Infinity RS152 Review (Surround Speaker)

[Worth Davis]

I own these - they have a metal bracket that mounts them a few inches from the wall and work fine - I have measurements, sec will post.

 

[prerich]

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.

This speaker is designed to be a surround speaker for duty in the rear or on the sides. The null area should be at your ears (none of the drivers should be radiating directly at the listener). This comes from the days of Dolby AC3 and the original THX stuff. The surround channels are intended to be defuse. When we went to TrueHD and DTS, that through AC3/OGTHX style out the window because everything was now discrete. The surrounds came down to ear level...(I'm still having an issue with that), and speakers were now intended to point directly at the listener.
The paradigm of purpose is what confronts this speaker - as it wasn't designed to sound like main speakers nor are its characteristics similar. I'm not sure if they're considered dipoles (are they 180 degrees out of phase with each other), or what. Their purpose however is clear, even from the measurements - a defuse, unintelligible sound stage.

 

[prerich]

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.

Bravo....we must know the purpose of a thing before we use it. If we do not, we will use it abnormally or abuse it (not mine Dr. Myles Munroe RIP).

 

[prerich]

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!!

Well...you don't listen to these like other speakers - as they're specific for surround side duty (you can get away with a high rear placement as well).

 

[spacevector]

I had these set up in my living room a while ago. Below are measurements from Anthem ARC. I do see the dip between 500Hz to 1kHz but it doesn't look as wide or severe as what the anechoic data shows.

 

[prerich]

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

I'm reading these comments and I'm wondering if people know what these are used for? They're used to create a defuse, disperse, unlocatable soundfield. You can't listen to them like mains. They're not designed to react like mains. If you used them for main duty....you need to see a Dr. who has a couch.

 

[Vladimir Filevski]

Please explain what you mean with there is no direct sound. there is obviously sound coming out of the drivers.

Woofer is not mounted on the front panel - so there is no direct sound, strictly speaking. Woofer is on the back panel, so all "direct" sound which is coming from it really is diffracted sound wave around the enclosure, 180 degrees from woofer axis. If anechoically measured, all mid (and high) frequencies from the woofer will be heavily attenuated - see the actual measurements [courtesy of @DaveFred] of one small woofer at 0 degrees on-axis (blue) and at 180 degrees (red). Here we can see the low-pass effect which I mentioned earlier:

You posted previously graphs presenting comb effect, which is sum of blue graph with delayed red graph (distance to back wall) - which is not the case with Infinity RS152.
So, the red graph will be similar to the natural anechoic response of Infinity RS152 woofer, measured from the front enclosure side (where the tweeters are) only if there is no mounting plate at one-inch distance from the woofer. Because the mounting plate has somewhat larger area than the woofer, there will be additional reflection/diffraction here, which make the 600 Hz dip. But if you mount this speaker on-wall, the small mounting plate will "fuse" with the wall, making one big continuous plane, without the 600 Hz dip.
Infinity RS152 mounted on the wall will have substantially different frequency response compared to anechoic one. And without the 600 Hz dip.
As for my explanation "there is no direct sound" - it is all reflected from the wall. Or, direct and reflected sound waves are with minimal time difference, so there is no comb effect. Maybe better and simpler explanation gave @Francis Vaughan:

It is acting as a horn loaded driver diffracting out past the edges of the cabinet.

 

[Deleted member 2944]

I'm reading these comments and I'm wondering if people know what these are used for? They're used to create a defuse, disperse, unlocatable soundfield. You can't listen to them like mains. They're not designed to react like mains. If you used them for main duty....you need to see a Dr. who has a couch.

Yes. Well put.
Some of the comments in this review are the most eye-rolling naive quips I've seen to date on ASR.

Dave.

 

[thewas]

I'm reading these comments and I'm wondering if people know what these are used for? They're used to create a defuse, disperse, unlocatable soundfield. You can't listen to them like mains. They're not designed to react like mains. If you used them for main duty....you need to see a Dr. who has a couch.

