HDMI: Dolby, DTS, Formats

Are Dolby Digital, DTS, and other high resolution audio formats supported by HDMI?

Are Dolby Digital, DTS, and other high resolution audio formats supported by HDMI? Are these the only audio formats that are supported by HDMI? Do I need a specific version of HDMI? These are all very good questions that need to be answered. First let's look at the various HDMI versions and specifications.

First lets talk about what HDMI is. HDMI are the initials that stand for High-Definition Multimedia Interface. HDMI is the newest digital interface standard, supported by the industry, to be used when connecting components of consumer electronics, like high definition television or home theater systems. HDMI allows personal computer manufacturers and audio/visual consumer electronics to bring to the market products that are rich in features and innovative.

HDMI is a signal that is all-digital and not compressed. All the predecessors of HDMI were analog interfaces. Using an analog interface means that a clean digital signal is converted into a “not as precise” analog, and sent out to the T.V, where the signal is translated back again into digital signal to show the screen display. Each time that the signal is converted, the digital signal weakens and loses strength and integrity. This causes some distortion of the quality of the picture. With HDMI the source digital signal is preserved, and there is no conversion of the signal to create the richest, sharpest picture quality available.

HDMI was designed from the very first version to carry 8-channels of 192kHz, 24-bit uncompressed audio, which is more than all the current consumer media formats. Plus HDMI can transmit any currently available compressed audio format. These formats include Dolby, like Dolby Digital EX 7.1, Dolby Digital Plus 7.1, and Dolby TruHD, and DTS, like DTS-ES 6.1, and DTS-HD Master Audio. These compressed formats are the only multi-channel or high-resolution audio formats that can be carried across the older S/PDIF or AES/EBU interfaces. HDMI 1.3 adds extra support for new lossless digital surround audio formats Dolby TrueHD and DTS-HD Master Audio. Plus most existing HDMI sources can output any compressed stream, and the newer HDMI sources can output uncompressed 6-channel, 96kHz audio from a DVD-Audio disk. There are A/V receivers on the market that can accept and process the 6- or 8-channel audio from HDMI.

Two competitive high definition optical disc formats were released in 2006, HD DVD and Blu-ray Disc. These two formats support higher fidelity audio than the old DVD format. These audio formats include DTS-HD Master Audio, Dolby Digital Plus, and Dolby TrueHD. Not all of these formats are mandatory by the BD and HD DVD formats. High definition players may provide a number of different ways to transmit this audio. Currently, the best fidelity is available when the player is set to output LPCM over HDMI when using one of these higher fidelity formats. This requires a preprocessor or audio/video receiver capable of handling multi-channel LPCM over HDMI. While this has been supported by the HDMI spec since version 1.0, not all devices that support HDMI 1.1 support this feature. In the future, it is likely that most devices claiming at least version HDMI 1.1 as a feature will support at least 5.1 LPCM over HDMI.

HDMI version 1.3 will allow for sending TrueHD and DTS-HD over a bitstream rather than LPCM. This would allow a preprocessor or audio/video receiver that has the necessary decoder to decode the data. It is not clear how this will be useful, as all the current players are decoding the audio stream because this is required for interactive audio. The players would either have to skip mixing of interactive audio, or encode the mixed audio to one of these other formats before sending it over HDMI. HDMI 1.3 will support the output of DTS-HD Master Audio and Dolby TrueHD streams for outside decoding by Audio Video A/V Receivers. These are lossless audio codec formats that are used on high definition DVD's and BluRay discs.

The answer to the question is that, yes HDMI will support Dolby Digital, DTS, and other high resolution audio formats. HDMI version 1.3 specifications have included specifications for very high bit rate lossless compressed streams like DTS and Dolby Digital.

What's the differences between DVI and HDMI?

Is there any difference between DVI and HDMI?

DVI stands for Digital Video Interface. HDMI stands for High Definition Multimedia Interface.

Ok, let's discuss what each of these interfaces is and how it works.

Digital Video Interface, or DVI, is actually a predecessor of HDMI. Digital Video Interface was made by the Digital Display Working Group (DDWG). The original design for DVI included conversion of analog signals by converting analog into a digital signal. This was done so that both analog and digital signal monitors could be accommodated by DVI. Data is transmitted by the use of transition minimized differential signaling (TMDS) protocol and provides a digital signal from a PC's graphics subsystem to the display unit.

There is DVI-A and this type of DVI is used for analog signals like VGA. The second type of DVI is DVI-D. This type of DVI is used for digital signals, and this type of signal is the one that all home theater products use and that are intended for consumer home use. DVI-I is the third type of DIV. This type is a combination of DVI-A and DVI-D.

Two levels of performance are supported by DVI-I. These levels are single link and dual link. Currently all home electronics products are designed around the single link standard. A dual link cable, however, is 100 % compatible with a single link cable plus the dual link cable offers the benefit of adaptability in the future for any wide band width applications. DVD-I is a complete, fully digital video transport protocol that is supportive of all digital video formats including 480p, 480i, 540p, 720p,1080p, and 1080i.

High Definition Multimedia Interface is the only uncompressed, all digital audio/video interface that is supported by the industry. Founders of HDMI include manufacturers of leading consumer electronics Panasonic, Phillips, Hitachi, RCA, Sony, Toshiba, and Silicone Image. HDMI is also supported by motion picture producers Universal, Fox, Disney, and Warner Brothers, as well as system operators EchoStar and DirecTV. High Definition Multimedia Interface provides an interface in between any video/audio source, like an A/V receiver, digital television, and DVD player over one cable total, instead of one cable for video and one cable for audio. HDMI will support high definition video, standard video, and / or enhanced video plus multiple channels of digital audio on one single cable. HDMI will also transmit every ATSC HDTV standard and will support eight channel digital audio. HDMI has plenty of band width to spare so any future requirements and enhancements can be accommodated.

