Polk T15 Bookshelf Speaker Review

[pozz]

Audioholics found that the tweeter height is not the reference angle:

Seeing as how these are marketed as surrounds, this makes plenty sense.

@amirm, did you compute the minimum far-field distance? And as asked by others, can this be a standard aspect to include?
And, I'm guessing it's too much to ask to re-measure but at -20V degrees being reference? Just changing the on-axis to the -20V bumped the preference score to a 1.4, over a full point boost.

Polk links to datasheets on their site:

• https://www.polkaudio.com/products/t15#
• Manual
• Datasheet

I'm very confused by the performance, the lack of Polk guidance about the speaker, and the Audioholics conclusion:

• "The Polk T15 is something of an odd duck to review as a stereo pair because of their direct-axis behavior. However, once they are positioned correctly for their design, they can produce a reasonably good sound for their cost. What the Polk T15 speakers set out to do, they accomplish. These are speakers designed for circumstances that are less than optimal for pristine high-fidelity listening; they are speakers for real-world conditions."

Where did Polk advertise or disclose this behaviour or their intentions?

 

[laudio]

If I wanted to spend $70 I would buy them. They are budget speakers and that's what I would expect.

For $70 I would probably buy a set of old Polk monitors... They go cheap and sound good. Probably couldn't hang one on the wall though.

 

[bigx5murf]

I'd be more interested in seeing the Polk LSiM or some of their vintage bookshelves, like SDA, CRS, or RT7.

 

[Doodski]

Polk Audio issues its manufacturer's warranty extending to 2 years for electronic products and 5 years for passive Loudspeakers through an authorized dealer.

That's pretty good for $70.00-$115.00 US

 

[restorer-john]

The T15 cries for independent DSP and AMPs for each driver. Our are members who are capable of that can do so, and then report?

You cannot be serious? That's hilarious. They are not worth it. Just take them as they are for $70.

 

[StevenEleven]

Still stuck with my Pioneer BS-22s (with nicer subwoofers than I really ever needed). Got some cash money burning a hole in my pocket. . .

 

[DownUnderGazza]

Ideal thought, would reversing the polarity on the tweeter help?

 

[MZKM]

They have a keyhole mount on the rear panel. That has but one purpose: to hang on the wall. They are another cheap rear surround speaker.

Many people use mounts that allow the speaker to be angled.

 

[amirm]

Ideal thought, would reversing the polarity on the tweeter help?

I thought about doing that but didn't want to spend 3 hours measuring it versus testing another speaker.

 

[Cahudson42]

You cannot be serious? That's hilarious. They are not worth it. Just take them as they are for $70.

Well, you don't know until you try.

I wonder how many of the 'active' DSP corrected speakers might test if the electronics were removed and tested passive...

 

[wwenze]

Well, you don't know until you try.

I wonder how many of the 'active' DSP corrected speakers might test if the electronics were removed and tested passive...

Probably pretty bad

Even Audioengine A5+ has a bass boost in the amplifier, presumably through analog methods.

 

[MZKM]

After some adjustments, here's the difference when listening -20V (speaker +20V relative to you, so surround use with no tilt):

Original:

Adjusted:

 

[Blumlein 88]

Man I want to see a measure of something with one driver. An 8 incher with a whizzer cone. I bet it would beat this speaker. Like this in an enclosure.

https://www.parts-express.com/visaton-bg20-8-8-full-range-speaker-with-whizzer-cone-8-ohm--292-548

Or maybe even on a flat baffle.

It looks very similar to a driver I used in a 42 hz transmission line once long ago. Actually if they haven't rotted the cones I may still have one in storage. I'll have to give it a go with REW. That one really had some low end to it, and didn't sound horrid. Not much response above 6 khz. Beamed a very narrow beam between 6 khz and 11 khz where it dropped off. I gave them to someone, and since they knew of the treble drop-off they added a super tweeter to it. A cheap nasty sounding thing with that tweeter.

I built them as a trial run using Transmission lines to learn was important about getting T-lines to work. I used what I learned to make some rather nice sounding 3 ways after that.

 

[hardisj]

Clearly explained by Amir at the end of his review - you apparently did not read through to the end.

I read it.

Still don't agree. The data shows abysmal performance. If we are talking "value" then it's still not even suggested over a slightly costlier option.

The Polk Audio T15 hits an incredibly low price point while producing something that doesn't look like trash. Measured performance does show trash and good bit of it. Normally this would be enough to get it a headless panther but post listening tests, I thought that would be too much damning so gave it one notch above.

I like to encourage you to save more money and buy the Pioneer if you can. Despite being much cheaper, I can't justify recommending the Polk T15 even though subjective performance was not horrible.

 

[hardisj]

Is it me, or is the "polk" logo off center?
It's bothering me. Make it stop!!!!

 

[MZKM]

I read it.

Still don't agree. The data shows abysmal performance.

If Amir listened to them on his desk, the tweeters were likely below his ears, which the measurements show has better performance than listening on-axis; so it’s not far-fetched.

If you want a ~$100 front-porter speaker for surround duty, your options are limited. That said, I own the Fluance XLBP (got for $100 from Amazon instead of $200) and it sounds fine. I wall-mount it so I have no idea what the measurements are for that anfor, but here’s the published graph (10dB scale):

 

[restorer-john]

Many people use mounts that allow the speaker to be angled.

Yep. Sold thousands of them, but not a single angled mount that attaches to a routed MDF/Particle Board keyhole slot. Angled mounts either held the speaker top and bottom, via a captive threaded nut or nut pair, screwed into the back directly or the base etc. They are what they are.

Here's how Polk describe them:

And they can't even silk screen their own logo straight or screw them in straight- one or the other.

 

[hardisj]

If Amir listened to them on his desk, the tweeters were likely below his ears, which the measurements show has better performance than listening on-axis; so it’s not far-fetched.

Look, I don't want to be "that" guy but are we going to now ignore objective data (the purpose of these reviews) in lieu of an informal listening test?

If anything, I think this shows how important it is to objectively test properly if it is deemed the reference axis is incorrect. It was objectively tested at one axis but subjectively evaluated on another reference axis?... At that point, you can't accurately compare the two sets of "data", nevermind the fact that the correct reference axis may not have been used. But that's been beat to death in earlier review threads...

 

[bobbooo]

After some adjustments, here's the difference when listening -20V (speaker +20V relative to you, so surround use with no tilt):

Original:View attachment 51893

Adjusted:
View attachment 51894

Out of curiosity, would it be possible to estimate the change in preference score using these adjusted curves?

 

[MZKM]

Out of curiosity, would it be possible to estimate the change in preference score using these adjusted curves?

I can really only change the on-axis, and that’s about it. I changed the listening window by taking the horizontal data and adding the difference between 0V and -20V. The PIR curve would not be easily corrected. as stated though, I got a ~1.4 score from changing the on-axis to -20V.