Feb 262012

How many A/V receivers do you think Best Buy (.com) carries that support 5.1 surround – 5 speakers plus a subwoofer? 14.  How many that support 7.1 channels or more? 44, with models that start at under $200.  Don’t ask me how it’s possible to make a box that amplifies 7 discrete channels and does surround sound decoding and various other A/V receiver duties for that price! But in all seriousness, you look at what’s being sold out there, and you’d start to assume that you need to have 7 speakers plus a subwoofer if you want the “true” surround sound experience.

What about content? DVD is limited to 5.1 surround (via Dolby Digital or DTS), and not a single streaming service I’m aware of supports better than 5.1 on any title. If you even the possibility of 7.1 surround, you have to get your content on Blu-ray (which delivers the best overall quality anyways). So of the roughly 40 titles that I have on Blu-ray (counting series of things as a single title), how many have a 7.1 soundtrack?  One.  And the 7.1 title in question – Transformers: Dark of the Moon – is not really a title that I’d recommend owning; even for someone like me who grew up with Transformers and collected the toys, I found the movie pretty bad.

But let’s not judge by my collection! There’s a handy site – www.blu-raystats.com – that has a searchable database of almost all known Blu-ray content, with handy filters to narrow down the selection.  Out of the 5,669 titles it reports with no filters, 295 are listed as having 7.1 soundtracks. Unfortunately, even this is deceptive. Even a cursory glance through the actual list quickly reveals that almost all of the movies are older titles that were definitely not recorded or mastered in 7.1 originally – so what you’ll hear out of the extra two speakers is just some the result of some DSP algorithm trying to create a more enveloping sound field. It doesn’t have positional information to know what sounds should really come from behind you.

So basically, 7.1 surround is nearly completely useless over 5.1 surround when it comes to most movie material.  In spite of this, I’ve had a 7.1 setup for some time anyways, as a result of over-buying equipment a dozen years ago. Room geometry here in our new home meant it was time to change some of the speakers in a system that’s worked very well. Was it worth sticking with 7.1, or did my understanding of the above send me down a different path? And what speakers did I go from and to?

One of the new speakers; that’s actually a picture of it hanging on my wall!

5.1 or 7.1?

From the above, it would seem like a foregone conclusion that it’s pointless to continue to run a 7.1 setup – but there’s two details I didn’t mention above.

First, you can indeed have a more “enveloping” sound field with more speakers, even if they’re playing exactly the same output. This is usually not a good way to go, versus putting the same budget into a smaller number of high quality speakers (and/or amplification), but it does mean that adding speakers is not going to be a complete loss. In this particular case, though, this was actually somewhat important, because the rear part of the room is now where we have various exercise equipment (which we need to use a lot more!). A 5.1 setup would have located the rear speakers to the sides of the main listening position (if you follow THX suggestions on speaker placement).  This wouldn’t have enveloped the exercise area, which seems quite unimportant – except for two added details. One, exercise machines are quite loud, so you need a decent amount of volume to hear dialog clearly. Two, we exercise at night, when cranking up the volume would be a great way to potentially wake up the kids. Having speakers on the rear wall, behind the exercise equipment, helps a lot with this – and with being able to watch anything with dialog while exercising.

Second, and more importantly, games can and do fully utilize a complete 7.1 sound system. That’s because unlike movies that come with a prerecorded soundtrack that has discrete audio for (usually) 5.1 channels, games generate their audio on the fly. So if something happens behind you (usually not a good thing, especially in shooting games!), the game will just tell the system to play a sound there, and if you happen to have a speaker there, you’ll actually here it. When I first went from 5.1 surround to 7.1 surround (since I already had all the speakers), I literally heard no difference in movies I watched. But when I switched over to playing games, it jumped out right away. I wasn’t even testing the new system out; I had finished that days ago and had just decided to play a game, but instantly heard a dimension that simply wasn’t there before.  Since I’m still a gamer, this combined with the above point (and the fact that I already had the processor and amps) made sticking with 7.1 a clear decision for me.

