Fundamentally, in the consumer sector there is no difference between HDMI versions 1.3, 1.3a and 1.3b. The version differences relate to production or testing factors and do not affect the properties or functionality of HDMI products.
HDMI Licensing LLC is actively working with manufacturers to reduce version numbers in order to avoid confusion among users. Meanwhile, a stronger focus has been placed on functionality when differentiating. The current HDMI version 1.4 is more powerful and supports many new applications, such as touchscreen, Ethernet channel, audio return channel or high-resolution 3D display up to 4K resolution. Its backward compatibility also allows the cable to be used with older HDMI interfaces. On this topic, please also see our advisory text on the HDMI 1.4a standard.
Do I also need a new HDMI cable for my new television?
The need for an HDMI 1.4 cable depends solely on your own application requirements. Many TV sets still have a version 1.3 interface and cannot exploit the potential of a 1.4 cable at all.
On the other hand, many living rooms contain 3D-capable TV screens whose 3D function, for example, is never used at all.
As the new standard, an HDMI 1.4 cable is an investment in the future for upcoming purchases, but not a must for operating older devices or applications.
If an HDMI accessory device (switch, repeater, splitter, etc.) is not equipped with a separate power source, is it still compliant and does it work?
An active HDMI device (such as an active switch, a splitter or a repeater) should have a connector for an external power supply in order to function properly. This is where the difference arises between "active" components, which contain electrical parts, and "passive" components such as some mechanical switches.
Active devices can also draw the required voltage from the 5V wire of the HDMI cable. According to the HDMI specifications, all HDMI sources must supply at least 55mA on the 5V wire in order to be able to read the EDID information of a display. Since 55mA is too low a current to operate most HDMI accessory devices (these need about 100 to 150mA), most devices supply a higher current than the HDMI specifications require.
Nevertheless, devices such as splitters or repeaters should be equipped by their manufacturers with an external power adapter, and as a customer you should make sure to purchase such devices.
In our shop we offer the HDMI repeater "The Bug" without an external power supply. This device has undergone extensive test series in our company, and we can therefore confirm optimal results with this device, even without an external power supply.
As HDMI increasingly spreads into the market of portable devices, such as photo and video cameras, smartphones and laptops, power consumption plays an important role. To extend battery life, many manufacturers keep the voltage on the 5V wire of an HDMI connection as low as possible, which is why an external power supply is unavoidable here.
Can a passive device (e.g. a mechanical switch) that has no active electrical components work?
Simple switches can work purely mechanically and without electrical components. In general, however, every passive device that splits or switches a signal introduces a tolerance that can decisively impair the signal strength. This applies even more to splitters than to switches. To compensate for the resulting signal loss with an interposed device, signal amplification via a power supply must take place. Ideally, this should be fed by a separate power adapter.
Passive components may work with short cable lengths and with certain devices. However, if you increase the cable length or replace a device in the system, transmission errors can occur.
Fundamentally, with switches too, it is advisable to use active ones, i.e. devices with an external power supply. This ensures flawless functionality, even with medium and long cable lengths and in the event that individual components are replaced.
How do I notice the difference between an expensive and a cheap HDMI cable?
If everything runs optimally, you do not notice the difference at all. With analog transmission technology, the signal can be improved by various factors such as gold-plated cables, better shielding or other things. However, this does not apply to an HDMI cable. There, put simply, either a 1 or a 0 is output at the end of the line, with no gradations.
The true quality of a cable becomes apparent when the applications become more demanding. Particularly long connections of 15m, 20m or even greater distances very often cause transmission errors here. The range extends from artifacts to color errors and dropouts up to complete failure. The culprits are often inadequate shielding of the cables and poor workmanship of the solder joints. A common practice with cheap cables is filling the connectors with hot glue, which brings a certain imprecision with it.
Time and again, AV receivers or source devices also appear that deviate from the applicable HDMI standard and complicate the interaction of the connected components. Insufficient supply voltage or signal strength are the most common sources of error here.
For extensive setups with several components (signal splitters; signal switches; several output devices; etc.) and for installation in cable ducts, we generally recommend high-quality cables, such as the SL-P series from Lyndahl.