HDMI and DVI actually are more alike than they are different. Both of these support the transmission of digital signals. Both DVI and HDMI are based on specifications that are similar, because HDMI specification was derived from the specification for DVI.

There are two important differences between DVI and HDMI. The first difference is that HDMI technology incorporates content security that is called High Definition Content Protection, also known as HDCP. The other huge difference between Digital Video Interface and High Definition Multimedia Interface is that DVI can only support digital video, and HDMI can support audio and video on the same cable.

This leads to another big difference between HDMI and DVI. The number of cables that need to be used and run during installation. With Digital Video Interface at least two cables are needed. One cable is needed to support the video signal, and one cable or cord is needed to support the audio signal, because DVI can only support video, not audio. With HDMI only one cable is needed for the installation. This is because the HDMI can support all formats of digital video plus it can support multiple channels of audio signal as well.

The good news is that despite their differences, a backward compatibility for video exists between HDMI and DVI. Because HDMI evolved from DVI, they are both identical when it comes to video. But remember, DVI can not support digital audio. A good example is an older DVI connection on the source and an HDMI connector to the display. In this case, all that is needed to see the video is an HDMI to DVI cable. However, a separate cable for audio is needed to carry the the digital audio so the sound can be heard.

The best HDMI should look for is Monster Cable. Check it out. Chao.

How can I be sure that my HDMI cables will support higher speeds, deep color, and 1080p?

HDMI cable is capable of providing the highest video resolution that is currently possible. However, an issue that can occur happens because HDMI cable is manufactured of twisted pairs of small-gauge copper conductors, instead of coaxial cable, and this can cause problems when the HDMI cable needs to be run over 50 feet. When an HDMI cable is too long several things may occur. One of these is sparklies, which are where pixels in the images drop out of the picture. Another problem with long cable runs is image degradation to the point that no image is displayed. If the cable is at the length that sparkles or image distortion occurs, then it is too long and an additional device needs to be added to boost or extend the signal. This is because with twisted pair cable it is impossible to keep tight control of any impedance, and without this tight control the signal may reflect along the cable between the signal source and the signal sink, causing interference with the original source bit stream.

Most of the interoperability or image quality issues are not related to the HDMI cable at all, however, but to the software that is used for the device communication and content protection. Quite often, these problems are caused by the HDCP handshaking software. Another common cause is the improper handling of the device capability information that is read through HDMI. It is almost never the HDMI cables that cause the compatibility problems. Non-compliant cables are very rare on the consumer market. The completeness of the HDMI specification has been verified by the fact that there has never been a compliant HDMI cable that is the root cause of HDMI playback issues with compliant devices.

Every HDMI cable is required to support a standard high definition television video signal at the minimum. They have been tested to verify that the cable meets the HDMI specification requirements. This is called a Category one test. HDMI Authorized Testing Centers, also called ATCs, have recently added the equipment to be able to test the cable’s ability to support 1080p, and higher rates, up to the maximum HDMI speeds. Category 2 testing is the name given to the testing done at these higher speeds. Because Deep Color and 1080p are becoming common market requirements, cable manufacturers want their cables verified with this Category 2 high speed test instead of the Category 1 test, so that their cables can be marketed as 1080p verified. Another HDMI testing service is Simplay Labs. They have been performing high speed cable testing for more than a year, and the logo Simplay HD is put on the cables manufactured by cable makers to convey that the cable has this level of quality. This does not mean that a Category 1 tested cable definitely will not support or pass a Category 2 test. A shorter HDMI cable, 3m or less in length, even if it does not have a specific 1080p marking, will probably pass the Category 2 test. The longer that the cable length is, the more demanding the 1080p signal is on the quality of the cable.

The quality of the HDMI receiver chip has a huge effect on the ability of the receiver to cleanly recover and display the HDMI signal. Most, if not all, of the high definition multimedia interface enabled televisions and projectors that support 1080p on the HDMI inputs are created with quality receiver chips that will cleanly recover the 1080p HDMI signal using almost any normal length cable, including those that have only passed the Category 1 test. This cable is not officially guaranteed to support these higher speeds, but in reality these cables usually work fine. This is great for consumers, especially ones who have already purchased HDMI cables before Category 2 testing was easily available. As long as the cables have been Category one tested, they should work just fine for HDMI applications involving 1080p and deep color.

Well I hope you got it.

What do these color coding means on the connectors?

When you look at an RCA or RGB connector, there are a variety of color codings on them. For each color there is a corresponding audio or video signal or format. In the back of all consumer electronics products there are matching color codings. This enables the consumer or professional who is doing the installation to use the color codings and greatly simplify the hook up.

An RCA jack, also called a phono jack, it is used for composite video and stereo audio. The name of the connector, RCA, comes from the Radio Corporation of America.

The RCA connector has been adopted for numerous uses other than the original intention, including power connector, RF connector, and loudspeaker cable connector. It is also commonly used for composite video signals, but this application gives very bad impedance matching. RCA connectors may also frequently be used to carry SPDIF-formatted digital audio, with these plugs orange colored to distinguish them from any other typical connections.