For most people, in most rooms, I still think you’ll get more out of focusing your budget in a 5.1 system, though.

Infinity Delta Series Speakers

A dozen years ago, when I bought my home theater speakers, a bunch of eBay wannabes that were flush with recent venture capital rounds were trying to get market share at all costs.  The “cost” in this case – to their investors – was usually that they’d run auctions for things that would often go for far less than normal retail prices. Unlike eBay’s 7-day auctions of user goods, these companies were directly offering up electronics and various other goods, in a much more time constrained format (presumably trying to create excitement). They tried to have these going 24 hours a day, so if you happened to be awake at 5am and they happened to offer up something at that time, you’d have very little in the way of competition. You had to be careful – as with most auctions, it usually just took one or two people willing to pay higher prices to turn something into a definitive non-deal – but you could get some decent stuff relatively cheaply.

I wound up with a set of six floorstanding speakers from the Infinity Delta Series line – a pair each of the Delta 60s, 40s, and 30s. These aren’t high end speakers, but I didn’t pay high end prices either. The one time I ran into the Delta 60s in an actual store, it was in Japan and they were going for 3 times what I paid for them! Thanks, dot-com bubble! After 12 years, they’re still in great condition. Here’s a picture of one of the Delta 60s (with the front grill off):

The distinguishing feature of the speakers was the EMIT-R tweeter you see at the top:

The mini-grill over the tweeter is actually pretty handy for keeping kids fingers out!

I don’t have an audiophiles ear, but the Deltas did a nice job on any of the things I threw at them over the years, especially thanks to the Sony TA-E9000ES preamp/processor that I used with them (an amazing unit that sadly broke many years later). The only reason I even looked at swapping them out in our new home is that they are large, floorstanding speakers.  This was kind of OK for the front and rear speakers, but in our new room geometry, didn’t work so well for the side speakers, because you have to walk through the room to get to our basement door, and there just wasn’t good clearance with the side speakers sitting there. So I decided to keep the Delta 60s and a Delta Center in front, and replace the rear channels.

Mirage OMD-R Surrounds

I replaced the side and rear speakers with Mirage OMD-Rs, which you see pictured above. They’re designed for wall mounting, and take up far less space (especially because the higher part of the wall on the left of the room is recessed). They aren’t small by any stretch, though; each speaker weighs 22 pounds. I was going to get the smaller and cheaper OMD5s, but they wouldn’t have been sufficient for the fairly big room that they were going into, especially since there’s a good distance between the rear of the room and the seating position for watching movies or playing games.

The OMD-Rs are bipole/dipoles, or some variation anyways, which is apparent when you remove the cloth grills:

There’s another midrange/tweeter pair facing the other way that’s not visible in the image above. I did a good bit of reading on monopole vs. bipole/dipole before going this route, though as with most good topics,  proponents of each approach didn’t agree with each other. Monopole configurations seemed favored for multichannel music listening, whereas bipole/dipole seemed to be generally accepted as more suitable for creative a wider sound stage and for ambient effects. The latter is what I expect to do, hence the choice I ultimately made. I didn’t have an opportunity to listen before buying (it’s hard to control listening tests enough to make an informed decision anyways, and room geometry has a huge effect you can’t test for), but the overwhelmingly strong reviews for the OMD-Rs plus forum recommendations helped make up my mind.

I haven’t had enough listening opportunities to comment on the sound – I just finished doing the installation a couple of weeks ago – and like I said earlier, I don’t have the golden ears of an audiophile in any case (though I’m still more selective and particular than most listeners).  They do definitely look good, though, and now I’ll need to fight the temptation to go for a matched system by replacing my front/center speakers…

 Posted by at 10:52 am

  2 Responses to “Is 7.1 surround useful?”

  1. […] few posts ago, I talked about 7.1 surround – and about how though it was mostly unnecessary for movies, I […]

  2. […] I changed my surround speakers, getting Mirage OMD-Rs to mount on the wall to better match our room and to make some space.  Then […]

 Leave a Reply

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>