Wharfedale Diamond 11.2 loudspeaker Measurements

Sidebar 3: Measurements

I used DRA Labs' MLSSA system and a calibrated DPA 4006 microphone to measure the right-hand sample of the Wharfedale Diamond 11.2's frequency response in the farfield, and an Earthworks QTC-40 for the nearfield and spatially averaged room responses.

My estimate of the Diamond 11.2's voltage sensitivity was 89dB(B)/2.83V/m, or 1dB higher than the specified 88dB. The Diamond 11.2's impedance is specified as "8 ohms compatible." However, the magnitude drops below 6 ohms in the midrange and the high treble. The minimum magnitude is 3.7 ohms at 215Hz (fig.1, solid trace), and there is a current-hungry combination of 5 ohms and –43° electrical phase angle at 129Hz. The Diamond 11.2 will work best with amplifiers that are comfortable with 4 ohm loads. There is a small discontinuity in the impedance traces at 230Hz, and an accelerometer-derived, cumulative spectral-decay plot reveals a very strong resonant mode at that frequency on the sidewalls (fig.2) as well as on the top panel.

1218wharf.WD112fig1.jpg

Fig.1 Wharfedale Diamond 11.2, electrical impedance (solid) and phase (dashed) (2 ohms/vertical div.).

1218wharf.WD112fig2.jpg

Fig.2 Wharfedale Diamond 11.2, cumulative spectral-decay plot calculated from output of accelerometer fastened to center of sidewall (MLS driving voltage to speaker, 7.55V; measurement bandwidth, 2kHz).

The saddle centered at 41Hz in fig.1 suggests that the reflex-loading slot is tuned to this frequency. The woofer, measured in the nearfield, had its minimum-motion notch, where the back pressure from the port resonance holds the cone stationary, at the same frequency (fig.3, blue trace). The slot's output (red trace) peaks between 25 and 80Hz, but its upper-frequency rolloff is marred by a strong peak at 750Hz and a discontinuity at 160Hz. The latter gives rise to a slight notch in the complex sum of the nearfield woofer and slot outputs (black trace below 300Hz). While there is the usual response peak in the upper bass, due to the nearfield measurement technique, this isn't quite as large as usual.

1218wharf.WD112fig3.jpg

Fig.3 Wharfedale Diamond 11.2, anechoic response on tweeter axis at 50", averaged across 30° horizontal window and corrected for microphone response, with nearfield woofer (blue) and port (red) responses and their complex sum (black), respectively plotted below 300Hz, 750Hz, and 300Hz.

Higher in frequency in fig.3, the black trace shows the Diamond 11.2's farfield response, averaged across a 30° horizontal window centered on the tweeter axis. It is respectably flat overall, though with a small notch in the upper midrange and an octave-wide, 4dB-high shelf in the top octave. This measurement was taken without the grille, which is how I preferred listening to the Wharfedales. With the grille, the height of the top-octave peak wasn't affected but the presence region was slightly attenuated. The plot of the Diamond 11.2's lateral dispersion, normalized to the tweeter-axis response (fig.4), reveals that the tweeter starts to become directional above 9kHz. In a normal-size room the on-axis peak will tend to compensate for this lack of off-axis energy, meaning that the Diamond 11.2's treble balance will sound neutral. The dispersion below the top octave is well controlled and the contour lines are relatively even. In the vertical plane (fig.5, again normalized to the tweeter-axis response), a suckout develops in the crossover region more than 5° above the tweeter axis. Make sure the stands you use with this Wharfedale are tall enough to place the tweeter axis on or just above the level of your ears.

1218wharf.WD112fig4.jpg

Fig.4 Wharfedale Diamond 11.2, lateral response family at 50", normalized to response on tweeter axis, from back to front: differences in response 90–5° off axis, reference response, differences in response 5–90° off axis.

1218wharf.WD112fig5.jpg

Fig.5 Wharfedale Diamond 11.2, vertical response family at 50", normalized to response on tweeter axis, from back to front: differences in response 45–5° above axis, reference response, differences in response 5–45° below axis.

The red trace in fig.6 shows the Diamond 11.2s' spatially averaged response in my room, generated by averaging 20 1/6-octave–smoothed spectra, taken for the left and right speakers individually using a 96kHz sample rate, in a vertical rectangular grid 36" wide by 18" high and centered on the positions of my ears. This was with the speakers as first set up in my room, in the same positions occupied by the similar-size Dynaudio Special 40s (blue trace) when I reviewed the latter for the September 2018 issue. The two models appear to have very similar responses throughout the midrange and low treble, but the Wharfedales have a touch more energy between 3 and 9kHz, and 3dB more in the top octave. The Dynaudios' in-room response is closer to what I've come to hear as being the correct amount of high treble, due to the increasing absorption by the room's furnishings as the frequency rises. More significant is that while the two pairs of speakers excite the lowest-frequency mode in my room to a similar degree, the Diamond 11.2s have less upper- and midbass energy than the Dynaudios. This is why I moved the Wharfedales closer to the room boundaries for the bulk of my auditioning.

1218wharf.WD112fig6.jpg

Fig.6 Wharfedale Diamond 11.2, spatially averaged, 1/6-octave response in JA's listening room (red); and of Dynaudio Special Forty (blue).

In the time domain, the Diamond 11.2's step response on the tweeter axis (fig.7) reveals that its tweeter and woofer are both connected in positive acoustic polarity. The tweeter's output arrives at the microphone before that of the woofer, but the decay of the tweeter's step doesn't blend smoothly with the start of the woofer's step. I wonder if this correlates with a small resonant ridge in the crossover region in the Wharfedale's cumulative spectral-decay plot (fig.8). Other than that, and some delayed energy associated with the on-axis suckout between 1 and 2kHz, this waterfall plot is very clean.

