Common Confusion in Home Theater: Part 5

3d1This post is part of my series of blog posts and slideshows regarding topics of common confusion in home theater. In this post, I cover HDMI, including the issue of cable length and the controversial value of expensive cables.

  • Part 1: Volume and zero dB, updating firmware, Blu-ray disadvantage
  • Part 2: Speaker resistance, analog vs. digital amps in AV receivers
  • Part 3: PCM vs. bitstream, Blu-ray player upscaling/upconversion
  • Part 4: THX certification, DLNA network access, and distortion and THD
  • Part 6: Closed-back vs. open-back around-ear headphones
  • Part 7: Understanding your room and room dynamics
  • Part 8: Room correction, speaker position, and more room dynamics
  • Part 9: Ethernet, component separates, and broadband internet routers

Thanks for reading. Don’t forget to leave a comment if you have questions or feedback.

curtsig2 - trans
Curt Robbins


HDMI

HDMI, the acronym for High Definition Multimedia Interface, has finally replaced a variety of older connection standards in home theater (and computers). Even the most barebones entry-level TVs and receivers feature at least a couple of HDMI ports. It’s now a fully ubiquitous standard that’s going to be around for a long time. The greatest attributes of HDMI are that it is fully digital, carries both high-resolution audio and high-definition video on a single cable, and allows you to connect mobile devices like camcorders and smartphones to your home theater.

There are two types of HDMI cables: Standard and high-speed. Standard is capable of lower-quality (interlaced) 1080 video, while high-speed varieties provide you with the full quality of which Blu-ray discs are capable. Always purchase a high speed type, preferably one that supports 3D and something called Audio Return Channel.

Covers All Components

Old school analog connection standards, such as S-Video, composite audio/video, and component video are now dinosaurs, their bones scattered across the same wasteland as TV-top rabbit ear antennas and cassette tape decks. The fact that nearly all home theater components can be connected via HDMI makes things much easier. HDMI makes things so simple, in fact, that your biggest challenge becomes ensuring that you have cables of the proper length (so you don’t, for example, come up two feet short of what’s necessary to connect your receiver to your TV). Home theater is a lot nicer when the length of your cables, and not their type and expense, is your biggest concern.

Cable Length Limits

HDMI cables were originally developed to not exceed roughly 16 feet in length. The three foot (one meter) interconnects used to input Blu-ray players and set-top boxes to receivers aren’t a concern here. However, it’s not uncommon for a display panel TV to be on the other side of the room from the AV receiver feeding it. This is certainly an option that should be available to you when you’re planning or upgrading your home theater. However, this type of arrangement requires a long HDMI cable to be run through the walls or floor.

Lengths greater than 20 or 30 feet can, under the right conditions, produce undesirable results, such as no picture or an image that suddenly disappears. This is determined largely by the quality of the equipment connected to the HDMI cable, namely the receiver and display panel. Properly implemented HDMI ports that support the latest HDMI standard (obviously possible only on newer equipment) are more capable than those found on lower quality, older equipment.

There are two solutions for long HDMI cable lengths. First, you can purchase a hardware device that acts as an HDMI signal booster. An example is the Spectrum Electronics DSR-701 Digital Signal Restorer. This $280 device is well-reviewed and said to do an excellent job with cable lengths up to 100 feet. Second, you can convert HDMI cable to CAT6 cable using a special converter box or adapter, with the majority of your cable run in the form of CAT6. When the cable reaches your TV, it must be converted back to HDMI using a similar sister device. This allows lengths of up to 100 feet to be achieved with no video performance degradation. One reputable converter box set is the $140 Ethereal Home Theater CS-HDC5EXTD, which supports up to 90 foot (30 meter) cable runs.

If you’ve already installed a long HDMI cable in your floor, walls, or ceiling, you probably don’t want to endure the expense and hassle of installing an additional CAT6 cable. Thus, for many consumers with existing HDMI cable runs, something like the Spectrum Electronics Digital Signal Restorer will be the most straightforward solution—and possibly the least expensive when professional cable installation costs are taken into account. For new installations, I’d recommend running both high-speed HDMI and CAT6 cable, giving yourself the option of whichever solution most appeals to you (and further future-proofing your home theater). When possible and practical, a set of $60 to $150 HDMI-to-CAT6 and CAT6-to-HDMI conversion adapters is certainly more cost effective than a roughly $300 HDMI signal booster (saving you money for your speaker budget).

Are Expensive HDMI Cables Worth It?

All high-speed HDMI cables are the same. Let me say it again: All high-speed HDMI cables are the same! For the most part (at distances under 20 feet or so), an $8 cable performs just like a $200 cable. I know, it sounds like a conspiracy. But the fact remains that an expensive cable offers almost zero improvement over a cheap model (as long as it’s a high-speed type). You simply want to avoid crappy cables featuring poor build quality and little insulation (such as the two-for-$5 specials at your local discount store).

Don’t let a big box electronics store convince you that an expensive gold-plated HDMI cable is necessary for a quality home theater experience. Profit margins are highest on accessories like cables, cases, cleaning accessories, and spare batteries. Ironically, big box electronics retailers make the least profit on big ticket items like speakers, receivers, and Blu-ray players, so they try to make it up with accessories like cables. Salespeople argue, “If you spent all this money on your equipment, why shortchange your investment with cheap cables?” While this is great logic, and an argument frequently employed, it’s simply false in the case of HDMI.

In fact, the very nature of HDMI, which is a fully digital signal, means that it’s either nearly perfect or there’s no picture whatsoever. Unlike the old over-the-air analog broadcasts of the past, there’s no in-between where a fully digital video signal can degrade with snow or static, but still be viewable. Video and audio carried via HDMI is either there or it isn’t.

When I last upgraded my home theater, Best Buy tried to convince me to purchase several short HDMI interconnect cables costing about $85 each. An $8 cable from Amazon provided me with the same quality. Still not convinced? Check out the blog article Why All HDMI Cables Are The Same by Geoffrey Morrison of CNET.


Curt Robbins is author of the following books from Amazon Kindle:

You can follow him on Twitter at @CurtARobbins, read his AV-related blog posts at rAVe Publications, and view his photos on Flickr.

Common Confusion in Home Theater: Part 4

3d1As part of my series of blog posts and slideshows regarding topics of common confusion in home theater, below I cover THX certification, DLNA network access, and distortion and THD. This series features excerpts from my new Kindle book Home Theater for the Internet Age.

  • Part 1: Volume in a zero dB world, updating firmware, and the disadvantages of Blu-ray
  • Part 2: Speaker resistance and analog vs. digital amps in AV receivers
  • Part 3: PCM vs. bitstream and Blu-ray player upscaling/upconversion
  • Part 5: HDMI (including cable length and controversial expensive cables)
  • Part 6: Closed-back vs. open-back around-ear headphones
  • Part 7: Understanding your room and room dynamics
  • Part 8: Room correction, speaker position, and more room dynamics
  • Part 9: Ethernet, component separates, and broadband internet routers

curtsig2 - trans
Curt Robbins


THX Certification

THX is a collection of audio and video certifications for both commercial cinema (movie theaters) and home theater environments. THX was born at Lucasfilm Studios in the early 1980s, when George Lucas was producing Return of the Jedi, and gained its name from Lucas’ first feature film, THX 1138. Lucas was concerned that the fidelity and overall experience he was creating in his studio wasn’t being translated into commercial cinemas. The first THX certifications were granted to movie theaters, not home theater components.

THX offers several different types of certifications, including those for amplifiers and display panels. To obtain THX certification, a particular component model must pass 200 tests. While THX certification doesn’t guarantee you’ll like the image produced by a display or the sound flowing out of an amplifier, it does ensure a solid performance level. Buying THX-certified equipment helps you get reliable mid to top-tier components with respect to quality and performance. It has little to do with price, however. Products at several different costs may feature the THX logo. It is, however, more common on higher-end, more expensive components.

THX has also released an app for Apple and Android devices that helps calibrate your home theater’s video and audio. For more information regarding home theater calibration, see the Room Calibration section below and the Room Dynamics & Positioning section of the Speakers chapter.

DLNA Local Network Access

DLNA, or the Digital Living Network Alliance, is a communications protocol that works over both wi-fi and Ethernet that allows a variety of media files, such as family photos, music files (including high-resolution varieties), and videos to be streamed from one device to another on a local area network (or LAN). In home theater, DLNA is typically implemented in audio/video receivers and Blu-ray players and accesses a storage device or computer elsewhere on your local network.

Not only must your receiver or Blu-ray player support DLNA, but the device on your network—on which the media files are stored and from which you want to access them—must also include this protocol. This “sending” device on your network could be a personal computer (running Windows 7/8 or Mac OS X), a network storage device (officially called a NAS, or Network Access Storage), or even a top-shelf router with an attached flash drive or USB hard drive. As long as the two devices have a valid connection, enough bandwidth, and DLNA, you can begin routing photos, music, and video from your home network to your receiver or Blu-ray player, using your big display panel and listening to audio and music through your living room speakers.

However, simply because you can use DLNA to get a particular media file from a PC or storage device on your network to your audio/video receiver or Blu-ray player doesn’t mean the receiving device can necessarily decode it. For example, if you have a bunch of high-resolution music files in AIFF format stored on your network, but your receiver (or Blu-ray player) isn’t capable of decoding the AIFF format, DLNA won’t help. DLNA includes no decoding logic or special software for this purpose. It is merely a way for two devices on a home network to recognize each other and stream media files from one to the other.

Distortion & THD

All home theater components produce a certain amount of distortion, something that damages the quality of the sound but, at low and even moderate levels, typically can’t be perceived. This distortion is measured as THD, or Total Harmonic Distortion. In the case of an amplifier, THD is a measurement of the comparison of the receiver’s input and output signals (revealing how much the unit’s amp distorted the audio signal).

Instead of burying you in percentages and decimals, simply realize that lower THD is better. Any reputable brand of AV receiver, Blu-ray player, or speaker, however, will typically exhibit so little THD that it isn’t noticed (except at maybe the loudest volumes). This is true of models at all costs. According to Gary Altunian at Stereos.about.com, “In reality, total harmonic distortion is hardly perceptible to the human ear. Every component adds some level of distortion, but most distortion is insignificant and small differences in specifications between components mean nothing.”

Note that THD becomes worse as volume increases. Most THD ratings for receivers are based on the unit’s full output, or greatest volume (0 db, as you’ll learn below). As a rule of thumb, simply ensure that a receiver’s THD rating is below 1% (typical THD ratings on good receivers are far lower, falling between 0.03% and 0.08%, but measuring techniques vary and are sometimes heavily influenced by a component manufacturer’s marketing department). THD is just one measure of the quality of an amplifier or speaker. If you’re shopping for reputable receiver models, THD shouldn’t typically be an issue that influences your purchasing decision.


Curt Robbins is author of the following books from Amazon Kindle:

You can follow him on Twitter at @CurtARobbins, read his AV-related blog posts at rAVe Publications, and view his photos on Flickr.

Common Confusion in Home Theater: Part 1

3d1There’s quite a few topics in home theater that are confusing for the average consumer. From volume levels on modern AV receivers to firmware updates to distortion, these topics make the purchase, installation, and enjoyable use of home theater gear both intimidating and sometimes perplexing. In the next few posts, let’s clarify some of these issues.

The following is an excerpt from my new Kindle book Home Theater for the Internet Age. The other blog posts in this series are listed below:

  • Part 2: Speaker resistance, analog vs. digital amps in AV receivers
  • Part 3: PCM vs. bitstream, Blu-ray player upscaling/upconversion
  • Part 4: THX certification, DLNA network access, and distortion and THD
  • Part 5: HDMI (including cable length and controversial expensive cables)
  • Part 6: Closed-back vs. open-back around-ear headphones
  • Part 7: Understanding your room and room dynamics
  • Part 8: Room correction, speaker position, and room dynamics
  • Part 9: Ethernet, component separates, and broadband internet routers

curtsig2 - trans
Curt Robbins


Volume in a Zero dB World

The volume, or intensity, of sound produced by a receiver or amp is expressed in decibels, or dB. The “bel” part of the term is in honor of Alexander Graham Bell, because decibels, as a unit of measure, were developed to objectively determine audio levels on the earliest telephone networks (and you thought it was all about jet engines and 1970s rock concerts by The Who….).

What is confusing about decibel readouts on today’s receivers—and has been in practice for only about the past decade or so—is the zero dB system employed. It’s inherently counter-intuitive. Basically, on the dB scale, zero (0) represents the receiver’s loudest output (if you turned up the volume to the maximum possible). You’d obviously have to decrease the volume to enjoy it at a reasonable level. These enjoyable volumes occur in the negative numbers. A reasonable zone might be -32, or maybe -25 (depending on the input source and your room). But it will always be expressed as a negative number. Because we’re talking about negative numbers, smaller numbers (ignoring the negative sign) equal higher volume levels (-10 will be much louder than -35). And this is where the confusion arises.

pioneer av receiverThere is a logic to this scheme, however. In the past, when higher numbers equaled greater volumes, the settings were entirely arbitrary, with wide variations among receiver manufacturers. One company might demark 1 through 10 (one being the softest, 10 being the loudest), while another would get more granular, adopting a 1 through 20 or even 1 through 100 scale. It was the wild west. The problem was that there was no objective way for a receiver to display to its owner the volume at which it was producing sound.

Zero dB originated in the commercial broadcasting and recording industries. On your home theater’s receiver, think of 0 dB as the tipping point for distortion and where you may begin encountering things like “clipping” (jarring cuts and dropouts in the sound) and other signs that the receiver is operating beyond its capacity to provide clean sound. Depending on the quality of your receiver, you may experience distortion at a volume below 0 dB. But a good unit won’t begin distorting until this point (a valuable litmus test when researching your purchase).

The specific dB level indicated by a receiver is still somewhat subjective. In addition to your receiver, your speakers and the room in which they reside significantly influence the actual volume at which you hear the audio reproduced. Take this number displayed on your receiver lightly, realizing that -25 dB with your old speakers or on your neighbor’s system won’t sound exactly the same on yours (but it should be in the ballpark).


Updating Firmware

A hardware component’s firmware is simply updatable software stored on a chip in the device that controls certain features and functions. Because players are basically audio and video-focused computers dependent upon complex decoding and processing software, manufacturers often release firmware updates that expand or enhance the functionality of their units—or fix existing bugs. It’s a good idea to keep the firmware of your home theater devices, specifically your Blu-ray player and AV receiver, up-to-date (check manufacturer websites on a regular basis).

The biggest reason to update your Blu-ray player firmware is to ensure that it can properly play the latest movie releases. Hollywood is continually revising copy-protection standards in an effort to thwart piracy. Sometimes new protection schemes can’t be recognized by a particular player (especially older models)—resulting in a movie that won’t play. Instead of having to purchase a new Blu-ray player (a ludicrous proposition at which consumers would obviously balk), you simply need to update your firmware to match the latest copy-protection encryption standards of new-release movies.

oppo bdp-103Depending on whether your Blu-ray player is connected to the internet, there are a variety of ways firmware updates can be applied. If your player features internet connectivity, simply follow the manufacturer instructions to obtain and install the update files. If your player lacks connectivity, you can download the files from the manufacturer website using a Windows or Mac computer and copy them to a USB flash drive. The USB drive is then inserted into the player to begin the installation of the update.


Disadvantages of Blu-ray

The biggest disadvantage of the Blu-ray format is that some discs can take a while to load (up to a minute or two), depending on the speed and quality of your player. This wait is so much greater than for DVDs that, on some titles, new owners sometimes believe they’ve run into a bad disc or that their player has locked up. More expensive and newer Blu-ray players feature faster processing chips, decreasing your wait time as the disc content loads into the memory of your player. If load speed is a concern, remember to demo, demo, demo. (For you geeky types, the Blu-ray video format transfers data at roughly 40 Mbps, which is why you can’t yet stream an uncompressed Blu-ray video over your internet connection.)

Models known for their speedy load times include OPPO’s $500 BDP-103, its $1,200 105 model, and the $400 Pioneer Elite BDP-62FD. Personally, my first choice would be the BDP-103 (pictured above). Those on a budget might prefer the BDP-62FD, which is very comparable to the entry-level OPPO (but not quite as powerful or refined).


Curt Robbins is author of the following books from Amazon Kindle:

You can follow him on Twitter at @CurtRobbins, read his AV-related blog posts at rAVe Publications, and view his photos on Flickr.