Analog to Digital (A/D input) and Digital to Analog (D/A output) converters are pieces of hardware which manage the Input and Output (I/O) in your audio interface. Even the most high-end Macs or personal computers use very basic, low-quality converters, which are the same ones incorporated into cheap computer systems.
 
You can upgrade your audio interface by choosing from a wide range of stand-alone interfaces available in the market. These outboard interfaces typically allow for more I/Os, improved A/D/A conversions, and additional features such as volume knobs. The hardware unit that has I/O jacks is also known as the ‘interface’, ‘breakout box’, or simply, the ‘I/O’. The archaic label ‘soundcard’ conventionally refers to circuit boards that needed to be affixed to the PCI slot of a computer. Many of the computers sold today do not have slots for PCI, thus rendering PCI soundcards useless. A FireWire or USB will solve the interface issue, as it takes the place of the soundcard.
 
A USB or FireWire interface gives you the flexibility of ‘hot-swapping’, as well as being able to transfer files to notebook computers. The slower USB 1.1, which works at 12 MB per second, may not work properly under the load of several channels, while FireWire technology operates at 400 MB per second. FireWire 800 is much faster at 800 MB per second, and USB 2 is more efficient than its previous version at 480 MB per second. PCI may operate at decent speeds, but the technology is inconvenient to use.
 
Your operating system must be compatible with the interface you choose. Your software must be able to identify the presence of the interface. Many Macs have USB or USB 2, and FireWire (IEEE 1394). PCs have either USB or USB 2 as well as FireWire. FireWire 800 is just now starting to be introduced and is not very widespread in its adaptation yet.
 
Regardless of the interface you have, the right cable is integral to your audio interface. The cable will connect your computer to the amplifier. Many amplifiers for consumer electronics utilize RCA jacks. Your output jack may be the round 1/8-inch mini – in this case, purchase a 1/8-inch-to-RCA adapter. Professional variants use XLR jacks with three pins.
 
If you do not have an amplifier, or it is located at a greater distance than cable length can reach, look for speakers that are USB-powered, like SoundSticks from Harman Kardon. These speakers attach using the USB port and work without an amplifier. Bose and Polk Audio also have non-USB speakers. CRT monitors require you to employ shielded speakers. AirFoil sends the audio to Apple’s Airport Express, for use with Mac computers.
 
Be sure to inspect your interface, and the number of physical inputs and outputs that it has for analog. Most companies state that their interfaces have so-and-so number of inputs, although some of these are digital, including ADAT and S/PDIF. ADAT inputs are necessary for additional mic pre-amps. To this, ADAT-output external mic pre-amps may be added. You can choose from the ADAT-interfaced Focusrite OctoPre, or Presonus Digimax. If you wish to do large amounts of audio recording for whatever purpose, consider acquiring more hard drive storage, plus a reliable backup system.

Choosing the best audio interface is the key to excellent home studio recording. The success of your studio does not bank solely on the soundcard you use, as this hardware unit also manages sound output and input from and to your computer system.
 
You can take your pick from so many products on the market, and most of them can give you high-quality recording capabilities at reasonable prices. With so many to choose from, how do you know what to buy? Here are a few questions, as well as some hints and tips, which will help you select the audio interface solution you require.
 
Do you use Apple’s Garage Band? With the aforementioned program, you can make do with the built-in soundcard, plus a specialized adapter for using musical instruments. One tool you can add to the rest of your equipment is a set of plug-and-play USB microphones from Samson. These microphones allow even the novice sound engineer to harness the full potential of Garage Band. A more sophisticated and high-end option would be ONE (by Apogee) for one-channel interfaces at $249.
 
