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Infinity RS152 Review (Surround Speaker)

amirm

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This is a quick review and raw measurements of the Infinity RS152 surround speaker. It was kindly purchased new (last year!) and sent to me directly for testing. They current costs US $449 for a pair but Harman is know to have blow out discounts on these speakers at times.

Edit: our company, Madrona Digital does fair amount of business with Harman which is the parent company of Infinity. So feel free to read as much bias as you like in this review.

This is a very odd configuration for a speaker with dual tweeters in front and woofer in the back:

Infinity RS152 review.jpg


Infinity RS152 review back panel.jpg



Infinity RS152 review rear woofer.jpg


One look at this speaker and I knew measurements of it were going to extremely difficult. For starters, where would one position the reference axis? I choose the infinity logo. This is problematic as it forces the measurement system to use a non-optimal axis in what is to be a complex sound field. Indeed post measurement analysis shows that error shoots up above 8 kHz. As you will see even outside of this, the results are extremely strange and don't at all match what Harman says (uniform wide directivity).

I thought about sitting on these measurements and review until I could make sense out of them but I simply don't have that option. Since inception of this site, I have never had such high volume of gear to test and so much stress to get them done. So I am just going to present what I have and let you all try to make sense out of them. :)

Infinity RS152 Measurements
Here is our main spin graph:

Infinity RS152 frequency response measurements.png


Told you the data is rough!

Early window for good or bad matches the on-axis but I am not sure of its relevance in surround scenario:

Infinity RS152 early window frequency response measurements.png


Same for predicted in-room frequency response:

Infinity RS152 predicted in-room frequency response measurements.png


Horizontal beamwidth is real head scratcher relative to what Harman advertises:

Infinity RS152 horizontal Beamwidth measurements.png


Beam width graph is gorgeous to look at but I am not sure of the audible results:

Infinity RS152 horizontal directivity measurements.png


Vertical data is complex as well:


Infinity RS152 vertical directivity measurements.png


Even impedance was strange with it shooting way up at lower frequencies:

Infinity RS152 impedance and phase measurements.png


I measured distortion and driver responses but frankly, they are too unreliable and strange to share. I mean what level do I go for when calibrating for 86 or 96 dB?

I have not listened to the speaker as I don't have a setup to test surround speakers in my 2-channel system.

Conclusions
I have none to offer other than cringing at the sight of two tweeters in opposing fashion trying to produce sound. And a woofer in the back which is also supposed to do midrange duty. Is this ever going to work? I don't know. You analyze it and tell me!

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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/
 

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milosz

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A weird speaker but I think it also shows your Klippel analysis machine makes certain assumptions about how speakers are used that doesn't apply to every speaker out there. As with the test of the Magneplanar LRS, the method works for box type speakers but falls down when trying to measure dipole, cardioid, or surround speakers like this one that depends on sound reflected off of a wall. I'm not saying that this is a good speaker- although it may work fine as a surround speaker to provide the whiz-bang gimmickry common in Hollywood / Disney productions these days.

What in fact you are measuring is how closely the speaker's performance matches the assumptions of the test. There's an inbuilt bias in the experimental design. I think for these tests to actually fit the definition of science, you'd need to limit testing to forward-firing box speakers that attempt to emulate a point source. Which is to say most speakers on the market. And it makes sense that Klippel developed their protocol to measure such speakers, because they are mostly what people buy and use.
 

dougi

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From the blurb it seems to imply it should be wall mounted. Plus the point of dual tweeters to cover a wider listening area.

Features
Surround channel loudspeaker ideally suited for multi-channel music and home theater systems
The RS152’s slender profile and integrated keyhole wall-mounting allows for flexible placement within your room. It is sonically matched to companion Reference Series floorstanding, bookshelf and center channel loudspeakers and powered subwoofers allowing you to create the ideal system solution for your needs.

Patented Hemispherical Soundfield Technology (HST)
Infinity’s engineers have developed and patented Hemispherical Soundfield Technology (HST) to eliminate the detrimental acoustical reflections typically associated with wall-mounting loudspeakers. With the HST design, a rear-facing woofer is scientifically positioned at a given distance from the wall while companion dual highfrequency drivers with advanced waveguides are each placed on either side of the angled front panels. This combination of driver positioning and waveguide pattern control provides remarkably balanced coverage across a 180-degree hemispherical listening area without the typical “hot and cold” frequency response inefficiencies found with mounting traditional loudspeakers on the wall. The end result is a loudspeaker with extremely flexible on-wall placement capability while maintaining consistent performance over a wide area even when listening from far off to one side.

