|
|||||||||
|
Powered by SFEBanner Review of the iMic USB Audio Interface
by Greg EpleyApril 25, 2004 First revision, August 2005 What is the iMic?The iMic USB Audio Adapter from Griffin Technology is a small, lightweight device that connects to a single USB port on most Windows PC or Macintosh computers. It provides one stereo line output and a switchable stereo microphone or line input.For more information on Griffin Technology and the iMic, see below for Company Info. Test Bed
Important Info for Blind or Visually Impaired UsersBefore we continue, let me first mention a few important items. The iMic unit itself is a small, flat, disc shaped unit approximately two and a half inches in diameter and just over three quarters of an inch in thickness. It has an 18 inch cable extending from one edge of the disc terminating in a standard USB male connector. The opposite edge of the disc contains two standard one eighth inch, 3.5mm audio mini jacks, one for input and one for output. These jacks are the same type commonly found on many stereos and portable audio devices. Between the two audio jacks lies a small slide switch that determines if the audio input jack functions as line input or microphone input.On both the top and bottom surfaces of the disc, just above and below each of the audio jacks, are small tactile icons. A tactile microphone icon appears above and below the audio input jack, and a tactile speaker icon appears above and below the audio output jack. I found it easier to locate the microphone icon for orientation, as it feels like a small pill capsule shape resembling an old style microphone. Think "Opposites" with the Audio Input JackSo how does one tell if the audio input is set for microphone or line input? You need to think in opposites, or rather think of it as which source you want to disable. Don't ask me why they did it that way but they did. So, to use the audio input jack as a microphone input, slide the switch toward the speaker icon - in other words, you're disabling the line input. To use the audio input jack as a line input, slide the switch towards the microphone icon - in other words, you're disabling the microphone input. This takes some getting used to and is backwards from the way you'd think, but this minor annoyance is just that - minor. Always remember to note the positions of the two tactile icons in relation to the position of the slide switch, and slide the switch away from the icon that represents the input you want to use rather than toward it. Also remember to check this carefully if you know you have everything set up right but can't seem to record, that slide switch may be in the wrong position.Testing the microphone inputOne thing I tried unsuccessfully to confirm prior to purchasing the iMic concerns the microphone input. Some sources claimed the microphone input was true stereo, others didn't specify enough, giving one the impression that the microphone input was monoral.Griffin Technology technical support said the input jack was stereo, but neglected to confirm beyond any doubt that the microphone input itself was stereo. After all, in electronics, that slide switch could have changed the stereo input jack into a monoral microphone signal for all I knew. What's so special about a stereo microphone or line input? First, most notebook computers don't have any line input jack - they only offer a monoral microphone input. Second, while most desktop computers do have a stereo line input, they, like their notebook cousins, have a monoral microphone input. This presents a major problem if you're wanting to record something in stereo on most notebook computers, or if your particular recording situation forces you to use a microphone level output signal, as microphone level output signals should be recorded to a microphone level input for best results. Now, as one of my primary reasons for purchasing the iMic was to gain a stereo microphone input, I was eager to test this first. Fortunately, I had a special stereo recording where a narrator mentioned the specific left or right ear the sample audio was supposed to play from. So, I used that recording as test material to determine how the microphone input worked. If the test material maintained the stereo seperation when recording from the microphone input on the iMic, then the microphone input had to be stereo, otherwise the stereo seperation would be lost and the microphone input on the iMic would be monoral. One of the first things I noticed when connecting the iMic to a computer is that it worked best for me to plug the iMic into the USB port after the computer was booted up. The most likely cause of this is that the computer recognizes the iMic during bootup and thinks that I want to use it for both input and output, so the external speakers on a desktop or the internal speakers on a notebook have a tendency to produce no sound if the iMic is attached prior to powering up the computer. This is just something to consider on your system, and is by no means required in order to use the iMic. In fact, there is no reason that both the input and output jacks on the iMic can't be used at the same time, assuming your recording software is using audio devices properly on your system. The behavior I noted should be individually tested on your system, not taken as a constant. Otherwise, installation of the iMic is as simple as plugging it into an available USB port on Windows XP systems. The iMic appears to work on both USB 1 and 2 ports, though it doesn't realize any performance advantage on USB 2 ports, as USB 1 is perfectly capable of doing the job. There are various ways to connect the iMic to your audio devices depending on your needs, so I'll leave that part up to you. Griffin Technology has some information on their iMic support page that you may find helpful in this regard. With the slide switch on the iMic set towards the speaker icon, which causes the audio input jack on the iMic to function as a microphone input, I recorded a small sample of the test material into Total Recorder. Upon listening to the recorded sample, I found that the sample audio retained the stereo seperation. I repeated the same test with everything hooked up using the line input and obtained the same results. Conclusion: the audio input jack on the iMic retains a true stereo signal in both the microphone and line slide switch positions. ConclusionSince most computers don't come with a stereo microphone input, and many also don't come with any line input, or a true stereo line input, the iMic is a worthwhile purchase for anyone who needs quality audio recording capabilities on the go. Of course there's no reason that desktop users can't use the iMic. Depending on your sound card and the software used to record, the iMic could serve as an additional input and output source to record in more complex situations.Griffin Technology doesn't release any precise technical audio specifications for the iMic due to its low, under $40 price. Most commonly found commercial audio software doesn't provide audio sampling beyond 16 bits, but the iMic supports up to 24 bits with the right software. However, unless you're extremely demanding you likely won't need anything beyond the standard 16 bits offerred by most computer sound cards. It's important to note that the iMic is not a sound card. It's a high quality audio interface that's isolated from the usual electrical interference you've probably encountered with your sound card's audio inputs and outputs. The iMic is portable and easy to move from one computer to another, offers stereo input on both the microphone and line input and allows the use of its input and output jacks at the same time. The street price runs anywhere from $35 to $40 and the iMic comes with a one year warranty. No drivers are required on Windows XP, just plug it in and go. Once you have your own iMic, you'll need to supply three things:
So what are you waiting for? If you record audio with your computer, or would like to, or want to record more complex audio on your desktop computer, the iMic is a high quality, low cost solution to the problem. Company InfoGriffin Technologyhttp://www.griffintechnology.com System requirementsThis information is from the iMic technical specs page on the Griffin Technology web site and is current as of August 2005. This information is subject to change at any time and the most current information should be consulted on the product manufacturers' web site prior to purchase. Neither the author, Thinkzo Systems or any of its affiliations are responsible for any errors or omissions.
Physical specifications
|
|||||||||
|
Copyright (c) 2002-2008, Thinkzo Systems |
