Home Theater/surround sound


With regards to surround sound in a home theater setup, it seems to me that today, even with 7.1, Dolby Atmos, etc., most things are still 5.1.  It seems even at most movie theaters, that they are still are using older surround technology vs. newer technology.  Even streaming services such as Netflix are using 5.1 for their video streams.  Most Blu-Rays are still using 5.1.  Makes you kind of wonder if 7.1/Atmos will ever become mainstream and overtake 5.1.  In most people's homes, given standard room sizes, would it make that much of a difference moving from a 5.1 setup to a 7.1 or Atmos setup?  I personally have a 5.1 setup and think it's fine.  Not sure if spending the extra money to get additional speakers, a new receiver, etc. is going to make that big of a difference.  Does 7.1/Atmos make you really feel like you are in the movie?  That's what some people claim.

The other thing is with speaker size.  Is bigger always better?  In movie theaters you always see these huge speakers sitting on the walls, and these seem big even for surround speakers.  In people's homes you see much more smaller "satellite" speakers, even for the fronts.  Do you get much better sound with larger speakers, even for surrounds?  Even a lot of retailers sell "home theater speaker" packages that have these tiny speakers, as opposed to large ones.  Also, how important is it to match speakers, meaning to have all the same size, brand, model, etc. (e.g. essentially what you get in a HTIB package)?  Some say this is the best way to go because everthing is matched to have the best sound and dynamic range.

The last question related to surround sound is why does it seem like people are moving away from all-around home theater surround sound?  I've ran across some recent articles that said that soon receivers will be no more, that people are not buying them.  I even read one article that said that surround sound for home theater is on it's way out.  All of these articles point to people opting for soundbars nowadays, and it seems that they're happy with just that.  I don't see how those can ever replace having an elaborate setup with a receiver, speakers, etc.

Thanks very much for your help.

I would agree with your first line of reasoning about 5.1 - it seems pretty well entrenched largely for the reasons you point out: it is compatible with the majority of surround sound installations the world over (and 6.1/7.1/etc systems are backwards compatible with it), and it is prevalent for most media. The use of 5.1 for streaming and other services is done as a space-saving measure - HDTV broadcast and HD streaming still generally rely on Dolby Digital 5.1 (the same as on DVD) for their audio as it is very compatible and very space efficient (especially compared to the lossless audio found on HD-DVD and Blu-ray). Greater-than-5.1 systems can have some advantages but generally I would not say they provide any exponentially greater degree of realism/immersion. It's also worth noting that there isn't a completely universal channel map for 7.1 (or greater) systems, as various different vendors have done different things with the extra pair (or pairs) of speakers. The Dolby/DTS scheme with a set of "rear surrounds" is probably the most common, but there are alternate maps from THX, Audyssey, Yamaha, Sony, Trinnov, Dolby, and JBL that put those speakers in other places. When you get into more exotic configurations, like 9.1, things become even more vendor-specific, as the additional speakers are tied to a specific DSP program's outputs, as opposed to a more-or-less agreed upon channel map (as is the case with 5.1 or 6.1).

Atmos is a bit different, since it doesn't rely explicitly on a fixed channel map, but instead pan metadata, to implement surround sound. The decoder uses that metadata to "place" the surround effects within its surround array (which is then configured at install to match whatever speaker configuration is chosen - from 5.1 to 24.1.10). This makes it more flexible for multi-channel systems, the downside being that content is still fairly scarce (there's a few Blu-ray releases that use Atmos, and not much else).

As far as the other questions:

- Speaker size can matter, but isn't the only determinant of speaker quality. The big difference between movie theaters and home theaters is their size - movie theaters are often massive auditoriums and require significant speaker power just for the movie to be heard throughout the auditorium, while home theaters are usually set-up in living rooms or converted bedrooms and don't need much in the way of power to get quite loud. That said, ideally the speakers in a home theater (or hi-fi stereo) will be capable of at least reproducing bass low enough to blend nicely with a subwoofer (or reproducing bass entirely by themselves), which is something that many small satellite speakers cannot do.