The standard colors for the different signals will be described below. There is a color for 13 different signals. These colors are white, red, green, blue, gray, brown, tan, purple, orange, and yellow. The colors green, blue, and red are repeated once, because these three colors have a place in analog audio and in component video.

The first category for color coding we discuss is analog audio codings on the connector. There are color codings for up to eight different audio connections. For the left connection the coding is the color white. The right analog audio connection has a red color coding. Green is the color coding on the connector for the center audio connection. Left surround audio connections are coded by the color blue. The right surround audio connection is colored gray. There are also two colors that are used to color code surround sound audio connections. The color brown is for the connection that goes to the left back surround audio connection. Tan is the color used for coding the right back surround connection for analog audio. The last color coding for analog audio is the color purple, or sometimes brown, and this color identifies the connector for the sub-woofer.

The next category for the color codes that should be discussed is the digital audio connector. This is the orange colored coaxial cable, and carries S/PDIF instead of analog audio. Composite video is another category, and composite video has a color on the connector that is yellow.

Component video is the last color category that will be covered. RGB stands for red, green, and blue. This term applies to various analog components. These components generally offer the greatest analog video signals that are available in consumer electronics. With RGB there is no limit in resolution or color depth, and no compression is used. RGB has been pretty much ignored, despite the suitability and quality, as it can't be easily applied with Digital Rights Management. In North America RGB was never popular for consumer electronics, as the format S-video was considered adequate.

Other types of component analogue video signals do not use the red, green, blue components, but rather a component that has no color, called luma, in combination with one or components that carry color, called chroma, that give only information on color. Both S-Video component video output (which uses two separate signals) and Y'PbPr component video output (which uses three separate signals) that are seen on DVD players are a good example. By converting video into signals called luma and chroma, this conversion allows for a process called chroma subsampling, a method which JPG images and DVD players use to reduce most storage requirements for video and images.

When component video is talked about today, the Y'PbPr component video scheme is usually what is meant. Many consumer products use this format of color coding, such as DVD players, video projectors, plasma displays, and others. In component video there are three components that have a color coding. The first component is Y, and the color it is coded to is green. Component Pb is associated with the color blue on the color coding. The component Pr has a color coding association that is red.

And we hope that you be able to hook up easily at any given time. Good luck.

Bi-amplification of Loudspeakers

Many audio enthusiasts see bi-amping as an intelligent upgrade for their hi-fi systems. Bi-amping is, simply, the process of "doubling up" on amplifiers in a system and hence doubling available power. This article seeks to point out some important considerations to bear in mind when bi-amping speakers.

Don't Mix & Match
It is crucial when bi-amping speakers that you not mix and match amplifiers. One current trend among audiophiles is to use a solid state amplifier for the bass frequencies, and a tube amplifier for the mids and highs. While this may initially seem logical, there are several reasons why this is a bad idea. Let's take a look at each one independently...

Rise Time
For one thing, two different amplifier designs will inevitably have different rise time specifications (sometimes referred to as event time). For the purposes of this discussion, we will define rise time as the time required for a signal to travel through an amplifier. Depending upon the amplifier circuit, the rise time will vary. Even a small mismatch in rise time will significantly degrade the sound of a bi-amped system.





Consider that in a bi-amped system, there are two possible configurations. The first, pictured above left, is more common. In this scenario, one stereo amplifier is dedicated to the high frequencies, and one amplifier to the low frequencies. The other scenario, pictured above right, is referred to as vertical bi-amping. In this scenario, one stereo amplifier is used to run both the high and low frequencies on one loudspeaker. (Note: In each of these scenarios, obviously two monoblocks could be used in place of one stereo amplifier).

In the case of "standard" bi-amping, any discrepancy in rise times would result in timing mismatches between the low and high frequencies. This sort of mismatch between frequency ranges will degrade the sound substantially because the precision in timing is important to maintain the integrity of harmonics. When a hammer strikes a string on a piano, it is not one frequency which is reproduced, but several - the fundamental and each of its harmonics. In a loudspeaker, it is likely that the fundamental will be reproduced by one driver, and the harmonics by at least one other driver. Hence any timing errors will result in a degradation of tonal balance, and a smearing of the soundstage.

In the case of "vertical" bi-amping, discrepancies in rise times will result in mismatches between the left and right channels. The results will obviously effect imaging, especially soundstage depth. A simple analogy clarifies the scenario: using amps with the same rise time is important when vertically bi-amping for the same reason using cables of the same length is important.

Gain
Another critical consideration is the gain of each amplifier used in a bi-amped system. The greater the gain of an amplifier, the more quickly the amplifier's output will increase as the preamplifier's volume control is augmented. Conversely, as the preamplifier's volume is attenuated, the amplifier's output will decrease at a rate directly proportional to its gain. One simple way to think of the net effect of an amplifier's gain is to associate high gain with bigger "steps" in volume and lower gain with "smaller" steps in volume.

What this means in the case of "standard" bi-amping, is that if the gain of the amplifiers is not matched, the volume of the highs and lows will be changing at a different rate as the volume on the preamplifier is adjusted. In the case of vertical bi-amping, the volume of the left and right speakers will change at a different rate. The effects of these volume discrepancies should be fairly obvious: in the first scenario tonal balance is altered, and in the second scenario the stereo channel balance is altered.

