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Polk R200, Investigation Re: I am very Disappointed with Dull non HiFi sound.

hex168

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An old trick to fix the spectrally uneven reflected response caused by a tweeter's limited high frequency dispersion was to use a rear-facing tweeter to fill in the reflected sound's high frequencies. I believe Snell used that, and before that, somebody I can't recall (darn, that happens a lot these days) used a cheap rear-facing little Audax mylar tweeter for that purpose (it's FR and dispersion are well-suited to that duty). You could give that a try and see what you think of it. It would be interesting to see a full spinorama and find out if it actually works.
 

YSC

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really interesting learning from this, I actually thinks this is the case where preference to dispersion comes to play, some seems like very wide directivity and some prefer very narrow, so it actually goes back to square 1: measurements hints what you likely like or dislike, but in room trial is also essential
 

napilopez

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To me the main takeaway of this thread is reinforcement of something I've longed believed: any time there are directivity flaws, it's likely to be heard as different things by different people in different rooms. To me optimizing directivity is not just about creating the best possible sound, but about creating the most consistent sound. That's actually one of the most important reasons for optimizing vertical directivity IMO.
John Atkinson has more experience then I do. However based on following the information disseminated by Olive and Toole and reading Tool's book I think it is fair to question if this is just a matter of toe in.
Maybe outside with no walls, inside with walls a HUGE amount of what we hear is reflected sound and the 1st reflections are a massive component of the Harman score. We hear more reflections in typical room than direct sound by a large factor, especially in a typical farfield set-up.
Floyd Toole states in many ways throughout his book that reflected sounds contribute best to the perceived sound quality of the speaker when they are similar to the direct sound and additionally the sense we have of spaciousness is very dependent on the quality of them.
Now what is perceived as the fundamental sound becomes less dependent on reflections as one moves up toward the higher octaves, but how much less and when?

I am not qualified to answer that.
Anecdotally I subjectively noticed the sound of the R200 in my main room was missing a sense of spaciousness, vibrancy, air and energy in the music. It was not subtle. It was immediately obvious and did not sound good to me at all.

I definitely think that the tweeter directivity likely contributes strongly to your impressions reason for your impressions, although did you try EQing the speaker yet? I'm guessing it won't help, but still curious!

Although it's likely the beaming tweeter is a problem for you and your setup, the reason I'm not 100% convinced that beaming is a problem for most people is that (as you mention) at higher frequencies, we just hear more of the direct sound especially with regards to tonality.

Of course the off-axis response still plays a role. Depends really on the size of the room too. Here's the graph from Toole's book (Section 10.3) about how perception of on-axis vs off-axis varies in a typical room, for those who haven't seen it:

index.php

(note that the middle portion is direct+early reflections, not just early reflections).

As you mention, it's hard to know "how much" the balance of direct and reflected sound changes. But in general, above 5-6 khz it seems, most of what we hear is the direct sound, which is why I don't usually consider a beaming tweeter to be that much of an issue for tonal balance . However it does affect spatial presentation, and you did mention that you found the speaker lacked spaciousness, so perhaps this is all related.
 

Ninjastar

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Interesting data.

So I have the R200 and enjoy them in my current space. However, I am going to be moving in 2 months time, so if I end up not liking them in my new space, at least I'll know why that might be. :)

I was fortunate enough to have bought them on that ridiculous PolkFest deal in early November '21 so that might also be contributing to why I like them so much (for what I paid).

Also interesting that you used the Revel M16 as a comparison for a speaker that demonstrates more consistent performance in different rooms because I have read different subjective reviews suggesting those as sounding both warm/rolled off and others who think they sound bright.
 
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Thomas_A

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To me the main takeaway of this thread is reinforcement of something I've longed believed: any time there are directivity flaws, it's likely to be heard as different things by different people in different rooms. To me optimizing directivity is not just about creating the best possible sound, but about creating the most consistent sound. That's actually one of the most important reasons for optimizing vertical directivity IMO.


