Wharfedale EVO 4.1 Review (Speaker)

[amirm]

This is a review and detailed measurements of the Wharfedale EVO 4.1 bookshelf speaker. I purchased it new a couple of months ago thank to generous partial funding from a member. The EVO 4.1 costs US $799.

I chose walnut among the few colors it comes in:

As you see it uses AMT tweeter in a 2-way configuration. A passive radiator fires into the stand and air jets out the to sides. Back panel shows nice sized binding posts:

Measurements that you are about to see were performed using the Klippel Near-field Scanner (NFS). This is a robotic measurement system that analyzes the speaker all around and is able (using advanced mathematics and dual scan) to subtract room reflections (so where I measure it doesn't matter). It also measures the speaker at close distance ("near-field") which sharply reduces the impact of room noise. Both of these factors enable testing in ordinary rooms yet results that can be more accurate than an anechoic chamber. In a nutshell, the measurements show the actual sound coming out of the speaker independent of the room.

Measurements are compliant with latest speaker research into what can predict the speaker preference and is standardized in CEA/CTA-2034 ANSI specifications. Likewise listening tests are performed per research that shows mono listening is much more revealing of differences between speakers than stereo or multichannel.

Reference axis was the center of AMT driver (aligned by eye). It is getting colder with the measurement room temp at 15 degrees C.

Wharfedale EVO 4.1 Measurements
Acoustic measurements can be grouped in a way that can be perceptually analyzed to determine how good a speaker is and how it can be used in a room. This so called spinorama shows us just about everything we need to know about the speaker with respect to tonality and some flaws:

We see a rather stepped response. Bass is shelved down, then we get to midrange that is rather flat but then there is a wide and large resonance center around 3.8 kHz. Close up measurements of the radiating surfaces shows the reason for the latter:

Since it is in the crossover region, seems to me they could have pulled that down by adjusting the filter/crossover point but they chose not to do so.

Use of passive radiator means that internal resonances are not radiating out so good to see that.

Back to our spin graph, off-axis response rapidly drops off in upper treble which we can clearly see impacting early window reflections:

The tall AMT tweeter is beaming (surface too large relative to frequency being produced) causing that sharp drop off. This will be a recurring theme in measurements to follow including our predicted in-room response:

The resonance is quite prominent. But what is the effect of room reflections contributing up to 8 kHz but then sharply less so past that?

Let's quantify the beaming using our beam width graph:

We have reasonable directivity for a while but then physics takes over and beam width narrows logarithmically with frequency (shown as a line here since horizontal axis is in log). Below that beam width is a bit larger than usual so the imaging would be more diffused around the speaker (good thing in small speakers in my opinion).

Our contour map shows what we already know:

The AMT tweeter is taller than it is wider so beams even more in that direction:

With such a narrow directivity I would normally say "stay at tweeter axis" but in this case, I probed to see if any other response is better with respect to resonance and there is:

10 degrees is not much though so I am not sure it matters in practice.

Distortion is typical of speakers in this size and class:

Tweeter resonance seems to also be responsible for distortion in the 2 to 4 kHz. So would have definitely been nice if that was fixed in the design.

For fans of timing domain analysis, here are the impulse and CSD/waterfall graphs:

Edit: forgot the impedance graph:

Wharfedale EVO 4.1 Listening Tests and Equalization
Once in a while it is good to have a "control" to see if these ears are operating to spec. I started playing the EVO 4.1 and was surprised that I heard no brightness at all! If anything there was good bit of bass emphasis. I walked up to the speaker and put my ear next to AMT tweeter and as I expected, it was not playing. In the process of moving the speaker from measurement lab to listening room and tightening the bi-wire post, one had moved out of position so tweeter was disconnected. The woofer plays high enough frequency that the tweeter not being there did not have an immediate effect. But man, did putting it in the circuit did. There was dramatic amount of high frequency content and brightness.

