HD Advisor v5.0

Posted Fri Mar 6, 2009 at 12:00 PM PST by

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Answers by Joshua Zyber

1080i/p Content on a 720p HDTV

Q: I have a Toshiba Regza 720p HDTV. I've read in the Instruction Manual and have noticed myself that the HDMI inputs accept 1080i and 1080p signals. Currently I have my Ps3 setup for 1080p, and my cable box and HD DVD player setup for 1080i. Essentially, what does it mean in terms of picture quality and is it better to have my equipment set up for 1080i/p respectively or should I have them set for 720p?

A: A digital HDTV has one and only one native resolution. A 720p model will display all content at 720p. Even if the set will accept input signals from higher or lower resolutions, it automatically scales everything to its native resolution before anything shows up on your screen.

If you want to watch a 1080i HD broadcast or a 1080p Blu-ray on your TV, those signals will need to be scaled to 720p first. You can choose to do this at the sources (the cable box and Blu-ray player) or in the TV. Your decision will depend on which component has the better scaling circuitry built in. A bad scaler will introduce artifacts such as shimmer, aliasing, or pixelation. A good scaler will be essentially seamless (of course, your new picture will still have a lower resolution and less detail). The best way to make this decision is simply to try it both ways and see if you can notice any difference. If one method is visibly inferior to the other, use the better-looking option. If you can't tell the difference, set everything to whichever method is most convenient for you and try not to worry about it.

HD Audio – PCM vs. Bitstream

Q: Just want to make sure myself and others understand how PCM vs. Bitstream audio streams work for Dolby TrueHD and DTS-HD MA. I have a Denon AVR-3808 and the "Dolby TrueHD" and "DTS-HD MA" indicator lights do not light up when utilizing my PS3 or BDP-S350 for Blu-ray playback. This is because neither player supports the high-end audio codes in bitstream format, correct? They support PCM which is basically a file unzipped by my receiver which is equivalent to TrueHD and DTS-HD MA. It pains me not to see the indicator lights light up on a $1,700 receiver. Will there be possible upgrades which allow the PS3 to output the high-end audio codecs via bitstream, or would I need to purchase another Blu-ray player to make this happen?

A: There are two ways to get high-resolution audio out of your Blu-ray player to your receiver in full quality. The first is to transmit the native audio bitstream over HDMI and let your receiver do the decoding. In that instance, your receiver's front panel should light up with an indication of which codec it has received.

In order to do this, you'll need a Blu-ray player capable of transmitting the native bitstream. Unfortunately, the Playstation 3 won't do that. From what I understand, this is a hardware limitation in the HDMI transmitter used in the console, and cannot be changed with a software update. However, according to the specs I looked up, the Sony BDP-S350 will "bitstream" the high-res audio formats. Go into the player's Setup menu and make sure all audio options are set to Bitstream. (I've been informed that Sony calls this setting "Direct.") You may also need to turn off Secondary Audio if that's an option.

The other method to get full high-res sound quality is to let the player decode the audio internally. For this, you'll need a player with Dolby TrueHD and DTS-HD Master Audio decoders built in (some models will only decode standard Dolby Digital or DTS on their own). The PS3 is fully loaded with all the decoders you'll need. After decoding, the player will transmit the audio as multi-channel PCM. Although you won't see a "TrueHD" or "DTS-HD" indicator light up on your receiver, there should be no loss in quality from decoding the audio in the disc player rather than in the receiver.

Dynamic Range Compression

Q: I live in an apartment with rather thin walls. I want to be able to have decent quality sound and actually hear the dialogue without blasting my neighbors' windows out. I've turned on the audio compression on the PS3, and turned on a feature called 'Midnight' on the amp, which is supposed to do the same thing. Nevertheless, the audio on most movies seems mercilessly loud when it comes to bullets and car chases, then I have turn up the volume to even hear the dialogue. So I'm sitting with my remote on a hair trigger the entire time, and that kind of robs from the viewing experience. I've tried tricks like turning up the center speaker, since that's where a lot of the dialogue comes from. Nothing's noticeably helped. Any advice you could give me would be very much appreciated.

A: For most Blu-ray viewers, a wide dynamic range (the difference between the highest and lowest points in a soundtrack) is a desirable benefit of high-resolution audio. In your case, it's actually a detriment. I'm going to start with some suggestions that shouldn't negatively affect your audio quality, and may even improve it. If those don't work, you'll have to move on to more invasive methods.

