
Our Verdict
Pros
- Build quality
- Included fans / BTF compatibility
- Excellent fan and ARGB hub inclusion
- Vertical GPU option
- Multiple layout options
Cons
- No included GPU riser cable
Should you buy it?
AvoidConsiderShortlistBuyIntroduction, Specifications, and Pricing
be quiet! has held off from joining the fish tank style case market for quite some time, only recently releasing the Light Base 600, and a larger version, the Light Base 900. Both cases are available in their now customary DX or FX versions and are available in either black or white to suit your mood. MSRP ranges from as little as $150 for a black be quiet! Light Base 600 DX, going up to $195 for a white be quiet! Light Base 900 FX, with the extra dollars spent on the FX version going towards the included fans. The Light Base series is a first for be quiet!, featuring a dual-chamber design.
Today I have the largest of them all, the be quiet! Light Base 900 FX in for review. The be quiet! Light Base series not only allows for inverted builds, but also includes the option to mount it on its back for a more laid-down affair. So, is the be quiet! Light Base 900 FX, a Lian Li 011 XL competitor, or do be quiet! have a little more work to do? Let's find out!
| Item | Details |
|---|---|
| Model | be quiet! Light Base 900 FX |
| Form Factor | ATX Full-Tower |
| Dimensions | (D) 532mm x (W) 327mm x (H) 484mm |
| Weight | 16.8kg / 37.03lbs |
| Materials | Steel, Plastic, Tempered Glass |
| Color | Black or White |
| Motherboard support | Mini-ITX, Micro-ATX, ATX, XL-ATX, E-ATX |
| BTF Motherboard Support | ASUS, MSI, GIGABYTE |
| Cooling Compatibility | Top: 3x120mm / 3x140mm or 120mm / 140mm / 240mm / 280mm / 360mm / 420mm Radiator | Rear: 1x 120mm / 1x 140mm (Included) or 120mm / 140mm Radiator | Bottom: 3x120mm / 3x140mm or 120mm / 140mm / 240mm / 280mm / 360mm / 420mm Radiator | Side: 3x 120mm / 3x140mm (Included) or 120mm / 140mm / 240mm / 280mm / 360mm Radiator |
| ARGB / FAN Hub | 5 Port Fan Controller (Pre-Populated) |
| Drive Support | Behind Motherboard: Max 2x 3.5"" HDD (1x scope of delivery) or Max 6x 2.5"" SSD (4x scope of delivery) Optional additional sled available seperatley |
| Front I/O | Power, Reset, USB 3.2 Type-A x2, USB 3.2 Gen 2 Type-C x1, Headphone/Mic Combo Jack, ARGB control |
| CPU cooler height (max.) | 190mm |
| PSU Length (max.) | 225mm |
| GPU Card Length (max.) | 495mm |
| Warranty | 3 Years |
Packaging

My review sample arrived looking like it had a bit of a rough journey to get to me. The packaging is a little beat up, but hopefully, everything will be fine once we get it open. The front of the packaging shows off the case from a front angle with text to denote the FX version of the be quiet! Light Base 900.

The back of the box is similarly damaged, and it's here that you see the alternative stance that the be quiet! Light Base 900 FX can be flipped into. The sides of the packaging feature print around some of the case specifications and further information about be quiet!

Best Deals: be quiet! Light Base 900 FX

Removing the packaging, thankfully, the case appears unharmed from transit. The case features standard top and bottom foam protection and is surrounded by a clear plastic bag for added cleanliness.
Outside the be quiet! Light Base 900 FX

The be quiet! Light Base 900 FX reveals itself with the packaging all removed and the accessory box still firmly tied into place. The accessory box includes some zip ties and mounting screws; it's a fundamental but competent inclusion that is pretty standard across the whole be quiet! range.
As the FX version, it includes four 140mm Light Wings fans. Don't underestimate the size of this case either; it's quite large and will take up a lot of desk real estate, but it looks amazing, and I can't wait to see more. Three of the side-mounted fans have reverse blades, keeping the aesthetic clean, and all the fans are PWM controlled. The be quiet! Light Base 900 FX can cater to a total of 10 fans, making it suitable for a wide range of setups and configurations, and also includes support for BTF motherboards.
Our Latest Mid-Tower Cases Review Coverage

Moving around the exterior, let's start at the top. The Light Base series includes LED strips along the top, front, and bottom of the case, with a total of 172 individual LEDs in the be quiet! Light Base 900 FX. The top also includes a backlit be quiet! logo in the silver strip of the case, and a large removable top panel that is secured using a captive thumb screw on the rear.
Removing this panel provides access to the top fan bracket, which can be removed from inside the case, as we will see later. The panel also includes a full coverage fine mesh dust filter that can be popped out of the casing for ease of cleaning.

Around the back, you can see that this full-tower is a dual-chamber design. The PSU bay is located to the left, with the motherboard IO in the middle, and a 120mm or 140mm fan mount to the right. The fan mount does include some vertical adjustment for lining up with an air cooler on the CPU. Below this, the 8-slot PCIe bracket is removable, to allow it to be repositioned for a vertical GPU mount; however, no riser cable is included. It is here that you can see all the captive thumbscrews for the top, bottom, and both side panels.

The rear side panel, although it may appear plain at first glance, actually includes a full-coverage dust filter for the entire panel. This filter, the same as the top, can be removed for cleaning. Looking a little closer, you can see four rubber pads that cover the mountings for the removable feet, should you want to lay this case on its back. The feet are simply twisted 90 degrees to unlock them, and can then be re-secured either on the top panel for an inverted layout, or here in the locating holes for a laid down system.

The front of the case includes the IO, with a power button, a USB 3.2 Gen. 2 Type-C, two USB 3.2 Type-A ports, a reset button, a combo audio jack, and an ARGB control button, should you want the case lighting to be a standalone feature. There is no labeling here, but given the included IO configuration, it is not required.