What number of inputs does your setup require? This depends on quite a few factors: the kind of music to be recorded is one. This will then dictate if you need one, two, or more inputs. Lower-priced audio interfaces often allow for a lower number of inputs. The minimum recommended number of inputs would be two for mic pre-amps. With this, you can record one instrument (such as a guitar) and vocals at the same time. The most basic setup for proper drum recording would require a minimum of four inputs for the pre-amp. One input is dedicated to the kick drum, another for the snares, and a couple of more inputs for stereo overhead recording. The more inputs you have for drum recording, the better the overall sound quality will be.
 
Is Pro Tools compatibility necessary? Many in the recording industry use Pro Tools by Digidesign. Recording will be convenient if all your tools are compatible with this utility. However, the simplest Digidesign product can cost a relatively large amount of money. The MBox 2 Mini only has one mic input plus a couple of line inputs, but it will set you back by $329. The next step would be the Digi 003, which allows 8 channels at $1600. Take note that you do not need Pro Tools hardware (and the high tag price) if you want to use different recording software. Pro Tools does not function without a Digidesign interface.
 
Will you use USB or FireWire? USB products can be purchased at lower prices than those of FireWire. USB is fine for one or two-channel recording. However, if you want to record with a higher number of channels, FireWire is necessary, as USB technology does not have the large capacity that FireWire has. FireWire is safer for sustaining larger amounts of data due to its higher bandwidth. The most sophisticated professional audio interfaces typically have dedicated cards for interfacing with the main computer.

How do you pick a digital audio conversion system and a software driver? The choice of DAC will greatly affect the sound your audio interface produces, through the conversion of signals from input to output, and analog to digital (and back). The software driver then manipulates the signals as digital data, and manages transmission of these signals to and from your audio interface’s computer.
 
DACs
 
You can test the sound of any DAC system or device by simply listening to the output itself – this may not prove to be a good qualifier, however, as subjectivity will always come into play. Your sound system and audio interface must also have sophisticated, high-end speakers for you to hear the sound in its purest form, as well as have signal paths that are free from any interference. For treble, scrutinize the sound of drum cymbals in a song or recording. Do this with the outboard device and without it. Change the outboard device if you wish to compare output quality. Ideally, with all things being equal, the DAC that sustains the cymbals’ definition and ‘shimmer’ best should be your choice. A low-quality DAC will make the difference in quality apparent. Other factors, such as bass, sound fluidity, warmth, and other technical and non-technical characteristics will also dictate your decision.
 
The card with the best DAC will not always result in the highest sound quality. You may have a difficult time choosing the card that is suited to your requirements and purposes. You may even buy a card you would not otherwise want to get, due to the DAC capacity. Choose a card that has the I/O and drivers you need. You can upgrade with additional DACs later on, and these extra devices will be better than most built-in DACs on many interfaces and soundcards in the market. After bulking up your system with equipment such as high-end pre-amps and monitors, you can consider buying converters. Prior to the installation of these added items, the difference in sound quality would be near-imperceptible. Get professional DACs for your interface or soundcard for superlative results.
 
Software Drivers
 
The software driver provides the vital programs that allow information traffic between your computer and the DAC. This data is formatted for access by the CPU if and when the audio application requires it. The computer’s operating system sets the regulations that the driver uses. If the driver decodes and ‘understands’ the data and rules properly, your audio interface will work as expected. Any errors on the part of the audio application or driver will make the operation falter. Any problems with how your driver works will be transmitted to the CPU, and vice-versa. The application itself may also be the root of the issue.
 
Choosing a software driver can be confusing. Some software may work great with some machines, and bog down others. Even changing your OS or any integral program can alter the way your audio interface runs. The universal rule here is: research and ask around. A software driver might as well be tailor-made, as the system setups, operating systems, DACs, and many other aspects of the entire recording system need to be taken into account before even getting or upgrading a software driver.

An audio interface is comprised of a hardware box or unit separate from your computer system that permits the input and output of sound to and from your computer. Part of it may also come with your computer, or be in-built, such as the case of a separate or default sound card. You may also use a hardware box with various kinds of plug-ins, such as quarter-inch phono plugs, RCA connectors for a cassette tape deck, and the more sophisticated XLR connectors used with high-end microphones.
 