Can I bend the HDMI cable?
Every HDMI cable has a certain tolerance in its flexibility. The bending radius depends on the diameter of the rubberized jacket (AWG) as well as the stiffness of the shielding braid underneath. To allow a 90° bend that is healthy for the cable, a conduit should have a diameter of at least 3cm. In general, the cable should be routed without applying force.
For routing an HDMI cable through a narrow conduit or cable duct, we recommend the SL-P crimp assembly set from Lyndahl.
Can HDMI cables be responsible for devices not working together properly?
The vast majority of problems with older devices concerning picture quality or compatibility with other devices are due to the software (firmware), which is responsible for the communication between the devices and the protection of the content, and have nothing to do with the HDMI cable. Problems in the communication between source device and display usually arise from the software during HDCP handshaking (verification of the HDCP compatibility of source and display), from incorrectly transmitted or read EDID information, or often when the connected devices do not all conform to the same technical standard.
Only in the very rarest cases is a cable known to be responsible for problems in picture transmission. No cable is known that was manufactured according to the HDMI specifications and constitutes the reason for faulty playback.
No picture via HDMI — what can be the cause?
In the early days of HDMI transmission, errors frequently occurred in the "handshake" function, or one of the devices was not compatible with HDCP copy protection. Meanwhile, these shortcomings have been remedied and practically no longer occur.
Of course, a display or projector must itself support 1080p resolution in order to display it. Otherwise, for example, no picture will be transmitted with a 1080i projector.
Particularly long signal paths of 15m, 20m or more can under certain circumstances lead to such great signal loss that no correct picture is displayed.
In particular, interposed adapters without a built-in booster amplifier can lead to picture interference in unfavorable cases.
No 3D via HDMI — how can that be?
A common error in current applications is splitting the HDMI signal to displays with different specifications. If, for example, the HDMI signal of a 3D Blu-ray player is distributed via a splitter to a 3D TV and a non-3D projector, the Blu-ray player will only output the lowest common device standard of the two displays — in this case, both the projector and the TV receive a signal without 3D. The same applies to different resolutions — here, the lowest common resolution is output on both screens.
In fact, HDMI 1.3 already supports 3D applications, but only up to a maximum resolution of 1080i. Beyond that, an HDMI cable of version 1.4 is required to transmit full HD resolution. In any case, however, the TV or projector must have a 1.4 interface in order to be able to reproduce the transmitted dual-scan technology.
In many households, the 3D Blu-ray player is routed through an AV receiver to a 3D TV or projector. However, if the AV receiver does not have a 1.4 interface, the Blu-ray player will recognize this device as not 3D-capable and accordingly will not output a 3D signal to the TV or projector.
What is EDID?
EDID stands for Extended Display Information Data. This data is stored (usually in a small EEPROM) in every DVI display or HDMI display. There is at least one EDID per input.
The source checks the DVI or HDMI port of the display for the presence of the EDID and uses the information read to optimize the output format of video and/or audio. The EDID data structure is either for VESA PC devices or for CEA-861B E-EDID (Enhanced EDID) devices. All displays that comply with the DVI or HDMI specifications must contain EDID.
An EDID PROM is only used in displays. It sits on the DDC channel and uses a 2-wire I2C bus for communication between display and source. The EDID PROM contains information about the display in which it sits. Its task is to provide the preferred (or maximum supported) resolution and the possible audio formats to the outputting source.
Example: When a DVD player is switched on, it reads the EDID information of a connected HDTV. Via its EDID content, the HDTV states that it is a Samsung 17“ LCD panel that can display a resolution of 1280x1024 pixels, but also supports the 480p, 720p and 1080i video modes. The EDID can also indicate that the device is an HDMI device with two speakers. The DVD player now compares the information it has read with what it can output via the HDMI port, sets its settings to 1080i with two-channel stereo sound and sends the signal to the HDTV.
Due to the complexity and constant changes in the field of digital and HD TV, we cannot guarantee the completeness of the information. Every day we strive anew to shed light on the darkness of digital video transmission and constantly gain new information, which we can then pass on to you.
