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  1. Home
  2. Passive In-wall Speakers
  3. Definitive UIW RSS III vs Definitive UIW RLS II

Definitive UIW RSS III vs Definitive UIW RLS II Comparison

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Definitive UIW RSS III

Passive In-wall | 40-30kHz

Definitive Technology UIW RSS III
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Definitive UIW RLS II

Passive In-wall | 22-30kHz

Definitive Technology UIW RLS II
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Definitive UIW RSS III Definitive UIW RSS I...
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Definitive UIW RLS II Definitive UIW RLS I...
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Definitive UIW RSS I...
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Definitive UIW RSS III vs Definitive UIW RLS II Speaker Comparison

In this review, we will be comparing UIW RSS III and UIW RLS II, two Passive In-wall speakers by Definitive Technology.

Let's have a brief look at the main features of Definitive UIW RSS III and Definitive UIW RLS II first before getting into our more detailed comparison.

Key SpecsDefinitive UIW RSS IIIDefinitive UIW RLS II
BrandDefinitive Technology
United States · founded 1990
Definitive Technology
United States · founded 1990
Design2-way2-way
Tweeter1" Hard-Dome1" Hard-Dome
Woofer2 x 3.5" Polypropylene2 x 6.5" Polypropylene
Frequency response40-30kHz22-30kHz
Sensitivity90 dB92 dB
Impedance8 ohms8 ohms
Power range10-200 watts10-350 watts
Weight3.40kg / 7.5lbs—
Dimensions (H x W x D)9.8750" x 8.3750" x 3.8750"
251.0 x 213.0 x 99.0mm
28.5000" x 7.0000" x 3.8750"
724.0 x 178.0 x 99.0mm

UIW RSS III and UIW RLS II are members of Definitive Technology's UIW series of speakers. Below you can find the loudspeakers from this series.

Definitive Technology UIW Series History
Model Body Frequency SensitivityImpedance Woofer
Definitive UIW RLS III
  
In-wall 24-30kHz 92 dB8Ω 2 x 5.25"
Definitive UIW RLS II
In-wall 22-30kHz 92 dB8Ω 2 x 6.5"
Definitive UIW RSS III
In-wall 40-30kHz 90 dB8Ω 2 x 3.5"
Definitive UIW RSS II
  
In-wall 26-30kHz 90 dB8Ω 2 x 4.5"

What size room are the Definitive UIW RSS III and Definitive UIW RLS II speakers good for?

The size of the room in which you are planning to use these loudspeakers is an important decision factor. Here we have compared their suitability to various sizes of environments considering their size and max power parameters:

Listening Environment* Definitive UIW RSS III Definitive UIW RLS II
Near-field Poor Are you nuts?
Small Room Average Bad
Mid-size Room Good Poor
Large Room Average Good
Very Large Room Poor Good

(* Approximate Room sizes: Small < 100sq. ft / 9 m2, Mid-size: 100-220 sq. ft / 9-20 m2, Large 220-400 sq. ft / 20-36 m2, Very Large: > 400 sq. ft / 36 m2. Average Floor Height: 9" / 2.7m. Typical room sizes differ from country to country, and the actual listening experience changes depending on floor height, room shape, surface materials, listening position, speaker locations, etc.)

The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.


Drivers

Both UIW RSS III and UIW RLS II are 2-way speakers.

Tweeter - 1 inchWoofer - 3.5 inchWoofer - 3.5 inch
Definitive UIW RSS III
Tweeter - 1 inchWoofer - 6.5 inchWoofer - 6.5 inch
Definitive UIW RLS II

TweeterWoofer

Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.

Driver Definitive UIW RSS III Definitive UIW RLS II
Driver Setup 2-way 2-way
Tweeter 1-inch 1-inch
Midrange - -
Woofer 2 x 3.5-inch 2 x 6.5-inch

UIW RSS III features a 1" Hard-Dome Tweeter and 2 x 3.5" Polypropylene Woofer. On the other hand, the UIW RLS II features a 1" Hard-Dome Tweeter and 2 x 6.5" Polypropylene Woofer.

Frequency Response

UIW RSS III has a frequency range of 40-30kHz whereas UIW RLS II has a frequency range of 22-30kHz. With a minimum frequency of 22Hz, the UIW RLS II can go significantly deeper on the low side and provide stronger bass compared to the UIW RSS III's min frequency of 40Hz.

The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the In-wall class in our database.

Low Frequency

In-wall Speakers

UIW RSS III
UIW RLS II
Min
Average
Median

Neither pair reaches down to 20Hz, the usual definition of full-range, which is normal for speakers of this size. If you want the bottom octave for movies or bass-heavy music, add a subwoofer to whichever you choose. Visit our Powered Subwoofers section to find out more about the available options.

Impedance and Sensitivity

UIW RSS III and UIW RLS II have the same Impedance of 8 ohms but where they differ is the sensitivity levels. UIW RSS III sensitivity is rated at 90 dB and the UIW RLS II's is at 92 dB. This 2 dB difference makes the Definitive UIW RLS II a more sensitive speaker compared to Definitive UIW RSS III, hence will play louder with the same amount of watts.

Sensitivity

In-wall Speakers

UIW RSS III
UIW RLS II
Min
Average
Median

Power Range

Power range is the range of input power in watts RMS that a loudspeaker is designed to handle. Staying within that range gives nominal performance; driving the speaker beyond its maximum wattage can damage it.

