The highest video resolution currently possible is HDMI, but one of the drawbacks of this technology is that the HDMI cable is not suggested for long cable runs, due to the fact that HDMI cable is manufactured out of twisted pairs of copper conductors that are small-gauge, instead of the usual coaxial cable, and this can cause problems when the HDMI cable needs to be run over 50 feet in length.
With twisted pairs cable, impedance can not be kept under strict control. Without this strict control, the signal may be reflected along the length of the cable between the source and the sink of the signal. This can cause interference with the source bit-stream.
The usual specification length of maximum run for HDMI cable is normally about 50 feet, or approximately 15 yards. The maximum cable run that will be efficient will be different for each individual cable, depending on the quality specifications of the cable manufacturer. A higher quality cable will cost more, but will also run further before any additional devices and technology are needed. Generally, the thicker the copper wire is in the pairs, the more costly the cable is, but the longer that cable can be run before experiencing signal problems.
To have HDMI cable that runs over the maximum effective length, 50 feet to 60 feet, will require additional technologies and devices. There are several excellent ways to extend your HDMI cable run and keep the signal effectiveness.
When an HDMI cable length gets too long the signal loses strength. This results in picture distortion, sparklies (where single pixels drop out of the picture), or no picture display at all, only sound capabilities. If any of these problems occur than the cable length is too long, and the signal needs to be adjusted by additional devices.
The available options to extend the HDMI cable run and still have a usable signal are various. There are signal restorers, signal boosters, signal extenders, signal equalizers, cables with thicker conductors,and fiber optic cables. The cost and effectiveness of these methods vary according to the method used.
An HDMI signal restorer re-synchronizes the signal coming in back up to the original HDMI specifications. This electronic device is small and powered by a transformer. The restorer is placed near the end of the cable run, by the display unit, and can restore a 1080p signal even if the cable transmitting the signal is specified for a lesser speed. A signal restorer can extend a usable signal by roughly 40 Meters.
An HDMI signal booster is a device that is placed to boost the signal over long cable runs. HDMI cable starts to lose signal strength after approximately 10 to 50 feet, depending on cable quality, which can cause display issues. A signal booster gives the signal a boost so that it stays strong throughout the length of a longer cable. Some HDMI cables over 75 feet long have a built in signal booster inside the cable.
A signal extender is another way to extend the HDMI cable run length, and keep a strong effective signal. This device boosts and then extends the signal down the length of the cable after the signal is received.
A signal equalizer for HDMI cable is a device that can assist in keeping the signal strength and quality over longer cable runs. An HDMI signal equalizer may also be called a signal enhancer because it enhances the signal, and then it removes any unwanted noise interference. This device does not remove any of the vivid colors or the dynamics of the HD technology, though.
To really boost the length of an effective HDMI cable run, fiber optic cable is an excellent, but possibly expensive, option. This type of cable is usually used after the 150 feet maximum run length has been reached with HDMI cable. Fiber optic cable can extend the effective run of HDMI cable to a maximum of 1,640 feet.
HDMI technology is termed as “all or nothing” technology. Either the signal is strong enough to give a high quality picture, or it is not strong enough. If the signal is not strong enough, then either picture distortion or no picture at all will be the result. The option chosen from those listed above to extend the strong signal along the longer cable run will depend in part on what total length the cable run will be. Some options allow longer runs to be more effective than other options.