The separate hardware unit may also be likened to a mixer, wherein the audio interface works with pre-amps and analog input methods. After the signal passes through the pre-amp, it is transformed into digital data, and transmitted to the computer by way of a digital output. Related software then translates the aforementioned data and sends it back to the audio interface. The interface can then reconvert it to analog format before playback. There are also various kinds of analog to digital and digital to analog conversion units (which were utilized in the signal translation process).
 
Here are some types of interfaces that focus on audio:
 
• the Audio Codec 1997, or AC97, which allows for transmission between ICs (Integrated Circuits) on motherboards from PC systems
• the ADAT interface
• the AES / EBU interface using XLR connectors
• AES47, utilizing the AES3 digital audio format for networks with ATM or Asynchronous Transfer Modes
• Bluetooth using A2DP
• I²S or Inter-IC Sound interfaces for ICs in products for the consumer electronics market
• the Multi-channel Audio Digital Interface, or MADI
• MIDI interconnections for low bandwidths that carry data (but not sound)
• S/PDIF through TOSLINK or co-axial cable systems
• TDIF using the proprietary TASCAM format for D-Sub cabling
 
Digital bus devices, such as FireWire, PCI, and USB-technology powered tools can store information in the digital audio format as well.
 
Digital Audio Conversion
 
What affects sound quality in your audio interface or sound card? Two integral parts of your sound card or audio interface dictate sound output quality. Default software drivers that come with the acquisition of the card is one, while the second is the DAC, or digital audio converter incorporated into the card itself. The microphone pre-amps of your audio interface can also influence the quality of any recorded data.
 
Choosing between an Audio Interface or Sound Card
 
As recent technological developments change sound cards and audio interfaces, many professionals are biased towards one option. Musicians and sound technicians generally go for audio interfaces rather than conventional soundcards. These interfaces may be based on FireWire or PCI technology. The audio interface usually includes a breakout unit or box, which stands separate from the main computer. The audio interface also uses a cable attached to the computer’s PCI card, or a connection made with FireWire or USB-type cables. The breakout box has ports where instrument cables, mixer cables, monitor cables, or microphone cables can be affixed. The standard soundcard is typically located in a PCI slot within the computer, where the cables are at the rear of the said card.
 
A large portion of the sound cards being sold today have decent DAC capabilities. This is a far cry from just some years ago, where a user was required to pay a high price for good digital audio conversion. The evolution of digital audio conversion systems can be compared to compact-disc player technology. The first CD playing systems usually resulted in tinny or hollow-sounding output. Eventually, sound engineers and specialists refined DAC by error correction, interpolation, oversampling, and various methods to hone the sound. Sampling is the nucleus of the digital audio conversion process. The converter decodes the forthcoming analog signal and translates it into data. Once the signal had been completely transformed into information that the system can handle, the computer can then administer it by combining it with separate data, storing it on the hard drive, etcetera.
 
The quality of digital audio conversion is directly proportional to the condition of output from the card. The type of card (be it FireWire, PCI, or USB-based) does not dictate the sound output quality. The technology used simply serves to transport, transmit, or hold the data. The DAC is what actually shapes the sound, if you will. It is the main aspect that influences sound output quality.

If you are looking to start a home gym, or just to buy some free weights to lift on the weekends then you are going to need to find a weight training equipment set most likely cheap.

There are a few select brand names of weight lifting equipment, but for every brand name of equipment there is an off brand generic set that will be sold for at the same quality for a fraction of the price. So if you are looking to find cheap weight training equipment then you are best off with one of those generic sets.

