In this review, we will be comparing Platinum 100 3G and 705 S3, two Passive Bookshelf speakers from Monitor Audio and Bowers Wilkins.
Let's have a brief look at the main features
of Monitor Audio Platinum 100 3G and B&W 705 S3 first before getting into our more
detailed comparison.
| Key Specs | Monitor Audio Platinum 100 3G | B&W 705 S3 |
|---|
| Brand | Monitor Audio
United Kingdom · founded 1972 | Bowers Wilkins
United Kingdom · founded 1966 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" | 1" Decoupled Carbon Dome |
|---|
| Woofer | 6" RDT III | 6.5" Continuum |
|---|
| Frequency response | 28-60k Hz | 50-28k Hz |
|---|
| Sensitivity | 85dB | 88 dB |
|---|
| Impedance | 4 ohms | 8 ohms |
|---|
| Power range | up to 150 watts | 30-120 watts |
|---|
| Weight | 15.20kg / 33.4lbs | 9.58kg / 21.1lbs |
|---|
| Dimensions (H x W x D) | 15.6" x 8.8" x 12.8"
398.0 x 225.0 x 325.0mm | 16.3" x 7.6" x 13.3"
413.0 x 192.0 x 337.0mm |
|---|
What size room are the Monitor Audio Platinum 100 3G and B&W 705 S3 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* |
Monitor Audio Platinum 100 3G |
B&W 705 S3 |
| Near-field |
Poor |
Poor |
| Small Room |
Average |
Average |
| Mid-size Room |
Good |
Good |
| Large Room |
Average |
Average |
| Very Large Room |
Poor |
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 Platinum 100 3G and 705 S3 are 2-way speakers.
Monitor Audio Platinum 100 3GB&W 705 S3
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Monitor Audio Platinum 100 3G |
B&W 705 S3 |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
1 x 6-inch
|
1 x 6.5-inch
|
Platinum 100 3G features a 1" MPD III Tweeter and 1 x 6" RDT III Woofer with a Crossover frequency at 2850 Hz. On the other hand, the 705 S3 features a 1" Decoupled Carbon Dome Tweeter and 1 x 6.5" Continuum Woofer.
Frequency Response
Platinum 100 3G has a frequency range of 28-60k Hz whereas 705 S3 has a frequency range of 50-28k 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'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
Platinum 100 3G is a 4 ohms speaker compared to the 705 S3 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 Platinum 100 3G can provide this impedance level.
These two speakers also have different sensitivity levels. Platinum 100 3G sensitivity is rated at 85dB and the 705 S3's is rated at 88 dB. This 3 dB difference makes the B&W 705 S3 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 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.
Monitor Audio Platinum 100 3G
Input Type and Bi-Amping / Bi-Wiring
Both Platinum 100 3G and 705 S3 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
B&W 705 S3's Binding post terminals allows Bi-amping or bi-wiring
Cabinet Type and Port Position
Both Platinum 100 3G and 705 S3 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 Monitor Audio Platinum 100 3G's and B&W 705 S3's external dimensions. 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) whereas B&W 705 S3 has external dimensions of 413.0 x 192.0 x 337.0mm (16.3-inch x 7.6-inch x 13.3-inch).
Monitor Audio Platinum 100 3G is 15mm shorter and 12mm less deeper than B&W 705 S3 but it is also 33mm wider.
Below you can see the front view size comparison of Monitor Audio Platinum 100 3G and B&W 705 S3 in scale.
Comparison image of Monitor Audio Platinum 100 3G and B&W 705 S3 Size and External Dimensions
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 Monitor Audio Platinum 100 3G is approximately 731.3cm2 / 113.4inch2 and base area of the B&W 705 S3 is approximately 647.0cm2 / 100.3inch2. The Platinum 100 3G requires 13% more surface area than the 705 S3 which gives it a small disadvantage on placement in tight spaces.