I definitely think that the tweeter directivity likely contributes strongly to your impressions reason for your impressions, although did you try EQing the speaker yet? I'm guessing it won't help, but still curious!

Although it's likely the beaming tweeter is a problem for you and your setup, the reason I'm not 100% convinced that beaming is a problem for most people is that (as you mention) at higher frequencies, we just hear more of the direct sound especially with regards to tonality.

Of course the off-axis response still plays a role. Depends really on the size of the room too. Here's the graph from Toole's book (Section 10.3) about how perception of on-axis vs off-axis varies in a typical room, for those who haven't seen it:

index.php

(note that the middle portion is direct+early reflections, not just early reflections).

As you mention, it's hard to know "how much" the balance of direct and reflected sound changes. But in general, above 5-6 khz it seems, most of what we hear is the direct sound, which is why I don't usually consider a beaming tweeter to be that much of an issue for tonal balance . However it does affect spatial presentation, and you did mention that you found the speaker lacked spaciousness, so perhaps this is all related.

I just wonder if the graph corresponds to a conventional speaker where the tweeters energy drops at higher angles with fr or if this is general, e.g. applicable for an omnidirectional speaker?
 

beaRA

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I appreciate your patience as I am just getting around to my promised measurements. Be gentle, as this is my first stab at quasi-anechoic measurements. Thanks to @napilopez for the easy to follow tutorial. First, a picture of my setup. This is a 13'x17.3' room with 8' ceilings full of stuff that I've done my best to push out of the way (the room is a WIP as I've just moved). I'm using a UMIK1 with the stock calibration file from miniDSP and the microphone was placed at the same height as the tweeter.

20220303_193710.jpg


I measured 2 Polk R100 samples and an Arendal 1961 Monitor for comparison. The first (red) was a replacement R100 sent to me by Polk in October 2021 since my original developed a crackling sound. The second (green) is the still working R100 from the defective pair, purchased in June 2021. The second R100 is the same sample used Erin's Klippel NFS measurement. On-axis measurements are shown below for each with the same 4.5ms window (dang short ceilings).

1646355600762.png


As you can see, both of my R100's share the same characteristic on-axis lift above 5kHz for which this ring radiator tweeter is known. Furthermore, my two samples shipped from Polk 4 months apart are a very close match to each other. The Arendal 1961 Monitor has a more neutral tuning in the treble range, but we know that Polk is compensating for the narrowing dispersion of the tweeter.

Seems to me like this thread is getting off topic. I'm convinced that @ROOSKIE has a defective R200 pair. It's possible that the dispersion pattern of the ring radiator tweeter is not the OP's preference. Still, we shouldn't be making broad conclusions on dispersion patterns based on listening impressions of a defective speaker with a tweeter level several dB below the manufacturer's intent.
 

Transmaniacon

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I appreciate your patience as I am just getting around to my promised measurements. Be gentle, as this is my first stab at quasi-anechoic measurements. Thanks to @napilopez for the easy to follow tutorial. First, a picture of my setup. This is a 13'x17.3' room with 8' ceilings full of stuff that I've done my best to push out of the way (the room is a WIP as I've just moved). I'm using a UMIK1 with the stock calibration file from miniDSP and the microphone was placed at the same height as the tweeter.

View attachment 190242

I measured 2 Polk R100 samples and an Arendal 1961 Monitor for comparison. The first (red) was a replacement R100 sent to me by Polk in October 2021 since my original developed a crackling sound. The second (green) is the still working R100 from the defective pair, purchased in June 2021. The second R100 is the same sample used Erin's Klippel NFS measurement. On-axis measurements are shown below for each with the same 4.5ms window (dang short ceilings).

View attachment 190247

As you can see, both of my R100's share the same characteristic on-axis lift above 5kHz for which this ring radiator tweeter is known. Furthermore, my two samples shipped from Polk 4 months apart are a very close match to each other. The Arendal 1961 Monitor has a more neutral tuning in the treble range, but we know that Polk is compensating for the narrowing dispersion of the tweeter.

