Beam 2 v. Arc Ultra stand alone surround effects

The Beam (Gen 2) relies more in HRTFs sound for rear and above.

You could be experimenting this better as the shape of your room, giving you different reflections by the size of the soundbar, if you like more the sound of the Beam and you don't want to add rear speakers, buy it. It is less power but if the volume isn't your problem, you can choose the Beam as I understood you like it more :)

What are HRTFs?

Head Related Function Transfer, there are things they do like a personalized eq per channel (or in Dolby Atmos for the coordinates of an object) with reverb, changes in phase, delay and more things to (frequently in headphones as they are easier to do and apply) emulate the calculations of the brain to know were a sound is.

So, if you do this; the sound goes already "processed" and your brain will think is in another position.

I know Sonos use them for the Sonos Ace and for the Beam (Gen 2). At less in the Beam for height, but it can also be for making a wider soundstage (horizontally). :)

 Never heard of this term before, thanks for posting an explanation of your use of the initialism.

Just out of curiosity, how do you ‘know’ Sonos uses this in some situations? Do you have access to the code base? Which devices do they use it for, which devices do they not?

I don't have access to their private code, only I know this tecnic I widely used across mush devices (like headphones with Dolby Atmos) to do the surround effects.

The Beam (Gen 2) I think as is the only way to do height channels (.2 or .4, some Sonos articles says one thing an others another, like it can do up to 5.1.2 and after saying 7.1.4) is by virtualize the channels, by doing this HRFT. And I know that the Beam (Gen 2) provide height sound without having physically speakers up-firing.

To do Dolby Atmos in headphones (like the Ace) you need yes or yes to do this because you only have left (L) and right (R) nothing above, in front or behind you.

I hope this helps and I comunite appropriately. :)

That's why they could be also using this or something similar for more situations, to make the stereo more wide. Or the soundstage.

Other Sonos products I dont think they could have this, because they aren't Dolby Atmos enabled and the Arc's have real speakers up-firing so they don't need to virtualize the sound.

I think they use this only when you're playing Atmos content; if not, I don't think so.

Thanks for the explanations, most interesting.

Really excellent reading:

https://en.wikipedia.org/wiki/Head-related_transfer_function

You only need two transducers, one for each ear. The trick is in the processing. After all, there are only two ears. Dig around and you can find some interesting demos. One demo that I experienced through headphones was a “haircut”. We were wearing headphones and “scissors” started in the rear at the base of our head and moved up to the crown. Hairs were so convinced that they were about to be cut, that they stood up and waited.

​@buzz Yes, I also listened like 4 years ago the haircut audio recorded with earphones that behind the speakers they had microphones.

And what I meant with that is exactly what you said, in headphones is easier because you have only two speakers and too much processing (for Dolby Atmos that you can play in different devices), only in Apple Music they have the processed binaural audio (only in AAC).

When you add more speakers and they aren't close to your ear, you need less processing because you have more real speakers but also now you have the conditions of your room and your shape of ear that you need to evade by again altering the eq (but only this now, all other tricks still).

It's like pull and pull (as we say in my country to mean it is very variable and dependable, in this context).

The most real audios are those who are physically recorded, but the songs in Atmos (or in another things like DearVR2 before the Boom! of Dolby Atmos) do the processing and could be more artificial and doesn't sound good at all (when is HRFT in between it). :)

Leo,

It’s not that I like it more. The Ultra has a wider sound stage and but simply seems to lack the same surround effects. I want an answer to whether the Ultra can match the Beam 2 in that regard. I have tested both in the same room, which is perfectly square 15’x15’ with a 10’ ceiling. Is there a way it can produce those surround effects as a standalone? If so, is the fault the way I am using Trueplay or is it just the way it is?

Thanks

Sounds like a question you should ask Sonos not other users. A phone call is usually the best way to start towards getting an answer.

Stanley,

I contacted Sonos and they are working on an answer. Do I expect it? No. Leo seems to know a lot of technical details, so I’ll wait for his response. Tried it in a large room with same result but it did fill the room with great sound. Looks like I’ll have to save up for surrounds if I want the real effects.

Maybe it's a fault of Trueplay, I don't own an Arc Ultra but I have a Beam (Gen 2).

I've watched a video of a cinephile and audiophile that bought the Arc Ultra and says in his video (Fotograma 24 in YouTube if you want to see, I think the video is auto dubbed by AI to english) that he needed to make the Trueplay like 10 times to get a flat response, as it should be. Maybe Sonos hasn't made anything to that, so you could experimenting that.