Here is another comparison that shows both speakers on a BDI Octave Media Cabinet, next to a standard size amplifier and turntable in scale:
Size Comparison image of Monitor Audio Platinum 100 3G and B&W 705 S3 on a Media Console
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 Monitor Audio Platinum 100 3G weighs 15.20kg / 33.4lbs and the B&W 705 S3 weighs 9.58kg / 21.1lbs. This makes the Platinum 100 3G 59% heavier than the 705 S3.
Here is a comparison of how Platinum 100 3G and 705 S3's weights compare with the average, max and min weights in Passive Bookshelf class.
Weight
All Bookshelf Speakers
Monitor Audio Platinum 100 3G
What's in the Box of B&W 705 S3?
Here are the items that come with the 705 S3:
- 2 Bookshelf loudspeakers
- 2 Grilles
- 2 Two-piece foam port plugs
- 8 Self-adhesive rubber feet
- 4 Jumper-straps
- Manual
- Bowers & Wilkins brochure
- Warranty Information
 Max Input Power |
150 watts
vs
120 watts
|
Handle more power from your amplifier |
 Minimum Impedance |
4 ohms
vs
3.1 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 |
 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 |
647cm2
vs
731cm2
|
Takes less floor space |
 Price per pair* |
3398USD
vs
6900USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Monitor Audio Platinum 100 3G |
Bowers & Wilkins 705 S3 |
| Brand |
Monitor Audio |
Bowers Wilkins |
| Speaker Type |
Bookshelf speakers |
Bookshelf speakers |
| Power Range |
up to 150 watts |
30-120 watts |
| Sensitivity |
85dB |
88 dB |
| Impedance |
4 ohms |
8 ohms |
| Impedance |
4 ohms |
3.1 ohms |
| Frequency Response |
28-60k Hz |
50-28k Hz |
Drivers |
|
|
| Woofer Quantity |
1 |
1 |
| Woofer Size |
6" |
6.5" |
| Woofer Composition |
RDT III |
Continuum |
| Woofer Surround Material |
n/a |
Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
n/a |
Decoupled Carbon Dome |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
| Crossover Frequency |
2850 Hz |
n/a |
| Firing Direction |
rear |
rear |
Physical Specs |
|
|
| Height |
398.0mm (15.7") |
413.0mm (16.3") |
| Width |
225.0mm (8.9") |
192.0mm (7.6") |
| Depth |
325.0mm (12.8") |
337.0mm (13.3") |
| Weight |
15.20kg (33.4lbs) |
9.58kg (21.1lbs) |
| Enclosure |
Bass Reflex |
Bass Reflex |
| Finish |
n/a |
MDF/Wood veneer |
| Available Colors |
Piano Black, Piano Ebony, Satin White |
Gloss Black,Satin White,Mocha,Rosenut |
| Mounting Bracket |
No |
No |
| Recommended Stand Height |
n/a |
24-26" |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
Yes |
Other |
|
|
| Parts Warranty |
5 Years |
5 Years |
| Labor Warranty |
5 Years |
5 Years |
These sit in different price classes - Monitor Audio Platinum 100 3G costs roughly 2x what B&W 705 S3 does. Expect it to lead on paper; the question is whether the gap is audible enough in your room to be worth it.
| Area | Better | Why |
|---|
| Bass | A | Monitor Audio Platinum 100 3G digs deeper - 28Hz against 50Hz. |
| Amplifier needs | B | B&W 705 S3 is more sensitive (88dB vs 85dB), so it goes louder on the same amplifier. |
| Amplifier match | B | B&W 705 S3 is the easier load at 8 ohms; the other is 4 ohms and wants an amplifier rated for it. |
| Headroom | A | 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 | Monitor Audio Platinum 100 3G: bi-amping; B&W 705 S3: bi-amping. B&W 705 S3 sits in a wider range (8 models), so a matched surround system is easier later. |
| Price | B | B&W 705 S3 is cheaper - $3,398 against $6,900, about 51% less; arguably a different class. |
A Monitor Audio Platinum 100 3G B B&W 705 S3
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 B&W 705 S3 much easier to justify. If your amplifier is modest, vintage or valve-based, B&W 705 S3 is the safer partner - the other will want more current or more watts to sound its best.
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.