the “small diameter” and it’s only about 12.5″. You can throw the tabs in the corner of the case, and theoretically the mounting surface only needs to be 12.5 inches square to mount these subs. Compared to a traditional 12.75 or 13 inch + OD rounded sub, this makes a world of difference. Great design and has actually influenced the design of some of the boxes I’ve personally made. Including the F-150 enclosure that this subwoofer will be built into!
Surround, Cone & Dust Cap
If you look inward from the tabbed ears, you’ll find a thick rubber rim attached to a mica-filled polypropylene cone. Nothing major to note here, other than that the rubber appears noticeably thick and durable compared to many other subwoofers I’ve tested and seen.
I think the most important aspect to highlight here is the design of the aluminum dust cap. The oversized dust cap in the center of the cone is actually an integrated heatsink. It is designed to pull heat away from the inner voice coil through a series of vents built into the inner cone behind the dust cap. As the cone moves up and down, it essentially pulls air into the subwoofer, through the back of the dust cap, and then back out.
Obviously, heat is a big component for subwoofers, so I thought it would be a smart design to use the dust cap design as an additional heat sink to disperse the heat without adding components that would ultimately increase the overall depth of the woofer.
Concentric tube design
Turning the subwoofer on its side you can really get a feel for how flat it is. It’s so thin (3.5″ installation depth) that even the width of my fist is wider than it is deep. In general, you can use your fist as a good yardstick to determine whether or not these subwoofers will fit in a tight space.
The way JL is able to make this subwoofer so flat is through a design they call “Concentric Tube Suspension Technology”. This is really at the heart of the TW3 design. It essentially allows the subwoofer spider to be much lower and closer to the surround that sits on top of the subwoofer. In fact, if you look inside the subwoofer from behind, you can see that the spider is on the outer edge of the subwoofer on the outside of the dust cap.
And by placing the spider on the outside of the subwoofer, it leaves plenty of room inside for a larger voice coil and most importantly, the subwoofer’s actual motor/magnet. If you turn the subwoofer over and look at the back, you’ll notice that there isn’t a large magnet sticking out. It’s actually positioned between the spider and the dust cap, so JL can still pack a powerful motor and voice coil for some serious performance.
Another interesting fact about this design, JL claims that the cone’s stroke can reach up to 2.15 inches. This means that the highest and lowest points that the cone passes through can reach more than 2/3 of the total depth of the subwoofer. Really impressive and this stat shows me how much air they can move.
Sticking to the tight space theme, JL knew that these subs would not only go into shallow areas, but generally tight spaces with limited volume for an enclosure. So it’s worth highlighting a few stats that are important if you decide to buy one of these:
- Sealed Enclosure: If you build a sealed enclosure to house this subwoofer, it only takes up 0.75 cubic feet of volume.
- Ported Case: If you are interested in building a ported case, you can also do so in a case that is at least 0.95 cubic feet.
Both are significantly smaller than, say, the W6, which has sealed and ported case requirements of 1 and 1.3 cubic feet, respectively.
How does it work?
In terms of performance, I really think there are very few low profile subwoofers that can match the TW3 for a comparable installation depth. I have heard, installed and fitted these to my own vehicles. Volume is great, not great JL W6 but super impressive for a 3.5″ deep subwoofer. A 12 in my F-150 was the perfect choice for a well-rounded system that can bump when I wanted it without distorting. Clarity is one of the powerful traditional subwoofers I’ve heard.
I’m a big fan of the TW3 design and performance. The price is high but it’s a great example of you get what you pay for. The Concentric Tube design still impresses me 10 years after its release.
To put this in perspective, if you compare some of the specs to JL Audio’s W6 subwoofer (another fantastic subwoofer that makes our list of the best component subwoofers), the TW3 is half the depth of the W6. The W6 has an excursion rating of 0.75″, while the TW3 has an excursion rating of 0.6″, meaning that although the TW3 is nearly 4″ flatter than the W6, it sacrifices only 0.15″ of linear excursion Has. Now I’m not comparing the performance between the two. But I do point out how efficient the TW3 design is in terms of how much air the cone can move!
All in all, if you’re looking for a trustworthy, reliable, powerful, low-profile subwoofer, and really just want one in the back of your truck or sports car, the 12TW3 will be one of, if not still the, best choice out there.