• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Polk T50 Review (Floor Standing Speaker)

valerianf

Senior Member
Joined
Dec 15, 2019
Messages
411
Likes
239
Location
Los Angeles
If at $150 Polk succeeds to make some margin it means that other manufacturers are amassing gold with their huge margins.
By the way I have some $50 bookshelf speakers from Polk and they are doing well for the surrounds.
 

Maiky76

Senior Member
Joined
May 28, 2020
Messages
340
Likes
2,586
Location
French, leaving in China
This is a review and detailed measurements of the Polk T50 tower speakers. I bought this recently for $149 from Amazon.

As you can imagine, a floor standing speaker at this price has to be quite light and this one definitely is. I can easily lift it as it weighs less than many bookshelf speakers. What a marvel of cost optimization:

View attachment 140541

Yes, my system area is dusty. Do you want more reviews or clean listening room???

This is a 2-way speaker with two passive radiators to improve bass response.

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.

I performed over 1000 measurement which resulted in error rate of about 1%.

Reference axis was the tweeter center. Grill was not used.

Polk T50 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:

View attachment 140542

I expected the response to be horrific but it is not that bad. Yes we have a peak around 1 kHz and then shelving up of the highs which is a requirement for "showroom selling" against its competitors which boost the heck out of that region.

Hard to see the sources of the uneven response from near-field measurement:

View attachment 140543

I guessed that the peaking at 1 kHz may be due to passive radiators resonating. The math is too complex to visually confirm though.

Early window frequency response shows vertical directivity messing with overall sum:
View attachment 140544

As noted -- and it is how I have my room -- use a thick carpet. That should be a nice absorber from 1 kHz up which we need to fix that trough and extra high frequency energy. High ceilings help to reduce the impact of bounce in that direction. Or you can stick an ugly absorber up there.

Predicted in-room response is not super smooth:
View attachment 140545

The effect of elevated treble is obvious. But that peak at 1 kHz followed by slight dip, not so much.

Edit: forgot to include distortion graphs:
View attachment 140563

View attachment 140564

Horizontal beam width is again, not too bad if we don't try to be too critical:

View attachment 140546

View attachment 140547

Vertical directivity gets worse if you sit below tweeter so tilt the speaker forward if that is the case:

View attachment 140548

Impedance is the typical 4 ohm or so:

View attachment 140549

Tons of resonances are visible likely due to think cabinet and who knows what else.

Polk T50 Listening Tests and Equalization
I must say, first impression was not bad at all. Unlike just about any bookshelf speaker, the T50 is able to handle tons of power and gets quite loud and dynamic with little evidence of stress. Throwing difficult sub-bass material at it didn't impact it since it simply doesn't try to play them (its bass response has a sharp cut off). Yes, there is a bit of brightness but judging that is often problematic as you don't know the content's spectrum and lack a frame of reference.

Best way to determine audibility of frequency response is to try to straighten it and see if you like it better. That is precisely what I do with EQ:

View attachment 140550

Ignore the first dip as that is for my room. Without it, there is enough bass activation to make the sound a bit boomy. The rest of the filters thankfully are mostly reduction which help with distortion as well. With all of them in place, the difference was not night and day but enough to make the T50 very enjoyable to listen to. Call me surprised!

Conclusions
Going into this review I expected the T50 to be junk. It did not turn out that way. It is a miracle of engineering and manufacturing to get a floor standing speaker in my hands for just $149 and have it not be broken. Objectively there are some issues but somehow subjectively, it seems less flawed. With a bit of EQ, it improves even more to a proper "hi-fi" class. Despite cheap bookshelves, the T50 is able to produce lots of volume and dynamics which I really value and enjoy.

I am going to recommend the Polk T50 especially with equalization.

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

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Hi,

Here is my take on the EQ.

