Need Help! CCT-Alaw Low-quality Recording Content

Discussion in 'Microphones (live or studio)' started by positivelyerik, Nov 23, 2010.

  1. Hey there,
    First time poster looking for suggestions.

    I'm recording some greeting messages for a call center. The call center is using old technology therefore the greeting messages have to be formatted as follows:

    CCITT - Alaw
    8-bit Mono

    The issue that I'm having is that when I do the original recording at standard broadcast quality and then convert it to this format it adds a lot of terrible static isn't clear enough. I would try recording at this format to begin with but my interface doesn't seem to be able to record at such a low file quality.

    Any suggestions of how to make these recordings sound good?
  2. RemyRAD

    RemyRAD Member

    Sep 26, 2005
    Nothing 8 bit is going to sound good. It just can't. Not sure what kind of software you're currently using? You might consider recording at full (16-bit, 44.1 kHz) quality and before you convert, use some brickwall filtering to reduce your high frequency response and create a cut off at approximately 4 kHz. Then downconvert because it's possible that no filtering is being done before the downconversion. Your static can be quantization distortion because the brickwall filtering was inadequate? Basically you're just trying to make clean telephone quality sound. So go ahead and brickwall low frequencies off at 250 Hz also. See if that doesn't help. But I know what 8-bit is going to sound like and it's not good. But if that's what they want that's what you need to give them. At least they're spending their money with you instead of purchasing a new better quality phone message box. And don't try to over optimize your levels as there is no headroom in the PHONE ZONE. So don't push it, buddy. (forget the tinkly music background on 8 bit)

    Your call is important to us so please stay on
    Mx. Remy Ann David
  3. Boswell

    Boswell Moderator Distinguished Member

    Apr 19, 2006
    Home Page:
    We had a thread about this sort of thing a couple of years back: try this.
  4. dvdhawk

    dvdhawk Well-Known Member

    Dec 18, 2008
    Western Pennsylvania, USA
    I just hope when you say 'call center' we're not talking about robo-call telemarketing 'greetings'.

  5. Hey!
    Thanks for the advice. I was already recording the original greetings at 16-bit 44,100; but you were right. The static was being added in the conversion process.

    I took your advise and added the suggested filtering before I did the conversion and the final result is much clearer. Thanks for the advise.

    In case you or anyone was curious, I'm told by them that this audio format; until recently was the standard for tele-communications.
  6. Lol. Nope! It's for the automated IVR greeting you get before you get to talk to a real person. It's for an insurance company; not telemarketing.

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