There are several ways you can go about finding and purchasing your next weight set starting with what is available locally. There are several major production stores such as Wal-mart that will have your generic weight sets available, or you can check out what kind of deal you can get with a specialty store or pawn shop. To start off your search for that cheap weight training equipment visit your local Wal-mart or Wal-mart brand store to see what they have available. When looking for a good set you don't want to sacrifice quality for a cheap price tag which is what you will most likely do if you are looking for a cheap set. Once you have checked out what your local Wal-mart has to offer you can visit a speciality store if there is one in your local area, or you can see what the local pawn shops have to offer. With a little time spent going from store to store you will be able to compare quality and price tags to see which weight training equipment is right for you.

If you have checked out what is available locally and you have still have been unable to find a cheap weight training set then you can go online to see if you can find a deal somewhere on the net. There are several sites that will specialize in weight training equipment, so I suggest you visit those first to so what they have in their inventory. if you have looked at a couple of those sites but you still haven't found the set that is right for you then I would suggest you try out an auctioneer site such as eBay to find a larger selection choice. The only thing you want to watch out for when purchasing from an auctioneer site is the quality of the equipment you are going to purchase. Sometimes things will be listed as barely used when realistically they are five years old with a new set of paint hiding rust and worn down bars. The key is to find an in between of quality and price where you can purchase a set that won't empty your wallet while still lasting a couple of good years.

So overall if you are trying to find some cheap weight training equipment do a little research and shopping around to see what is available online and in your local area.

If you are looking to bulk up or just add a little muscle to burn away that excess fat then you are going to have to do some weight training. The two options you have are between your basic free weights that can be lifted at home or at the gym, or weight machines which can be purchased for your home but are better used at the gym.

If you are unsure which method of weight training is going to be best for you then you need to understand a few things. Lifting weights can be dangerous if you are not properly informed and understand proper technique and what is the right amount to be lifting. With that in mind you are going to be much less likely to injure yourself when working with a weight machine that has safety settings to where if your muscles fail or your grip loosens you won't end up breaking your foot. So if you are relatively new to the weight lifting scene then I would suggest hiring a personal trainer and working out on machines at the gym.

Now for those people who have been lifting for years and understand the proper techniques and how to get the most from their workouts free weights might be the direction you want to head. The reason why more experience lifters will want to lift free weights over a machine is that free weights can add more resistance since the weight you are lifting is determined by your grip. lets just say there are more customizable options when lifting with free weights. You have more exercises you can do and work out different parts of the body by varying your grip and the weight lifting style.

With all of this in mind you can check out for yourself which one is going to be easier for you to use, or which one is going to be more beneficial for your muscle building. Even though weight machines and free weights are considered two different types of workouts there is no saying that you have to limit yourself to just one. They are both great for beginners and those more advanced to help build muscle and burn away fat. The only determining factor into which one you should use if not both is your knowledge of weight lifting and proper technique. If you went ahead and hired a personal trainer they will most likely have you doing a combination of free weights and weight machines to get the most results. The thing is if you don't have a personal trainer and you are new to weight lifting it will be a much safer bet to start with machines then move onto free weights.

So overall if you are trying to determine which method of weight training is right for you, weight machines, or free weights just take a look at your overall knowledge of the weight lifting field. Try to do a little research on exercise techniques and which ones will build the muscle you are looking for then make your choice cause altogether they are both great methods to build muscle.

You have decided to take the plunge and start getting into shape. You need to make an investment and purchase professional weight training equipment. Before you buy, consider some fundamental factors. Your budget, space available, desired results, and experience are all considerations. Make sure your fitness level is appropriate for the training you want to do. Before you start any exercise training, always consult with a physician.

*How much will I have to invest? Initial investment can range from $20.00 for a pair of dumbbells to thousands of dollars for a machine. Once you determine your goal, you can then decide how much to spend.

*What type of bar do I purchase? That is a matter of preference and budget. One thing to remember is your bench needs to match your bar. There are two types of bars standard and olympic. Olympic weights and bars are larger and cost more. They accommodate more weight and are what the professionals use.

*Can I train without a machine? Certainly, you can start with dumbbells, a bar and a bench. This is free weight training, which is the next question.

