Dolby Podcast Episode 59 - March 12, 2009
Craig answers listener questions and reveals home theater demo secrets from industry experts. In this episode, Craig covers:
- Should you use the built-in speakers in your TV with your surround sound system,
- Troubleshooting a Dolby TrueHD center channel volume issue
- Availability of Dolby Volume for TVs and AVRs
- How to get the most out of two-channel stereo content with Dolby Pro Logic, and
- Great demo content picked by the experts.
Craig Eggers: Streaming to you from our headquarters in San Francisco, this is Dolbycast, the insider's guide to entertainment technologies, from the experts at Dolby Laboratories. We're here to give you the straight talk and news on everything you need to know about technologies that excite your eyes and ears.
Greetings, Dolbycast listeners, and welcome back. Hey, between all the appearances by our many guests, we've received some really great email from you, our listeners. Thank you very, very much. Questions regarding home theater speaker design, system design, setup. And a lot of those questions, we've addressed directly as well as indirectly with some of our recent guests. We've also received some very unique listener questions, some of which we've never really addressed before.
So, in today's Dolbycast, we'll attempt to answer some of those questions, and we'll share with you some industry experts' ideas on great demonstration content, the kinds of content we've talked about, the kinds of content you want to consider when you demonstrate your home entertainment system to your friends.
But before that, let's jump into some interesting listener questions.
We received a question that we've never really addressed here on Dolbycast. It comes from John, who asks, "My question to you is: my TV has built-in stereo speakers. When I turn on my surround sound system, should I turn off my built-in TV speakers or not, and does it matter?"
Great question, John. And this really gives us an opening to speak about how to connect your television set to your home theater system and really optimize the performance of your entire system.
The short answer to your question is to turn your TV speakers off. Now, with that said, a little bit of background.
First of all, there's a couple of ways that you could actually connect your television set to your AV receiver. Today's high-definition television sets have digital audio outputs: either a coaxial audio output or an optical audio output. A lot of digital television sets also offer HDMI, which obviously enhances audio and video performance. And then there's the common way to connect your television set to your AV receiver, which is the standard method of audio left and right, your stereo pair. These are identified by the white and red audio outputs on the back of your television set.
So, back to the original answer. Why do I advise you to turn the TV volume down? First of all, I found that TV sound being played back simultaneously by the AV receiver and the TV can actually introduce some undesirable delay echo into your system. You may have experienced this; I know I did just recently.
I had a friend that connected their Blu-ray player directly to their digital television set via HDMI, to transport the video. And because they had an AV receiver that did not have Dolby Digital Plus, Dolby TrueHD, they went out of the digital audio output of their Blu-ray player into their AV receiver. Well, they left their television set volume on, and they called me up and said, "Hey, every time we play back our Blu-ray player, we get echo. What's going on?"
Well, I went over to their house and rapidly found out that they had the TV volume up and it was introducing all kinds of echo and delay. So you don't want to have your TV volume up.
Now, there's another reason why I really encourage you to turn your TV sound down. And when you consider, from a surround sound perspective, if you have a stereo television set and the speakers are on, what you're really doing is you're introducing all the audio information that you're trying to actually decode into its individual elements via your receiver in a very confined space—that being the speakers on board the television set. That's not a good thing when you're trying to reproduce the ambiance, the immersiveness that home entertainment, home theater is all about.
So let your speakers in your system do the heavy lifting. Let them create the surround sound ambiance, the effect, and the dialog reproduction.
Now, if you're not careful, when you connect your stereo television set to your receiver via the stereo pair, you can introduce a whole another set of problems. For example, utilizing pseudo-surround sound or sound expansion processing in your television set. If you have that on and you're sending that process signal directly to your AV receiver, you can actually negatively impact the way the receiver does its logic decoding of the stereo signal.
So I advise, if you have a television set, and you have surround sound, and you're using it, turn it off if you connect it to your AV receiver via the stereo pair.