1218wharf.WD112fig7.jpg

Fig.7 Wharfedale Diamond 11.2, step response on tweeter axis at 50" (5ms time window, 30kHz bandwidth).

1218wharf.WD112fig8.jpg

Fig.8 Wharfedale Diamond 11.2, cumulative spectral-decay plot on tweeter axis at 50" (0.15ms risetime).

Other than its rather lively cabinet, the Wharfedale Diamond 11.2's measured performance is generally excellent, especially considering its affordable price.—John Atkinson

COMPANY INFO
Wharfedale, IAG UK
US distributor: MoFi Distribution
1811 W. Bryn Mawr Avenue
Chicago, IL 60660
(312) 738-5025
ARTICLE CONTENTS

COMMENTS
hollowman's picture

Thx, JA, for a fair and comprehensive review.
Since you mentioned the Rogers LS3-5A, any plans to review the new Falcon model?
Speaker: Jerry Bloomfield, Falcon Acoustics – Oxford, England (below) presented at RMAF this October:
https://www.youtube.com/watch?v=x9CzHERDEDc

supamark's picture

this one?

https://www.stereophile.com/content/falcon-acoustics-ls35a-loudspeaker

because Herb reviewed it about 3.5 years ago.

DougM's picture

Thanks JA for reviewing a truly affordable product, which is something I've often picked on you for not doing often enough. You're so expert, and so objective, and have so much experience listening to state of the art gear, that I sometimes feel that in pointing out the colorations that budget products exhibit, you sometimes inadvertently give a more negative impression of the piece being reviewed than you actually intend to. I think most listeners who are going to buy such budget gear won't notice these imperfections to the degree that you do. That being said, over the last decade or two, I've tried quite a few budget speakers, looking to find one that would satisfy me. And that search ended with the Diamond 9.1, which RJR (RIP) reviewed in Stereophile when it was a current model. Since I got them I've felt no need to look for any new speakers, as I feel that none would please me more than they do.

Ortofan's picture

... the $500/pr. ELAC Uni-Fi UB5 and/or the $600/pr. ELAC Debut 2.0 F5.2 foorstanding speakers?

bsher's picture

I, for one, would LOVE to see a fairly comprehensive comparison article of sub-$1000 bookshelf speakers like these Wharfedales, Elac UniFi B5, Dali Oberon 3, Totem Rainmakers, KEF Q350 (a more appropriate competitor), here or in S & V, including how they perform near the rear wall, on an actual bookshelf (where many of them will, out of necessity, end up). Anyone else?

Bogolu Haranath's picture

If the limit is $1,000, the new KEF LSX possibly will outperform them all .......... They are self powered and wi-fi enabled .......... Check KEF website for details :-) .............

Mauro's picture

Hey John and stereophile guys, you made me start this hobby with wharfedale diamond’s and I was pleased, you made me move on to KEF LS50’s and I am still really thankful..but it seems to me that we still have to wait for the next affordable standmount to beat KEF’s..or am I wrong?

Indydan's picture

But, I can say that the Ryan R610 will walk all over the Kef LS50. I have heard both, and there is no comparison. The Ryan is more expensive at US $2K, but still affordable.

Mauro's picture

There are not so many Ryan dealers in Europe but good to know that other companies are addressing the 2k market with good value for money products.

Other suggestions for the 1-2k$ range to challenge the LS50?

Bogolu Haranath's picture

Yes, the Elac Adante AS-61 bookshelf speakers are priced now at $2,000 ........ I saw some places where they are selling below $2,000 .......... See the review at Sound & Vision magazine, available on line ....... The LS-50s are now on sale for $1,000 :-) ...........

Bogolu Haranath's picture

You can also check Elac Navis self-powered bookshelf speakers, $2,000/pair ......... They don't need a power-amp :-) ............

Mauro's picture

In Europe Adante is over 3k, but Navis instead is around 2k!
I would really like to listen a pair of Navis and read a review with a nice comparison with the similar configuration of the passive Unifi UB5. The same applies to the KEF LS50 and LS50 wireless.
That’s not clear to me which are the advantages of going active. I think that editors should dig into this topic..

Who knows if stereophile is going to cover these active speakers. There seems to be a growing trend going on...

Bogolu Haranath's picture

You can drive active speakers with your phone ........ What do you think? :-) ........

Your phone can access to million and millions of songs available from streaming services :-) .........

Mauro's picture

I was more focused on time alignment of drivers, lower output impendance for lows and top quality amplifier for highs. But I guess you are making a point with music streaming for two channel guys..that sounds convenient indeed! :)

Bogolu Haranath's picture

You can evaluate the sound, as a total package, amp + speakers, with active speakers ........... You can use a pre-amp if you have other sources such as a turntable, DAC etc .......... If you like tube sound, you can use tube pre-amp :-) ..........

Mauro's picture

Interesting... Actually in these days after reading some stuff on ps audio bhk amp, I was also considering a hybrid amp (not from ps audio..out of my budget, but from Lector here in Europe). But what you suggest is interesting and in someway simpler: a tube preamp and an active speaker. Never thought of it!

Bogolu Haranath's picture

You can consider using Rogue Audio RH-5 tube pre-amp/headphone amp, $2,500 ......... It is rated Class-A by Stereophile and was reviewed by HR ......... It is also a great headphone amp, which can drive almost any headphone .......... RH-5 + Navis bookshelf, $4,500 .......... RH-5 + Navis floor-stander, $6,500 :-) ...........

Indydan's picture

Did not know you were in Europe. You might not get many speakers in the 1-2K range that will beat the LS50 in every manner. You could audition the Harbeth P3esr or the Neat Motive SX2. They excel at different things, and might be a better match for your amplification.

Mauro's picture

Really appreciated!

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