In this review, we will be comparing Theatrus TS15 Passive 15" Subwoofer and KUBE 8b, two Powered Subwoofer speakers from Aperion and KEF. Being Powered subwoofers, they both have built-in amplifiers so you don't need an external power amp or an integrated amp to power them. Let's have a brief look at the main features of Aperion Theatrus TS15 Passive 15" Subwoofer and KEF KUBE 8b first before getting into our more detailed comparison.
The sections below take each area in turn: driver and amplifier, frequency response, physical size and connectivity.
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Drivers
The efficiency of a subwoofer is directly proportional to the total radiating are squared hence the woofer quantity and diameter.Both Aperion Theatrus TS15 Passive 15" Subwooferand KEF KUBE 8b have a single woofer setup however the Aperion Theatrus TS15 Passive 15" Subwoofer's woofer is 15-inch whereas the KEF KUBE 8b features a 8-inch woofer.
Frequency Response
Theatrus TS15 Passive 15" Subwoofer has a frequency range of 18-400 Hz whereas KUBE 8b has a frequency range of 34-140 Hz. With a minimum frequency of 18Hz, the Theatrus TS15 Passive 15" Subwoofer can go significantly deeper on the low side and provide stronger bass compared to the KUBE 8b's min frequency of 34Hz.
Below graphs depict how these two speakers compare with the max, min and average values of the Min and Max Frequencies of other speakers in the Subwoofer class in our database.
Low Frequency
Subwoofer Speakers
Aperion Theatrus TS15 Passive 15" Subwoofer
High Frequency
Subwoofer Speakers
Aperion Theatrus TS15 Passive 15" Subwoofer
Cabinet Type
Both Aperion Theatrus TS15 Passive 15" Subwoofer and KEF KUBE 8b have Acoustic Suspension type cabinets. Acoustic Suspension aka Sealed type subwoofers have enclosures that are sealed hence no ports or holes exists on the cabinet. Sealed designs helps to provide more accurate and tight bass responses compared to ported designs.
Physical Specs
The size of a speaker can sometimes be an important decision factor due to space constraints or in some cases purely for esthetic reasons. In this section, we are going to compare Aperion Theatrus TS15 Passive 15" Subwoofer's and KEF KUBE 8b's external dimensions. Aperion Theatrus TS15 Passive 15" Subwoofer has external dimensions of 500.4 x 500.4 x 401.3mm (19.7 x 19.7 x 15.8inch) whereas KEF KUBE 8b has external dimensions of 294.0 x 296.0 x 339.0mm (11-9/16 x 11-5/8 x 13-5/16inch).
Aperion Theatrus TS15 Passive 15" Subwoofer is clearly the larger of the two speakers. Its body is 204.4mm wider, 206.4mm taller and 62.3mm deeper than KEF KUBE 8b.
Base Surface Area Comparison
Base surface area of a loudspeaker may become a determining factor when the space in your room or desk is limited.
The base surface area of the Aperion Theatrus TS15 Passive 15" Subwoofer is approximately 2008.1cm2 / 311.3inch2 and base area of the KEF KUBE 8b is approximately 1003.4cm2 / 155.5inch2. The Theatrus TS15 Passive 15" Subwoofer requires 100% more surface area than the KUBE 8b which gives it a small disadvantage on placement in tight spaces.
Weight Comparison The weight of a subwoofer may become an important factor if you need to move and reposition the unit often to find the optimal positioning, also known as 'Subwoofer Crawling'. The Aperion Theatrus TS15 Passive 15" Subwoofer weighs 35.02kg / 77lbs and the KEF KUBE 8b weighs 11.36kg / 25lbs. This makes the Theatrus TS15 Passive 15" Subwoofer 208% heavier than the KUBE 8b.
Here is a comparison of how Theatrus TS15 Passive 15" Subwoofer and KUBE 8b's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
Aperion Theatrus TS15 Passive 15" Subwoofer
 Woofer Size |
15 inches
vs
8 inches
|
Larger woofer |
| Low Frequency Response |
18 Hz
vs
34 Hz
|
Generates deeper bass |
 High Frequency Response |
400k Hz
vs
140k Hz
|
Generates higher frequency |
 Height |
294mm
vs
500mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
1003cm2
vs
2008cm2
|
Takes less floor space |
 Price per pair* |
600USD
vs
1449USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Aperion Theatrus TS15 Passive 15" Subwoofer |
KEF KUBE 8b |
| Brand |
Aperion |
KEF |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Sensitivity |
88 dB |
n/a |
| Impedance |
4 ohms |
n/a |
| Frequency Response |
18-400 Hz |
34-140 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
n/a |
300-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
15" |
8" |
| Woofer Composition |
|
|
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
40-140 Hz |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
500.4mm (19.7") |
294.0mm (11.6") |
| Width |
500.4mm (19.7") |
296.0mm (11.7") |
| Depth |
401.3mm (15.8") |
339.0mm (13.3") |
| Weight |
35.02kg (77lbs) |
11.36kg (25lbs) |
| Enclosure |
Acoustic Suspension |
Acoustic Suspension |
| Grille |
Yes |
n/a |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
|
2 Years |
| Labor Warranty |
|
2 Years |