These EQ are anechoic EQ to get the speaker right before room integration. If you able to implement these EQs you must add EQ at LF for room integration, that usually not optional… see hints there: https://www.audiosciencereview.com/...helf-speaker-review.11144/page-26#post-800725

The raw data with corrected ER and PIR:

Score no EQ: 3.7
With Sub: 5.7

Spinorama with no EQ:
  • Lots of resonances -> need better internal damping
  • Directivity is not that smooth
Polk T50 No EQ Spinorama.png


Directivity:
Better stay at tweeter height or just above
Horizontally, better toe-in the speakers by 10/20deg and have the axis crossing in front of the listening location, might help dosing the upper range.
Polk T50 2D surface Directivity Contour Only Data.png


Polk T50 LW Better data.png


EQ design:
I have generated two EQs. The APO config files are attached.
  • The first one, labelled, LW is targeted at making the LW flat
  • The second, labelled Score, starts with the first one and adds the score as an optimization variable.
  • The EQs are designed in the context of regular stereo use i.e. domestic environment, no warranty is provided for a near field use in a studio environment although the LW might be better suited for this purpose.
Score EQ Amirm: 4.1
with sub: 6.1

Score EQ Score: 5.6
with sub: 7.5

Code:
Polk T50 APO EQ Score 96000Hz
July122021-105756

Preamp: -0 dB

Filter 1: ON PK Fc 351.50,    -1.07,    1.83
Filter 2: ON PK Fc 982.92,    -5.29,    2.26
Filter 3: ON PK Fc 5379.97,    -0.71,    1.67
Filter 4: ON PK Fc 6057.75,    -1.38,    1.39
Filter 5: ON PK Fc 12724.75,    -3.70,    1.34

Polk T50 EQ Design.png


Spinorama EQ Amirm
Polk T50 Amirm EQ Spinorama.png


Spinorama EQ Score
Polk T50 Score EQ Spinorama.png


Zoom PIR-LW-ON
Polk T50 Zoom.png


Regression - Tonal almost flat On when Score EQed
Polk T50 Regression - Tonal.png


Radar no EQ vs EQ score
Nice improvements
Polk T50 Radar.png


The rest of the plots is attached.
 

Attachments

  • Polk T50 APO EQ Score 96000Hz.txt
    293 bytes · Views: 25
  • Polk T50 Vertical 3D Directivity data.png
    Polk T50 Vertical 3D Directivity data.png
    1.3 MB · Views: 26
  • Polk T50 Horizontal 3D Directivity data.png
    Polk T50 Horizontal 3D Directivity data.png
    1.3 MB · Views: 28
  • Polk T50 Normalized Directivity data.png
    Polk T50 Normalized Directivity data.png
    994.2 KB · Views: 26
  • Polk T50 Raw Directivity data.png
    Polk T50 Raw Directivity data.png
    1.3 MB · Views: 31
  • Polk T50 Reflexion data.png
    Polk T50 Reflexion data.png
    553.1 KB · Views: 32
  • Polk T50 LW data.png
    Polk T50 LW data.png
    512.1 KB · Views: 32
  • Polk T50 2D surface Directivity Contour Data.png
    Polk T50 2D surface Directivity Contour Data.png
    301.3 KB · Views: 36
  • Polk T50 3D surface Vertical Directivity Data.png
    Polk T50 3D surface Vertical Directivity Data.png
    436 KB · Views: 33
  • Polk T50 3D surface Horizontal Directivity Data.png
    Polk T50 3D surface Horizontal Directivity Data.png
    436.2 KB · Views: 39
Last edited:

AVKS

Active Member
Joined
Mar 5, 2020
Messages
106
Likes
131
They've sold for as little as $75 each and, with performance like this, represent very high value in this price bracket. No idea if/when they'll get that cheap again though.
 

Putter

Senior Member
Forum Donor
Joined
Sep 23, 2019
Messages
429
Likes
655
Location
Albany, NY USA
Yeah, when I got to 2-way with two passive radiators, I was thinking 'ooh, I think the marketing people let the engineers figure that part out... wonder how it worked out...'

From what I've read the passive radiator should be 1.5 to 2x the size of the woofer (from http://www.mh-audio.nl/Calculators/PassiveRadiator.html - ALWAYS use a passive radiator that is larger in diameter than the active driver, as the displacement of the passive radiator usually has to be 1.5 to 2 times that of the driver.) So they got that right using a double passive. It may be a fool's errand, but I have to wonder if some extra bracing and absorbent materials could go some way to improving the response. In other words, it's a modder's dream, cheap enough to fool around with and good enough response that a minor crossover mod could improve.
 
