Check your machine for what it's capable of using ndash many have internal switches for different EQs.Ģ. AES is the only EQ setting for 30 ips whereas 15 or 7.5 ips can be run at AES or IEC EQ. Generally test tapes featuring AES/NAB EQ are desired, although there can be advantages to using IEC/CCIR EQ for recording ndash look for this in a future Tape Op article. Make sure the tape is the appropriate speed you plan to run your deck at and that (duh!) it is the right width (1/2", 2" etc.).
You can get around buying one if you happen to have a tape from a pro studio, or from school, which has test tones recorded on it at a known level, although these can sometimes be misleading ("what operating level?"). These tapes, frequently from Magnetic Reference Laboratories and known as MRLs, are fairly expensive. You will use this to set playback levels and EQ. This is a tape, which has been recorded at a known level of magnetism for at least three frequencies, 100 Hz, 1 kHz, and 10 kHz. Thus the tape deck uses a -6 dB per octave low-pass equalization to obtain flat frequency response.Īrmed with this knowledge, we are now ready to match the tape machine's electrical characteristics to the tape we wish to use for recording. On playback, magnetic tape exhibits a 6 dB per octave rise in output. Playback equalization must be applied to compensate for the nature of the medium. Its purpose is to compensate for the characteristics of the recorder and the tape. Recording equalization (set to AES/NAB or IEC/CCIR standards in most cases) is applied before our audio gets to the tape. In analog recording, a built-in EQ is applied at both ends of the process. We all understand the purposes of equalization. There is some low-level intermodulation distortion, however. in pro decks), it doesn't affect the audio being recorded too much. Since the bias frequency is way beyond our hearing range (100- 200 kHz. That shove is provided by high-frequency bias. The tape needs a bit of a shove to get it into the linear part of its transfer function. Well, if the tape's already been erased, you might wonder, why do we need more of the same signal fed to the record head? Turns out that magnetization is not a linear function. The bias oscillator in your analog tape machine serves two purposes: it erases the tape as it passes the erase head, and it provides recording bias, as a smaller amount is sent to the record head.
Keep in mind that this is just the tip of the iceberg - there's enough info and tips on this to fill a book - but don't be afraid to learn how to do this yourself - you need this knowledge! Here's how it works: Your recordings will sound better (than if you left it uncalibrated for years!) and you won't be afraid to try new tape formulations or work on tapes from other studios. If you're an engineer working with analog tape decks, you should know how to set decks up for different operating levels, bias for varying brands and formulations of tape, and how to calibrate your deck for a flat EQ response. Otherwise you can't select "RSE" on the head unit.Bias and equalization you've probably heard and used the terms for years, possibly without really understanding their effect on the quality of your recordings. If you have the rear DVD player, it's also easy to splice into those audio lines, but to use it requires the rear DVD player to be powered on.
My 2003 has an iSimple that provides the line-in, but it gets used more for bluetooth streaming and playing from the USB input.
That's how my 2005 is currently set up and it's easy to insert a cheap bluetooth adapter there as well. Then select XM on the head unit and it runs. Just splice into the audio wires between the satellite receiver and the head unit, using a switched audio jack (or something like RCAs and a toggle switch).
Later ones with XM radio are even easier. The tape deck has to send a message over the E&C bus to the head unit to switch over, but once it's playing from tape it doesn't notice the deck is gone (until the next time you start the car). I once set one up with a switch so when you switched to line-in it also cut the power to the tape deck (just to save wear on the tape deck and not have to hear it spinning). You may need to insert a tape to make the unit switch over, but you'll still get direct line-in sound from it. If you have factory tape deck, I think those ran analog audio, so all you have to do is wire in a switched 1/8" headphone jack, once you identify the correct wires.