In this review, we will be comparing UIW RSS II and UIW RSS III, two Passive In-wall speakers by Definitive Technology.
Let's have a brief look at the main features
of Definitive UIW RSS II and Definitive UIW RSS III first before getting into our more
detailed comparison.
| Key Specs | Definitive UIW RSS II | Definitive UIW RSS III |
|---|
| Brand | Definitive Technology
United States · founded 1990 | Definitive Technology
United States · founded 1990 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Hard-Dome | 1" Hard-Dome |
|---|
| Woofer | 2 x 4.5" Polypropylene | 2 x 3.5" Polypropylene |
|---|
| Frequency response | 26-30kHz | 40-30kHz |
|---|
| Sensitivity | 90 dB | 90 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 10-250 watts | 10-200 watts |
|---|
| Weight | 5.67kg / 12.5lbs | 3.40kg / 7.5lbs |
|---|
| Dimensions (H x W x D) | 11.6250" x 9.8750" x 3.8750"
296.0 x 251.0 x 99.0mm | 9.8750" x 8.3750" x 3.8750"
251.0 x 213.0 x 99.0mm |
|---|
UIW RSS II and UIW RSS III are members of Definitive Technology's UIW series of speakers. Below you can find the loudspeakers from this series.
Definitive Technology UIW Series
History
What size room are the Definitive UIW RSS II and Definitive UIW RSS 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 II |
Definitive UIW RSS III |
| Near-field |
Poor |
Poor |
| Small Room |
Poor |
Average |
| Mid-size Room |
Good |
Good |
| Large Room |
Good |
Average |
| Very Large Room |
Average |
Poor |
(* 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.
**This post contains affiliate links, and we will be compensated if you make a purchase after clicking
through our links. As an Amazon Associate I earn from qualifying purchases.
Drivers
Both UIW RSS II and UIW RSS III are 2-way speakers.
Definitive UIW RSS IIDefinitive UIW RSS III
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 II |
Definitive UIW RSS III |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 4.5-inch
|
2 x 3.5-inch
|
UIW RSS II features a 1" Hard-Dome Tweeter and 2 x 4.5" Polypropylene Woofer. On the other hand, the UIW RSS III features a 1" Hard-Dome Tweeter and 2 x 3.5" Polypropylene Woofer.
Frequency Response
UIW RSS II has a frequency range of 26-30kHz whereas UIW RSS III has a frequency range of 40-30kHz. With a minimum frequency of 26Hz, the UIW RSS 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
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 II and UIW RSS III have the same Impedance of 8 ohms and their sensitivity is also same at 90 dB.
Sensitivity
In-wall Speakers
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 RSS II can handle a max power of 250 watts RMS, whereas UIW RSS III has a max power handling value of 200 watts RMS, 50 watts less than the UIW RSS 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.
Input Type and Bi-Amping / Bi-Wiring
UIW RSS II features Spring post type posts and UIW RSS III 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 II's and Definitive UIW RSS III's external dimensions. Definitive UIW RSS II has external dimensions of 296.0 x 251.0 x 99.0mm (11.6250-inch x 9.8750-inch x 3.8750-inch) whereas 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).
Definitive UIW RSS III is 38mm narrower and 45mm shorter than Definitive UIW RSS II but they have the same thickness of 99.0mm.
Weight Comparison The weight of a loudspeaker can become an important factor if you need to move and reposition the unit often. Weight of a speaker can also "sometimes" be an indicator of the rigidity of the enclosure and the quality of the internal components used. The Definitive UIW RSS II weighs 5.67kg / 12.5lbs and the Definitive UIW RSS III weighs 3.40kg / 7.5lbs. This makes the UIW RSS II 67% heavier than the UIW RSS III.
Here is a comparison of how UIW RSS II and UIW RSS III's weights compare with the average, max and min weights in Passive In-wall class.
Weight
All In-wall Speakers
What's in the Box of Definitive UIW RSS II?
Here are the items that are included inside the box of UIW RSS II:
- 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 RSS III?
Here are the items that come with the 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
 Max Input Power |
250 watts
vs
200 watts
|
Handle more power from your amplifier |
 Woofer Size |
4.5 inches
vs
3.5 inches
|
Larger woofer |
|
Low Frequency Response |
26 Hz
vs
40 Hz
|
Generates deeper bass |
 Height |
251mm
vs
296mm
|
Easier to fit in smaller spaces |
 Base Surface Area |
210cm2
vs
248cm2
|
Takes less floor space |
 Price per pair* |
1098USD
vs
1398USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Definitive Technology UIW RSS II |
Definitive Technology UIW RSS III |
| Brand |
Definitive Technology |
Definitive Technology |
| Speaker Type |
Passive In-wall Speaker |
Passive In-wall Speaker |
| Power Range |
10-250 watts |
10-200 watts |
| Sensitivity |
90 dB |
90 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
26-30kHz |
40-30kHz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
4.5" |
3.5" |
| Woofer Composition |
Polypropylene |
Polypropylene |
| Woofer Surround Material |
Buty Rubber |
Butyl Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Hard-Dome |
Hard-Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
Physical Specs |
|
|
| Height |
296.0mm (11.7") |
251.0mm (9.9") |
| Width |
251.0mm (9.9") |
213.0mm (8.4") |
| Depth |
99.0mm (3.9") |
99.0mm (3.9") |
| Weight |
5.67kg (12.5lbs) |
3.40kg (7.5lbs) |
| 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 |
Siblings in Definitive Technology's UIW series, so they share a family sound. It comes down to size, output and price.
| Area | Better | Why |
|---|
| Bass | A | Definitive UIW RSS II digs deeper - 26Hz against 40Hz. |
| Amplifier needs | evenly matched | Similar sensitivity (90dB vs 90dB) - both want much the same power. |
| Headroom | A | Definitive UIW RSS II takes more power (250W vs 200W) - more in hand in a big room. |
| Size | depends | Definitive UIW RSS III is easier to place; Definitive UIW RSS II is bigger, which usually goes with fuller bass. Your room decides. |
| Price | B | Definitive UIW RSS III is cheaper - $1,098 against $1,398, about 21% less. |
A Definitive UIW RSS II B Definitive UIW RSS III
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 RSS II measures better, Definitive UIW RSS III costs about about 27% 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 II the better fit for a large room and a very large room, and Definitive UIW RSS III for a small 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.