This takes time, and in a typical audio recording scenario, it happens twice: once to data on its way into the computer, and again on the way out. Bulk transfers are sporadic, and would wreak havoc on your pristine audio streams.Įven in an isochronous transfer, however, the devices at either end of the link have to package up the data, transmit it and then unpack it again. The difference between a bulk transfer and a real-time streaming (isochronous) transfer. In this mode, the data is transferred in real time, but if any of it gets lost or damaged, the transfer simply ploughs on regardless. A USB audio interface, by contrast, would transmit its data as an ‘isochronous transfer’. This offers no guarantees as to how long the process will take, but incorporates robust error correction that ensures any lost or corrupted data gets re-sent. Data sent to a USB hard drive, for instance, would be transmitted as a ‘bulk transfer’. Most connection types offer different transfer modes to reflect these different priorities. We need to maintain a continuous stream of data, and if that stream is interrupted, we can’t afford to wait around while the missing bits are tracked down. For sound recording, though, the mere ability to transfer large amounts of data isn’t enough. When we’re backing up to a hard drive, it’s not disastrous if things occasionally get held up: what really matters is that the data gets there intact in the end. With some types of computer peripheral, it’s more important to transfer data reliably than to transfer it continuously. However, this bandwidth can still be eroded if that connection is shared by multiple devices. Thankfully, those days are behind us, and all of the connectors you’re likely to find on a modern computer offer enough bandwidth for big multitrack recording projects. That was all right if you just wanted to record the odd vocal or guitar part, but not much use if you were tracking an entire band live on the studio floor. The original USB 1.1 specification, for instance, offered just enough bandwidth to send stereo 24-bit, 44.1kHz audio in both directions at once. The number of bits that can be sent over a connection every second is known as its bandwidth, and historically, not all types of connection had a bandwidth that was adequate for audio recording. It doesn’t know or care whether those bits add up to a photo of your kids, a chapter of your latest novel, or the best vocal take of your life. A microchip called a controller at either end of the link takes care of sending and receiving these ones and zeroes, but as far as the controller is concerned, all that matters is that a string of ones and zeroes has successfully been transmitted. This link is then used to transfer digital data: high and low voltages that represent binary digits or ‘bits’. In more or less common use today, you’ll find USB 2.0, 3.0 and 3.1 Thunderbolt 1, 2 and 3 Gigabit Ethernet PCIe… So what’s the difference, and which ones are best for audio recording? Bits And BandwidthĪt the most basic level, what all these connections do is to make an electrical link between the computer and the other device. We don’t live in an ideal world, so computers sport a wide range of different connectors. In an ideal world, there would perhaps be just one universal system for connecting all hardware. Standard protocols mean computer manufacturers don’t have to choose for you. Only you know what devices you might want to attach to your computer. We can use it to attach a printer, but we can also connect a graphics tablet, a soundcard, a games controller, an external hard drive or a novelty photo frame. Rather than develop a socket specially for printers, we create a standard socket that anything can connect to, as long as it speaks the right language. The solution is to come up with universal connection systems. If all of these different peripherals had their own different ways of connecting, no computer could work with all of them. So, where possible, they leave these choices up to the user. Manufacturers can’t predict how large a screen you might want, or what sort of keyboard you like, or whether you’ll want to add a graphics tablet, a scanner, or a high-performance audio interface. Out In The OpenĬomputers are designed to be expandable. What’s the difference between USB 3, USB-C, Thunderbolt and other standards, and which one is best for you? Here’s our guide through the maze of protocols and connectors. First of all, we look at the different ways interfaces can connect to computers.
USB 2 VS USB 3 AUDIO IMNTERFACES SERIES
But with so many on the market, how do you know which one is right for you? This series of Web articles explains some of the key aspects of interface design, giving you the information you need to make an informed choice. The audio interface might be the most important piece of kit in your entire studio.