I don't have an iPhone so I don't ever made an Advanced Trueplay but also without it, in my new flat and before in another house the surround sound are that, not everyone but much sound from behind and Dolby Atmos even without physical speakers sound very good.

Try to test both without Trueplay and look (or better; listen to) for which one sounds like is wrapping you more :)

At least with my Beam it sounds good without "extras" but with a Sub Mini and Era 100 as surrounds sounds even better, maybe with the difference of cost you can buy the surrounds or a Sub (but by the shape of your room you really need to Trueplay). It is the same with the Arc Ultra but it can enhance the sound even more.

At the end is your decision and your pocket. For me in a rectangle of like 8mx6.5m (24'x19.7') it standalone sounds very good with deep bass and not every sound from behind (because the lack of Trueplay and the spacious room, also my TV is 79" and Sonos says the Beam is for up to 65" TVs) but much and from the besides they were sound clearly.

Sonos tying soundbar selection to tv size is quite strange, aside from an Arc possibly being wider than the tv what difference does it make? 

Possibly they were looking at optimal viewing distances for tv sizes and confusing the soundbar selection issue by not directly stating that, instead dropping the context and going directly to screen size as the criteria?

Ugly website but a fun to play with calculator:

https://www.rtings.com/tv/reviews/by-size/size-to-distance-relationship

65" distance is 8' 10"

Yes I know, inclusive I joke with my family saying that Sonos suggestions (in the size of room, also they are very subjective) are like at the potential of 10, their products are so powerful. Obviously caring very much about the quality rather than the volume.

​@leo07 

Thanks for interjecting the subject of HRTF. I’ve learned something new...I think...given my miniscule level of understanding 🤔

This talk about HRTF is very interesting although I’m not inclined to do a deep dive into it. However, given the Wiki excerpt below it could explain why in a “perfect room” one individual may perceive a surround or Dolby Atmos presentation differently from another. 

Now….taking that into consideration when you introduce the “not-so perfect room” you get individuals who will say the sound is excellent all the way down to terrible with varying degrees in between. If Sonos is employing HRTF science, they probably settled on a “mean” parameter. Said parameter would likely satisfy most knowing that there will be disagreement by a select few. Sonos cannot predict/control the environment wherein speakers such as the Beam and Arc series (past and present) will be placed.

That’s all I have to add. 😉

Thanks for the input. I actually have a bedroom setup with the Beam 2, Sub Mini and two Era100’s. Sounds amazing. When I tried the same setup in the Sun Room, which is 15’x15’x10’, it also sounded great. When I tried the Ultra as a standalone in our family room, which is open at one end, the Ultra sounded amazing but the same problem occurred--surround effects were the same. In both rooms where I tested the Ultra, the distance to rear wall was minimal (3’ and 2’). The Beam 2 had no problem creating surround. Might call tech support again to see if they have come up with a solution.

Absolutely ​@AjTrek1, the HRFT is very dependent, not all the people ears are the same, but often the companies as you said do a mean, so for anyone is perfect (maybe only some people) and for anyone is annoying/non functionally.

​@Rock46 I think you should discuss it with Sonos.

As far as I know the Arc Ultra is better standalone for height effects, LFE, and surround. However, you might try to add your Era 100 as surrounds to listen if that improves a lot the sound or keeps without playing better the surround effects.

Also to enhance the not-perfect room is probably that Sonos applies the Trueplay calibration also to this effect to again re-build the eq forms.

Leo,

Called and spoke to level 2 tech at Sonos. In a nutshell, there is nothing wrong with the Arc Ultra. It is just the way it interprests the surround signal and since it has more speakers than the Beam2, that is where they differ. He said that he has received other messages referring to the same thing. Said that they may be working on a software/firmware update to solve the problem. 

When he was done troubleshooting, he sent me a 30% off discount coupon that I could use to purchase a single item. I might return the Arc since I bought it for $899. List is $1099 and 30% off would bring the cost down to $740. Then I can purchase two ERA100’s for rears.

It sounds like a good deal, you’ve got real surrounds for the same price. I hope for all who are experimenting this that the firmware update is real.

We have nothing left to do, only wait.

Real surrounds will beat reflective or virtual surrounds every time. Sounds like a good deal to me.