Concluding Remarks
Bi-amping provides many benefits, especially when using lower powered tube amplifiers where the system's overall power output can be doubled easily by simply bi-amping the loudspeakers. Many of our customers at Symphony Sound bi-amp with SET tube amps (2A3's, 300B's, etc.) and enjoy wonderful sound as a result. However, it is important to bear in mind that if certain guidelines are not followed, bi-amping can actually do more harm than good. If careful attention is paid to gain and rise time, it is possible to mix and match amplifiers, but only is unusual circumstances do we feel this is a sensible and prudent approach.

xxxxxxxxxxxxxx

Rhodium Properties

ON RHODIUM

Rhodium is an element with atomic number 45 and the chemical sign Rh. The name comes from the Greek "Rhodon" which means rose.

Rhodium, which is a platinum metal, is the rarest metal on earth (apart from the radioactive metals) and is only a few (less than 10) tons a year are produced. The metal is silvery white and has a higher melting point and lower density than platinum. Rhodium has low electrical resistance, low and stable contact resistance and high resistance against corrosion.

Rhodium is mainly used in alloys with platinum and palladium. Rhodium can only be plated on nickel, silver, gold or platinum. Plated rhodium is extremely hard wearing. Rhodium is sometimes used in spark plugs for aircraft engines, the tip of fountain pens, telephone relays and in the reflectors of headlamps, mirrors and optical instruments. Rhodium is also used in jewellery, as decorations and as a catalyst.

Because of its low and stable contact resistance and its high resistance against corrosion and wear (for example contact surfaces grinding against each other) it is eminently suitable as material in different kinds of connectors. A surface plated with gold, which is a very soft metal, is worn off much faster than a surface plated with a hard metal like Rhodium.

Summing up: Gold is beautiful, but if you want the best (in sound as well) use Rhodium.

MORE:
Atomic number: 45
Atomic symbol: Rh
Atomic weight: 102,9055
Electron config: [Kr]5s14d8
Atomic radius: 134,5 pm
Melting point: 1964 °C
Boiling point: 3695 °C
Oxidation states: 3

SOURCES
Rhodium occurs natively with other platinum metals in river sands of the Urals and in North and South America. It is also found with other platinum metals in the copper-nickel sulfide area of the Sudbury, Ontario (Canada) region. Although the quantity occurring there is very small, the large tonnages of nickel processed make the recovery commercially feasible. The annual world production of rhodium is only 7 or 8 tons.

PROPERTIES
The metal is silvery white and at red heat slowly changes in air to the resquioxide. At higher temperatures it converts back to the element. Rhodium has a higher melting point and lower density than platinum. It is highly reflective, hard and durable.

USES
Rhodium's primary use is as an alloying agent to harden platinum and palladium. Such alloys are used for furnace windings, thermocouple elements, bushings for glass fiber production, electrodes for aircraft spark plugs, and laboratory crucibles. It is useful as an electrical contact material as it has a low electrica resistance, a low and stable contact resistance, and is highly resistant to corrosion. Plated rhodium, produced by electroplating or evaporation, is exceptionally hard and is used for optical instruments. Rhodium is also used for jewelry, for decoration, and as a catalyst.

HANDLING
Exposure to rhodium (metal fume and dust, as Rh) should not exceed 1 mg/m3 (8-hour time-weighted average, 40-hour week).

COST
Rhodium costs about $ 1.000/troy oz.

xxxxxxx

1/4" Stereo, Balanced or Insert?



There's a lot of confusion surrounding 1/4" connectors, especially the kind with 3 contacts.

An example of a 3 contact 1/4" plug, Switchcraft part number 297, is shown above. This part is also called a 1/4" TRS connector, where TRS stands for tip, ring, and sleeve, referring to each of the 3 contact surfaces on the connector. While this type of connector is often called a "stereo" connector it is important to understand that the stereo configuration is not the only way the 1/4" TRS connector is used.

Following are the 3 most common signal configurations for this connector:

• The first is as a stereo connection, most often used with headphones. In this application the tip connection is used for the left *unbalanced positive signal. The ring is used for the right signal. The sleeve is the ground connection for both the right and left. This type of connection is commonly found on high end consumer audio equipment and on professional mixing consoles and recording equipment.
• The second common use for the 1/4" TRS connector is as a *balanced audio connector. In this case the tip connection is used for the "hot" connection, the ring is the "cold" connection, and the sleeve is connected to the cable shield. The balanced 1/4" connection is often used as a line level output on professional audio equipment.
• The third use is as an insert connection, often found on mixing consoles. In this application the tip is used as the send, or output signal from the mixer channel. The ring is used as the return, or input signal to the mixer. On some mixer models the tip and ring are reversed. The sleeve is used as the ground connection for both signals. In this application the signal path in the mixer is broken when the 1/4" plug is connected to the insert jack causing the signal path to flow through the equipment attached to the insert cable. An insert cable would normally have the 1/4" TRS connector on one end and split out to two seperate connectors to attach to the input and output of the outboard equipment.

So, what is the important lesson here?

Don't assume that just because the cable fits the interconnection will work. It is in many cases possible to connect one of the types listed above to one of the other types with an adapter cable. Look closely at equipment manuals to find out exactly how the inputs and outputs are wired. If the two pieces of equipment don't have the same connection type you may need an adapter cable or additional equipment to make your connection.

*Balanced vs. Unbalanced signals - The complete explanation of balanced audio wiring is too big a topic for this post, so I will be doing a complete post on this subject in the near future. Suffice it to say that balanced wiring is a way of reducing external interference in an audio line that requires 2 signal wires twisted together, and in the case of most audio installations surrounded by a braided or foil shield. For a balanced cable to be effective both the signal source equipment and receiving equipment must have balanced connections.
An unbalanced line relies solely on the shield for protection from interference and only requires 1 signal line plus the shield conductor which also acts as the signal ground.