Before sending people to Dr. couches you should read Toole's book where he is explaining why surround dipoles who tried to make diffuse sound field are not expedient, they were a poor solution from times of the first (analogue) Dolby Pro Logic which provided a single mono rear channel. But these Infinity are not dipoles who try to achieve that but bipoles who try a very wide but not diffuse sound field which can be achieved much better with other designs without the problems of the 2 distant tweeters. These have similar problems like the poor horizontal MTM centre channel offerings but for the tweeter frequencies, a faulty approach pushed by marketing.

 

[prerich]

Before sending people to Dr. couches you should read Toole's book where he is explaining why surround dipoles who tried to make diffuse sound field are not expedient, they were a poor solution from times of the first (analogue) Dolby Pro Logic which provided a single mono rear channel. But these Infinity are not dipoles who try to achieve that but bipoles who try a very wide but not diffuse sound field which can be achieved much better with other designs without the problems of the 2 distant tweeters. These have similar problems like the poor horizontal MTM centre channel offerings but for the tweeter frequencies, a faulty approach pushed by marketing.

I'm very familiar with Dr Toole. we've actually talked and gave me his advice on purchasing an Infinity MTS system, and as many know I'm a Revel fanboy. The point is the purpose of the speaker ... I use a vertical center channel...always have - always will. However that center channel radiates directly to me..like a typical speaker - typical test will work with that. You made the point as the Pro logic design provided a single mono rear channel - but it was matrixed (if you read the writings of Jim Fosgate).
These Infinities are not the typical direct radiating speakers that you find in discrete multi-channel systems. I remember a time when a surround speaker had to be located above the listener at least 6ft high, now they point them at you - at ear level - times change, configurations change - and with it parameters. My couch comment ....is when you take something and measure it like it's something else.....that will make the entire premise wrong. Trust me ...I don't own these speakers....but I also won't measure them by a standard prepared for a speaker with different parameters (I mean ...how can you get an on axis response from these when the design is totally off axis, relying on reflectivity)? Has anyone gone inside this speaker to see if it is indeed a bipole (that they're wired in-phase with each other)? The Infinity 25es was a Bipole/dipole with a flippable switch and direct sound from a tweeter. Infinity also had the QPS-1 that was sold with the Prelude P-FR system....it was a quadrupole speaker (with one direct radiating full range speaker and 4 smaller poles). This speaker seems to be one designed on Infinity's death bed and was not intended for direct radiating sound.

 

[prerich]

Woofer is not mounted on the front panel - so there is no direct sound, strictly speaking. Woofer is on the back panel, so all "direct" sound which is coming from it really is diffracted sound wave around the enclosure, 180 degrees from woofer axis. If anechoically measured, all mid (and high) frequencies from the woofer will be heavily attenuated - see the actual measurements [courtesy of @DaveFred] of one small woofer at 0 degrees on-axis (blue) and at 180 degrees (red). Here we can see the low-pass effect which I mentioned earlier:
View attachment 124355
View attachment 124355
You posted previously graphs presenting comb effect, which is addition of blue graph with delayed red graph (distance to back wall) - which is not the case with Infinity RS152.
So, the red graph will be similar to the natural anechoic response of Infinity RS152 woofer, measured from the front enclosure side (where the tweeters are) only if there is no mounting plate at one-inch distance from the woofer. Because the mounting plate has somewhat larger area than the woofer, there will be additional reflection/diffraction here, which make the 600 Hz dip. But if you mount this speaker on-wall, the small mounting plate will "fuse" with the wall, making one big continuous plane, without the 600 Hz dip.
Infinity RS152 mounted on the wall will have substantially different frequency response compared to anechoic one. And without the 600 Hz dip.
As for my explanation "there is no direct sound" - it is all reflected from the wall. Or, direct and reflected sound waves are with minimal time difference, so there is no comb effect. Maybe better and simpler explanation gave @Francis Vaughan:

Excellent.

 

[Haint]

Super low end?

I think many into audio AND home theatre would consider this. After all a big name audio brand.

Super low end to me, means more like Sound design, Lloyds and all in one junk stereos.
This is a very valid lower priced speaker, but no way "Super low end" Yikes!

