In this review, we will be comparing Lumina III and RTi A5, two Passive Floor-standing speakers from Sonus Faber and Polk Audio. Let's have a brief look at the main features
of Sonus Lumina III and Polk RTi A5 first before getting into our more
detailed comparison.
What size room are the Sonus Lumina III and Polk RTi A5 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:
In the following sections, we will get into more detail in order to better understand how the Sonus Lumina III and Polk RTi A5 compare and hopefully end up with enough arguments to decide which one of these loudspeakers is the better choice for you.
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Drivers
One of the fundamental differences between these two speakers is that Lumina III is a 3-way design whereas the RTi A5 is a 2-way speaker. 3-way designs utilize a midrange driver in addition to the tweeter and woofer on 2-way designs. Designing a crossover for a 3-way speaker is a complicated process and generally increases the overall cost of the speaker.
Driver |
Sonus Lumina III |
Polk RTi A5 |
Driver Setup
|
3-way
|
2-way
|
Tweeter
|
1.15-inch
|
1-inch
|
Midrange
|
1 x 6-inch |
- |
Woofer
|
2 x 6-inch
|
2 x 6.5-inch
|
Lumina III features a 1.15" high definition DAD Tweeter , a 6" Midrange and 2 x 6" paper cone Woofer with a Crossover frequency at 350 and 3500 Hz. On the other hand, the RTi A5 features a 1" Tweeter and 2 x 6.5" Polymer composite Woofer .
Frequency Response
Lumina III has a frequency range of 40-24k Hz whereas RTi A5 has a frequency range of 40-26k Hz.
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 Floor-standing class in our database.
Low Frequency
Floor-standing Speakers
High Frequency
Floor-standing 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
Lumina III is a 4 ohms speaker compared to the RTi A5 which has a nominal impedance of 8 ohms. Lower impedance speakers, especially the ones that are rated at 4 ohms may put more pressure on the amplifier unit especially when played at high volume levels, so make sure the amp you pair with the Lumina III can provide this impedance level.
These two speakers also have different sensitivity levels. Lumina III sensitivity is rated at 89 dB and the RTi A5's is rated at 90 dB. This 1 dB difference makes the Polk RTi A5 a more sensitive speaker compared to Sonus Lumina III, hence will play louder with the same amount of watts.
Sensitivity
Floor-standing 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.
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
Both Lumina III and RTi A5 features dual binding post speaker terminals for bi-amping or bi-wiring.
Cabinet Type and Port Position
Lumina III has a bottom firing port whereas RTi A5 has a front firing ports. Polk RTi A5's front-firing port gives more flexibility in placement in regards to proximity to walls compared to Sonus Lumina III with its rear-firing port.
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 Sonus Lumina III's and Polk RTi A5's external dimensions. Sonus Lumina III has external dimensions of 989.0 x 228.0 x 278.0mm ( 38.9 x 9 x 10.9inch) whereas Polk RTi A5 has external dimensions of 1007.0 x 269.0 x 404.0mm ( 39-5/8 x 10-9/16 x 15-7/8inch) .
Polk RTi A5 is clearly the larger of the two speakers. Its body is 41mm wider, 18mm taller and 126mm deeper than Sonus Lumina III.
Below you can see the front view size comparison of Sonus Lumina III and Polk RTi A5 in scale.
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 Sonus Lumina III is approximately 633.8cm2 / 98.2inch2 and base area of the Polk RTi A5 is approximately 1086.8cm2 / 168.5inch2. The Lumina III requires 42% less surface area than the RTi A5 which gives it a small advantage on placement in tight spaces.
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 Sonus Lumina III weighs 15.90kg / 35lbs and the Polk RTi A5 weighs 18.18kg / 40lbs. This makes the RTi A5 14% heavier than the Lumina III.
Here is a comparison of how Lumina III and RTi A5's weights compare with the average, max and min weights in Passive Floor-standing class.
Weight
All Floor-standing Speakers
What's in the Box of Sonus Lumina III?
Here are the items that are included inside the box of Lumina III:
Floorstanding loudspeaker1 Manual 2 Jumpers2 Grilles 2 Fabric dust guards4 Spikes 4 Under spikes 4 Spikes locks
What's in the Box of Polk RTi A5?
Here are the items that come with the RTi A5:
Cherry floor-standing speakerDetachable black cloth grille4 Screw-on spike feetOwners ManualOnline registration sheetPolk Audio product brochure
Driver Setup |
3-way
vs
2-way
|
Have a dedicated mid-range driver |
Height |
989mm
vs
1007mm
|
Easier to fit in smaller spaces |
Base Surface Area |
633cm2 (228x278mm)
vs
1086cm2 (269x404mm)
|
Takes less floor space |
Sensitivity |
90 dB
vs
89 dB
|
Play louder with same amount of amplification power |
Nominal Impedance |
8 ohms
vs
4 ohms
|
Less selective with amplifiers |
Woofer Size |
6.5 inches
vs
6 inches
|
Larger woofer |
High Frequency Response |
26k Hz
vs
24k Hz
|
Generates higher frequency |
General |
Sonus Faber Lumina III |
Polk Audio RTi A5 |
Brand |
Sonus Faber |
Polk Audio |
Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
Power Range |
50-250 watts |
20-250 watts |
Sensitivity |
89 dB |
90 dB |
Impedance |
4 ohms |
8 ohms |
Frequency Response |
40-24k Hz |
40-26k Hz |
Drivers |
|
|
Woofer Quantity |
2 |
2 |
Woofer Size |
6" |
6.5" |
Woofer Composition |
paper cone |
Polymer composite |
Woofer Surround Material |
n/a |
Butyl Rubber |
Tweeter Size |
1.15" |
1" |
Tweeter Type |
high definition DAD |
n/a |
Aimable Tweeter |
No |
No |
Midrange Driver |
6" |
No |
Crossover Frequency |
350 and 3500 Hz |
n/a |
Firing Direction |
bottom |
front |
Physical Specs |
|
|
Height |
989.0mm (38.9") |
1007.0mm (39.6") |
Width |
228.0mm (9") |
269.0mm (10.6") |
Depth |
278.0mm (10.9") |
404.0mm (15.9") |
Weight |
15.90kg (35lbs) |
18.18kg (40lbs) |
Enclosure |
Bass Reflex |
Bass Reflex |
Finish |
real multilayer wood |
Real wood veneer |
Available Colors |
Black, Wenge, Walnut |
Cherry |
Grille |
Yes |
Yes |
Moisture Resistancy |
No |
No |
Connections |
|
|
Biamp Inputs |
Yes |
Yes |
Other |
|
|
Parts Warranty |
|
5 Years |
Labor Warranty |
|
5 Years |