Subwoofer Cables, Fact or Fiction?



A common myth/misconception propagated by the hi-fi audio cable industry is that a special, usually larger and heavier, audio cable is required to connect a powered subwoofer to an audio system. In truth, any good quality audio cable that can be used for interconnecting audio components will be excellent for use as a powered sub cable.

The input of the powered sub is a high impedance type which means only a tiny amount of power is transferred through the cable, the power amplification occurs inside the subwoofer at its internal power amp. Because there is so little power transferred through the cable, its conductor size is insignificant. Typically 22, 24, or even 26 gage conductors are appropriate, and will not have noticeable signal loss even at lengths well over 100 ft.

The signal most commonly used by a powered subwoofer is a limited bandwidth line level audio signal. In this case limited bandwidth means that high frequency information is removed from the signal either at the a/v receiver - preamp/processor, the subwoofers input circuitry, or in some cases both. Capacitance is the primary factor in high frequency loss in audio cables. Since high frequencies are not used by the subwoofer the capacitance of the subwoofer cable is not as important a specification as it would be for interconnecting full range components.

So, don't be fooled by high priced "subwoofer" cables, use a normal audio interconnect and your sub will sound just as good.

Can you make a component video to RGB cable?



On an almost daily basis we receive requests for a cable to convert component video to RGB or the opposite. I'd love to be able to build one of these, and would probably sell quite a few of them. However, there are a few technical issues in the way.

Before I get into the details of what we can and can't do I think it would be helpful to define some of the relevant video standards and terms:
• Component Video - Also known as Y/Pb/Pr, Y/Cb/Cr, YUV, and EIA/CEA-770.

The component video standard calls for three parallel channels on 75 ohm impedance coaxial cables. Component video cables are typically terminated with RCA connectors for consumer applications or BNC connectors for professional applications. The three channels are known as Y (luminance) essentially a black and white representation of the image, Pb (blue color difference) , and Pr (red color difference). All three of these signals are derived from different combinations of the red, green, and blue primary colors present in the image.

The component standard describes several different signal formats which differ in resolution and scanning method (interlaced or progressive). The standard explicity defines the formats as 480i and 480p in both 4:3 and 16:9 aspect ratios - called standard definition, and 720p and 1080i - called high definition. The number indicates the visible horizontal lines of resolution in the image, the letter indicates progressive or interlaced scan. Additional formats are also present on some equipment.

• RGB Video
RGB uses 3, 4, or 5 parallel channels to seperately carry the red, green, and blue primary color signals and timing information. The 4th and 5th channels are used for different implementations of the timing (sync) signal. The 3 channel version has sync combined with the green signal and is also know as sync on green. The 4 channel version has the horizontal and vertical sync pulses combined on a seperate line, this version is known as RGBS or RGB composite sync. The 5 channel version has the horizontal and vertical sync pulses on two seperate lines, this version is called RGBHV or RGB with seperate sync. RGB cables are made with 75 ohm coaxial cables and usually have BNC connectors though RCA connector are occasionally used.

• VGA
VGA and its relatives SVGA, XGA, and UXGA are very similar to RGBHV. This standard is used in computer displays and some projection systems. In addition to the seperate Red, Green, Blue, Hsync, and Vsync signals present in RGBHV the VGA family also have some additional lines for digital data communications between the display and computer. VGA cables have 5 coax lines and a varying number of twisted pairs and single conductors for digital data. The standard VGA connector is a 15 pin high density d sub (hd15).

So, how do you convert from RGB to Component or Component to RGB?
Simple enough, all you have to do is combine the RGB signals according to a specific formula to derive each of the component video signals. For example Y = .299R + .587G + .114B. The Pr and Pb signals are derived with similar equations. The reverse conversion is also accomplished with a similar set of equations starting with the Y,Pb, and Pr values. Also, the horizontal and vertical timing signals (sync) have to be processed and combined with the appropriate channel.

While it looks simple on paper it is too complex to be achieved with a simple cable, fortunately there is a type of device called a transcoder designed to do this sort of conversion. Transcoders vary in price from approximately $250 to $1500 depending on signal quality and features. Many scalers combine transcoding with more advanced switching and format/resolution conversion.

How about RGBHV to VGA?

Good news, this can usually be done with a simple adapter cable with 5 BNC or RCA connectors on one end and a HD15 connector on the other. For this to work the devices on both ends must be set up for the same resolution and format. This cable is just adapting, not converting.

How about Component to VGA?

Many video projectors and plasma displays accept a component signal on an HD15 connector, in this case you can use a simple 3 RCA to HD15 cable to make the connection. It's critical to make sure the display is specifically equipped to accept component on this input since the cable isn't converting component to VGA, it is just adapting the connection for the HD15 input.

Conclusion-

The wide variety of signal formats and standards can make integrating a system challenging. Fortunately it is possible to make the necessary conversions with minimal or no loss of signal quality using the appropriate adapters, cables, and transcoders.

Till next time....

Conclusion -

Using the guidlines presented in this paper to select the proper type of audio cable for a project will optimize system performance and in most cases reduce the overall cabling expense. The chart below lists some common audio cable applications and expamples of recommended product types.

