In this review, we will be comparing No.36 and SPL-120, two Powered Subwoofer speakers from REL and Klipsch. 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 REL No.36 and Klipsch SPL-120 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.
Drivers
The efficiency of a subwoofer is directly proportional to the total radiating are squared hence the woofer quantity and diameter.Both REL No.36and Klipsch SPL-120 have a single woofer setup however the REL No.36's woofer is 15-inch whereas the Klipsch SPL-120 features a 12-inch woofer.
Frequency Response
No.36 has a frequency range of 15 Hz (-6dB, in room) whereas SPL-120 has a frequency range of 24-125 Hz. With a minimum frequency of 15Hz, the No.36 can go significantly deeper on the low side and provide stronger bass compared to the SPL-120's min frequency of 24Hz.
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
High Frequency
Subwoofer Speakers
Cabinet Type
The REL No.36 has a Sealed type cabinet. On the other hand the Klipsch SPL-120 have Bass Reflex type enclosure. Bass Reflex type subwoofers (aka Ported, Vented or Reflex Port) have enclosures that uses a port, hole or vent cut into the cabinet. Ported designs are generally more efficient than the Sealed 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 REL No.36's and Klipsch SPL-120's external dimensions. REL No.36 has external dimensions of 541.0 x 743.0 x 816.0mm (21-5/16 x 29-1/4 x 32-1/8inch) whereas Klipsch SPL-120 has external dimensions of 450.0 x 375.0 x 540.0mm (17-11/16 x 14-3/4 x 21-1/4inch).
REL No.36 is clearly the larger of the two speakers. Its body is 368mm wider, 91mm taller and 276mm deeper than Klipsch SPL-120.
Size, drawn to scale
Both speakers and both views share one scale, so everything here is directly comparable. Hover a box for its dimensions.
One scale for both, standing on the same surface and pushed back to the same wall, so the deeper one visibly sticks out further.
REL No.36 needs about 199% more floor or shelf area. REL No.36 is 276mm deeper, so it stands that much further out from the wall. REL No.36 is 91mm taller.
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 REL No.36 is approximately 6062.9cm2 / 939.7inch2 and base area of the Klipsch SPL-120 is approximately 2025.0cm2 / 313.9inch2. The No.36 requires 199% more surface area than the SPL-120 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 REL No.36 weighs 91.80kg / 202lbs and the Klipsch SPL-120 weighs 20.45kg / 45lbs. This makes the No.36 349% heavier than the SPL-120.
Here is a comparison of how No.36 and SPL-120's weights compare with the average, max and min weights in Powered Subwoofer class.
Weight
All Subwoofer Speakers
What's in the Box of REL No.36?
Here are the items that are included inside the box of No.36:
- Subwoofer
- Grille
- 6 ft AC power cord
- 32 ft Neutrik Speakon cable
- User manual and warranty information
- Reference remote
- 2 AAA batteries
- Line Array mounting hardware
What's in the Box of Klipsch SPL-120?
Here are the items that come with the SPL-120:
- Powered sub
- Grille
- 6.5-feet AC power cord
- User Manual
- Important Safety Instructions
- Warranty Information
 Woofer Size |
15 inches
vs
12 inches
|
Larger woofer |
| Low Frequency Response |
15 Hz
vs
24 Hz
|
Generates deeper bass |
 Handheld Remote |
Yes
vs
No
|
Control the speaker by the included RC |
 High Frequency Response |
125 Hz
vs
Hz
|
Generates higher frequency |
 Height |
450mm
vs
541mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
2025cm2
vs
6062cm2
|
Takes less floor space |
 Price per pair* |
499USD
vs
12000USD
|
costs less (*prices may change depending on the seller, location and time) |
Size, drawn to scale
Both subwoofers and both views share one scale, so everything here is directly comparable. Hover a box for its dimensions.
One scale for both, standing on the same floor and pushed back to the same wall, so the bigger one visibly takes more of the room.
