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Recording Audio from FM Tuner

Discussion in 'Recording' started by Unregistered, Nov 26, 2012.

  1. Unregistered

    Unregistered Guest

    I'm working on a project that requires recording audio from an FM broadcast. I'm not using the station's stream because the quality is too low (64bit).
    I'm guessing the best way to record to my mac is to go into a sound card usb device, but am unsure if the portable sound card machines currently avail. now (ie. MOTU Microbook II, Focusrite Scarlett 2i2 etc) will accommodate rca inputs. It seems they will only take XLR.
    Can I go from XLR to RCA?

    Or would it be better to make the leap to the Sound Devices USB Pre2 which has on board rca 'in's (as well as a bunch of other goodies.).

    Any thoughts or ideas appreciated.
     
  2. Boswell

    Boswell Moderator Distinguished Member

    You would be OK with the Scarlett 2i2 or similar interface. Just use a pair of RCA-TS jack adaptors plugged into the XLR/TRS combo sockets and presto! you have RCA inputs. I assume you are thinking of using a dual RCA-RCA cable to take a stereo feed from the tape outputs of a domestic FM tuner.

    By the way, make sure you avoid the low-cost USB audio adaptor products that are mediocre quality and have no control of input level.
     
  3. RemyRAD

    RemyRAD Guest

    There's one other thing you have to do when you record FM broadcasts. The stereo pilot which carries the multiplexed stereo signal is around 19 kHz. FM broadcast cuts off at 15 kHz. This 19 kHz may get recorded? Some receivers have filters on them to filter this 19 kHz out. Not all do. And you don't want that in your recording. Either way, it will be in your recording and after your recording, you can apply a filter to cut off everything beyond 15 kHz. It'll still sound just fine. You won't lose anything, really. Because, you see, that 19 kHz, if you were to play that FM signal through a large PA system, that 19 kHz could heat up tweeters causing them to fail, i.e. blow up. Some receivers actually used to have a push button on the front to eliminate that 19 kHz at the outputs.

    WKTK 105.7 FM THE BALTIMORE ROCK STATION (overnight disc jockey 1976/77)
    Mx. Remy Ann David
     
  4. Unregistered

    Unregistered Guest

    Recording Audio from FM Tuner (Now need advice on my ZoomH4n)

    Thanks for these tips. I realized after some hunting around one Google that I can use my Zoom H4n as sound card DA/AD interface. Got myself some good quality cables (thanks for that tip), am plugged in and am rolling!

    BUT

    In the midi interface on my mac, I am only allowed the choice of 48kHz/16bit in/out put, despite the fact that the Zoom is capable of 24/96 recording. Any thoughts on that issue appreciated.

    Thanks for the advice about the 15/19kHz filtering!
     
  5. Boswell

    Boswell Moderator Distinguished Member

    Well done, but what you may not have found in your Google searching is that, when used as a real-time audio interface, the H4N is restricted to 2-channel 16-bit operation by the USB Class Components that it uses. That quality may be sufficient for your purposes, but the interfaces we were recommending earlier did not have these restrictions and could be used at 24bits up to at least 96KHz.
     

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