Example Application Chart

Application: Speaker

Permanent Install:
SSC-122SSA105 12 AWG stranded BC twisted pair and PVC jacket

Portable:
Gepco GSC132 13AWG stranded BC twisted pair and TPE all weather jacket

Patching:
Gepco GSC122OFC 12AWG stranded OFC BC w/ transparent PVC jacket

Application: Instrument

Permanent Install:
N/A

Portable:
Gepco GLC20 20AWG stranded TC w/ 95% BC braid and semi-conductive PVC tape and flexible matte PVC jacket

Patching:
Gepco GLC20 20AWG stranded TC w/ 95% BC braid and semi-conductive PVC tape and flexible matte PVC jacket

Application: Mic/Line

Permanent Install:
Gepco 61801EZ 22AWG stranded TC twisted pair w/ 100% foil shield and PVC jacket

Portable:
Gepco M1042 20AWG stranded TC w/ 95% TC braid and TPE all weather jacket

Patching:
Gepco XB401 24AWG stranded OFC BC w/ 95% TC braid and flexible matte PVC jacket

Application: Digital Audio S/PDIF

Permanent Install:
Gepco VPM2000 20AWG Solid BC w/ 95% TC braid and 100% foil Shield and PVC jacket

Portable:
Gepco VE61859M 22AWG stranded BC w/ 95% BC braid and flexible matte PVC jacket

Patching:
Gepco VE61859M 22AWG stranded BC w/ 95% BC braid and flexible matte PVC jacket

Application: Digital Audio AES/EBU

Permanent Install:
Gepco 5596EZ 24AWG Stranded OFC BC w/ 100% foil shield and PVC jacket

Portable:
Gepco 5596M 24AWG Stranded OFC BC w/ 95% OFC BC braid and flexible matte PVC jacket

Patching:
Gepco 5596M 24AWG Stranded OFC BC w/ 95% OFC BC braid and flexible matte PVC jacket

Definitions

Wire : metal in the form of a usually very flexible thread or slender rod

Cable : an assembly of electrical conductors insulated from each other but laid up together usually by being twisted around a central core.

Conductor : a material or object that permits an electric current to flow easily

Insulator : a material that is a poor conductor (as of electricity or heat)

Current : a flow of electric charge; also: the rate of such flow

Inductance : a : a property of an electric circuit by which an electromotive force is induced in it by a variation of current either in the circuit itself or in a neighboring circuit b: the measure of this property that is equal to the ratio of the induced electromotive force to the rate of change of the inducing current

Capacitance : a : the property of an electric nonconductor that permits the storage of energy as a result of the separation of charge that occurs when opposite surfaces of the nonconductor are maintained at a difference of potential b: the measure of this property that is equal to the ratio of the charge on either surface to the potential difference between the surfaces.

Balanced Line : a : an audio transmission line where the signal is applied differentially between two conductors, each of which has equal impedances to ground or common.

Impedance : a : the apparent opposition in an electrical circuit to the flow of an alternating current that is analogous to the actual electrical resistance to a direct current and that is the ratio of effective electromotive force to the effective current

That's all for the moment, folks. Thank for reading & visiting. Would like to wish "Gong Xi Fatt Choy" for those who celebrate Chinese New Year & Prosperity year ahead.

The Fins

Choosing the Right Audio Cable

One of the most common types of cabling in professional audio systems is a shielded twisted pair. Generally used for mic and line level analog audio it can also be used for AES EBU digital audio. When using a shielded twisted pair for analog mic/line level signals, there are a couple factors to take into consideration, both of which relate to the cables flexibility and durability. We can break this down by the cables intended use. Generally for permanent installations the cable should utilize a foil shield with a UL listed jacket. These cables tend to be less flexible because of the materials utilized to make the jackets. Also, the foil shield offers a more cost effective cable. For portable or live use, the cable should utilize a braided shield, which offers a longer flex life. However, the jacket choice depends on the environment the cable will be used in. If the cable will be used outside it must have a jacket resistant to sunlight and water. This will make the cable less flexible. If the cable will be used for AES EBU signals the most important factor, yet again, is characteristic impedance. These cables should have 110 Ohm characteristic impedance.

A shielded quad conductor is generally used for microphone level signals where external interference is likely to be a problem. When terminated the conductors that are diagonally opposite are connected together. This is done to reduce EMI coupling by making the effective center of each conductor pair the center of the cable. This gives the cable a higher capacitance. Although the number of conductors and their physical relationship improves the cables EMI rejection, it does not make it useful for long runs. The most important aspect of this cable should be its shield. Since these cables are generally used for portable or patching purposes they must be flexible and utilize a braided shield for a long flex life.

2Be Con't...

Cable Configuration -

Cable configuration is also a determining factor of function. The major types of cable configurations to be analyzed are a pair of parallel conductors, a twisted pair of conductors, a shielded single conductor, a shielded twisted pair of conductors, and a shielded quad conductor.

A parallel pair of conductors is generally used for a balanced signal with no ground (i.e. speaker cable). However, it can be used for an unbalanced signal with a ground and is generally used when the benefits of twisting are irrelevant such as AC power wiring. In the case of loud speaker cabling the most critical factor is the conductor size. It is important to use the appropriate size to minimize losses over length of run so the amplifier may still apply its control over a loud speaker’s driver. The primary factor is the total impedance presented to the amplifier by the speaker. This value is derived from the number of speakers their impedance and the cables direct current resistance described in Ohms/Mft. However, in most applications only one speaker is connected to one channel of an amplifier. This simplifies the equation and we can now use a general rule of thumb: the longer the cable the higher the resistance; in addition, the thicker the wire the lower the resistance.