Now, in the past, some manufacturers have actually offered a center channel input on the back of their television sets. Now, in this case, you actually would take the line level stereo audio outputs from your television set, send them directly to your AV receiver, and then come back out of your AV receiver, from the line level center channel output, directly into your television set. Now, what this would actually do would be to enable you to send those center channel dialog signals directly to your speaker system on board your television set, and in theory more firmly anchor that dialog to the screen, because, obviously, the speakers are closer to the screen than anything else.
It's a great idea, initially, when you think about it, but the only issue I really see here is most television sets don't have the power and they don't have the quality or the timbre of speakers to match the performance of your AV system. Your center channel speaker in your home theater system was literally designed to reproduce dialog. It was designed to match the performance and timbre of the rest of the speakers in your system. So go ahead, use that. I don't advise coming back direct into your television set if it has a center channel input.
That brings us to another point. A lot of television sets have fixed as well as variable audio outputs. Now, variable audio outputs TV manufacturers put on their television sets because they enable the consumer to literally utilize their TV remote control to change channels as well as adjust volume of their home theater system.
When I worked at Toshiba, we used to put variable audio outputs on television sets. And this basically allowed that process, created simplicity. We talked about the whole convenience aspect of that.
Now, if you've got variable audio outputs on your television sets, chances are you've also got fixed audio outputs, or you've got a software switch in the on-screen menu that enables you to choose between variable audio outputs and fixed audio outputs.
Listen to me and hear me. If you've got a television set with variable audio outputs, make sure you change it to the fixed, line level outputs. That's where you're going to get your best performance. So, if you connect the variable audio outputs, you might not get any television volume at all from your system. Not a good thing.
So, with all those caveats and background, the answer to the question is: turn your television volume off, and when you listen to your home entertainment system, you'll get a better experience.
We'll be right back, right after this break.
[musical interlude]
Craig: Hi, this is Craig from Dolbycast. Hey, we love to get your questions. Send those questions to dolbycast (at) dolby.com. Or give us a call: 1-888-6-DOLBY-C. That's 1-888-6-DOLBY-C.
[musical interlude]
Craig: Hey, we're back at Dolbycast, with listener questions.
We received a question about Dolby TrueHD playback from a listener, Bradley. Bradley writes, "Is the Dolby TrueHD center channel output at a lower volume level than Dolby Digital?" Bradley also continues, "Often, when I put in a Blu-ray that's decoded in Dolby TrueHD, I have to turn up the center channel volume by approximately 1.5 dB." And Bradley's question is, "Just wondering if it's the recording itself, or is it how my new receiver outputs that channel?"
Bradley, I checked with our folks down in Burbank. These are the professionals that deal with the content providers and help them create all that great content that we see out there in Blu-ray and with Dolby TrueHD. And they offered a couple of possible answers. And I don't think they're really the right answer.
First of all, they suggested that the Dolby TrueHD soundtrack might be different. But this is really unlikely if it's occurring on every disc and you're having this happen on every disc that you play back that has a TrueHD soundtrack.
Another possibility is that the disc is authored with internal mixer levels set this way, or possibly you're listening to a disc with different down-mix coefficients. Now, again, this is probably unlikely because you seem to be experiencing this on the majority of the Blu-ray discs that have TrueHD soundtracks.
Now, what you didn't say, Bradley, is you didn't say how your components are actually connected to your AV receiver. And this could be the issue, because there could be some hardware gain issues here, and it would really depend on where you decode the audio and how it gets to your receiver.
An example. This could happen. You could see this happen if you decode Dolby Digital signals directly via your receiver, via the digital coaxial or optical audio inputs. But maybe you're decoding Dolby TrueHD in the player and transporting that signal to your receiver via the external audio inputs. This type of connection—again, depending on your receiver—could possibly expose some hardware gain differences in levels.
One final possibility: if your receiver maintains separate calibration levels for memory, for different audio codecs, then this could possibly explain what you're experiencing.
So, Bradley, I would suggest that you check with your receiver manufacturer on that specific issue. And you know what? I'll try to check, too, and see what I can learn.
