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Polk Audio Legend L200 Bookshelf and L400 Center Speaker Measurements and Analysis

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l200 outdoor testing4.jpg  l400 outdoor testing.jpg

The Polk L200 and L400 speakers were measured in free-air at a height of 7.5 feet at a 1-meter distance from the microphone, and the measurements were gated at an 11-millisecond delay. In this time window, some resolution is lost below 250 Hz and accuracy is completely lost below 110 Hz. Measurements have been smoothed at a 1/12 octave resolution.

L200 Spin-O-Rama.jpg

Polk L200 SpinoRama

The above graph shows the direct-axis frequency response and other curves that describe the L200’s amplitude response in a number of ways. For more information about the meaning of these curves, please refer to our article Understanding Loudspeaker Measurements Part 1. We were only able to do the set of measurements needed for this graph for the L200, which involve a frequency response test for every 10-degree increment over a complete circle around the speaker on both the vertical and horizontal axis (which add up to 72 response sweeps). The L200s put up a good showing here. The midrange region is admirably flat. There is a slight lift above 10 kHz, but that is not likely to be heard aside from adding a touch of ‘air’ on the recordings that actually have content that high. We can see from the directivity indexes that the ring radiator tweeter starts to beam a bit below 10 kHz, and those who want the full upper treble experience are advised to listen as close to on-axis as is practical with respect to the speaker, perhaps by toeing it in towards the listening area. The listening window curves and early reflections curve suggest a speaker that has good correspondence from on-axis to off-axis angles. 

L200 waterfall response 3D.jpg  L400 waterfall response 3D.jpg

L200 waterfall response 2D.jpg   L400 waterfall response 2D.jpg

The above graphs depict the speaker’s lateral responses out to 100 degrees in five-degree increments. More information about how to interpret these graphs can be read in this article: Understanding Loudspeaker Review Measurements Part 2. In these graphs, we see how well the off-axis angles match the on-axis response, and, for the most part, they do pretty well, excepting the beaming tweeter above 10 kHz.

One interesting feature we can see in comparing these responses is how the L400 maintains a broader dispersion at higher frequencies versus the L200. The reason for this is the smaller diameter of the midrange driver in the L400; generally speaking, the smaller the radiating diaphragm, the wider dispersion it will have at higher frequencies. The high-frequency beaming of the tweeters isn’t as big of a deal as the reader might imagine; there rarely is any substantial amount of spectral energy in most recordings above 10 kHz, so in the case that a listener has to sit at an off-axis angle where the upper treble is diminished, chances are they won’t be missing much anyway. 

Something else to note is the lack of lobing nulls in the L400. Every single center speaker I have ever tested had some kind of interference between the horizontally-aligned drivers at some off-axis angle. The better center speakers managed to push those nulls off to far off-axis angles, but the L400 just does not exhibit any horizontal interference whatsoever. The reason for that is that the horizontally-aligned bass drivers are low-pass filtered at a frequency low enough that, in their operational range, they act acoustically as a single source since the highest-frequency wavelengths that they are allowed to play is still greater than the distance that they are separated; their crossover frequency, 270 Hz, has a 52” long wavelength, and the actual center-to-center spacing between the bass drivers is about 26”. The reader will never understand how much joy it brings this reviewer to finally see this long-sought ideal finally achieved.

L200 Polar Map.jpg     L400 Polar Map.jpg

The above polar map graphs show the same information that the preceding graphs do but depict it in a way that can offer new insight regarding these speakers’ behavior. Instead of using individual raised lines to illustrate amplitude, these polar maps use color to portray amplitude, and this allows the use of a purely angle/frequency axis perspective. The advantage of these graphs is they can let us see broader trends of the speaker’s behavior more easily. For more information about the meaning of these graphs, we again refer the reader to Understanding Loudspeaker Review Measurements Part II.

In these graphs, we see that tweeter does start to beam a bit in upper treble; most dome tweeters have this characteristic, and we see that the ring radiator does too. The listener will want to be listening within a 30-degree angle to catch upper treble frequencies, but that is within a normal area for most listening positions. Those who are sensitive to upper frequencies or just want to take down the treble a bit can angle the speakers outward (or straight ahead with no toe-in, which puts a central listener about 20-30˚ off tweeter axis) a bit so that they are not facing the listening position directly. In a manner of speaking, just changing the direction of these speakers acts as a tone control; the further you listen off-axis, the less bright they will sound. One interesting aspect of the L400s is how even the dispersion is out to 8 kHz. The directivity matching between the tweeter, midrange driver, and bass drivers is superb in this speaker. Not only has Polk avoided the lobing problems in typical center speakers, they have excellent integration between all of the drivers for the off-axis response. Polk, now you are just showing off!

L200 Vertical Waterfall Response.jpg

The above graph shows the L200’s speaker’s response behavior along its vertical axis where zero degrees is directly in front of the tweeter, negative degree values are below the tweeter, and positive degree values are above the tweeter. There is nothing unusual about the measured performance here, and most two-way speakers have this kind of response. The vertical response doesn’t matter as much as the horizontal response, so long as the listener’s ear level is roughly level with the tweeter. One interesting aspect that is not easy to see from this particular graph is that the -10 degree angle is actually a bit flatter than the tweeter height response. So if you want the ultimate in linearity from the Polk L200’s, listen at an angle slightly below that of the tweeter.