Joined
Jun 12, 2021
Messages
8
Likes
9
From what I've read the passive radiator should be 1.5 to 2x the size of the woofer (from http://www.mh-audio.nl/Calculators/PassiveRadiator.html - ALWAYS use a passive radiator that is larger in diameter than the active driver, as the displacement of the passive radiator usually has to be 1.5 to 2 times that of the driver.) So they got that right using a double passive. It may be a fool's errand, but I have to wonder if some extra bracing and absorbent materials could go some way to improving the response. In other words, it's a modder's dream, cheap enough to fool around with and good enough response that a minor crossover mod could improve.


Thanks for answering a question about these speakers I've had from the first time I saw them advertised - Why two passive radiators? That link was helpful. Thanks for sharing it.
 

ROOSKIE

Major Contributor
Joined
Feb 27, 2020
Messages
1,225
Likes
2,153
Location
Minneapolis
Someone with a commercial account could chime in, but I’m getting ~$110 at the cheapest to ship from Florida to California for 1 of these; so yeah, expensive.
Some larger comercial companies negotiate extremely low shipping. Polk is pretty big.
Could even be as low as $10/$20 or less. I beleive Amazon pays UPS only around $6 per package essentially at a flat rate, that is likely lower than most anyone else can negotiate.
I have heard some places just pay a monthly rate for as many items as they can ship.
 

ROOSKIE

Major Contributor
Joined
Feb 27, 2020
Messages
1,225
Likes
2,153
Location
Minneapolis
Thanks for answering a question about these speakers I've had from the first time I saw them advertised - Why two passive radiators? That link was helpful. Thanks for sharing it.
You need double the displacement of the active driver. You can get that any number of ways.
 

Tks

Major Contributor
Joined
Apr 1, 2019
Messages
3,065
Likes
4,951
Some larger comercial companies negotiate extremely low shipping. Polk is pretty big.
Could even be as low as $10/$20 or less. I beleive Amazon pays UPS only around $6 per package essentially at a flat rate, that is likely lower than most anyone else can negotiate.
I have heard some places just pay a monthly rate for as many items as they can ship.
$6 per package okay. But $6 for something like this? That would be criminal in my view.
 

Gatordaddy

Member
Forum Donor
Joined
Apr 1, 2020
Messages
92
Likes
121
$6 per package okay. But $6 for something like this? That would be criminal in my view.

The corporate account i've used with UPS can get something like a 130lb oversized pelican case priority overnighted with 50000 dollars insurance for around 300 bucks. Shipping companies charge consumers an unimaginable amount of markup.
 

JWAmerica

Active Member
Joined
Jul 8, 2021
Messages
298
Likes
188
I don't get it, how do you even ship something of this size for $150?

Just crazy.

Super cheap drivers bought by the tens of thousands. It has been done before. All it is takes is someone with half a brain to optimize the driver selection and crossover.
 

Miker 1102

Active Member
Forum Donor
Joined
May 21, 2021
Messages
105
Likes
43
That's a really linear, low distortion tweeter, especially at the 2khz x-over point. In a loudspeaker like this, it's pretty amazing.
Yes. I just made a comment on a another forum about how I keep swapping these in my system above speakers that cost eight times as much because they don't fatigue my ears.
 

McFly

Addicted to Fun and Learning
Joined
Mar 12, 2019
Messages
724
Likes
1,394
Location
NZ
I happened to browse past these the other day in a store here that's asking $980 (so thats like, at time of writing, $680USD) per speaker. I didn't think much more of it.

Now I see you guys can get them for $75-150 each, hooo-ley crap.
 

bigjacko

Addicted to Fun and Learning
Joined
Sep 18, 2019
Messages
667
Likes
316
The corporate account i've used with UPS can get something like a 130lb oversized pelican case priority overnighted with 50000 dollars insurance for around 300 bucks. Shipping companies charge consumers an unimaginable amount of markup.
Can it ship the furthest two point in USA? I assume it has to use flight for that because trucks are not that fast. What about international if since they already use flight within USA?
 

Miker 1102

Active Member
Forum Donor
Joined
May 21, 2021
Messages
105
Likes
43
This is a review and detailed measurements of the Polk T50 tower speakers. I bought this recently for $149 from Amazon.

