If you are considering buying an audio receiver for your new home theater, many salespeople will suggest that you also buy some cables at the same time. In fact, does choosing a different cable affect the playback quality of the new system? Given that coaxial cables and HDMI cables are the two most popular cables in TVs, how should we choose between these two cables? What makes them recognized by the public? What is the difference between coax cable and high-definition multimedia interface cable?
What are coaxial cable and HDMI cable?
What is the difference between coaxial cable and HDMI cable?
How to identify the quality of coaxial cable?
It can be seen from the literal meaning that it is coaxial, so who is coaxial? This refers to two conductors coaxial, one inner conductor and one outer conductor. And their role can be imagined: one is the way of data transmission, and the other is the data transmission loop. The coax cable is composed of inner and outer conductors. The two conductors are coaxially arranged. The transmission signal is completely restricted to the outer conductor. The outer conductor is grounded as a shielded transmission line to ensure good shielding performance, low transmission loss and strong anti-interference 3. Use frequency bandwidth.
It is often used for the transmission of higher frequency signals. The coaxial cable has 2 concentric conductors, and the insulation shielding layer is also concentric. For common coax cables such as copper wire conductors, the insulating material is usually Teflon or polyvinyl chloride. Coaxial lines are suitable for various applications of signals, among which the most widely used are TV transmission, short-distance connection and operation of computer systems. As an important part of the long-distance telephone network, coaxial-cable has been widely used by cable operators, telephone companies and Internet providers around the world, and is also widely used in homes. Since the beginning of the 20th century, coaxial cables have existed as a technology and have many unique advantages in terms of reliability and accurate transmission. The key to the success of the same axis lies in its shielding design. This design allows the copper core of the cable to transmit data at high speed without interference or damage from environmental factors, but it also has its limitations. Type or sometimes wireless signal instead.
HDMI cable is a dedicated digital interface suitable for image transmission. It can transmit audio and video signals at the same time. The maximum data transmission speed is 5Gbps. Nowadays not only graphics cards are equipped with HDMI interfaces, but various video output devices are all supporters of HDMI interfaces. For example, common Blu-ray players, PS4 game consoles, TV boxes, etc. It can be said that the HDMI interface is the mainstream interface in many fields. Display with HDMI interface is obviously more useful, not only a device that can be connected to a computer host. Therefore, if you currently buy a monitor, if you can have an HDMI interface, you must bring it. After all, who knows what you will do with the monitor in the future? At the same time, there is no need to perform digital / analog or analog / digital conversion before signal transmission.
In addition, HDMI can be used with Broadband Digital Content Protection (HDCP) to prevent unauthorized copying of copyrighted audio and video content. The additional space provided by the HDMI standard will also be applicable to future audio and video formats. Before the HDMI cable standard was announced, digital video and audio interfaces were separate, and the video interface was DVI. Compared to dvi, it is smaller than hdmi interface volume and can transmit audio and video signals at the same time. The dvi cable length should not exceed 8 m, otherwise there is no cable length limitation of HDMI cable type as it affects the quality of the screen. Basically high-definition multimedia We have reduced the number of simple connecting cables that we can use with just one cable confusion situation behind the media center.
Coax carry analog signals, while HDMI cables carry digital signals. Digital signals tend to have less interference or less anti-interference. Over time, the attenuation of digital signals is also smaller than the attenuation of analog signals.
If the media source of the home surround sound device contains both audio and video signals, the High-Definition Multimedia Interface cable will provide the highest audio and video signals. If your device only transmits audio signals (such as a CD player), both the coaxial-cable and the High-Definition Multimedia Interface cable can reproduce the same excellent sound quality.
The coax cable may have some noise problems in its return path. Therefore, the receiving device needs more intelligence to control this error. On the other hand, the HDMI cable type has no noise.