L200 and L400 Low Frequency Responses.jpg 

The above graphs show the L200 and L400’s low-frequency responses that I captured using groundplane measurements (where the speaker and microphone are on the ground in a wide-open area). In these graphs we see a nicely flat response down to 50 Hz. Room gain may be able to net a usable bass response down to nearly 40 Hz. This extension is better than the average bookshelf speaker and center speakers, and it is no wonder that they didn’t benefit much from subwoofers on acoustic recordings. One aspect of these responses that I like to see is the omission of any kind of mid-bass bump that some manufacturers give to their bookshelf speakers to affect a deeper bass response than what is actually there. The Polk’s play it straight, and the low-frequency response is very linear. No exaggerated bass here. 

L200 Impedance and Phase.jpg   L400 Impedance.jpg

The above graphs show the electrical behavior of the L200 and L400 speakers. Polk specs these speakers as 4 ohm, and that is mostly correct in that this is too stiff of a load to qualify for a nominal 8 ohms or even 6 ohms. While the minima doesn’t really dig below 5 ohms, they do occur along with steep phase angles, and that may be a tough load for cheap amplifiers, especially the L400. I doubt that anyone who buys these speakers will end up pairing them with a budget AVR, so I don’t see this electrical load ever being a serious issue. One feature to note is the balanced impedance peaks in the low frequencies on the L200, and that means that the port length and diameter is a good fit for the enclosure size. The L400, on the other hand, looks to have relatively large ports for the enclosure size as can be seen from the much larger lower frequency peak. Port tuning can be seen to be right at 50 Hz for the L200s and around 45 Hz for the L400. Sensitivity measurements put the L200s at 86.3 dB for 2.83v at 1 meter and the L400 at 87.6 dB for 2.83v at 1 meter. These measurements are close to Polk’s own specifications for these speakers and are very normal sensitivities for bookshelf speakers and center speakers in this class. 

Conclusion

Expectations are high when a major loudspeaker manufacturl200 hero pair.jpger such as Polk launches a new flagship series. This is as it should be since no one doubts that a company like Polk has the resources to produce very well-engineered loudspeakers. The question for the Legend series is has Polk done something innovative with this opportunity or have they phoned in an unexceptional effort? In my opinion, Polk has released some exceptional loudspeakers that merit their higher cost.

Let’s briefly go over some of the strengths and weaknesses of these speakers before bringing this review to a close, and, as always, I will start with the weaknesses - or at least I would start with weaknesses but there just aren’t any serious weak points of these speakers. I could say they are a bit pricey, but you do get a well-conceived, well-designed, and well-built product for your money; if you want this level of audio performance, build quality, and nice appearance, it is just not going to be cheap. You also get the reassurance of good post-purchase support from a large company like Polk. Are they expensive? Yes, but you are getting your money’s worth.

The Polk L400 center speaker has to rank among the best I have ever tested.

Something else I could nitpick is that for the price, these aren’t very ‘expensive-looking’ speakers. As was discussed before, they are fairly conservatively styled and so are not flashy or glitzy. That might be a con for some people and a pro to others, but since good looks are a matter of personal preference, I can’t fairly hold that against them. All I can say is that I don’t think anyone could honestly say they look bad but perhaps a bit too restrained for some people’s tastes. If I wanted to stretch hard to find something negative to say about them, I might say that there was no need to include the ability to bi-wire or bi-amp with speakers of this design type, but Polk is just responding to market-demand here, and, unfortunately, there are audio enthusiasts who look for that feature, even from speakers that couldn’t really benefit from it.

l400 7.jpg 

Let’s now talk about the strengths of the L200 and L400 speakers. As was mentioned above, the overall performance is quite good. The L200s have a nice tonal balance along with a terrific soundstage that you could just disappear into. They also have very good dynamic range capability and bass extension for their bookshelf speaker form. For many musical tastes, the addition of a subwoofer is not needed. The L400 center speaker has to rank among the best I have ever tested. At $1,800, it’s an expensive center speaker, but it does everything extremely well. It totally avoids the off-axis problems of conventional center speaker designs, even three-way center speakers. It’s a center speaker that is so good it could easily be used as a left or right front speaker as well and would very likely make a great choice for a stereo pair. There is no reason that you couldn’t use three L400s for the entirel200 outdoors5.jpg front stage speaker setup if space permitted or in a large 3-section entertainment unit. Outside of the sound quality is the aforementioned build quality. These are hefty and substantial builds, and they feel like it. The packing and presentation are also in line with the pricing. Their sleek yet understated appearance make them a good fit in just about any internal decor; while they can get loud, they certainly don’t look loud. 