Seems to me like this thread is getting off topic. I'm convinced that @ROOSKIE has a defective R200 pair. It's possible that the dispersion pattern of the ring radiator tweeter is not the OP's preference. Still, we shouldn't be making broad conclusions on dispersion patterns based on listening impressions of a defective speaker with a tweeter level several dB below the manufacturer's intent.
Thanks for the measurements, it does seem something is wrong to produce such strange measurements.
 

napilopez

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I appreciate your patience as I am just getting around to my promised measurements. Be gentle, as this is my first stab at quasi-anechoic measurements. Thanks to @napilopez for the easy to follow tutorial. First, a picture of my setup. This is a 13'x17.3' room with 8' ceilings full of stuff that I've done my best to push out of the way (the room is a WIP as I've just moved). I'm using a UMIK1 with the stock calibration file from miniDSP and the microphone was placed at the same height as the tweeter.

View attachment 190242

I measured 2 Polk R100 samples and an Arendal 1961 Monitor for comparison. The first (red) was a replacement R100 sent to me by Polk in October 2021 since my original developed a crackling sound. The second (green) is the still working R100 from the defective pair, purchased in June 2021. The second R100 is the same sample used Erin's Klippel NFS measurement. On-axis measurements are shown below for each with the same 4.5ms window (dang short ceilings).

View attachment 190247

As you can see, both of my R100's share the same characteristic on-axis lift above 5kHz for which this ring radiator tweeter is known. Furthermore, my two samples shipped from Polk 4 months apart are a very close match to each other. The Arendal 1961 Monitor has a more neutral tuning in the treble range, but we know that Polk is compensating for the narrowing dispersion of the tweeter.

Seems to me like this thread is getting off topic. I'm convinced that @ROOSKIE has a defective R200 pair. It's possible that the dispersion pattern of the ring radiator tweeter is not the OP's preference. Still, we shouldn't be making broad conclusions on dispersion patterns based on listening impressions of a defective speaker with a tweeter level several dB below the manufacturer's intent.

Thank you for the measurements and thank you forpointing out the obvious that I had been missing -- if the tweeters are defective on ROOSKIE's pair, as increasingly appears to be the case, then that's probably as far as any deep evaluation of sound should go. I think perhaps the best to do in this case @ROOSKIE would be to demonstrate these findings to polk and get the units replaced under warranty. There's more than enough to suggest something is likely wrong. Then you can see if that changes your mind or at least you can sell them knowing they are no longer defective.

By the way, good job @beaRA with your measurements. Solid match for erins and the deviation in the presence region is small and likely due to positioning and/or mics:
R100 erin beara.png
 

beaRA

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Thank you for the measurements and thank you forpointing out the obvious that I had been missing -- if the tweeters are defective on ROOSKIE's pair, as increasingly appears to be the case, then that's probably as far as any deep evaluation of sound should go. I think perhaps the best to do in this case @ROOSKIE would be to demonstrate these findings to polk and get the units replaced under warranty. There's more than enough to suggest something is likely wrong. Then you can see if that changes your mind or at least you can sell them knowing they are no longer defective.

By the way, good job @beaRA with your measurements. Solid match for erins and the deviation in the presence region is small and likely due to positioning and/or mics:
View attachment 190273
Hey not bad! I'll also note that Erin chose a reference axis between the tweeter and midrange. My measurements were directly at tweeter height as I assumed that would be most comparable to what @ROOSKIE did.
 

mcdn

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@ROOSKIE unless i missed it, you still haven't posted a diagram or photos of your room. From your description though it sounds like it is very unusual, with essentially no reflective surfaces either side of the speakers as there are large openings to other rooms.