Load Z Length of Run
<100’>100’

16 Ohms 16AWG 14AWG
8 Ohms 14AWG 12AWG
4 Ohms 12AWG 10AWG

As a simple reference the table to the left can be used to determine the wire gage necessary. If multiple speakers are connected to a single amp channel the effective load must be calculated first. Formulas for calculating the resistance of serial and parallel loads can be found in most basic electronic texts. However, in the case of high impedance loudspeaker systems or 70V systems wire gage is the key design consideration. For a 70V system, wire gages as small as 18AWG can be used to connect multiple speakers. This is due to transformers wired in parallel across the amplifiers output and an amplifier that provides a constant output voltage is used. A twisted pair of conductors offers the same functionality of a parallel pair with the additional benefit of common mode rejection. This makes the cable less susceptible to electro magnetic noise by reducing the loop area of the cable. When a signal is applied differentially between the two conductors it creates what is known as a common mode signal. Due to the signals equal yet opposite position relative to ground, the common mode signal will be attenuated.

Shielded single conductors (known as coaxial cables) can be used for a wide variety of signal types ranging from analog audio to digital video. The physical characteristics are crucial when choosing a single shielded conductor for video or digital audio. However, less demanding when used for instrument level or analog unbalanced audio. In the case of digital audio the characteristic impedance is the determining factor. If a cable is terminated at its characteristic impedance electronically it will appear infinitely long, consequently reducing signal reflections. The characteristic impedance of a analog audio to digital video. The physical characteristics are crucial when choosing a single shielded conductor for video or digital audio. However, less demanding when used for instrument level or analog unbalanced audio. In the case of digital audio the characteristic impedance is the determining factor. If a cable is terminated at its characteristic impedance electronically it will appear infinitely long, consequently reducing signal reflections. The characteristic impedance of a cable is determined by the relationship of the center conductor to the shield and the dielectric that separates them. For example, the characteristic impedance of an unbalanced digital audio cable (S/PDIF format) should be 75Ohms. In the case of unbalanced analog audio the cables shielding is important. These cables are generally used for instrument level signals as well as line level audio signals. Given that a single conductor offers no common mode rejection to electromagnetic coupling, the shield plays an important role of protecting the cable from EMI. However, this is not to say that shielding is unimportant for digital audio. In the case of instrument cabling, a semi conductive PVC tape is utilized as well as a shield to minimize handling noise.

2Be Con't...

I came across these theory of...

Choosing the Right Audio Cable...

Determining what cable to use for different aspects of a system can sometimes be challenging. However, there are a few rules of thumb to follow when choosing what cable to use. First and foremost, cost does not determine quality. A lower cost cable may actually be more suitable for a given signal type and usage than a more expensive cable of the same type. In addition, there are many key distinctions among similar looking cables.

> The number of conductors
> The size and construction
> The geometry between pairs
> Shielding
> Insulation
> Jacketing

All of these parameters combined help determine the cables intended use. Because there are many different cable types, this article is limited to low voltage audio cables. Future articles will cover video and data cable selection criteria.

Number of Conductors -

When determining how many conductors are necessary, you are limited to either unbalanced or balanced. With an unbalanced connection at least a single conductor and a ground is required and with a balanced connection at least two conductors with or without a ground conductor is required. If interfacing between balanced and unbalanced, you require at least two conductors. However, complexity arises when mixed formats must be connected. With balanced and unbalanced terminals, there are numerous likely interconnection schemes. Ground loops and shorted outputs are possible problems.

Gage -

There are two major considerations for gage. First, is the conductor large enough to carry the necessary amount of current without overheating? Second, does the conductor offer an adequately low resistance over length so that losses are acceptable.

Conductor Construction -

The construction of the conductor relates to the cables flexibility as well as ease of termination. A solid center conductor is less flexible and more susceptible to stress over time. Cables with solid center conductors are better suited for permanent installation where the cable would remain in a raceway. This would limit the cables movement and reduce stress from flexing. A stranded center conductor is more flexible than a solid center conductor and offers a longer flex life. Cables using stranded center conductors are more appropriate for portable use, so the cable may be flexed often.

Insulation -

Not only is insulation a flame retardant, it protects the inner conductors from abrasion. However, its most crucial function is separation and symmetry. The spacing of the conductors determined by the insulation is known as the dielectric constant. It is the dielectric constant that determines the capacitance between signal carrying conductors as well as the shield. These capacitances combined with the natural resistive properties of the conductor(s) constitute a low pass filter. This means the larger the capacitance per foot, with a longer cable, the more high end roll off experienced. The shorter the run the less critical it becomes for analog audio. However, for runs over 100 feet a low capacitance cable should be used.

Shielding -

There are three main types of shields used in cable construction: braided, spiral, and foil. A braided shield offers the best structural integrity. They are flexible and have a long flex life. Braided shields are usually specified with a coverage area; however, this does not denote the amount of attenuation the braid offers, rather the physical coverage area of the braid. The number of strands, the grouping of those strands, the number of crossovers per inch, and the angle determine the braided shields effectiveness. In addition, a braided shield offers a lower resistance path to ground. This makes cables with a braided shield more appropriate for portable use. A foil shield can achieve 100% coverage and minimizes electromagnetic interference, particularly radio frequency interference. Again, the 100% is related to physical coverage and does not mean faultless EMI shielding. Foil shields are also more flexible than braided shields. However, the flex life for a foil shield is shorter than a braided shield. This makes foil shielded cable more suitable for permanent installation. Foil shields are usually combined with a bare drain wire to lower resistance and provide a simple termination point for the shield. A spiral shield has great flexibility and is easily terminated. However, over time flexing the spiral can spread it and cause a gap in the shielding. This leads to a short flex life, which makes a cable with a spiral shield appropriate for permanent installation.