Let me say as always that this kind of "showroom sound" does have a short term preferential effect. The sound is hyper detailed and since it only impacts lower treble, it is not overly hissy and lispy. But you do "hear into the recording" like nobody's business. On female vocals the focus on their voice becomes extreme as if their face is poking through the middle of the speaker. It requires a lot of discipline and understanding the unnaturalness of this sound to get you want to tame it and tame I did:

Once I pulled the resonances though, I thought I lost some sparkle so dialed a bit back in upper register per hole in the frequency response. Tonality was now more natural but I kept thinking the sound was a bit tubby. Just didn't like the bass for some reason. I decided to pull down the upper bass with that broad filter and that fixed the issue. I was throwing away too much of the response so I pushed the overall level a few notches to improve gain.

Once there, the sound was OK and maybe fine but I just couldn't enjoy it. Maybe it needs more surgery with EQ. Maybe it is the directivity. Either way, I could get into it.

I tested for sub-bass response. While many speakers in this class don't play it, the EVO 4.1 does but severely distorts it at medium to high levels. So best to use a high-pass filter.

At this point I stood back pondering if it is me that doesn't like the sound as the overall response is not that bad. So turned off EQ, listened for a few minutes but then quickly switched to Revel M16. Oh wow, what a revelation. The sound was so much warmer yet I could hear nice high frequency detail. The improvement was dramatic and not what I had expected.

Conclusions
Expectations are high when you go up from a few hundred dollars and are dealing with a small bookshelf speaker. I am afraid Wharfedale seems to have gone for marketing sound here rather than high fidelity. There is no excuse for that resonances in treble other than to please people in short-term listening and showroom setting. It is a shame as I think they could have corrected for it.

There are some positives in the form of the passive radiator that keeps internal resonances inside the box. And decent directivity index allowing equalization.

I can't recommend the Wharfedale EVO 4.1.

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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

 

[enio nery]

so majority of the money that you will pay for a pair of these goes to Aesthetics. i was contemplating on buying the 4.2S but i opted to buy a friend's Revel M16 Instead.

 

[Beave]

Looks like they prioritized the nice veneer more than they did the crossover.

If you still have the speakers, you could remove the binding straps for bi-wiring/bi-amping, then measure the responses of the woofer and tweeter separarately, without having the issues that one gets when doing nearfield responses.

 

[Beave]

so majority of the money that you will pay for a pair of these goes to Aesthetics. i was contemplating on buying for the 4.2S but i opted to buy a friend's Revel M16 Instead.

Haha, you beat me to it by about 1 second!

 

[amirm]

If you still have the speakers, you could remove the binding straps for bi-wiring/bi-amping, then measure the responses of the woofer and tweeter separarately, without having the issues that one gets when doing nearfield responses.

That's exactly what I did for the near-field measurements you see in the review.

 

[Beave]

That's exactly what I did for the near-field measurements you see in the review.

Oh, ok, thanks! Sometimes it's hard to tell with the tweeter response.

Edit to add: Upon looking a little closer, I can see that removing the binding straps cleans up the near-field responses by removing the contamination coming from the nearby driver (the woofer response bleeding into the tweeter response and the tweeter response bleeding into the woofer response). But you still have the lack of baffle step compensation on the woofer and some possible irregularities on the tweeter response due to the nearfield measurement. When removing the binding straps, you don't need to do nearfield responses to see the woofer and tweeter responses. Just a normal frequency response on axis for each would be revealing of driver responses and would tell us some about the crossover slopes.

 

[Beave]

How big is that woofer from surround edge to surround edge? They spec it as being a 5" woofer. It looks big mostly because of the large dark ring around it. Remove that, and then account for the lost area of the large phase plug/pole piece extension, and it starts to look pretty small.

 

[dfuller]

Well, that's a resounding "Meh." isn't it.

 

[diddley]

Well that's one of the list, Thanks for the review Amir and the effort.

 

[amirm]

But you still have the lack of baffle step compensation on the woofer and some possible irregularities on the tweeter response due to the nearfield measurement. When removing the binding straps, you don't need to do nearfield responses to see the woofer and tweeter responses. Just a normal frequency response on axis for each would be revealing of driver responses and would tell us some about the crossover slopes.

How would you isolate the port from woofer response then?

 

[Beave]

How would you isolate the port from woofer response then?

Good question, and I don't know the answer. You might not be able to, or maybe somebody else more familiar with speaker testing knows how.

