In this review, we will be comparing 705 S3 Signature and Platinum 100 3G, two Passive Bookshelf speakers from Bowers Wilkins and Monitor Audio.
Let's have a brief look at the main features
of Bowers & Wilkins 705 S3 Signature and Monitor Audio Platinum 100 3G first before getting into our more
detailed comparison.
| Key Specs | Bowers & Wilkins 705 S3 Signature | Monitor Audio Platinum 100 3G |
|---|
| Brand | Bowers Wilkins
United Kingdom · founded 1966 | Monitor Audio
United Kingdom · founded 1972 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Decoupled Carbon Dome | 1" |
|---|
| Woofer | 6.5" Continuum | 6" RDT III |
|---|
| Frequency response | 50-28k Hz | 28-60k Hz |
|---|
| Sensitivity | 88 dB | 85dB |
|---|
| Impedance | 8 ohms | 4 ohms |
|---|
| Power range | 30-120 watts | up to 150 watts |
|---|
| Weight | 10.35kg / 22.8lbs | 15.20kg / 33.4lbs |
|---|
| Dimensions (H x W x D) | 16-1/4" x 7-9/16" x 11-11/16"
413.0 x 192.0 x 297.0mm | 15.6" x 8.8" x 12.8"
398.0 x 225.0 x 325.0mm |
|---|
What size room are the Bowers & Wilkins 705 S3 Signature and Monitor Audio Platinum 100 3G 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* |
Bowers & Wilkins 705 S3 Signature |
Monitor Audio Platinum 100 3G |
| Near-field |
Average |
Poor |
| Small Room |
Good |
Average |
| Mid-size Room |
Average |
Good |
| Large Room |
Poor |
Average |
| Very Large Room |
Bad |
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.
Drivers
Both 705 S3 Signature and Platinum 100 3G are 2-way speakers.
Bowers & Wilkins 705 S3 SignatureMonitor Audio Platinum 100 3G
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Bowers & Wilkins 705 S3 Signature |
Monitor Audio Platinum 100 3G |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 6.5-inch
|
1 x 6-inch
|
705 S3 Signature features a 1" Carbon Decoupled Carbon Dome Tweeter and 1 x 6.5" Continuum Woofer. On the other hand, the Platinum 100 3G features a 1" MPD III Tweeter and 1 x 6" RDT III Woofer with a Crossover frequency at 2850 Hz.
Frequency Response
705 S3 Signature has a frequency range of 50-28k Hz whereas Platinum 100 3G has a frequency range of 28-60k Hz. With a minimum frequency of 28Hz, the Platinum 100 3G can go significantly deeper on the low side and provide stronger bass compared to the 705 S3 Signature's min frequency of 50Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Bookshelf class in our database.
Low Frequency
Bookshelf 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
705 S3 Signature is a 8 ohms speaker compared to the Platinum 100 3G which has a nominal impedance of 4 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 Platinum 100 3G can provide this impedance level.
These two speakers also have different sensitivity levels. 705 S3 Signature sensitivity is rated at 88 dB and the Platinum 100 3G's is rated at 85dB. This 3 dB difference makes the Bowers & Wilkins 705 S3 Signature a more sensitive speaker compared to Monitor Audio Platinum 100 3G, hence will play louder with the same amount of watts.
Sensitivity
Bookshelf 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.
Platinum 100 3G can handle a max power of 150 watts RMS, whereas 705 S3 Signature has a max power handling value of 120 watts RMS, 30 watts less than the Platinum 100 3G.
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.
Bowers & Wilkins 705 S3 Signature
Monitor Audio Platinum 100 3G
Input Type and Bi-Amping / Bi-Wiring
Both 705 S3 Signature and Platinum 100 3G features dual binding post speaker terminals for bi-amping or bi-wiring.
Monitor Audio Platinum 100 3G's Binding post terminals allows Bi-amping or bi-wiring
Cabinet Type and Port Position
Both 705 S3 Signature and Platinum 100 3G have rear firing ports. Rear ported speakers generally need more room between the backside of the speaker and the wall compared to sealed and front/bottom ported speakers. Placing the speakers too close to the walls may cause the bass to sound boomy.
If you are limited in space and can't get the speakers away from the backwall, check our Speakers with Front Firing Ports page.
Monitor Audio Platinum 100 3G Port
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 Bowers & Wilkins 705 S3 Signature's and Monitor Audio Platinum 100 3G's external dimensions. Bowers & Wilkins 705 S3 Signature has external dimensions of 413.0 x 192.0 x 297.0mm (16-1/4 x 7-9/16 x 11-11/16inch) whereas Monitor Audio Platinum 100 3G has external dimensions of 398.0 x 225.0 x 325.0mm (15.6 x 8.8 x 12.8-inch).