*Which is better, free weights or machines? Ah, the big question of debate. Check the Internet and you will find hundreds of varied opinions on this from machines restrict your body’s natural movement, to free weights cause strains and you will need a spotter. The debate is endless. Machines are easier to control and absolutely safer. It is a matter of opinion and preference. Do your own research and purchase what meets your needs.

*I want to purchase a machine but how do I select which one? A good start is your local gym. If you are a member no problem, just try what is available and what seems right for you. If your not a member and do not want to take one of those freebies they are always offering, I would recommend a professional specialized sports equipment store. Most of these have the equipment set up for you to try and a knowledgeable sales staff. Local sporting goods stores also carry a limited number of machines, which usually will cost less, then the professional equipment stores. The Internet is an excellent source of information.

*Do I need to wear those big belts? Once again, controversy, I would wear it during my entire lifting workout. A beginner does not take any chances, wear it.

*I just want to build my upper body, is there a machine for that? A machine is available for every major muscle group you want to train. Focusing on one particular muscle group is not a good idea. You may want to research this a little further.

The novice can become overwhelmed with all the equipment and choices. Remember what is important. Weight lifting is an excellent way to stay in shape and bulk up. The choices are endless. How many sets and repetitions should I do? How heavy of weight should I lift and for how long?

You've seen it on TVs and movies. You hear all your friends talking about it. Despite all this, you have never gone scuba diving. Fortunately for you, changing this is quite simple. Learning how to scuba dive is much less intimidating than you might think. While there are a few technical parts, and some physical skills you'll need to master, learning how to dive is a fun process that almost anyone can complete.

First thing you will need to do is decide where you want to take your course. Naturally, your first inclination might be to find the closest place and get a certification there. There is nothing wrong with this, but if you live in a landlocked area, keep in mind that you will be learning to dive in a lake or spring. This is still a lot of fun, but it is a very different experience from the open ocean. Some people choose to travel and get their certifications at top diving destinations. Others simply learn to dive with their local shop, and save their travel dollars for after they're certified.

Here's a hot tip: basic open water diving classes can be much cheaper in certain countries. Places such as Honduras and Thailand are well known for offering low cost programs. I myself got my certification in Thailand, on the island of Koh Tao, and paid much less than I would have in the US. I had one-on-one private instruction, and got to dive in amazing tropical waters. The cost savings doesn't add up to the cost of a plane ticket, but it's still something to consider.

Once you have found your shop, you will start your open water course. These are typically provided by PADI or SSI. Both are legitimate schools, and it really doesn't matter which one you choose as a beginner. The class will take you four days, during which you will do some classroom work, some drills in the pool, and, best of all, four open water dives. If you pay attention during the classroom parts, focus on getting your skills down in the pool, you should have a lot of fun on your open water dives. Keep cool, don't panic, and you'll have a blast. Once you have completed this class, you will be a certified open water diver. This means you can now go diving with most dive companies, provided your dive is no deeper than 18 m. If you want to go deeper, you'll have to take your advanced open water class, but that's topic for another article.

Learning how to dive opens up whole new world to you. The oceans of the planet are filled with a vast array of wonders that you will never see it unless you take the plunge and learn how to dive. It's not cheap, and it isn't always easy, but it is most certainly worth it. Good luck learning to dive, and I'll see you on the bottom.
 

The emergence of compound bows in the market has added a new category to hunting sports. It is claimed by compound bow enthusiasts that the advanced design of this bow permits those who love to hunt with the rifle to enjoy the excitement of learning how to hunt in a different way. Also, compound bows have the advantage of being lighter than rifles.  And many archers are not hunters at all, they simply enjoy archery for the sport.

The design of compound bows has evolved substantially to provide a weapon that is now more convenient for the hunter to use. What makes compound bow hunting more challenging is that you have to be closer to the animal to make a kill. This is a challenge that many hunters may find more exciting than hunting with a rifle.