UIW RLS II can handle a max power of 350 watts RMS, whereas UIW RSS III has a max power handling value of 200 watts RMS, 150 watts less than the UIW RLS II.

Note that higher power handling does not make a speaker louder: that depends mainly on sensitivity and impedance. The calculator below shows how loud each of these actually plays on a real amplifier.

Which plays louder on your amplifier?

Starting with a popular amplifier - change it to the one you own, or any you are considering, and watch both numbers move.

Definitive UIW RSS III
 
Definitive UIW RLS II
 

Input Type and Bi-Amping / Bi-Wiring

UIW RSS III features Spring post type posts and UIW RLS II has a Spring post type posts. None of these speakers feature bi-amping/bi-wiring.

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 Definitive UIW RSS III's and Definitive UIW RLS II's external dimensions. Definitive UIW RSS III has external dimensions of 251.0 x 213.0 x 99.0mm (9.8750-inch x 8.3750-inch x 3.8750-inch) whereas Definitive UIW RLS II has external dimensions of 724.0 x 178.0 x 99.0mm (28.5000-inch x 7.0000-inch x 3.8750-inch).

What's in the Box of Definitive UIW RSS III?

Here are the items that are included inside the box of UIW RSS III:
  • In-wall/In-cieling bipolar speaker
  • Grille
  • 7 Foam strips
  • 2 Screws
  • Paint mask
  • Wall template
  • Owners Manual
  • Online Product Registration Card

What's in the Box of Definitive UIW RLS II?

Here are the items that come with the UIW RLS II:
  • In-wall loudspeaker
  • Grille
  • Self-adhesive foam gasket
  • Paint mask
  • Wall-Mount Template
  • Owners Manual
  • Online Product Registration Card


Reasons to choose Definitive Technology UIW RSS III over Definitive Technology UIW RLS II

Height 251mm vs 724mm Easier to fit in smaller spaces
Price per pair* 1098USD vs 1998USD costs less (*prices may change depending on the seller, location and time)

Reasons to choose Definitive Technology UIW RLS II over Definitive Technology UIW RSS III

Max Input Power 350 watts vs 200 watts Handle more power from your amplifier
Sensitivity 92 dB vs 90 dB Play louder with same amount of amplification power
Woofer Size 6.5 inches vs 3.5 inches Larger woofer
Low Frequency Response 22 Hz vs 40 Hz Generates deeper bass
Base Surface Area 176cm2 vs 210cm2 Takes less floor space

Definitive UIW RSS III vs Definitive UIW RLS II Specs Table

Detailed comparison of specifications
General Definitive Technology UIW RSS III Definitive Technology UIW RLS II
Brand Definitive Technology Definitive Technology
Speaker Type Passive In-wall Speaker Passive In-wall Speaker
Power Range 10-200 watts 10-350 watts
Sensitivity 90 dB 92 dB
Impedance 8 ohms 8 ohms
Frequency Response 40-30kHz 22-30kHz
Drivers
Woofer Quantity 2 2
Woofer Size 3.5" 6.5"
Woofer Composition Polypropylene Polypropylene
Woofer Surround Material Butyl Rubber Butly Rubber
Tweeter Size 1" 1"
Tweeter Type Hard-Dome Hard-Dome
Aimable Tweeter No No
Midrange Driver No No
Physical Specs
Height 251.0mm (9.9") 724.0mm (28.5")
Width 213.0mm (8.4") 178.0mm (7")
Depth 99.0mm (3.9") 99.0mm (3.9")
Weight 3.40kg (7.5lbs) n/a
Enclosure In-wall In-wall
Moisture Resistancy Yes Yes
Connections
Biamp Inputs No No
Other
Parts Warranty 5 Years 5 Years
Labor Warranty 5 Years 5 Years

Verdict

Siblings in Definitive Technology's UIW series, so they share a family sound. It comes down to size, output and price.

AreaBetterWhy
BassBDefinitive UIW RLS II digs deeper - 22Hz against 40Hz.
Amplifier needsBDefinitive UIW RLS II is more sensitive (92dB vs 90dB), so it goes louder on the same amplifier.
HeadroomBDefinitive UIW RLS II takes more power (350W vs 200W) - more in hand in a big room.
SizedependsDefinitive UIW RSS III is easier to place; Definitive UIW RLS II is bigger, which usually goes with fuller bass. Your room decides.
PriceADefinitive UIW RSS III is cheaper - $1,098 against $1,998, about 45% less; arguably a different class.

A Definitive UIW RSS III  B Definitive UIW RLS II
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 speakers are judged; anything missing on either side is left out rather than guessed.

Which should you choose?

The usual trade-off: Definitive UIW RLS II measures better, Definitive UIW RSS III costs about about 82% more% less. Whether that gap is worth the money is the call only you can make - and in a normal room it is often smaller than the numbers suggest. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 40Hz anyway, which makes the cheaper Definitive UIW RSS III much easier to justify. Match it to your room: we rate Definitive UIW RSS III the better fit for a small room and a mid-size room, and Definitive UIW RLS II for a large room and a very large room.

And remember what a spec sheet cannot show: how each looks in your room and whether the finish suits it, what dealer support and warranty are like where you live, and how they actually sound to you. If you can hear them first - ideally with your own music - that will tell you more than any number above.


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