Finally, before we move inside, let's look underneath. The bottom of the case is identical to the top and includes a whole coverage dust filter. By making them identical, flipping the case for an inverted layout will have no external changes, which is a great idea. The feet feature rubber pads that provide a good grip on table surfaces, preventing slippage. Note that there is another backlit be quiet! logo here, again the same as the top to provide the same lighting if the case is indeed inverted.
Inside the be quiet! Light Base 900 FX

I've removed the tempered glass side panel so we can have a good look around here. The front glass panel can also be removed by unscrewing two Phillips head screws, making building and maintenance more straightforward to access. All included cable grommets are color-coded, as is all the internal wiring. Good job, be quiet!
The be quiet! Light Base 900 FX also includes a handy GPU anti-sag bracket that features both vertical and horizontal adjustment, and it can also be angled to work in a variety of builds. Why more manufacturers don't offer such a robust solution is beyond me, and it's these little areas where attention to detail is key.
The recessed side can be used for fans, or perhaps a distro block, should you decide to water cool this case; it lends itself to it very well, and given the space provided, would be an ideal base for a high-end water-cooled system.


At the top of the case, with the external cover removed, you can see the removable fan and radiator bracket. Two captive thumbscrews hold this in place with nice, large openings above for airflow, with only bracing splitting this area up. The bottom features more of the same, nothing too fancy, just clean, functional, and simplistic.

Another quick look at the GPU bracket, with side-mounted grommets above, to the recessed area for the side fans. The GPU bracket is also not located on the main motherboard tray; an extension panel is fitted to give more cable pass-through options and allows for significant height adjustment on the bracket.


Now let's look around the back. Featuring a hinged 2.5" SSD tray, the rear of the be quiet! Light Base 900 FX has a fair bit going on. To the left is the side fan mount, and circling to the top, there is a 6-port ARGB hub. Plus, be quiet! has done the right thing here; they have also included 6 PWM ports too!


There is then the PSU that sits behind the motherboard tray cutout, with a dual HDD caddy below. This caddy can cater for a combination of 2.5" or 3.5" drives, but only 1 sled is included. Moving to the bottom, we have another ARGB/fan hub, the same as the top. Both fan hubs are SATA powered, and having a total of twelve connections is fantastic. The rear also features a good number of tie-down points, pre-installed Velcro ties, and a good-sized cutout for CPU cooler mounting or maintenance while in the case.
Installation, Testing, Finished Product, and Final Thoughts
Kris' Test System Specifications
| Item | Details |
|---|---|
| CPU | AMD Ryzen 5 9600X (Buy at Amazon) |
| Motherboard | MSI MAG B850 Tomahawk MAX WiFi (Buy at Amazon) |
| GPU | ASUS Prime GeForce RTX 4070 Super OC (Buy at Amazon) |
| RAM | Corsair VENGEANCE DDR5 16GB (2x8GB) (Buy at Amazon) |
| SSD | Corsair MP700 Elite 1TB (Buy at Amazon) |
| Cooler | be quiet! Dark Rock Elite (Buy at Amazon) |
| Power Supply | be quiet! Dark Power 13 1000W (Buy at Amazon) |
| Monitor | Acer VG272U V3 (Buy at Amazon) |
| OS | Microsoft Windows 11 Pro (Buy at Amazon) |

I have built in a lot of be quiet! cases over the years, and I do mean a lot. The build quality from be quiet! has always been exceptional, regardless of whether it's their entry-level case or their flagship model. Adding to that, the build experience was just as good; it's just more convenient when you have access to decent-sized cutouts with nice, rounded edges for running cables through, or a layout that just makes sense. Color matching between the metal and plastic is good, and the paint finish is well presented across all areas.


The rear of the case is spacious, and while our test system doesn't take up too much room, you could pack a hell of a lot more into the space provided. There is also the option to remove the drive sled from the back, providing more space if you have a lot of cables, which helps tidy everything up.
The system I have built for testing includes an AMD Ryzen 5 9600X CPU housed in an MSI B850 Tomahawk Max Wi-Fi Motherboard paired with two sticks of 16GB Corsair Vengeance DDR5-6000. Our CPU is kept cool using the be quiet! Dark Rock Elite. For storage, I am using a Corsair MP700 Elite 1TB NVMe M.2 drive. Finally, for graphics, I have an ASUS Prime RTX 4070 12 GB Super. Testing is completed with PBO enabled, AXMP1, and MSI Smart fan configuration.
All testing was completed using Aida64 Engineer's System Stability Test v7.65.7400 for 2 hours. Other software used was HWiNFO 64 v8.28-5770, TechPowerUp GPU-Z v2.66.0, and CPU-Z v2.15.0 x64.

With the included fans in their stock configuration, there is positive pressure within the be quiet! Light Base 900 FX. Air enters through the rear side panel and is exhausted out of the rear after passing through the CPU cooler. Temperatures for today's review, with an ambient of 28C, came in with the CPU running a maximum of 78C and averaging at 75C. Moving on to our GPU, the ASUS Prime RTX 4070 12 GB Super hit a high of 75C and an average of 73C. These results put it as one of the best cases I have tested here at TweakTown so far, and given the amount of airflow the case has to offer, it's no surprise either.




Should you buy a be quiet! Light Base 900 FX then? If you are looking for a case with great build quality, great performance, and a good paint finish, I would undoubtedly say yes. Add to that, it is spacious and easy to build in, is versatile for a range of configurations, and includes not just one, but two ARGB/fan hubs.
Then, well, I think you get the idea; it's just a damn good case and one you certainly shouldn't ignore, even if you have your heart set on the Lian Li equivalent.