REL No.36 needs about 199% more floor area. REL No.36 stands 276mm further into the room. REL No.36 is 91mm taller.
| General |
REL No.36 |
Klipsch SPL-120 |
| Brand |
REL |
Klipsch |
| Speaker Type |
Powered Subwoofer |
Powered Subwoofer |
| Max Amplifier Output |
1000 watts |
300 watts |
| Frequency Response |
15 Hz (-6dB, in room) |
24-125 Hz |
Amplifier |
|
|
| Watts RMS (Continuous) |
1000-watt RMS |
300-watt RMS |
| Watts Peak (Max) |
n/a |
600-watt RMS |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
15" |
12" |
| Woofer Composition |
Carbon fibre |
Cerametallic |
| Tweeter Size |
- |
- |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Firing Direction |
n/a |
front |
Physical Specs |
|
|
| Height |
541.0mm (21.3") |
450.0mm (17.7") |
| Width |
743.0mm (29.3") |
375.0mm (14.8") |
| Depth |
816.0mm (32.1") |
540.0mm (21.3") |
| Weight |
91.80kg (202lbs) |
20.45kg (45lbs) |
| Enclosure |
Sealed |
Bass Reflex |
| Finish |
Piano Black Lacquer, 12 coats |
n/a |
| Available Colors |
Black |
n/a |
| Grille |
Yes |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
Other |
|
|
| Parts Warranty |
|
2 Years |
| Labor Warranty |
|
2 Years |
A sealed subwoofer against a ported one. That is the most consequential line on this page: it decides how the bass rolls off, how it behaves in a small room, and how much output you get for the size of the box.
| Area | Better | Why |
|---|
| Bass depth | A | REL No.36 goes deeper - 15Hz against 24Hz. Under 20Hz is felt more than heard - the bottom of a pipe organ and the bottom of a film mix. |
| Amplifier power | A | REL No.36 has the bigger amplifier - 1000W against 300W RMS, about 5.2dB more on tap. In a large room that is headroom before the DSP starts limiting. |
| Driver area | A | REL No.36 moves more air: 15" against 12" is 1.56x the cone area, not the 1.25x the diameters suggest. More area means the same output with less excursion, and less distortion with it. |
| Enclosure | depends | REL No.36 is sealed - a sealed box rolls off gently and is usually the easier one to integrate in a small or awkward room; Klipsch SPL-120 is ported - a ported box gives more output low down for its size, at the cost of a steeper roll-off below tuning. Neither is better in the abstract; ported tends to suit films and sealed tends to suit music, and both generalisations have exceptions. |
| Speaker-level inputs | A | REL No.36 takes a speaker-level connection as well as line level. That is what lets it work with an integrated amplifier or a vintage receiver that has no subwoofer output at all. |
| Cabinet size | depends | Klipsch SPL-120 is about 72% smaller by volume. In a subwoofer that is a real trade rather than a preference: box volume is how you get output low down without a bigger amplifier. |
| Price | B | Klipsch SPL-120 costs less - $499 against $12,000, about 96% less. |
A REL No.36 B Klipsch SPL-120
depends neither is better in the abstract - it turns on your room, your system or how you will use them. Only specs published for both subwoofers are judged; anything missing on either side is left out rather than guessed.
Which should you choose?
The usual trade-off: REL No.36 measures better, Klipsch SPL-120 costs about 96% less. In a normal room, placement will make a bigger difference than the gap between these two. Films or music? If this is mainly a home cinema, Klipsch SPL-120 will hit harder for the money; if it is mainly for music in a normal-sized room, REL No.36 is usually the easier one to make sound right. Check your amplifier first: if it has no subwoofer or preamp output, REL No.36 is the only one of these two you can connect at all.
One thing outweighs everything above: where the subwoofer stands. Room modes can add or remove 10dB or more at a given seat, which is far larger than any difference on this page. Before spending more, try the sub in two or three positions - the crawl test, where you put it in the listening seat and crawl the room to find where the bass sounds best, costs nothing and usually beats an upgrade.