Dual 1" (25mm) CMMD™ tweeters with advanced waveguides
The combination of the acoustical science and patented designs found in the 1" (25mm) CMMD™ (Ceramic Metal Matrix Diaphragm) tweeter and advanced waveguide provides seamless sonic integration with the CMMD™ woofer while providing excellent high-frequency detail and smooth coverage across a wide listening area.
 

Dave Tremblay

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Woofers mounted against the wall like that are only good to 300-400Hz in my experiments. After that, it’s a nightmare. This looks consistent with that. If those front drivers were full range it would probably be fine, but tweeters?!?! Not a good design choice. Wonder who designed it, or why...
 

Loathecliff

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Quote "With the HST design, a rear-facing woofer is scientifically positioned at a given distance from the wall "

So unless your room replicates theirs, all the alleged qualities are lost?

Don't we all try to position our speakers "scientifically"? (females and aesthetics not withstanding)
 

whazzup

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Sad that no listening impression was done. Just clearly state disclaimers that the speaker was not in a optimum placement?
 

Koeitje

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Shouldn't the on-axis be on the tweeter, meaning this speaker has 2 on-axis? Don't know why that would be....but w/e.
 

MZKM

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These are mine…
_________

Note: Rating is for free-standing monopole speakers

Preference Rating
SCORE: -0.1
SCORE w/ sub: 2.4

Sensitivity (free-field): 79.7dB (300Hz-3kHz ; spec (wall-mounted?): 90dB)
Frequency response (free-field): +/-10.6dB 62Hz-20kHz

Spinorama 33.png
Horizontal Directivity 29.png
Horizontal Directivity Normalized 32.png
Vertical Directivity 30.png
Vertical Directivity Normalized 30.png
chart 38.png
 

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MZKM

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Patented Hemispherical Soundfield Technology (HST)
Infinity’s engineers have developed and patented Hemispherical Soundfield Technology (HST) to eliminate the detrimental acoustical reflections typically associated with wall-mounting loudspeakers. With the HST design, a rear-facing woofer is scientifically positioned at a given distance from the wall while companion dual highfrequency drivers with advanced waveguides are each placed on either side of the angled front panels. This combination of driver positioning and waveguide pattern control provides remarkably balanced coverage across a 180-degree hemispherical listening area without the typical “hot and cold” frequency response inefficiencies found with mounting traditional loudspeakers on the wall. The end result is a loudspeaker with extremely flexible on-wall placement capability while maintaining consistent performance over a wide area even when listening from far off to one side.
And this is why I bought it. Though I couldn’t find said patent.
Paid $140 for them during Infinity’s last large sale.

These are (hopefully) replacing my pair of Fluance XLBP surrounds (MSRP $200, paid $100), which are your typical bipole:
61RV-X-5FoL._AC_SY355_.jpg



I will try my best to do some in-room measurements of both when wall-mounted.

The Sound Power DI almost never going above 5dB is giving me hope. My surrounds have terribly poor placement, where for 1 of them the couch is nearly under the speaker which is mounted about 6ft up, so vertical off-axis is hugely important.
 
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thewas

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Patented Hemispherical Soundfield Technology (HST)
Infinity’s engineers have developed and patented Hemispherical Soundfield Technology (HST) to eliminate the detrimental acoustical reflections typically associated with wall-mounting loudspeakers. With the HST design, a rear-facing woofer is scientifically positioned at a given distance from the wall while companion dual highfrequency drivers with advanced waveguides are each placed on either side of the angled front panels. This combination of driver positioning and waveguide pattern control provides remarkably balanced coverage across a 180-degree hemispherical listening area without the typical “hot and cold” frequency response inefficiencies found with mounting traditional loudspeakers on the wall. The end result is a loudspeaker with extremely flexible on-wall placement capability while maintaining consistent performance over a wide area even when listening from far off to one side.
The difference from wishful marketing thinking and reality of 2 so far from each other located tweeters becomes obvious, not a 180 degree listening window is realised but an interference nightmare. If that doesn't get a broken panther I don't what should...

Harman uses is also on some JBL Pro loudspeakers where they show some plots which are clever chosen (showing the beamwidth instead of the polars) to hide its problems. https://www.audiopro.de/medias/item/16483/jbl_ctrlhst_v4.pdf
 

Vladimir Filevski

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This loudspeaker MUST be mounted on the wall and measured (and listened) as such, regarding correct reproduction of bass and midrange frequencies by the woofer.
Tweeters are not angled enough for avoiding comb filtering, though.
 

Puddingbuks

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Is there a point in reviewing these kind of super low end speakers? People spending so little on audio gear will not read this. The people who do come here on asr never settle for this kind of performance.

I rather see the Genelec 8351b finally being reviewed.
 

Vict0r

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I guess the only way to review these is to just listen to them and subjectively compare them to their direct competitors by ear. THE HORROR!! :p
 
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