Wharfedale Diamond 10.2 review part 1

 

Unpacking:

 

One box contains a pair of loudspeakers. When opening the box we can see that it’s fairly protected from shipping damage by using molded cardboard on each corner of the speaker cabinet and each speaker is wrapped in its own plastic foam and plastic bag.

The box also contains a plastic folder with the provided manual together with a quick setup guide. The manual covers the entire Wharfedale Diamond 10 range, including subs and center channel speakers. The manual is quite informative and even the most novice Hifi enthusiast should be able to understand it.

When unwrapping the loudspeakers from the plastic foam and bag I was a bit surprised to see that the speakers where a bit dusty and that they needed some dusting. Apparently the factory where they pack the loudspeakers must be dusty or maybe they have been stored in a dusty environment before being packed.

First look:

 

I must say that the Diamond 10.2 at a first glance looks quite elegant and luxurious considering the modest price. My speaker has the Walnut Pearl veneer finish and it looks good and almost like real veneer even though it’s made of fake plastic veneer.

The front baffle has a high gloss piano black finish which contrasts nicely against the Walnut Pearl veneer and the plastic chrome design rings on the mid-woofer and tweeter.

The 165mm Kevlar (6.5”) mid-woofer has truncated frame to fit the slim front. The cone area (150cm2) however suggests that this is a 7” and not a 6.5” mid-woofer.

The 25mm fabric soft dome (1”) tweeter is mounted in a plastic design ring with a metal diffusion grid for dome protection.

The Diamond 10.2 has dual binding posts for bi-wire or bi-amping capabilities. The binding post plate is made of metal even though it looks like plastic and must say I like this unusual set of binding posts.

If you are using speaker cable with banana plugs as I do you must first remove some plastic protection caps from the binding posts before using them. These plastic protection caps are a bit tricky to remove, but it’s easiest to remove them with your finger nails. Here could a wife with long finger nails come in handy! 🙂

If we take a closer look we can see some minor defects on the veneer which isn’t perfectly attached and we have some scratches here and there. Nothing big, but it’s fully visible at closer range. If you take a step back from the speaker it looks flawless.

One of the front grill covers had some visible glue remnants on the upper front corner and the other speaker had what looks like a small thumbprint on the mid-woofer cone. It looks like the Kevlar cone has been subjected to some rough treatment when attached to the speaker cabinet.

In one of the speakers only the lower bass-reflex port functioned properly the upper port was blocked by damping material. This had to be fixed by unmounting the mid-woofer and adjusting the damping material.

None of these minor defects except the blocked port would affect the performance of the loudspeaker, but the cabinet finish rating drops a couple of notches. Placed on a stand and looking from one step back, they look gorgeous.

Cabinet construction:

 

The Diamond 10.2 has a curved cabinet with a 16mm thick 4 layer MDF sandwich construction for the side panels. The front baffle is made of 25mm MDF and the back, top and bottom uses 16mm MDF. The cabinet has an internal 16mm MDF bracing from top to bottom

The speaker is rather light weight and weighs about 6.5 Kg including the front grill. It seems like the side panel sandwich construction is the reason for this. I would have preferred solid side panels, back, bottom and top of at least 19mm MDF.

A simple knock test on the side panels reveals some resonances.

The back of the cabinet is equipped with dual 38mm rear bass-reflex ports, one behind the tweeter and one behind the mid-woofer. The ports are slightly conical in shape.

I think the lower port is redundant and the chosen position isn’t optimal. A 50mm (2”) port would roughly have the same area as the dual 38mm ports and it  would have been more suitable if it was located behind the tweeter.

Each port has a mesh net on the end of the port to prevent accidental filling the cabinet with unwanted items, which is a good thing for a family with small children. 🙂

The front grill cover is fastened on the head of the tweeter and mid-woofers Allen wooden screws. The drivers are fastened with 6 screws for the mid-woofer and 4 screws for the tweeter.

The tweeters front plate is cut-out in order to have a closer (130mm) center to center spacing between the mid-woofer and tweeter.

First listening impressions:

 

Before I sat down and listen to the Diamond 10.2 loudspeaker I let them break-in for about 5 hours at a moderate listening level. During this period when I walked around in the room I noticed it had a nice bass extension. As a background music listening speaker they sounded nice and had an overall warm sound characteristic.

After the short break-in period I sat down for a more critical listening session and the first impression was the same. It had good bass extension and warmth, but something didn’t sound right!

What I heard was some sort of unbalance between the left and right loudspeaker and some muddiness in the upper mid-range. Then I listened to one loudspeaker at a time and I thought the left loudspeaker sounded more natural than the right.

What could be wrong? The diffuse and somewhat unfocused sound I heard could be a classical out of phase issue in one of the loudspeakers. I checked my loudspeaker cabling and that was ok. Next step was to try to reverse the polarity on one of the drivers in the right loudspeaker.

Luckily this was easy managed thanks to the dual binding posts. First I tried to reverse the tweeter and that didn’t help. In fact it was even worse. Now I clearly heard that the left and right loudspeakers where out of phase with each other.

Then I switched back the polarity of the tweeter and switched the polarity on the mid-woofer instead and that was it! Now the sound fell in place. Clearly the right loudspeaker’s mid-woofer were connected out of phase.

After a long listening session I still felt that the right loudspeaker had a slightly different sonic character as it sounded a tiny bit darker than the left speaker. Not much, but noticeable. When I swapped the left and right speaker the impression stayed. Clearly it was nothing wrong in the signal chain.

Troubleshooting:

 

What to do? I ended my listening session here as it was time to examine the loudspeakers in more detail. I dismounted the tweeters and mid-woofers from both enclosures and checked the wiring.

It seemed to be correctly wired. The red wire to plus and the black wire to minus on the mid-woofer. The yellow wire to plus and the blue wire to minus on the tweeter. Both loudspeakers appeared to be wired correctly.

Then I dismounted both cross-over boards from the back wall of the loudspeakers and…….


Can you see it? Yes, on the right speaker’s cross-over board the red and black wire to the mid-woofer is swapped!

Apparently the loudspeaker driver assembler guy connected the color of the wires correctly, but the guy who made the cross-over board did a faulty job.

It’s really bad !

Sum up:

 

If I sum up my impressions so far with the dusty speakers, glue remnants on the front grill, minor veneer imperfections, blocked bass-reflex port and the faulty wired cross-over, the build quality seems to be fairly low. Ok, I might have had bad luck with my set of speakers, but still……

Perhaps this is the price to pay for a China made modest priced loudspeaker, but one could wish for a better quality control at the factory. This is something Wharfedale clearly needs to work on and improve.

I intended to describe my sound impressions of the Wharfedale Diamond 10.2 in more detail in this part of the review, but I will wait until I’ve done more tests and measurements on the speakers in order to fully explore any issues needed to be corrected.

Perhaps this wasn’t the perfect start for a review, but in the review part 2 I will do a full set of measurements including on and off-axis frequency measurements, impedance and distortion measurements. I will also comment my findings from the measurement results of the Diamond 10.2 loudspeaker.

 
Go to review part 2!