The high-definition multimedia can handle 10-bit, 12-bit, and 16-bit color depth, and can perform finer rendering of a billion colors. Coaxial lines cannot carry so much depth, so HDMI is indeed the best choice for HD resolution.
The high speed HDMI cable has the fastest data transmission speed. The old version has a speed of up to 10.2Gbps, while the new version of HDMI 2.0h has a speed of up to 18Gbps. The High-Definition Multimedia Interface cable can be easily connected to the latest devices, such as DVD players, HDMI TVs, etc., without any distortion or interference during data transmission. The data transmission rate of the coaxial-cable is 0.1Gbps (100Mbps). Although its advantage lies in its data transmission range.
Coaxial lines are cheaper and easier to install. They are also easier to modify than standard HDMI cables. High-Definition Multimedia Interface cables per foot are more expensive than coax cables.
Check the degree of insulation medium. The cross section of the standard coaxial cable is very round, and the outer conductor of the cable and aluminum are attached to the outer surface of the insulating medium. The more rounded the outer surface of the medium, the smaller the gap between the aluminum foil and its outer surface, and the larger the gap if not rounded. Practice has proved that the smaller the gap, the better the performance of the cable. In addition, the air with a large gap easily invades the shielding layer and affects the service life of the cable.
Measure the consistency of the insulation medium of the coax cable. The main point of the diameter fluctuation of the coaxial cable media affects the echo coefficient of the cable. This inspection can cut out the insulation medium of a section of cable, and carefully check the outer diameter of each point with a micrometer to see if they are consistent.
Test the braided network of coaxial lines. The textile network cable of the coaxial cable plays an important role in the shielding performance of the coaxial cable, and it is also the loop line of the power supply in the centralized power supply cable TV line. Therefore, the quality inspection of the coax must check whether the textile network is tight and smooth. Cut the outer sheath of the coaxial-cable, cut a short section of the coaxial cable braided net, and judge the number of braided nets. If it matches the given index value, it is qualified. In addition, the single textile net wire is surveyed with a spiral micrometer. At the same price, the thicker the wire diameter, the better the quality.
Check the quality of the aluminum foil. Aluminum foil plays an important role in shielding coax cables. It plays an important role in avoiding confusion between external open-circuit signal interference and cable TV signals. Therefore, the quality of aluminum foil should be checked for new coax cables. First, cut the jacket layer and observe whether the surface of the braided network wire and the aluminum foil layer maintains good gloss. Secondly, take a section of cable, tightly wrap it on a small metal shaft, straighten it and turn it in the opposite direction, repeat several times, and then cut Cable jacket layer to see whether the aluminum foil is cracked or not. A small piece of aluminum foil can be cut out and repeatedly rubbed and stretched in the hand. After repeated rubbing and stretching, it still hasn't broken. Those with necessary toughness are qualified products, otherwise they are defective products .
Check the tightness of the outer sheath. The outer sheath of the high-quality coaxial cable is tightly packed, which can reduce the gap in the shielding layer, avoid the air from entering and cause oxidation, and avoid the relative sliding of the shielding layer to cause the electrical performance to drift, but too tightly packed will cause inconvenience for stripping. To increase the difficulty of construction. The inspection method is to take a 1m long cable and remove the protective layer at the end, so that the core cannot be pulled out with force.
Check the cable shape. Cable looping is not only a cosmetic issue, but also a quality issue. The cables are looped and flat, and the cables are kept on the same concentric plane. The cables and the cables are in overall contact in an arc and parallel, which can reduce the mutual stress of the cables, and the stacking is not easy to deform and break. Therefore, this is not May be taken lightly.
If you are setting up, upgrading your home theater, or installing a surround sound system, you need to check the audio and video cable options. Most devices have both coax cable and HDMI cable output, which is why you should know the difference between coaxial cable and HDMI cable. You should do sufficient research before purchasing cables and choose products according to your hobbies and needs. At the same time, you need to ensure that you are selecting a qualified cable supplier.