Polk Signature Elite ES20 Review (Bookshelf Speaker)

[Power Pop 23]

thanks!! I want to now if the SE worth the 180usd difference.

Amir reviewed the smaller Polk 'S15' and the Polk 'ES20'

Polk Audio Signature S15 Speaker Review

This is a review and detailed measurements of the Polk Audio Signature S15 bookshelf speaker. It was kindly sent to me by a member for the review and costs US $229 per pair. If I did not tell you the price, you would think the S15 retails for $1000 given its very nice and "high-end" looks...

www.audiosciencereview.com

Polk Signature Elite ES20 Review (Bookshelf Speaker)

This is a review and detailed measurements of the Polk Signature Elite ES20 bookshelf speaker. I purchased it from Amazon for US $349 a pair including shipping. I really like the look and finish of this series from Polk. Despite budget pricing, it looks nice and purposeful as you can tell...

www.audiosciencereview.com

based on these reviews, I would buy the Polk ES20 instead of the S20

 

[maxcerruti]

This is a review and detailed measurements of the Polk Signature Elite ES20 bookshelf speaker. I purchased it from Amazon for US $349 a pair including shipping.
View attachment 205739

I really like the look and finish of this series from Polk. Despite budget pricing, it looks nice and purposeful as you can tell from the unique rear port plate:
View attachment 205740

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 tweeter center. No grill was used. Measurement temperature was about 62 degrees F (17 degrees C).

Polk ES20 Measurements
Let's start with our usual "spinorama" graph:
View attachment 205741

On axis is reasonably good, marred by some resonances between 600 and 1000 Hz. And some unevenness in high treble area. There is a directivity dip around 4 kHz.

I forgot to note on the graph the deep bass extension. F10 is at nearly 35 Hz! This is partly due to a cabinet that is deeper than normal.

We see the cause of that roughness around 600 Hz in our near-field measurements:

View attachment 205742

We see more of a dip in directivity caused in vertical axis mostly:

View attachment 205743

Fortunately my listening room has a thick carpet and high ceilings so I will be hearing a more optimal off-axis response than averaged above.

Predicted in-room response with my custom trend line is thus:
View attachment 205745

I usually draw the trend line after my listening tests are completed and do in a manner that is consistent with that experience. See the next section.

I was impressed by the smooth and constant horizontal beam width and dispersion:

View attachment 205746
View attachment 205747

This also has wider than usual response which should create a more diffused field around the speaker (my preference).

Vertically we have the usual restrictions but again, the sweet spot is larger than I normally see in this class:
View attachment 205748

I like the low distortion especially at 86 dBSPL:
View attachment 205749

But notice how that resonance around 600 Hz is also showing up here in the form of distortion. This means that we will have impact beyond that frequency due to harmonics.
View attachment 205751

We see the same resonance in impedance graph and waterfall:
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Finally for fans of timing tests, here are the impulse and step response:
View attachment 205754

View attachment 205755

Polk ES20 Listening Tests
My female starting track which lacks bass sounding a bit muddy/tubby and somewhat bright. So I brought out the EQ tool:

View attachment 205756

First filter was around 600 Hz. It is a small filter but per past experience, it not only removed a bit of muddiness but also reduced distortion. The latter caused the sound to be more open and clear. Once there, on tracks with good bass, the sound was more or less balanced. But with female tracks without such, it sounded too bright to me. A quick and dirty shelving filter fixed that nicely.

Once there, I was extremely impressed with the fidelity. Track after track sounded beautiful. Not only was the tonality right but there was this clarity and lack of distortion that kept impressing me. ES20 could play pretty loud and distorted gracefully in that the woofer just lost deep bass and became a tubby. Pull back a bit and you were golden.

Conclusions
I can see Polk having to both want to create an accurate speaker while working within strict budget and retain channel that demands "showroom sound." To that end, they have done a very good job here, producing bass response that is way above what you expect. And do so with very little distortion. The only issue is the port/cabinet resonance which makes the sound muddy and screws up upper bass a bit. And elevated treble which can be a bit much if bass response is not there. Fortunately both of these factors are excess output meaning EQ not only fixes them, but also reduces distortion. Result is a speaker and sound that you can really be proud of.

I can recommend the Polk Signature Elite ES20 as is but hugely so with equalization. You are getting so much performance for so little money.

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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/

Hi Amir, thanks for the great review! I bought the speakers and happy with them so far! I am an absolute beginner when it comes to parametric EQ, but I have applied your suggested EQ in my WiiM amp app and the speakers sound better! They are still a bit bass-heavy, though, and boomy and my next door neighbour claims he can definitely hear the bass through our shared wall! Can you recommend a further parametric filter (in addition to the above) to make the bass less boomy but still retain some bass (which is the reason I bought these speakers for)? Thx so much!

 

[ShadowBoxer]

You can typically reduce the boomy mid-bass by decreasing FR around 250HZ. Tweak the Q (wider or narrower) to your listening taste. Same with the PEQ center freq point. Possibly moving it down (but probably not up). This FR range depends on your room, so someone else giving you the precise numbers they use in their room would likely not be the correct parameters for you. Experimentation with placement, or even better, measurement with a microphone & software, may be necessary for the ideal optimization.

Bass freqs are the most prone to travel through walls...just the nature of physics.

 

[maxcerruti]

You can typically reduce the boomy mid-bass by decreasing FR around 250HZ. Tweak the Q (wider or narrower) to your listening taste. Same with the PEQ center freq point. Possibly moving it down (but probably not up). This FR range depends on your room, so someone else giving you the precise numbers they use in their room would likely not be the correct parameters for you. Experimentation with placement, or even better, measurement with a microphone & software, may be necessary for the ideal optimization.

Bass freqs are the most prone to travel through walls...just the nature of physics.

Thx so much!! Given I am a newbie in this field, could you please explain how I action whet you said via the WiiM amp app settings? I can choose a filter type (LS, PK or HS), a frequency for this , a gain and a Q value by typing or increasing / decreasing values.

Much appreciated

 

[ShadowBoxer]

You might try the (LS) low-shelf (ie bass) filter first. This will be easier if the PEQ tool allows you to visualize the curve.

 

[staticV3]

Hi Amir, thanks for the great review! I bought the speakers and happy with them so far! I am an absolute beginner when it comes to parametric EQ, but I have applied your suggested EQ in my WiiM amp app and the speakers sound better! They are still a bit bass-heavy, though, and boomy and my next door neighbour claims he can definitely hear the bass through our shared wall! Can you recommend a further parametric filter (in addition to the above) to make the bass less boomy but still retain some bass (which is the reason I bought these speakers for)? Thx so much!

If you or a friend has an iPhone, try measuring the in-room response using HouseCurve.

In the HouseCurve settings, set smoothing to Off to clearly see your bass peaks and dips.

You will most likely have one or two significant peaks in the bass response, which are frequencies of constructive interference.

Take note of the exact frequency and height in dB, and add a Peaking filter with matching frequency, but inverse dB in the WiiM App.

If you have a +11dB peak at 78Hz, add a 78Hz, -11dB Peaking filter in WiiM.

Play around with the Q value to best match the peak for a smooth response.

You can take consecutive measurements as you refine the EQ to help find the best settings.

You can also let HouseCurve calculate the ideal PEQ settings for you.