I'm presenting a review of the Wharfedale Diamond Series Center, specifically the 12.C.
Personally, I find this series to offer excellent finish quality for its price range.
Let's delve into its performance!
Impedance
The speakers show stable performance even with increased output signals.(0.1 V to 2.83 V)
I believe this is a common feature of speakers with good fundamentals.
However, there's a slight resonance at around 300Hz.
Frequency Response
The tonal balance across the full spectrum is fairly decent.
Distortion is noticeable around 3~5kHz.
The lower limit of the bass is approximately 82.3 Hz (-6dB), and there's a gentle decline at -12dB/oct starting from around 120Hz.
Nearfield Measurement
The measurements looks clean without unnecessary complications, but the high-frequency response of the woofer suggests that the linear distortion on the face of the speaker is due to the woofer's response around the crossover.
Directivity
The horizontal directivity seems entirely uncontrolled.
The directivity errors created by the MTM structure's twin woofers can be quite bothersome.
I'll revisit this aspect when discussing The Beam width.
The vertical directivity seems unlikely to produce significant errors due to its structure.
However, an uncontrolled bloating is observed in the crossover.
Beam width
The primary purpose of setting up a center speaker is undoubtedly for home theater configuration.
While this might not be a serious issue if used alone, it becomes a significant drawback for multiple viewers as the allowable horizontal (left/right) tolerance angle is less than +/- 20 degrees over a wide range of 1~3kHz.
Polar Plot
This intuitively highlights the issues with horizontal directivity mentioned earlier.
It's evident that there's significantly less radiation horizontally compared to directly in front, especially around 1~2kHz, with a narrow allowable angle.
THD
The performance is excellent.
While distortion levels below 100Hz are low and consistent, we omit this part due to the characteristics of the EIHD plot, which might unduly favor the test speaker.
The first SPL graph reveals persistently low distortion even in the bass.
At 95dB SPL@1m, the performance continues to impress.
Multitone test
The multitone performance is also exceptional.
Everything looks clean and faultless.
80Hz~
The same goes for measurements from 80Hz and up.
Despite the unit's resonant frequency being around 100Hz, limiting signals below 80Hz seems to reduce distortion.
The speaker's defense against distortion is so robust that no anomalies were detected, even at 96dB SPL@1m, where multitone distortion remains at -30dB.
Compression test
The compression performance is outstanding.
A sharp spike at around 180Hz is identified as a measurement error rather than a characteristic of the speaker. It demonstrates strong performance across the entire spectrum.
Grill test
The grill introduces significant linear distortion.
It notably enhances frequencies particularly around 5~7kHz by up to 3.5dB.
My personal take is that for a center speaker, its narrow horizontal directivity across a broad spectrum is inevitably a major limitation.
However, considering the price(USD 220.0 in South Korea), it's bewildering how this speaker manages such strong distortion resistance.
Moreover, the finish is also of a very high standard.
I apologize for repeating myself, but it's baffling how such a product can be created at this price, even managing to include a relatively excellent finish.
That's all for my review.