 

[D!sco]

What a shame. I had reasonably high hopes for this series. Maybe the three way with the 6.5" and dome midrange will be better, but this isn't confidence inspiring.

 

[Dennis Murphy]

What a shame. I had reasonably high hopes for this series. Maybe the three way with the 6.5" and dome midrange will be better, but this isn't confidence inspiring.

That was a surprise. Wharfedale's tend to have a reputation for a warm sound. I happened across this review of the 4.1 on Crutchfield:

Overall, solid build and great looking speaker. They do have that Wharfedale sound, decent bass and mids, but the very reserved on the top end. Felt like a blanket was over the tweeter.

Guess it's not best to rely on owner reviews.

 

[boblinds]

Rate This Speaker? WTF?? Since I'm guessing that no effort is going into verifying that voters have actually heard, much less measured, the speaker, what conceivable objective value does this vote have? What has happened to Audio SCIENCE Review?

 

[respice finem]

Design over performance IMHO. Probably it could be made to perform better as a fully active design with DSP crossover, but then it would have to compete with studio monitors...

 

[amirm]

Rate This Speaker? WTF?? Since I'm guessing that no effort is going into verifying that voters have actually heard, much less measured, the speaker, what conceivable objective value does this vote have? What has happened to Audio SCIENCE Review?

People are asked to vote based on "scientific" measurements provided in the review. That is, their interpretation of the data.

 

[Doodski]

Rate This Speaker? WTF?? Since I'm guessing that no effort is going into verifying that voters have actually heard, much less measured, the speaker, what conceivable objective value does this vote have? What has happened to Audio SCIENCE Review?

It's just a arbitrary voting thing. Sometimes I vote most times I don't.

EDIT: I gave this speaker a #3 Fine. It has exaggerated highs and I EQ that way anyway so it would maybe be OK for me.

 

[Walter]

That was a surprise. Wharfedale's tend to have a reputation for a warm sound. I happened across this review of the 4.1 on Crutchfield:

Overall, solid build and great looking speaker. They do have that Wharfedale sound, decent bass and mids, but the very reserved on the top end. Felt like a blanket was over the tweeter.

Guess it's not best to rely on owner reviews.

I wonder if that reviewer had the same issue Amir did when he first started listening? Maybe he's been listening to nothing but the woofer the entire time.

 

[FeddyLost]

Looks like EVO 4.1 is a kind of forced decision due to single tweeter for whole EVO 4 line. Most of other EVO 4 speakers use 2" dome midrange and higher crossover for tweeter.
This speaker is bad compromise as it uses small and heavy woofer (to have decent bass) with this AMT. Proper crossing it around 4K would make lower distortion but most probably induce big suckout in mid-highs, so design team leaned towards "showroom sound".

 

[pierre]

Directivity is very narrow. The speaker would work well nearfield with EQ but at longer distance I don't think so.

Score is 4.6 and would be 6.7 with a perfect subwoofer.
With an EQ optimizing the LW, the score goes up to 6.2 (w/sub 8.1).

Here is a possible EQ

EQ for Wharfedale EVO 4.1 computed from ASR data
Preference Score 4.6 with EQ 6.2
Generated from http://github.com/pierreaubert/spinorama/generate_peqs.py v0.14
Dated: 2021-11-21-12:23:31
Preamp: -0.2 dB
Filter  1: ON PK Fc  1494 Hz Gain -2.69 dB Q 0.10
Filter  2: ON PK Fc  4072 Hz Gain -2.99 dB Q 3.05
Filter  3: ON PK Fc  1638 Hz Gain +2.04 dB Q 2.50
Filter  4: ON PK Fc  8466 Hz Gain +1.59 dB Q 4.00
Filter  5: ON PK Fc  5490 Hz Gain -0.99 dB Q 4.00
Filter  6: ON PK Fc   780 Hz Gain +0.71 dB Q 4.00
Filter  7: ON PK Fc  2504 Hz Gain +0.58 dB Q 4.00
Filter  8: ON PK Fc  3354 Hz Gain -0.63 dB Q 4.00
Filter  9: ON PK Fc   297 Hz Gain -0.71 dB Q 4.00

And here we see the difference on the psinorama:

Optimising the LW also optimise the PIR: