5 of the Most Common HDMI Questions Answered
In the last 12 months sales of high definition televisions have skyrocketed. Today’s cutting-edge HDTVs and high definition sources demand dramatically higher data rate transfers than previous generations of Audio / Video components. They place incredible bandwidth/performance demands on HDMI cables. In fact, today’s most advanced components operate very close to the limits of current HDMI technology.
Online forums have been inundated with questions about HDMI cables. As an industry insider I have been answering a number of these questions. Here are five of the most often asked.
1. Is there really a difference between expensive HDMI cable and inexpensive cable?
There is a difference between expensive and budget HDMI cables. It revolves around the quality of the cable build and the materials used. The question is whether this will affect my set up. First you should determine the length between your source and your display. If this is less than 15 feet a “standard” cable will be ok.
If it is more than 15 feet you are best to consider a “high speed” cable. Make sure that you buy from a reputable source and that the cable is marked with the HDMI logo and says that it is a version 1.3 (don’t worry about a, b or c as these are only testing protocols) If you live in a coastal or high humidity area it is worth considering getting a cable with gold connectors. While this will not improve your signal it will stop corrosion degrading the signal over time.
Some people assume that as the signals are digital either the cable works or not. Sometimes however the 1s and 0s aren’t all there because of signal degradation due to inferior cable construction. That can be especially true with audio and video sources such as CDs and DVDs. The signal will degrade gracefully, to a point and then it will break up. Music and video is not like data. Digital signal processors can work with a degraded signal and deliver less than perfect sound and pictures.
You can never improve a digital signal by using an expensive cable but you can certainly degrade a signal using an inferior cable.
2. Is it OK to bend HDMI cables?
It is best to avoid bending an HDMI cable, certainly do not kink it. What this does is changes the distance between wires, shielding and insulation internally within the cable.
The process of cable manufacture can have a dramatic effect on how the transmitted information looks from one side of the cable to the other. This means that a cable with better shielding and a more precise distance between the “intelligence” and “ground” wires, will yield a better connection with less interference. Many things can affect your signal. The electrons will create a standing wave in the cable; this will create a small magnetic field around the cable. Any imperfection or splice in the cable will disrupt these waves and will reflect/refract the waves. Magnetic information can also leak from one cable to another.
3. Should I buy 1.3a HDMI Cables or 1.3b HDMI Cables or what?
There is a bit of confusion in the market about all of the versions. What you are referring to here is the specification version, not to be confused with the connector type.
As long as you choose version 1.3 you will be ok. The suffixes of a, b or c merely refer to the testing protocols and really have no consumer impact, although makers are using them to market. (bigger numbers/letters are better…)
4. Will I be able to get the same quality video/audio with a HDMI to DVI-D cable?
“DVI-I” stands for “DVI-Integrated” and supports both digital and analog transfers, so it works with both digital and analog Visual Display Units. “DVI-D” stands for “DVI-Digital” and supports digital transfers only. DVI also includes provision for a second data link for high resolution displays, though many devices do not implement this. In those that do, the connector is sometimes referred to as DVI-DL (dual link).
When you convert HDMI to DVI you drop the audio as DVI does not support any audio signals. You will need to take a separate cable link between your source and the sound system for this to work.
You will need also to review the software settings in your source so that they know that you are not outputting audio from the HDMI but a separate outlet.
Some new DVD players, TV sets (including HDTV sets) and video projectors have DVI/HDCP connectors; these are physically the same as DVI connectors but transmit an encrypted signal using the HDCP protocol for copy protection. Computers with DVI video connectors can use many DVI-equipped HDTV sets as a display; however, due to Digital Rights Management, it is not clear whether such systems will eventually be able to play protected content, as the link is not encrypted.
5. When I connect my laptop Blu-ray to my HDTV I get an error about violating copy rights. What can I do?
You are facing an HDCP (High def copy protection) issue here.
HDCP is a form of digital copy protection developed by Intel Corporation to prevent copying of digital audio and video content as it travels across various cables and connections, even if such copying would be permitted by fair use laws. Each device handshakes with the other and then passes an encryption key to say that it is OK to display or play the signal. It does this for every frame, typically 30 times per second. If you are having problems with blank audio or video it is more than likely that one of your devices does not support HDCP.
Typically if you are connecting with HDMI all the way through the connection chain you should not have this problem.