- Matching speakers is important, but having all five or seven or N channels be the same model is not a requirement. Ideally each pair of speakers is the same (e.g. the front left and right speakers are the same model), and even more ideally the center channel matches the front/main speakers, so that as sound pans across those three channels (the "LCR") there is more consistency. However that matching doesn't always require 3 of the same model - many speaker manufacturers will sell a purpose-built "center channel speaker" that is voiced to be compatible with speakers sold as front/main channels. The surrounds, ideally, will be tonally similar to the LCR speakers, but don't have to be identical, and quite honestly don't have to be anything exceptional in terms of their sound quality either (as the surround-sound content in most movies is used just for effects - like an airplane whizzing past - so while fidelity is important, it isn't as important as for speakers that reproduce dialog or music (which is generally all on the LCR speakers)). In a perfect world we could have all five or seven or N channels be the same, but that isn't always practical (e.g. you want/need wall or ceiling mounted, or in-wall/in-ceiling speakers for the surround channels), so I'd say try to match at least the LCR and get surrounds that are "good enough" for their role, and not lose too much sleep over it. Using full-size speakers for surrounds isn't something I'd suggest - while newer multi-channel encoding schemes (technically this includes Dolby Digital and DTS, but I'll qualify that in a minute) can, and do, implement full-range on all channels you're still usually dealing with effects on the surrounds, not full dialog/music, so there's not much to be gained from a large full-range speaker as a surround channel. So what about older formats? Dolby Surround (and many other, later, matrix simulacra) are band-limited for their surround content so there's absolutely no point in having full-range speakers there, because the content simply doesn't make use of it. As far as Dolby Digital and DTS go - there are examples of both full-range and band-limited mixes largely depending on what the original movie was mixed for (e.g. there's lots of older, Dolby Surround sourced mixes put into Dolby Digital for a DVD release that may not have very impressive surround effects, and then there's newer releases that have fantastic discrete, full-range surround from Dolby or DTS and provide excellent examples of what DVD (or Laserdisc) is capable of). But even if you're going for a pure high-def-only system (e.g. you will only ever watch Blu-ray/HD-DVD on it), big full-range surrounds don't make a lot of sense (at least in my view) because it just isn't a heavy requirement of the content. So if you're after big, full-range speakers for your mains or the entire LCR setup, find a pair of matched/voiced (e.g. from the same line of speakers from the same manufacturer) bookshelves or satellites for the surrounds - it will probably save you some money, make installation simpler, and still yield a good sounding system.

- It's tough to say what the future holds. If I had to guess I'd say we'll see more divergence than anything else - elaborate multi-channel home theaters are unlikely to go away, but "mid-range" 5.1 or 7.1 package systems will likely go the way of the dinosaur, and be replaced by simpler soundbar configurations which still provide an upgrade over a TV's built-in speakers, without the complexity of wiring up a 5.1 or 7.1 system. Soundbars will never fully re-create the listening experience of a discrete multi-channel system, but newer ones can do a good job of "faking it" with their DSP effects and specially designed speakers. If you're considering a soundbar, I'd say its worth thinking about its price versus the price of a 5.1 or 7.1 speaker system, as well as how much space (and time) you have to devote to the project - if you need something simple for a bedroom, a soundbar may be an obvious buy, but I wouldn't spend thousands (or tens of thousands) of dollars on a soundbar; if you need something more compact than a 5.1 system, there's still a lot to be said for a conventional stereo system with a pair of high quality speakers and a good amplifier.

- Home theater receivers themselves *are* probably on the way out, largely because they're quite anachronistic these days. They trace their roots back to an era when it wasn't atypical for a home user to own multiple, different, machines to play a variety of media formats: VHS, CD, cassette, videogame consoles, vinyl, AM/FM, and television all generally required a single-function piece of equipment to implement. However newer multi-media devices are all about convergence - you can get a single device, like Xbox One, that will do everything - it will stream music and video, play videogames, play CDs, DVDs, and Blu-rays, play live TV, etc and it only requires a single connection back to your TV/sound system (via HDMI) as opposed to the myriad connector types associated with all of the separate boxes. So the need for a big switch-box that integrates all of those different sources together is fairly minimal. There have also been significant advances in amplifier technology in the last ten-twenty years, and newer designs are capable of significantly higher efficiency (which means they can be smaller and don't require a huge box with huge heatsinks and cooling fans to keep them working), so its quite easy to create an all-in-one package that drives speakers and plays/streams all of your media content (which is what most HTIB solutions do these days). So, I wouldn't be surprised if, in the future, we see the home theater receiver as we know it being relegated to the history books, and more integrated devices fulfilling that role as we move away from needing ten different "boxes" just to enjoy music and film. Elaborate home theater installations will still rely on some sort of surround sound decoder/processor/controller device but in recent years even those have started to diverge from the traditional idea of the multi-channel AV preamp and more closely resemble computers these days.

If you have any further questions, feel free to ask.  

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Questions regarding HTPC integration to home theaters, and general purchasing advice regarding home theater and audio systems, including headphones. Please no car audio or over the top PA systems.


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