Bowers & Wilkins 705 S3 Signature is 33mm narrower and 28mm less deeper than Monitor Audio Platinum 100 3G but it is also 15mm taller.
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.
Monitor Audio Platinum 100 3G needs about 28% more floor or shelf area. Monitor Audio Platinum 100 3G is 28mm deeper, so it stands that much further out from the wall. Bowers & Wilkins 705 S3 Signature is 15mm 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 Bowers & Wilkins 705 S3 Signature is approximately 570.2cm2 / 88.4inch2 and base area of the Monitor Audio Platinum 100 3G is approximately 731.3cm2 / 113.4inch2. The 705 S3 Signature requires 22% less surface area than the Platinum 100 3G 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 Bowers & Wilkins 705 S3 Signature weighs 10.35kg / 22.8lbs and the Monitor Audio Platinum 100 3G weighs 15.20kg / 33.4lbs. This makes the Platinum 100 3G 47% heavier than the 705 S3 Signature.
Here is a comparison of how 705 S3 Signature and Platinum 100 3G's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
Bowers & Wilkins 705 S3 Signature
Monitor Audio Platinum 100 3G
 Sensitivity |
88 dB
vs
85 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 |
 Base Surface Area |
570cm2
vs
731cm2
|
Takes less floor space |
 Price per pair* |
5200USD
vs
7599USD
|
costs less (*prices may change depending on the seller, location and time) |
 Max Input Power |
150 watts
vs
120 watts
|
Handle more power from your amplifier |
 Minimum Impedance |
4 ohms
vs
3.7 ohms
|
Very low impedance levels puts more pressure on amplifier |
|
Low Frequency Response |
28 Hz
vs
50 Hz
|
Generates deeper bass |
 High Frequency Response |
60k Hz
vs
28k Hz
|
Generates higher frequency |
 Height |
398mm
vs
413mm
|
Easier to fit in smaller spaces |
| General |
Bowers & Wilkins 705 S3 Signature |
Monitor Audio Platinum 100 3G |
| Brand |
Bowers Wilkins |
Monitor Audio |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
30-120 watts |
up to 150 watts |
| Sensitivity |
88 dB |
85dB |
| Impedance |
8 ohms |
4 ohms |
| Impedance |
3.7 ohms |
4 ohms |
| Frequency Response |
50-28k Hz |
28-60k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6.5" |
6" |
| Woofer Composition |
Continuum |
RDT III |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Decoupled Carbon Dome |
n/a |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
n/a |
2850 Hz |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
413.0mm (16.3") |
398.0mm (15.7") |
| Width |
192.0mm (7.6") |
225.0mm (8.9") |
| Depth |
297.0mm (11.7") |
325.0mm (12.8") |
| Weight |
10.35kg (22.8lbs) |
15.20kg (33.4lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Available Colors |
n/a |
Piano Black, Piano Ebony, Satin White |
| Mounting Bracket |
|
No |
| Grille |
Yes |
n/a |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
Yes |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
No single best speaker here - they are built to different priorities, and the right one depends on your room, your amplifier and what you listen to.
| Area | Better | Why |
|---|
| Bass | B | Monitor Audio Platinum 100 3G digs deeper - 28Hz against 50Hz. |
| Amplifier needs | A | Bowers & Wilkins 705 S3 Signature is more sensitive (88dB vs 85dB), so it goes louder on the same amplifier. |
| Amplifier match | A | Bowers & Wilkins 705 S3 Signature is the easier load at 8 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom | B | Monitor Audio Platinum 100 3G takes more power (150W vs 120W) - more in hand in a big room. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | depends | Bowers & Wilkins 705 S3 Signature: bi-amping; Monitor Audio Platinum 100 3G: bi-amping. |
| Price | A | Bowers & Wilkins 705 S3 Signature is cheaper - $5,200 against $7,599, about 32% less. |
A Bowers & Wilkins 705 S3 Signature B Monitor Audio Platinum 100 3G
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?
Neither runs away with it - they trade advantages. Let the "depends" rows and your own room settle it. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 50Hz anyway, which makes the cheaper Bowers & Wilkins 705 S3 Signature much easier to justify. Match it to your room: we rate Bowers & Wilkins 705 S3 Signature the better fit for near-field listening and a small room, and Monitor Audio Platinum 100 3G for a mid-size room and a 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.