Home Theater Audio Connections

In today’s home theater environments, quality audio is paramount. In the old days, you could connect your tape deck or CD player via simple red and white analogue component cables. These are still used today for many sources, but there are better alternatives.

Each RCA cable represents a channel of audio and so the red and white cables represent left and right audio channels. This works fine for simple two channel audio. The problem is that home theater audio has between 6 and 8 channels. In theory, you could still have six separate audio component cables, but this gets complex rapidly. The first DVD player I had included a built in AC-3 decoder and had six separate RCA output channels.

The other solution work, but is not efficient. Imagine if you had multiple AC-3 components like a DVD player, cable box and videogame system. Now you would need 18 cables (6×3) which is very complex and inefficient. A solution to this problem is another technology called an optical digital audio cable or more commonly known as a toslink cable. Here is a picture of a toslink cable courtesy of Monoprice which is a very inexpensive place to purchase these cables.

Toslink Cable
These are high bandwidth optical cables that and can provide all 6 or 8 channels through one cable. This with a Toslink cable, you can replace all six RCA connectors and cables with one one Toslink. This is the most common cable type used today. In fact my Comcast cable box has a Toslink as does my XBox and DVD player.

The other alternative to the Toslink in another cable type called digital Coax. This cable is interesting because it combines the benefits of multi-channel Toslink and with convenience of RCA connections. Basically this connection type includes what looks like a traditional RCA connector and traditional RCA cable. The different is that while you plug in standard RCA cables, the actual signal sent across the cable is digital allow for 6 or 8 channels over one cable. In many respects this is the best of both worlds, by allowing Toslink density without the need for a special cable. Unfortunately, in my experience these types of connections are less common and instead Toslink has become the standard. Note that like Toslink the signal is binary and so a cable will either work or not. I say this because many vendors will try to sell you high priced cables for this. Do not be fooled, they maybe helpful if you are running long distances, but these provide limited value in most environments. In my setup, I am just using an extra RCA cable that I had hanging around and it works perfectly.

What does this mean to me?

The answer is that you should be aware of the important of Toslink or Digital Coax cables and make sure that any receiver you purchase has a full complement of these.

More Home Theater Cables – Component Video

I previously posted an article on HDMI vs DVI video cabling. During that post, I highlighted the difference between the two technologies. They are the best connection methodology since they are all digital. If you must use an analogue connection then you should use component. These connection methodology splits the signal up into three separate channels, red, blue and green. It does support HD and so is the best analogue option if you cannot do DVI or HDMI.

IP Telephony — Vonage

There are a number of companies promoting IP Telephony based solutions. A classic example of this is Vonage. The question I get asked is what is it and should I use it? The answer is that it depends.

The first basic answer is that IP telephony basically uses your Internet connection for phone calls. Thus if you make a call, your call does not use a phone line in your house, but rather uses your Internet connection.

Before we get into the details about which is better, we need to review the background. A traditional telephone network is switched in nature. What this means is that when you call someone, you have two dedicated connections (listen and talk) between the two people on the phone. This connection is created based off of the phone number and then is broken when you hang up. IP, the protocol used by the Internet is different. In an IP environment, data is sent in the form of packets. Thus a voice is broken into many small packets and these packets are sent over the Internet and reconstructed at the destination. The thing to be aware of is that these can travel different routes to the destination and so the order they arrive may not be the same as they were send. (e.g. A,B,C could arrive in another order e.g. A,C,B)

What does the above really mean?

Benefits of IP Telephony:

  1. Cost – These services tend to be substantially less expensive than traditional telephony.
  2. Portability – With these services you are identified by a unique ID to the carrier. This idea is not geographic sensitive so you could connect your device in California and still receive calls at your 617 number
  3. Features – IP telephony based systems often offer more advanced functionality than traditional telephony such as web-based voicemail

Negatives of IP

  1. Reliability – THis is not to say that the service providers are not reliable, but rather is a testament to Internet connections. Generally broadband networks are built much less reliably than telephone networks. For example, if your power goes off, your phones will still works and your Internet connection typically won’t. Ask your self, which goes out more, Internet service or phone service? Remember the IP telephony will only be as reliable as your Internet connection.
  2. ence on Internet Connection – Since the phone is based off of your Internet connection, it will be impacted by the utilization of your connection. If you download/upload large files or perform any other action that requires a substantial amount of Internet bandwidth, your phone will be negatively impacted
  3. Sound Quality – This has improved dramatically over the years and is probably pretty close; however remember since IP Telephony is not using switched network, voice quality will vary depending on network utilization or Internet traffic problems.
  4. 911 Service – This was an early problem with IP Telephony since it is no longer affiliated with a physical location. You should check with your carrier to ensure that 911 services work properly. In some cases dialing 911 will not work properly which is a very bad thing.
  5. Service – If you have a problem you will likely have to work with your IP telephony provider and your high speed Internet provider. The problem here is that the service I have found from my Internet Provider (my cable company) is not nearly as good as that from my telephone company. The last time I had an Internet outage, it took them a week to get here and fix it. If I had IP telephony, I would have been out of service for that time. My telephone company is much more responsive.