There are a lot of wealthy and elitist people on this forum unfortunately (highly typical for audiophile focused communities). I have already pointed out in past threads that to 99% of the larger public, $600/pair speakers are not "budget", like most on this forum refer to them as. The guy you quoted is wanting $10,000/pair speakers reviewed, as though that's something most people buy.

 

[YSC]

One stupid idea, with such complex sound field, why not just put it near a wall and measure a single point swept and see if it remotely resembles something nice?

 

[amirm]

One stupid idea, with such complex sound field, why not just put it near a wall and measure a single point swept and see if it remotely resembles something nice?

You don't need me or Klippel for that....

 

[YSC]

You don't need me or Klippel for that....

But you got the speaker on hand

 

[amirm]

But you got the speaker on hand

But not the setup as you asked.

 

[thewas]

These Infinities are not the typical direct radiating speakers that you find in discrete multi-channel systems. I remember a time when a surround speaker had to be located above the listener at least 6ft high, now they point them at you - at ear level - times change, configurations change - and with it parameters. My couch comment ....is when you take something and measure it like it's something else.....that will make the entire premise wrong.

The problem is that these loudspeakers are not marketed as special solutions like the old school 6ft high placed ones you mention but as regular modern surround loudspeakers with the corresponding usual placement, see https://www.infinityspeakers.com/on...66b123/pdfs/Infinity_Reference_152_162_OM.pdf and thus they should be rated also like such.

If you noticed I didn't comment on the woofer response as like you say they are made for wall mounting, I only criticised the dual tweeters. They claim that thanks to them a very wide and uniform radiation is obtained

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.
Source: https://www.infinityspeakers.com/bookshelf-speakers/REFERENCE+RS152.html

when everyone with a little experience in loudspeaker design knows that rather the opposite is achieved with two distant tweeters and which is confirmed by the measurements of the NFS.

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

 

[beagleman]

There are a lot of wealthy and elitist people on this forum unfortunately (highly typical for audiophile focused communities). I have already pointed out in past threads that to 99% of the larger public, $600/pair speakers are not "budget", like most on this forum refer to them as. The guy you quoted is wanting $10,000/pair speakers reviewed, as though that's something most people buy.

I get what you mean. Look at all the multi hundred and thousand dollar interconnects and speaker cables.

I still have to wonder, why some would be so out of touch with reality. I mean can they not realize what normal priced stuff costs?

 

[prerich]

The problem is that these loudspeakers are not marketed as special solutions like the old school 6ft high placed ones you mention but as regular modern surround loudspeakers with the corresponding usual placement, see https://www.infinityspeakers.com/on...66b123/pdfs/Infinity_Reference_152_162_OM.pdf and thus they should be rated also like such.

If you noticed I didn't comment on the woofer response as like you say they are made for wall mounting, I only criticised the dual tweeters. They claim that thanks to them a very wide and uniform radiation is obtained

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.
Source: https://www.infinityspeakers.com/bookshelf-speakers/REFERENCE+RS152.html

when everyone with a little experience in loudspeaker design knows that rather the opposite is achieved with two distant tweeters and which is confirmed by the measurements of the NFS.

I looked at the link for setting up the speakers - they really don't go into the specifics of setting up the surrounds (no directions on height or anything else other than this statement:
"For surround-sound use, place the speakers alongside the listening position. Final placement depends on room acoustics, availability of space and your listening preference (Figures 2 and 3)."
that's a bit ambiguous indeed. We may be arguing about semantics - as this speaker design has always been strange to me in the modern discrete surround speaker era. One thing you did mention....that's very correct....it was used for marketing and I'll add expedience.

P.S. Yep ...the horizontal bandwidth is all over the place........

 

[Sancus]

Putting this up against a wall is going to fill in the low frequencies but I can't see how it will fix much of anything above 500hz, and the in-room measurement there seems to confirm that. The speaker is cheap as dirt and I'm sure it will do its basic job but I still don't see anything I'd actually recommend to anyone lol.