There is no shortage of competition in the price range of these bookshelf speakers and center speakers, but the Polk Legend bookshelf speakers and center speakers are rock-solid choices. They would be strong contenders for me were I shopping for speakers in this range. Those who are looking for speakers for movies and television watching should definitely pay close attention to the L400 center speaker. Consider that the center speaker carries the bulk of the weight of modern surround sound mixes. Many people buy speakers based on the left and right fronts, but for surround sound mixes, it makes far more sense to choose the speaker set based on the center speaker. It is the crux of modern sound mixes. The L400 is an outstanding center speaker that dodges the pitfalls of traditional center speaker design through flat-out intelligent engineering. Hopefully, other manufacturers will take a few notes from this design. The Polk Legend L200s and L400 have met my high expectations of what the engineers at Polk could accomplish at higher price points, and I can easily recommend them to anyone who wants their sound system to sound great.

The Score Card

The scoring below is based on each piece of equipment doing the duty it is designed for. The numbers are weighed heavily with respect to the individual cost of each unit, thus giving a rating roughly equal to:

Performance × Price Factor/Value = Rating

Audioholics.com note: The ratings indicated below are based on subjective listening and objective testing of the product in question. The rating scale is based on performance/value ratio. If you notice better performing products in future reviews that have lower numbers in certain areas, be aware that the value factor is most likely the culprit. Other Audioholics reviewers may rate products solely based on performance, and each reviewer has his/her own system for ratings.

Audioholics Rating Scale

  • StarStarStarStarStar — Excellent
  • StarStarStarStar — Very Good
  • StarStarStar — Good
  • StarStar — Fair
  • Star — Poor
MetricRating
Build QualityStarStarStarStarStar
AppearanceStarStarStarStar
Treble ExtensionStarStarStarStarStar
Treble SmoothnessStarStarStarStar
Midrange AccuracyStarStarStarStarStar
Bass ExtensionStarStarStarStar
Bass AccuracyStarStarStarStarStar
ImagingStarStarStarStarStar
Dynamic RangeStarStarStarStar
Fit and FinishStarStarStarStar
PerformanceStarStarStarStarStar
ValueStarStarStarStarhalf-star
About the author:

James Larson is Audioholics' primary loudspeaker and subwoofer reviewer on account of his deep knowledge of loudspeaker functioning and performance and also his overall enthusiasm toward moving the state of audio science forward.

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Recent Forum Posts:

shadyJ posts on October 03, 2020 05:50
Beave, post: 1422798, member: 77067
Stereophile review with measurements of the little brother Polk L100 bookshelf speakers here:

Stereophile Review of Polk L100

Looks like a little bit of a tough impedance, plus a big resonance can be seen on the port output around 700Hz.

I wonder if the bump ShadyJ saw in the response of the L200 speakers around 500-600Hz is also a port resonance showing up for that speaker?

Also, the ring radiator tweeter's dispersion is quite narrow, with it dropping off to the sides (beaming) starting as low as around 5kHz.
I did do near-field measurements of the L200, and I do see some evidence of a resonance at around 500Hz in a near-field measurement of the port. That may be cause for that off-axis peak in that range. I am guessing it is.
Beave posts on October 03, 2020 04:12
Stereophile review with measurements of the little brother Polk L100 bookshelf speakers here:

Stereophile Review of Polk L100

Looks like a little bit of a tough impedance, plus a big resonance can be seen on the port output around 700Hz.

I wonder if the bump ShadyJ saw in the response of the L200 speakers around 500-600Hz is also a port resonance showing up for that speaker?

Also, the ring radiator tweeter's dispersion is quite narrow, with it dropping off to the sides (beaming) starting as low as around 5kHz.
ryanosaur posts on May 14, 2020 18:16
Danzilla31, post: 1390949, member: 85700
Ryan

Look Ryan he even agrees with us he's being mean he linked it in the like section!

This is just too much somebody has to reign this guy in!
And all I did is ask if he Listened to them, yet. Nothing about his thoughts!

He probably has them boxed up and is using them as a makeshift coffee table while kicking back, drinking a beer, and enjoying those Polks.




BTW: Love you, Shady!
36160
Danzilla31 posts on May 14, 2020 13:32
Ryan
Danzilla31, post: 1390901, member: 85700
Man I'm so with you on this one Ryan Shady is being very mean to us in my opinion. More then usual!
Look Ryan he even agrees with us he's being mean he linked it in the like section!

This is just too much somebody has to reign this guy in!
kini posts on May 14, 2020 12:20
shadyJ, post: 1390289, member: 20472

Polk Audio wowed the audio world with their massive Legend L800 tower speakers, but those towering speakers have overshadowed the fact that Polk released other speakers in the Legend series also, although those other speakers did not boast Polk’s SDA technology. While the L800’s SDA technology was indeed impressive, we found the L800s to be a good loudspeaker in a multitude of other ways as well, so it stood to reason that the other speakers in the Legend series should have the same high level of engineering. We decided to put that theory to test, so in for review today we have the Polk Audio Legend L200 bookshelf speakers and L400 center channel speaker. Let’s dive in to explore these speakers and then listen to them and measure them to see if they keep the promises they make as a part of Polk’s flagship series…

READ: Polk Legend L200 Bookshelf and L400 Center Speaker Review
Thanks for another great review. And thanks for the music recommendation. Never heard of Kandace Springs. I now have all her albums in my curation.
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