In this review, we will be comparing Diamond 12.3i and Concord, two Passive Floor-standing speakers from Wharfedale and KLH.
Let's have a brief look at the main features
of Wharfedale Diamond 12.3i and KLH Concord first before getting into our more
detailed comparison.
| Key Specs | Wharfedale Diamond 12.3i | KLH Concord |
|---|
| Brand | Wharfedale
United Kingdom · founded 1932 | KLH
United States · founded 1957 |
|---|
| Design | 2-way | 2-way |
|---|
| Tweeter | 1" Soft-Dome | 1" |
|---|
| Woofer | 2 x 5" Mica-infused polypropylene | 2 x 6.5" Kevlar |
|---|
| Frequency response | 45-20k Hz | 28-23k Hz |
|---|
| Sensitivity | 89 dB | 94 dB |
|---|
| Impedance | 8 ohms | 8 ohms |
|---|
| Power range | 30-150 watts | up to 225 watts |
|---|
| Weight | 19.55kg / 43lbs | 20.45kg / 45lbs |
|---|
| Dimensions (H x W x D) | 38-3/4" x 9-3/4" x 13-3/4"
985.0 x 248.0 x 350.0mm | 40-3/8" x 8-5/16" x 14-15/16"
1026.0 x 212.0 x 380.0mm |
|---|
The sections below take each area in turn: drivers, frequency response, physical size and what you get in the box.
Drivers
Both Diamond 12.3i and Concord are 2-way speakers.
Wharfedale Diamond 12.3iKLH Concord
TweeterWoofer
Front view, drawn to scale - cabinets and drivers share one scale, so sizes are directly comparable. Hover a driver for its size.
| Driver |
Wharfedale Diamond 12.3i |
KLH Concord |
|
Driver Setup
|
2-way
|
2-way
|
|
Tweeter
|
1-inch
|
1-inch
|
|
Midrange
|
- |
- |
|
Woofer
|
2 x 5-inch
|
2 x 6.5-inch
|
Diamond 12.3i features a 1" Soft-Dome Tweeter and 2 x 5" Mica-infused polypropylene Woofer. On the other hand, the Concord features a 1" anodized aluminum Tweeter and 2 x 6.5" Kevlar Woofer.
Frequency Response
Diamond 12.3i has a frequency range of 45-20k Hz whereas Concord has a frequency range of 28-23k Hz. With a minimum frequency of 28Hz, the Concord can go significantly deeper on the low side and provide stronger bass compared to the Diamond 12.3i's min frequency of 45Hz.
The graph below depicts how these two speakers compare with the max, min and average Low Frequency values of other speakers in the Floor-standing class in our database.
Low Frequency
Floor-standing 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
Diamond 12.3i and Concord have the same Impedance of 8 ohms but where they differ is the sensitivity levels. Diamond 12.3i sensitivity is rated at 89 dB and the Concord's is at 94 dB. This 5 dB difference makes the KLH Concord a more sensitive speaker compared to Wharfedale Diamond 12.3i, 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. Staying
within that range gives nominal performance; driving the speaker beyond its maximum wattage can damage it.
Concord can handle a max power of 225 watts RMS, whereas Diamond 12.3i has a max power handling value of 150 watts RMS, 75 watts less than the Concord.
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
Diamond 12.3i features Binding post posts which make bi-amping or bi-wiring possible. Concord has a 5-Way post which doesn't feature bi-amping/bi-wiring.
KLH Concord's 5-Way post terminals
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 Wharfedale Diamond 12.3i's and KLH Concord's external dimensions. Wharfedale Diamond 12.3i has external dimensions of 985.0 x 248.0 x 350.0mm (38-3/4inch x 9-3/4inch x 13-3/4inch) whereas KLH Concord has external dimensions of 1026.0 x 212.0 x 380.0mm (40-3/8 x 8-5/16 x 14-15/16inch).
Wharfedale Diamond 12.3i is 41mm shorter and 30mm less deeper than KLH Concord but it is also 36mm wider.
Below you can see the front view size comparison of Wharfedale Diamond 12.3i and KLH Concord in scale.
Comparison image of Wharfedale Diamond 12.3i and KLH Concord 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 Wharfedale Diamond 12.3i is approximately 868.0cm2 / 134.5inch2 and base area of the KLH Concord is approximately 805.6cm2 / 124.9inch2. The Diamond 12.3i requires 8% more surface area than the Concord which gives it a small disadvantage 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 Wharfedale Diamond 12.3i weighs 19.55kg / 43lbs and the KLH Concord weighs 20.45kg / 45lbs. This makes the Concord 5% heavier than the Diamond 12.3i.
