XTZ SUB 12.17

Subwoofers are very specific products. It might seem that the market was dominated by speakers manufactures, but this is not entirely true. Specialized companies often offer much more interesting, more powerful subwoofers than those which can be found in catalogues with common speakers. What do we want when choosing a subwoofer? Obviously - it has to be big, powerful and able to bring out frequencies which will significantly extend the capabilities of our stereo or home cinema system. And that's what XTZ SUB 12.17 is.

XTZ company is not specialized only in the production of subwoofers. In its offer you can find a lot of different kinds of devices like speakers, headphones and amplifiers, or even professional room acoustics measurement systems. The company was founded in 2004 by Olle Eliasson, who has been working with music and hi-fi system since he was thirteen. On the company's website, we won't find much bragging or stories of revolutionary technologies that were born when Olle Eliasson watched the aurora borealis or was winding transformers in his basement. None of that prattle in fact. XTZ has a typically technical and professional approach.

Swedish equipment offers more for less, due to good projects, large-scale production which lowers the cost per unit, and cooperation with renowned partners from Europe, Asia, and USA. An important factor that allows to reduce the final price is also a short distribution chain. In a typical model, the device must visit several places before it can come to our living room. Each of the middlemen gets their margin of course. In XTZ's business model, there are only three stages - a factory, a shop, and customers' home. The equipment can also be ordered on the manufacturer's website. You can try it out, and if you don't like it - return the box and get your money back. The idea is very modern, but apparently it works perfectly well.

XTZ SUB 12.17
From the first moment you see it, you know to take the SUB 12.17 seriously.

Design and functionality

Reviewing XTZ's offer of speakers and amplifiers, I quickly came to conclusion that its engineers don't spread themselves too thin, but create what most customers are looking for. Similarly, the described model came to our editorial office in a box the size of a comfortable chair with plastic handles to facilitate its transport. SUB 12.17 may not be the biggest subwoofer I've ever reviewed, but I needed to sweat a little to set it in the room. And it's not the most impressive nor the most expensive model among XTZ's subwoofers. We can choose one of three color versions - black piano, white, and matte black - all at the same price. The quality of the finish made a very good first impression, as you can probably see on the pictures.

Many manufacturers of subwoofers try to reconcile the requirements of modern housing with the fact that subs are not so small by their nature. This is why we are seeing more and more subwoofers equipped with 14-16 cm drivers or even flat boxes hung on the wall. Apparently XTZ's designers don't accept such compromises. In their opinion, a subwoofer should be big and there is no point fighting with this fact. However the possibility to customize the sound and adapt it to your system and room acoustics is another issue. Here the company did a great job. On the rear panel, we have two RCA inputs, a balanced input and output for connecting another subwoofer. There is also a three-pin IEC power connector, the mains switch, and diagnostic socket. At the top of the aluminium rear panel, there are three knobs, three switches, and a small LED indicating that the device is active. We can set the cut-off frequency (40 - 160 Hz), phase (continuously adjustable in the range of 0-180 degrees) and volume by these potentiometers. Switches are used to select the active mode (automatic or always-on), deactivate the low pass filter and choose one of three settings of the built-in equalizer.

But this is not the end of XTZ's features list. At the front, there are two bass-reflex ports, in addition to the 12-inch driver with the very rigid diaphragm and wide suspension. From the outside, the tunnels look the same, but they have been tuned to different frequencies. Two sponge plugs are included in the box, so we can use them in any configuration. Manufacturer even gives us a simple chart showing what happens when we close the left or right port, or both. So finally, we have four options, of which perhaps one works best in our system. Combine this with tree settings of built-in equalizer and you have 12 different configuration options, and all this without the use of complex microphone calibration systems.

Cons? At the bottom of the subwoofer, there are four rubber feet or rubber spikes to be exact. We can remove them and screw other, higher spikes in their place, but unfortunately these are not included so if you have a thick carpet, you have to buy them on our own. Advantages? The overall quality, a grille which won't fall off even when the situation gets extreme, a great set of adjustments and a very reasonable price. €645 is a really fair deal for such a device.

XTZ SUB 12.17
Everything you would expect from a subwoofer for this price, or actually a bit more.

Sound performance

During the first listening session, I allowed myself to perform a power test to check the bass range. Let's be honest, when we buy a subwoofer, we want to examine how big and deep the bass can be, as soon as possible. Later we reduce the volume to a decent level and test the settings so that the new device fits into the whole hi-fi system. First listening session resolved all doubts - XTZ is immensely powerful! The bass boomed hugely, with the cut-off frequency about 100 Hz and the power set to maximum. Despite the obvious overkill, the bass remained well controlled, relatively fast, and precise. Of course, I noticed the gentle boost - the result of leaving both ports open, but this time I didn't want to check the linearity or the 'propriety' of the Swedish subwoofer, but its dynamic abilities. So let me sum this up quickly - even the owners of good floorstanding speakers should not be disappointed by the power and depth of SUB 12.17. My trousers were shaking, headphones placed on stands were moving, and after a few minutes, even acoustic panels on the walls were starting to resonate. Thus, I learned what I wanted to know - XTZ is a mighty sub. Now I can examine its sound more carefully.