But how do you find the best compound bow for your needs? There are so many designs and models to choose from as companies try to outsell their competitors. There have also been many developments and innovations that have substantially altered the appearances and features of compound bows.

The first step is to determine how you will use your compound bow. You will have to identify whether you will use it for hunting or for targeting. You will then have to look at the different specifications such as draw weight, draw length, design of the cam and wheel, accuracy, weight, geometry of the deflex and reflex riser, let-off, brace height, speed, and price. After determining these values, the next step is to go to check the Internet or go to your local hunting store.

Before the actual purchase, you will need to have a qualified person measure your draw length. This will ensure that the draw length of the bow will be adjusted to suit your exact measurements.

Another important factor to consider is the draw weight. You will need to test several bows to find the most comfortable draw weight for you. Compound bows allow the draw weight to be adjusted in increments of 3 to 5 pounds. The usual maximum draw weights are between 45 to 90 pounds. This is a very important factor so make sure to actually shoot a few arrows from several bows to compare.

Of the different kinds of bows, compound bows have the widest range of choices. For example, there are various cam types, such as the single cams, hybrid cams, binary cams, and twin cams. With regards to the limbs, there are solid limbs and split limbs.

When it comes to axle length, there are three basic types. The short axle bow has an axle-to-axle length of under 32 inches. The mid axle length bow has an axle-to-axle length of 32 inches to 38 inches. The long axle bow has an axle-to-axle length of more than 38 inches. Those who prefer compact bows for hunting will want the short axle bows while finger shooters and those who want to join tournaments prefer the long axle bows. However, the most common type is the mid axle length bow that provides the right combination of long-range accuracy and maneuverability.

Here are some of the frequently asked questions about compound bows and their answers

Question: What is a compound bow and how does it differ from the traditional bows like the recurve bow, cross bow, and long bow?

Answer: A compound bow uses a system made up of cables, levers and cams to store energy and allow it to be released instantly when the weapon is fired. Unlike the recurve and longbows, the limbs of the compound bow are more rigid. The use of cams and the principal of leverage make it easier for the archer to draw the string despite the more rigid limbs. They also permit the storage of more energy so that the arrow can attain a longer distance.

Question: What are the advantages of a compound bow over the traditional bows?

Answer: The levering system of the compound bow magnifies the force that is applied to the arrow after the archer has drawn the string but reduces the force that he must maintain on the string. One of the cams reduces the force that the archer has to apply to enable him to take a more accurate shot. Another advantage of the compound bow is that it is hardly affected by temperature or humidity so that it can be used in a wide range of conditions. Another benefit is that the type of cam can be changed if you prefer to shoot the arrow more gently.

Question: What are the disadvantages of compound bows?

Answer: The weight of compound bows is usually less than the weight of traditional bows. Thus, it is more easily affected by errors in form when drawn to full length. Specifically, there is a stronger possibility for the archer to slightly twist from left to right or vice versa.

Question: Do compound bows require a different kind of arrow?

Answer: Wooden arrows are not used for compound bows because they could break or shatter as a result of the stronger forces that are applied. This could be very dangerous for the archer. Thus, the shafts of arrows for compound bows are usually made of carbon or aluminum alloy. Arrows with various lengths and stiffness are made available by manufacturers to allow for the various draw lengths and draw weights.

Question: What are the types of cam systems used?

Answer: There are four basic types of cam arrangements for compound bows. The single cam compound bow has a power cam on the bottom and an idler wheel on the top. The power cam is elliptical in shape while the idler wheel is round. The hybrid cam has a power cam on the bottom limb and a control cam on the top limb. Both cams are elliptical in shape. The twin cam system has two elliptical or round wheels that have to be synchronized. The binary cam system is a modification of the twin cam system where the cams are made to be slaves of each other. All of these cam systems have their pros and cons. Therefore, your choice would depend on how you plan to use your compound bow and your preferences.