My suggestion would be to push the speakers all the way back to the wall. This will reduce SBIR issues in the bass, and increase the level of side wall reflections. It's at least worth a try...
 

napilopez

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Hey not bad! I'll also note that Erin chose a reference axis between the tweeter and midrange. My measurements were directly at tweeter height as I assumed that would be most comparable to what @ROOSKIE did.
oh good shout - that's likely it then. Here's my on-axis of the R200 in white vs 5 degrees below the tweeter axis, which is a bit closer to erins reference point, although presumably a bit exaggerated. You seen the presence region become elevated, so that explains that.

index.php
 
OP
R

ROOSKIE

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@ROOSKIE unless i missed it, you still haven't posted a diagram or photos of your room. From your description though it sounds like it is very unusual, with essentially no reflective surfaces either side of the speakers as there are large openings to other rooms.

My suggestion would be to push the speakers all the way back to the wall. This will reduce SBIR issues in the bass, and increase the level of side wall reflections. It's at least worth a try...
Howdy,
My room is described somewhere here but I didn't post a diagram.
I could do that.
My regular usage includes several subwoofers so SBIR is mainly dealt with. For the tests posted here the speaker is alone but normally I use the woofers and then DSP to tame some of the room modes.

Interestingly I thought the speaker sounded worse in a more refective room. (The 2nd smaller room)
If what I don't like is the nature of the designs reflection energy than it would make sense that more might actually be worse.
Pushing them could still be something to try and see, best to actually try vs imagine.

1st though thanks @beaRA for posting your measurements. Look good. Glad you were up for it and hopefully you can use your new skills going forward. Much appreciated. Your set is well in line with the previous stuff, including your October unit.
I think I ought to contact Polk tmrw before more testing with my current pair.

I can use DSP to add in the 3db and simulate the response however I would still wonder if anything else was happening in the sound field that shouldn't be. Best to have Polk help me replace them.

I will measure the impedance curve as well. Maybe some clue there.
 

napilopez

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Howdy,
My room is described somewhere here but I didn't post a diagram.
I could do that.
My regular usage includes several subwoofers so SBIR is mainly dealt with. For the tests posted here the speaker is alone but normally I use the woofers and then DSP to tame some of the room modes.

Interestingly I thought the speaker sounded worse in a more refective room. (The 2nd smaller room)
If what I don't like is the nature of the designs reflection energy than it would make sense that more might actually be worse.
Pushing them could still be something to try and see, best to actually try vs imagine.

1st though thanks @beaRA for posting your measurements. Look good. Glad you were up for it and hopefully you can use your new skills going forward. Much appreciated. Your set is well in line with the previous stuff, including your October unit.
I think I ought to contact Polk tmrw before more testing with my current pair.

I can use DSP to add in the 3db and simulate the response however I would still wonder if anything else was happening in the sound field that shouldn't be. Best to have Polk help me replace them.

I will measure the impedance curve as well. Maybe some clue there.
Good idea with the impedance curve. The most bizarre thing remains that both units seem to have the same exact "error". So strange, unlikely to be shipping damage. Most likely a bad batch of tweeters for whatever reason

Hope Polk is good about the replacement!
 

Thomas_A

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I appreciate your patience as I am just getting around to my promised measurements. Be gentle, as this is my first stab at quasi-anechoic measurements. Thanks to @napilopez for the easy to follow tutorial. First, a picture of my setup. This is a 13'x17.3' room with 8' ceilings full of stuff that I've done my best to push out of the way (the room is a WIP as I've just moved). I'm using a UMIK1 with the stock calibration file from miniDSP and the microphone was placed at the same height as the tweeter.

View attachment 190242

I measured 2 Polk R100 samples and an Arendal 1961 Monitor for comparison. The first (red) was a replacement R100 sent to me by Polk in October 2021 since my original developed a crackling sound. The second (green) is the still working R100 from the defective pair, purchased in June 2021. The second R100 is the same sample used Erin's Klippel NFS measurement. On-axis measurements are shown below for each with the same 4.5ms window (dang short ceilings).