As you can imagine, a floor standing speaker at this price has to be quite light and this one definitely is. I can easily lift it as it weighs less than many bookshelf speakers. What a marvel of cost optimization:

View attachment 140541

Yes, my system area is dusty. Do you want more reviews or clean listening room???

This is a 2-way speaker with two passive radiators to improve bass response.

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.

I performed over 1000 measurement which resulted in error rate of about 1%.

Reference axis was the tweeter center. Grill was not used.

Polk T50 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:

View attachment 140542

I expected the response to be horrific but it is not that bad. Yes we have a peak around 1 kHz and then shelving up of the highs which is a requirement for "showroom selling" against its competitors which boost the heck out of that region.

Hard to see the sources of the uneven response from near-field measurement:

View attachment 140543

I guessed that the peaking at 1 kHz may be due to passive radiators resonating. The math is too complex to visually confirm though.

Early window frequency response shows vertical directivity messing with overall sum:
View attachment 140544

As noted -- and it is how I have my room -- use a thick carpet. That should be a nice absorber from 1 kHz up which we need to fix that trough and extra high frequency energy. High ceilings help to reduce the impact of bounce in that direction. Or you can stick an ugly absorber up there.

Predicted in-room response is not super smooth:
View attachment 140545

The effect of elevated treble is obvious. But that peak at 1 kHz followed by slight dip, not so much.

Edit: forgot to include distortion graphs:
View attachment 140563

View attachment 140564

Horizontal beam width is again, not too bad if we don't try to be too critical:

View attachment 140546

View attachment 140547

Vertical directivity gets worse if you sit below tweeter so tilt the speaker forward if that is the case:

View attachment 140548

Impedance is the typical 4 ohm or so:

View attachment 140549

Tons of resonances are visible likely due to think cabinet and who knows what else.

Polk T50 Listening Tests and Equalization
I must say, first impression was not bad at all. Unlike just about any bookshelf speaker, the T50 is able to handle tons of power and gets quite loud and dynamic with little evidence of stress. Throwing difficult sub-bass material at it didn't impact it since it simply doesn't try to play them (its bass response has a sharp cut off). Yes, there is a bit of brightness but judging that is often problematic as you don't know the content's spectrum and lack a frame of reference.

Best way to determine audibility of frequency response is to try to straighten it and see if you like it better. That is precisely what I do with EQ:

View attachment 140550

Ignore the first dip as that is for my room. Without it, there is enough bass activation to make the sound a bit boomy. The rest of the filters thankfully are mostly reduction which help with distortion as well. With all of them in place, the difference was not night and day but enough to make the T50 very enjoyable to listen to. Call me surprised!

Conclusions
Going into this review I expected the T50 to be junk. It did not turn out that way. It is a miracle of engineering and manufacturing to get a floor standing speaker in my hands for just $149 and have it not be broken. Objectively there are some issues but somehow subjectively, it seems less flawed. With a bit of EQ, it improves even more to a proper "hi-fi" class. Despite cheap bookshelves, the T50 is able to produce lots of volume and dynamics which I really value and enjoy.

I am going to recommend the Polk T50 especially with equalization.

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

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
Thank you so much for doing this review. This made my day!! I had been hoping you would do these as these were what got me interested in this site and learning about sound measurement(Though I am just getting the basics) . I really wanted to know if measurements and my hearing were parallel and I thought these sounded so good for 200. I can honestly say I enjoy them almost as much at the 2500 dollar pair I have because of their non fatiguing nature. Thanks again!!!
 

DACs_Lover

Member
Joined
Jul 4, 2021
Messages
81
Likes
217
Amir, have you ever measured Mark Levinson No.53 shown in the photo? I am eagerly waiting to see the measurements. Thank you.
 

gsp1971

Senior Member
Forum Donor
Joined
May 26, 2021
Messages
419
Likes
682
Location
Europe
Hi @amirm
Thanks for the review.
I can't help but notice that you have failed to recommend other speakers which exhibit much less deviation from linearity both on-axis and off-axis, the KEF LS50 being the best example that comes to mind.
Is price a consideration when you decide what to recommend?
 
Top Bottom