Which would I choose? In my neighborhood, Internet connectivity is not reliable. To me reliability relates not just to my house maintaining signal, but also the network as a whole. It is not uncommon for us to lose cable signal for short periods of time every few weeks. This is not a major problem for TV, but is not acceptable for our telephones. We also lose power now and again which of course also causes problems with the Internet while our phones still work.

My general recommendation is that IP telephony is a great option for an extra phone line, but I would not recommend it for the primary house phone. There are just too many issues around support and reliability.

What is RAID and why should I care?

I previously posted about various approaches of protecting your data from loss. The issue as I mentioned is a risk of hardware failure, user error or virus. All these are major issues, but the second two can be handled by carefully what is done on the computer. The first problem, hardware failure is more random in nature and there is little you can do to prevent it. RAID is a method to protect you from hardware failure.

RAID stands for “Redundant Array of Independant Disks” and is a family of algorithms designed to leverage multiple disk drives. Each algorithm is called a “RAID level”. Here is a summary of the RAID levels:

  • RAID 0 – This is the most basic form of RAID and does not provide any redundancy and instead is focused on performance. (Assume a RAID 0 configuration containing 2x250GB drives) RAID 0 takes the drive resources and pools them into one large volume. Thus in this case, the computer would see one large 500 GB drive. As data is written to the drive, it will be written in a round robin fashion to each drive in the pool. This provides for better performance since you are writing to two drives instead of one, but also provides greater risk since each drive has half your data and if you lose one drive, you will corrupt all your data.
  • RAID 1 – This approach provides a high level of reliability for data at the cost of more disk space. (Assume a RAID 1 configuration containing 2x250GB drives)RAID 1 mirrors data between two drives. Thus as data is written to the first drive, the same data is simultaneously written to the second drive. The result is that the two drives are exactly the same and either one cane be used to access the full data set. The downside is that capacity is reduced in half compared to RAID 0, and in this example, you would see 250 GB of available storage. This is the approach I use.
  • RAID 5 – This is a more complex approach than the other two. It uses a complicated algorithm to create mathematical data that can be used to re-construct data in the case of a failure. It is designed to augemt RAID1 by providing better capacity. Because of the complexity in calculating these mathematical equations, RAID 5 typically requires dedicated hardware to perform the calculations. This is the most common RAID technology you see in corporate environment. Another side note is that this approach typically requires at least 3 hard drives.

Should I use RAID?

Yes, I think that RAID is a very important technology and encourage all readers to consider it.

Which RAID level should I choose?

There is no question that RAID1 is the best choice for most users. In larger environments, RAID5 would typically make more sense.

How do I enable RAID?

There are different ways to enable RAID. One method to create a RAID set is to use software. Most OSes include the ability to create a RAID set in software. This approach should only be considered for RAID0 or RAID1, and is generally the least reliable approach and should be avoided in a Windows environment. A number of vendors make dedicated RAID cards that you plug into your computer and will handle the creation and management of RAID sets. These are inexpensive and are recommended. The third option is that some motherboards included embedded RAID hardware which makes the creation and management the easiest. My recommendation is to either purchase a RAID card or use the embedded feature in your motherboard, if available.

How to backup your data

I work in the Data Protection industry and can tell you that one of the things companies really worry about is protecting their corporate data. Unfortunately, while business understand the concerns, consumers typically don’t. The issue is that most consumer PC’s have a single hard drive that contains all of the users data. If that drive somehow gets corrupted either due to mechanical failure, virus or potentially user error, all the data will be lost. This is a more common occurence then you might think. There are a number of different options to consider to protect yourself against this. Here are some suggested approaches.

  • Backup to CD/DVD — This approach works fine and DVD burning packages such as Nero include backup tools. To get the best benefit you might also want to consider taking the DVD backups to a remote location to get better protection. (e.g. If there is a fire at your house then you will likely lose the PC and the DVDs if they are stored in the same location.) The downside of this approach is that DVDs only hold up to about 4.5 GB. With todays hard drives exceeding 500 GB in size, you could need up to 11 of these to do one backup.
  • Backup to a hard drive — This approach uses a second hard drive to backup the data contained in the primary hard drive. The second drive could be internal or external (e.g. USB). The latter is better because it can also provide geographic protection if you unplug it and take it to different location. The good news is that hard drives offer large capacities and should easily be able to protect all the data on the primary drive. The downside is that hard drives are fairly expensive. You also need some kind of software to manage the backup operations.
  • Third party service — There are third party service providers that can backup your computer. They will typically use your Internet connection and send data to a remote site when your computer is idle. This way you can simultaneously solve the problem of backing up and offsiting your data. One of services that I think looks good for this is called Carbonite. For $50/year they will provide an online backup service.

Which method should I choose?

Any of the above methods will work, but in my opinion, the most effective data protection method is the one that is fully automated. Neither of the first two options are automated and require you to schedule and run backups. Because of this, I recommend the third option. The beauty of this approach is that you just install the software once and backups just run automatically with no end user interaction required. The service is a little bit more expensive, but think about the alternative of losing all of your data.

How do you do it?

I use none of the methods above. Instead I use an open source application called “rsync”. The application synchronizes data between to machines. In my case, I “rsync” between a computer at home and a remote computer. Thus the remote computer serves as both a backup and provides geographic protection.