We had a question from a listener, Marty. And I love this question. Marty writes, "Surely there must be televisions that are equipped with Dolby Volume. Do you have a list?" And Marty also continues. He says, "Are all of the vendors identifying Dolby Volume as such, or are they using their own names for this technology?"
Marty, great question. First of all, there is only one version of Dolby Volume. We don't license it under different names. You'll see Dolby Volume in the marketplace. When it's present on television sets, there'll be a Dolby Volume logo and they'll talk about Dolby Volume in their spec sheets.
Toshiba Regza television sets, in North America, Europe, Japan this year. Look for them to debut shortly. Toshiba basically begins rolling out their product line in March-April, and it continues through August. So look for Toshiba Regza television sets, because they will have Dolby Volume in them this year.
And while we're on the topic of Dolby Volume, we had a question from a listener by the name of Nick, from San Diego. And Nick writes, "When can I expect to see Dolby Volume in more AV receivers, specifically the $500 to $1,000 price range? I'm holding off on upgrading my current receiver until this great technology becomes more affordable."
Answer, Nick. Nothing to announce yet—yet, he says—at least on this Dolbycast. But I'm very optimistic you'll see some exciting products in the price range you're speaking about later this year. Stay tuned to Dolbycast. We'll continue to keep you updated on this important technology.
I would be remiss, though, Nick, if I didn't mention that the Arcam AVR600 is now in the marketplace. It's getting some great reviews. It's equipped with Dolby Volume. It's more than you plan to spend, but I have to tell you: it is a wonderful product.
We also received a question from Keith, who's a longtime listener of Dolbycast. Keith writes to us, "Hi, Craig. My TiVo can download content from Netflix and Amazon. The Amazon downloads the full files so there are no hiccups in the viewing experience. My question is: will the two-channel audio stream contain a Pro Logic matrix signal so the playback through my receiver set on Pro Logic will give a decent surround sound experience?"
And Keith also continues, "Further, given the bandwidth required for Dolby Digital 5.1 and Amazon's full-download paradigm, why don't they offer Dolby Digital 5.1 with their content?"
Well, a couple questions there, Keith. I have to tell you, most two-channel mixes of movies are basically a fold-down of the multichannel mix. So, if you engage Dolby Pro Logic II or Dolby Pro Logic IIz, you can enjoy a 5.1 or 7.1 listening experience with this content—albeit not as discrete, obviously, as if you had Dolby Digital or Dolby Digital Plus 5.1 as your source for your audio.
So the takeaway here: any time you've got a stereo movie coming into your system, be it from VHS, Laserdisc, television, any type of content coming in, engage Dolby Pro Logic, Dolby Pro Logic II, Dolby Pro Logic IIz, and you'll get an expanded surround sound listening experience. I know, obviously, with CDs, I listen to all my CD content—which is stereo, obviously—in Dolby Pro Logic II music mode. And it provides a spectacular listening experience, so check it out.
An answer to your second question. We think that Dolby Digital and Dolby Digital Plus are great tools for streaming and downloading high quality, multichannel audio content. As you know, the VUDU box already takes advantage of the bandwidth efficiencies as well as the quality of Dolby Digital Plus. So, as they say in the business, stay tuned, and we'll keep you advised.
And when we come back, three industry experts share their ideas on great demonstration content.
[musical interlude]
Craig: And back at Dolbycast. We're going to talk about great demonstration content in just a moment here, but I want to take a pause to reflect on some questions we've been receiving.
We've been receiving a lot of questions with regards to HDMI, specifically what it carries, what it transports, how to make that connection, how to make the handshake, the security implications of HDMI. A lot of great questions from you, our listeners.
And I tell you what: in a future Dolbycast, we're going to interview someone from Silicon Image and get them in here and have them talk about HDMI, where it is, where it's going, and answer some of those questions we've been specifically getting from you, our listeners. So stay tuned for that in a future Dolbycast.