For a long time I wondered whether I should start from tunings knobs and switches, or maybe clogging the ports on the front. I decided to look at the graph and implement the most audiophile option in order to get the widest bandwidth with maximum linearity. The switch of the equalizer was set to the reference position, the left port remained open, and the right one was closed with the foam insert. After this, I had to adjust the cut-off frequency, gain, and phase. I must admit that this configuration appealed to me instantly. The sub stopped roaring and thundering, and started to purr gently, adding some deep bass where the main speakers' abilities ended. After a few adjustments, I turned the volume of the sub down a bit and listened to a dozen songs from our playlist. In some of the calm songs, XTZ reminded me of its existence only by a gentle, pulsating, but also very, very low bass. But when the music was faster and louder, the sub immediately began to show its power, without exaggeration. Again I felt a very good reaction speed, which is so important in the music where rhythm and timing matters most.

During the first few days, I have learned that the SUB 12.17 is all that a good subwoofer should be. We have a whole package here - power, depth, speed, and even sound temperature. Its bass is not artificially pumped - it is a real, thick, and fleshy sound we all like. So I changed the equipment and continued adjusting the sub to the sound of the main speakers. It lasted several weeks, during which I listened to, inter alia, Albedo HL 2.2, Larsen 6, Bryston Mini A, T+A Criterion TCD 210 S, and Pylon Audio Diamond 25. With all the minor or major adjustments the sub sounded very well with all of them. My favourite configuration among all mentioned above was the one with Albedo HL 2.2 speakers as they are very dynamic and precise, but the configuration with Larsen 6 speakers was perhaps the most interesting one. Larsen's strange boxes benefited so much from the presence of a subwoofer. So I am sure that if you spend some time to find proper settings for your hi-fi system and your acoustic environment, the SUB 12.17 will cooperate with every equipment.

XTZ SUB 12.17
Three equalizer settings combined with knobs on the back are enough to tune the sub to most speakers on the market.
XTZ SUB 12.17
A clever design of two bass-reflex ports allows the user to choose one of four sound characteristics.

Build quality and technical parameters

XTZ SUB 12.17 is an active subwoofer with a single 12-inch speaker in a ported enclosure. It is powered by 500 Watt class D amplifier. The engineers paid much attention to the housing, which is made of 25-mm MDF. The panels were glued and reinforced by a few internal frames and damped with several layers of various materials. Dimensions of the enclosure are chosen so as to perfectly fit the diameter of the speaker. The driver is a high-speed unit, using a membrane with long cellulose fibers. According to the Swedish engineers, it allows to combine the rigidity with low weight, which is crucial to achieve a deep and controlled bass. Since the suspension of the subwoofer speaker must endure extreme cone excursion, it is made from Nitrile Butadiene Rubber and optimized by laser measurements. The speaker also has an aluminum coil with Airflow Maximizer Design system, resistant to high temperatures. Built-in equalizer uses a DSP, which allows you to adjust bass characteristics to our requirements and devices.

XTZ SUB 12.17
The SUB 12.17 looks very good in black piano lacquer. Black matte and white finishes are available for the same price.

System configuration

T+A E-Serie Power Plant Balanced, T+A E-Serie Music Player Balanced, Larsen 6, Bryston Mini A, T+A Criterion TCD 210 S, Pylon Audio Sapphire 31 StereoLife Edition, Pylon Audio Diamond 25, Albedo HL 2.2, Cardas Clear Reflection, Enerr Tablette 6S, Enerr Symbol Hybrid, Solid Tech Radius Duo 3.

XTZ SUB 12.17
Swedish designer don't like to mess about. Big box, big woofer, two ports on the front. No argument.


A well-designed, properly manufactured and reasonably priced subwoofer. The SUB 12.17 is able to do everything a good sub should do. It has a massive and sturdy housing, a powerful driver and amplifier, and a lot of adjustment options - both electronic and acoustic. Using the settings, you can tune the subwoofer to every speaker. XTZ can enrich our music, gently pulsating in the background and adding a concert depth to it, but with a touch of a switch, it can also become a real beast, shaking the walls when you're watching a movie. All things considered I think it will be a difficult task to find a better subwoofer at this price.

Company logo on the front just above the floor and...
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Technical data

Output power: 500 W RMS
Frequency response: 19 Hz - 160 Hz
Inputs: 2 x RCA, 1 x XLR
Driver: 12"
Dimensions (W/H/D): 39,5/40/50
Weight: 25,9 kg
Price: €645
Manufacturer: XTZ

Sound performance



Editor's rating


StereoLife Recommendation