Since you live in an apartment, I'll assume that major renovations and full-blown soundproofing are not an option. Still, there are things you can do to reduce the vibrations that carry through your walls and disturb your neighbors. The first thing you should try is to move your speakers away from the walls and elevate them off the floor with isolation feet. You want to reduce or avoid hard contact with surfaces that connect throughout the building.

Next, you should break up sound reflections in your room with rugs and wall treatments. You don't necessarily need to buy expensive audiophile acoustic treatments. Shelves and artwork can also break up reflections. Try to eliminate large, flat expanses of empty wall or floor. In extreme cases, attaching fabric to the ceiling may help. Reducing reflections will improve audibility of subtle details more clearly, which will reduce your need to crank up a soundtrack's volume. Likewise, you should also try to eliminate other sources of noise that may be muddying your sound. Turn off your computer, air conditioning, and other noisy appliances if possible.

If none of that is enough, you'll need to be more aggressive.

You've already taken a few of the steps I'll recommend. Turning on Dynamic Range Compression (or "Night Mode") will reduce output from both the highest and lowest registers of the audio. Failing that, raising the center channel gain while lowering the other channels (especially the subwoofer and front mains) should allow you to hear dialogue without blasting the rest of the soundtrack. Keep in mind that you should make these settings in whichever device is performing the audio decoding. If your disc player is doing the decoding, you'll want to turn on Dynamic Range Compression there, not in the receiver. If you're sending a native audio bitstream and letting the receiver decode, that's where you'll turn on DRC.

The low-end of the audio is the part that creates the greatest feeling of loudness, and also the part that carries most through walls to your neighbors. If DRC and turning up the center channel aren't enough, set your crossover to filter out frequencies below 120 Hz, then turn your subwoofer way down or disconnect it entirely. You might also try downgrading the lossless audio formats (TrueHD and DTS-HD Master Audio) to standard Dolby Digital or DTS by connecting a Toslink optical cable rather than HDMI.

Of course, these last few actions will have a (perhaps dramatically) negative impact on overall audio quality, but sometimes you gotta do what you gotta do.

(My thanks to reader Chase for a few of these tips.)

5.1 vs. 7.1 Audio

Q: I currently have a Blu-ray player and a 5.1 receiver and speaker system. If I upgrade the receiver to a 7.1 receiver capable of playing back Dolby TrueHD and DTS-HD, but don’t add the two more rear speakers, will I still be able to notice a difference in sound quality? Or do I really need to add the two speakers as well before the difference becomes noticeable?

A: The most important thing to note here is that you won't lose any parts of a movie's soundtrack by playing a Blu-ray disc with a 7.1 audio track on a 5.1 sound system. If you only have five speakers, you receiver will automatically redirect any sounds designated for the center rear speakers out to the other left and right surround channels instead. Everything will still be there, just spread out to the sides a little more.

The difference between a 5.1 and a 7.1 audio configuration shouldn't have any effect on overall audio fidelity. All you're doing is adding two more speakers that will help to fill in the rear soundstage and give you a couple more discrete points for directional audio cues. This is mostly beneficial in large listening spaces with a significant gap between the left and right surrounds, but is a lot less useful in smaller rooms, where the surround channels are probably already close enough together to create a convincing rear soundfield. Depending on how your room is laid out, you may be just as well off sticking with 5.1 rather than trying to cram in a couple extra speakers that might only serve to muddy the back soundstage.

Replacement Remotes

Q: Our house was broken into three weeks ago. Besides our TV being stolen, they stole all the remotes for our Blu-Ray Disc Player and Sound System. We'll be getting our insurance money shortly to replace everything. How do we get new remotes?

A: I'm sorry to hear about your bad fortune. For replacement remotes, you can contact the manufacturer about purchasing new controllers, however they will probably charge you an arm and a leg. Alternately, you can try third-party vendors like Mr. Remote or Replacement Remotes.com. You might also check eBay.

Perhaps a more convenient option would be to simply purchase a new universal remote that has the codes for your equipment either pre-programmed or downloadable. I'm a fan of remotes from the Harmony line, which will allow you to download codes from their extensive database that covers almost any device you can imagine.

Be sure to check back next week for another round of answers. Keep those questions coming!

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Tags: Joshua Zyber, HD Advisor (all tags)