In this review, we will be comparing UIW RSS III and UIW RLS III, 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 III first before getting into our more
detailed comparison.
Definitive UIW RSS III Key Specs
- 2-way Design
- 1" Hard-Dome Tweeter
- 2 x 3.5" Polypropylene Woofer
- 40-30kHz Frequency Response
- 90 dB Sensitivity
- Impedance: 8ohms
- Power Range:10-200watts
- Dimensions (H x W x D): 251.0" x 8.3750" x 3.8750"( 251.0 x 213.0 x 99.0mm )
Definitive UIW RLS III Key Specs
- 2-way Design
- 1" Hard-Dome Tweeter
- 2 x 5.25" Polypropylene Woofer
- 24-30kHz Frequency Response
- 92 dB Sensitivity
- Impedance: 8ohms
- Power Range:10-325watts
- Dimensions (H x W x D): 604.0" x 5.8750" x 3.8750"( 604.0 x 150.0 x 99.0mm )
What size room are the Definitive UIW RSS III and Definitive UIW RLS III 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 III |
| 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.)
In the following sections, we will get into more detail in order to better understand how the Definitive UIW RSS III and Definitive UIW RLS III compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.
**This post contains affiliate links, and I will be compensated if you make a purchase after clicking
through my links. As an Amazon Associate I earn from qualifying purchases.
Drivers
Both UIW RSS III and UIW RLS III are 2-way speakers.
| Driver |
Definitive UIW RSS III |
Definitive UIW RLS III |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 3.5-inch
|
2 x 5.25-inch
|
UIW RSS III features a 1" Hard-Dome Tweeter and 2 x 3.5" Polypropylene Woofer . On the other hand, the UIW RLS III features a 1" Hard-Dome Tweeter and 2 x 5.25" Polypropylene Woofer .
Frequency Response
UIW RSS III has a frequency range of 40-30kHz whereas UIW RLS III has a frequency range of 24-30kHz. With a minimum frequency of 24Hz, the UIW RLS III can go significantly deeper on the low side and provide stronger bass compared to the UIW RSS III's min frequency of 40Hz.
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 In-wall class in our database.
Low Frequency
In-wall Speakers
High Frequency
In-wall Speakers
None of these speakers achieves full range experience which is commonly agreed as 20Hz-20kHz. In order to achieve lower lows / deeper bass, we recommend you pair these with a subwoofer. Visit our Powered Subwoofers section to find out more about the available options.
Impedance and Sensitivity
UIW RSS III and UIW RLS III 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 III's is at 92 dB. This 2 dB difference makes the Definitive UIW RLS III a more sensitive speaker compared to Definitive UIW RSS III, hence will play louder with the same amount of watts.
Sensitivity
In-wall Speakers
Power Range
Power
range is the range of input power in watts RMS that a loudspeaker is designed to handle. While using an amplifier within this range ensures the nominal performance , inputting a power that is higher than the max wattage can result in a damaged speaker.
UIW RSS III can handle a max power of 325 watts RMS from the amp the whereas UIW RSS III has a max power handling value of 200 watts RMS , 125 watts less than the UIW RLS III.
Keep in mind that a higher max power handling value doesn't necessarily make that a louder speaker
compared to a lower max handling speaker. Loudness or the sound level is also impacted by parameters
such as Impedance, sensitivity and system efficiencies.
Input Type and Bi-Amping / Bi-Wiring
UIW RSS III features Spring post type posts and UIW RLS III has a Spring post type posts. None of these speakers feature bi-amping/bi-wiring.
Physical Specs
Size of a speaker can sometimes become 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 III'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 III has external dimensions of 604.0 x 150.0 x 99.0mm ( 23.7500-inch x 5.8750-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 speakerGrille7 Foam strips2 ScrewsPaint maskWall templateOwners ManualOnline Product Registration Card
What's in the Box of Definitive UIW RLS III?
Here are the items that come with the UIW RLS III:
In-wall loudspeakerGrilleSelf-adhesive foam gasketPaint maskWall-Mount TemplateOwners ManualOnline Product Registration Card
Height 
Price per pair* 
Max Input Power 
Sensitivity 
Woofer Size 
Base Surface Area