Jacketing -

The jacket of a cable serves as a bundle and physically protects the inner conductors. This makes the criteria for materials used unique. In certain cases, the jacket material may be required to meet standards set by a governing body such as underwriter’s laboratory (UL). In this case, ratings are assigned to the jacket material which relate to its flammability. Cables with a UL rating of CMP, CL3P, and CL2P are considered to be plenum rated. This means that the cable is suitable for use in a plenum, which is an environmental air space or duct. Cables that have a UL rating of CMR, CL3R, and CL2R are considered suitable for riser use. This means that the cable is can be used in vertical riser shafts from floor to floor in a building. A cable with a rating of CM is considered suitable for general use. This means a cable is suitable for general purpose use, with the exception of risers and plenums. Each rating utilizes different mixtures of materials to craft the jacket. Plenum cables tend to be the least flexible, riser rated cable are flexible, but tend to have a memory, and general cables tend to be the more flexible. One of the most commonly used types of jacket material is PVC or polyvinylchloride. PVC is available in numerous blends customized to many applications. It resists most solvents, oil, flame, and sunlight. Although, standards like these have been set you must consult your local authority to determine the appropriate cable rating for the job.

2be con't...

Three types of power supplies commonly used in Audio

Batteries...
Either “one time use” or rechargeable

Batteries, especially the rechargeable type, are pretty much an ideal power source for audio components if they are correctly sized. A battery is a reliable source of clean, quiet power. That is if the battery is large enough to power the component for a reasonable time without significant discharge. One problem is that the impedance of a battery increases as it discharges, the higher the impedance the faster the rise in voltage ripple. If the frequency of the voltage ripple is in the audio range then this can cause undesirable noise to be heard from the component.

Another obvious con for battery powered systems is the constant requirement for either replacement or recharging.

Wall Wart power supplies...
This is the little black box supplied with your Firestone Audio Component (FAC)

The standard wall wart power supply is a non linear, unregulated power supply; these are the simplest and least expensive solution for powering your Firestone product.

With the wall wart you have 120VAC going in and 24VDC coming out (assuming a stable 120VAC source). It includes a rectifier to convert the AC power to DC and a smoothing circuit to help tame the pulsating DC. Unfortunately there is still a significant amount of ripple on the DC side and the small space available in most wall warts limits the amount of filtering that can be used to reduce the ripple. The result is degradation in the DC power and a corresponding degradation in audio quality.

Another problem with an unregulated power supply is that the output voltage will rise and fall with changes to the input voltage. Any variation on the AC input side will be directly translated into DC variation on the output side. If your AC wall power has hash, surges, spikes, brown outs or some other ugliness; this will appear on the DC side as well and degrade the audio quality. These DC artifacts are known as noise and ripple. Fortunately your FAC is equipped with ”power regulation” and “low pass filter” circuits to help minimize the bad effects of this.

Last but not least is the low power output capability of the wall wart. Electronics that are “power challenged” tend to sound thin or flat at frequency extremes and don’t have the oomph to follow the peaks and large dynamic swings in the music. The FAC’s as with any audio component will draw considerably more current during intense passages in the music; this is when the wall wart may not have the jam to follow along.

Linear, Regulated Power Supplies...
This is the SUPPLIER Power Supply upgrade.

To help deal with the AC voltage variation and other assorted nastiness from the wall power, the Firestone engineers designed the SUPPLIER power supply. The SUPPLIER is a linear, regulated power supply so this means the DC output voltage is largely independent of the AC input voltage. It is designed to output a stable 24 VDC despite variances to the AC input voltage. Is it perfect? Of course not, but it’s a major improvement over the relatively large voltage swings seen at the DC output of a wall wart.

The Supplier also has vastly superior filtering for both DC ripple and noise. This is where you’ll experience a majority of the increase in sound quality; tighter bass, clearer highs and a better defined midrange. To my ear the biggest improvement is in the dynamic contrasts, dynamics are noticeably improved. Also, if your system can reveal it you’ll experience an increase in the magical, low level detail as the line noise and hash present with the wall wart are filtered away by the Supplier.

The SUPPLIER also has much higher power output and superior reserve power compared to the wall wart. Its high current output effortlessly follows the music regardless of dynamics and helps your FAC deliver the very best from the music.

So is it really worth the EXTRA COST?
YES, with one exception. If you are using the Fubar II with a low resolution system then the improvements may not be as apparent. I personally can detect the addition of the Supplier 100% of the time in my system in an A - B - A test; all I have to do is listen to the low level detail in the music.

Chao...

SUPPLIER Power Supply...Is It Really Worth the Extra Cost?

This is a great question and one we get quite often get. Many people just can’t understand how a power supply from TNB can help improve the sound of an audio component.

Before we talk specifically about the SUPPLIER Power Supply Upgrade lets talk a little about power supplies in general. If you look at the history of Hi-Fi one can see the continued progression of bigger, better and cleaner power supplies being added to high-end components. If you examine any high-end component you’ll find that clearly half the cost or more is in the power supply section. One could argue that improvements in electricity are the source of all improvement in Audio.

If you could order up the ideal power supply it would be one that provides unlimited current while the voltage remains perfectly constant. Nice in theory but not practical in the real world as every type of power supply has limitations that stray from this ideal. As with most any audio component, to power their circuits. They require a clean, free from any contamination, stable 240 volts AC to sound their best.

2 BE con't ....