Here is a comparison of how Diamond 12.3i and Concord'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 Wharfedale Diamond 12.3i?
Here are the items that are included inside the box of Diamond 12.3i:
- 2 Floorstanding loudspeakers
- 2 Grilles
- 4 Outrigger feet
- 8 Spikes (pre-installed on outrigger feet)
- 8 Isolation pucks
- Eight M6x25mm phillips-head screws
- User's Manual
What's in the Box of KLH Concord?
Here are the items that come with the Concord:
- Floorstanding loudspeaker
- Grille
- 4 Spike feet (w/ locking nut attached)
- 4 Protective discs
- 4 Rubber feet
- Port plug
- Manual
- ATTENTION! note
 Bi-Amping and Bi-Wiring |
Yes
vs
No
|
Allows bi-amping and bi-wiring connections |
 Height |
985mm
vs
1026mm
|
Easier to fit in smaller spaces |
 Max Input Power |
225 watts
vs
150 watts
|
Handle more power from your amplifier |
 Sensitivity |
94 dB
vs
89 dB
|
Play louder with same amount of amplification power |
 Woofer Size |
6.5 inches
vs
5 inches
|
Larger woofer |
|
Low Frequency Response |
28 Hz
vs
45 Hz
|
Generates deeper bass |
 High Frequency Response |
23k Hz
vs
20k Hz
|
Generates higher frequency |
 Base Surface Area |
805cm2
vs
868cm2
|
Takes less floor space |
 Price per pair* |
1000USD
vs
1198USD
|
costs less (*prices may change depending on the seller, location and time) |
| General |
Wharfedale Diamond 12.3i |
KLH Concord |
| Brand |
Wharfedale |
KLH |
| Speaker Type |
Floor-standing speaker |
Floor-standing speaker |
| Power Range |
30-150 watts |
up to 225 watts |
| Sensitivity |
89 dB |
94 dB |
| Impedance |
8 ohms |
8 ohms |
| Frequency Response |
45-20k Hz |
28-23k Hz |
Drivers |
|
|
| Woofer Quantity |
2 |
2 |
| Woofer Size |
5" |
6.5" |
| Woofer Composition |
Mica-infused polypropylene |
Kevlar |
| Woofer Surround Material |
Rubber |
Butyl Rubber |
| Tweeter Size |
1" |
1" |
| Tweeter Type |
Soft-Dome |
n/a |
| Aimable Tweeter |
No |
No |
| Midrange Driver |
No |
No |
Physical Specs |
|
|
| Height |
985.0mm (38.8") |
1026.0mm (40.4") |
| Width |
248.0mm (9.8") |
212.0mm (8.3") |
| Depth |
350.0mm (13.8") |
380.0mm (15") |
| Weight |
19.55kg (43lbs) |
20.45kg (45lbs) |
| Enclosure |
|
Bass Reflex |
| Finish |
MDF/Vinyl |
MDF/Wood-grain vinyl |
| Available Colors |
Grey |
Black |
| Grille |
n/a |
Yes |
| Moisture Resistancy |
No |
No |
Connections |
|
|
| Biamp Inputs |
Yes |
No |
Other |
|
|
| Parts Warranty |
5 Years |
10 Years |
| Labor Warranty |
5 Years |
10 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 | KLH Concord digs deeper - 28Hz against 45Hz. |
| Amplifier needs | B | KLH Concord is more sensitive (94dB vs 89dB), so it goes louder on the same amplifier. |
| Headroom | B | KLH Concord takes more power (225W vs 150W) - more in hand in a big room. |
| Size | depends | Similar cabinet size - neither is easier to fit. |
| Expandability | A | Wharfedale Diamond 12.3i: bi-amping. |
| Price | B | KLH Concord is cheaper - $1,000 against $1,198, about 17% less. |
A Wharfedale Diamond 12.3i B KLH Concord
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?
KLH Concord is the easier recommendation: it leads on most of the measured areas and costs less. Take Wharfedale Diamond 12.3i if its size, looks or fit in your room suit you better. If a subwoofer is in your plans, the bass gap largely stops mattering - you would be crossing over above 45Hz anyway, so judge these on the other rows instead. If your amplifier is modest, vintage or valve-based, KLH Concord 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.