View attachment 190247

As you can see, both of my R100's share the same characteristic on-axis lift above 5kHz for which this ring radiator tweeter is known. Furthermore, my two samples shipped from Polk 4 months apart are a very close match to each other. The Arendal 1961 Monitor has a more neutral tuning in the treble range, but we know that Polk is compensating for the narrowing dispersion of the tweeter.

Seems to me like this thread is getting off topic. I'm convinced that @ROOSKIE has a defective R200 pair. It's possible that the dispersion pattern of the ring radiator tweeter is not the OP's preference. Still, we shouldn't be making broad conclusions on dispersion patterns based on listening impressions of a defective speaker with a tweeter level several dB below the manufacturer's intent.

One tip is to wrap some damping around the microphone holder/stand to reduce reflections.
 

Chrispy

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My first thought was why would these speakers be particularly great in the first place?
 

DanielT

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An old trick to fix the spectrally uneven reflected response caused by a tweeter's limited high frequency dispersion was to use a rear-facing tweeter to fill in the reflected sound's high frequencies. I believe Snell used that, and before that, somebody I can't recall (darn, that happens a lot these days) used a cheap rear-facing little Audax mylar tweeter for that purpose (it's FR and dispersion are well-suited to that duty). You could give that a try and see what you think of it. It would be interesting to see a full spinorama and find out if it actually works.
Yes:

Plus a little about Carlsson speakers, Peter Snell in general and the pros, cons of dipoles in that thread.:)

 
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Wave Function

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Which amplifier was used to power the R200s for Rooskie's tests? I didn't notice that anywhere in this thread. I assume Rooskie would use a sufficiently powerful 4-ohm capable amp, but without the amp being stated, that's still an uncomfirmed assumption.

About the speakers being defective: given that these are sold by the pair in the same box, defects could be highly correlated with two of the same pair. The same problematic condition with the employee, machine, or factory environment that made one speaker have a defect could cause the next speaker or next few speakers to have the same or similar defect, and then two of them end up in the same box.

Whereas when you buy two studio monitors or towers which are boxed and sold individually, you're less likely to get two that were built on the same assembly line a short time apart.

I agree with the suggestion to try to return them to Polk for repair or exchange under warranty. Another suggestion is to buy another pair of the same from a brick & mortar retailer that will let you return them in person so you don't have to worry about shipping costs, listen to those, and if the new pair don't sound dull like the first pair you'll know it's because the first pair is defective. Then you can return the new pair if you don't keep them.
 

Thomas_A

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Curious if there some tweeter batch variations. Serial no. of speakers tested?
 

napilopez

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Which amplifier was used to power the R200s for Rooskie's tests? I didn't notice that anywhere in this thread. I assume Rooskie would use a sufficiently powerful 4-ohm capable amp, but without the amp being stated, that's still an uncomfirmed assumption.

About the speakers being defective: given that these are sold by the pair in the same box, defects could be highly correlated with two of the same pair. The same problematic condition with the employee, machine, or factory environment that made one speaker have a defect could cause the next speaker or next few speakers to have the same or similar defect, and then two of them end up in the same box.

Whereas when you buy two studio monitors or towers which are boxed and sold individually, you're less likely to get two that were built on the same assembly line a short time apart.

I agree with the suggestion to try to return them to Polk for repair or exchange under warranty. Another suggestion is to buy another pair of the same from a brick & mortar retailer that will let you return them in person so you don't have to worry about shipping costs, listen to those, and if the new pair don't sound dull like the first pair you'll know it's because the first pair is defective. Then you can return the new pair if you don't keep them.
If you go the route of buying another pair from a place with a good return policy, it would make it easy for you to compare the tweeters and then both settle the debate about them being defective as well as have data that would be harder for Polk to refute
 

raindance

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I'd be fascinated (and surprised) to learn that both his tweeters are faulty. I keep seeing this type of logic suggested on this forum and I just don't understand it.
 
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