Great demonstration content makes a great entertainment system sound and look even better. We polled some industry experts recently, and some friends of Dolbycast, regarding their picks for great demonstration content. And here's what we heard back.
Ara Derderian of the HT Guys told us, "The scorpion scene in Transformers is the best audio I've ever heard outside the sound stages at Sony." Pretty remarkable. For concert footage, Ara likes The Goo Goo Dolls at Red Rocks. He says, "It's out on DVD, but was shown in HD on HDNet channel."
Ara, I have to agree with you. Transformers is one absolutely incredible soundtrack. We've used it several times at CEDIA as well as CES shows.
We also spoke to Joel Silver of Image and Science Foundation. ISF has several reference discs that they recommend each month. Currently, the ISF reference Blu-ray movie transfer is Untouchable by Paramount. Joel tells us he likes the entire flick. The ISF reference Blu-ray concert video is Elton at 60. Joel recommends the opening track plus Benny and the Jets.
Joel, I agree with you 100 percent. I've recommended Elton at 60 many, many times here on Dolbycast. The video quality of Elton at 60 is absolutely spectacular. My only regret is that the audio is uncompressed 24/48 PCM. I would have preferred even more quality, perhaps a 24/96 Dolby TrueHD soundtrack. Universal uses Dolby TrueHD, for their Police and Nine Inch Nail concerts on Blu-ray, so maybe we'll see Elton at 60 in a future, expanded release, with maybe a 24/192 or a 24/96 Dolby TrueHD soundtrack. It's an incredible disc. Like I said, it's something I personally recommended in the past.
We also spoke to Joe Kane. Joe Kane has been a recent guest here on Dolbycast. As you may know, Joe has a much more eclectic approach to demonstration content. Joe tells us he likes to pick reference content that is basically movies and content he likes to watch, hence his selections are more based upon drama rather than full-on action.
So some of Joe's picks include Baraka, chapter 12. Joe cites the city sequence, including New York and Tokyo, as great for audio as well as video.
When he was here with us, Joe also mentioned Casablanca. And again, he mentioned it: Casablanca, the second and fourth chapters. Joe says, "We run this for video quality." Those of us who are frequent listeners remember me talking to Joe about the fact that Casablanca's black and white. Why are you choosing black and white for a reference video? But it absolutely is a spectacular demonstration disc.
For audio, Joe likes the dogfight scene in Flyboys. According to Joe, "The video here is borderline acceptable, but the audio mix is very compelling." And I've used that scene to demonstrate my home theater system also in the past.
Joe also talked about How the West was Won. This is out in Smilebox, a curved screen simulation. Joe recommends the opening sequence through the Erie Canal, says it's a great demo for picture quality. So you might want to check that out also.
For audio and video, Joe recommended The Phantom of the Opera, specifically chapters 2, 5, and 20. Frequent listeners to Dolbycast will remember that this was one of the very first Dolby TrueHD discs from Warner Home Video. Joe notes, "The picture quality is stunning, and the audio-visual combination can bring audience members to tears."
And finally, Joe mentions Seven Years in Tibet, starting specifically at chapter eight, the point where they're accepted into Tibet. Joe mentions in his note to me that "This is an example of vertically filtered video, but still offers great quality."
Now, I have to tell you, we'll have to get Joe back on a Dolbycast I the future to explain what "vertically filtered video" is. But I might add that I agree 1,000 percent with Joe. Seven Years in Tibet is an incredible movie, won an Oscar for best cinematography. Incredible landscapes and, really, a beautiful demonstration tool.
Well, anyway. There you have it. Those are some of our experts' opinions with regards to great demonstration content. How about you? Tell us your favorite picks for demonstrating your home entertainment system, and we'll get them on in a future Dolbycast. We've already received some great ideas from you, and we'd love to hear from you, our listener community.
That wraps up this edition of Dolbycast. Hey, send your letters to dolbycast (at) dolby.com, or contact us at 888-6-DOLBY-C. That's 888-6-DOLBY-C.
I'm Craig Eggers. This is Dolbycast. Talk to you soon.
[music]