Volume too low + echo in *

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Hello,

I’m having the following problem when using a headset on XP
connected to an on-board Realtek soundcard on an AsusTek M2N68-AM Plus
motherboard:

– Using any sound recorder (Windows’, Audacity, XLite), the level is
just too low when speaking at a conversational level, even with the
microphone level pumped all the way up (line displayed totally flat in
Recorder)
http://img704.imageshack.us/img704/7981/headsetlowvolumeecho.jpg

– In addition, when making a call with XLite and Asterisk, I get a bit
of echo

– Same issues when trying with a different headset

– Enabling “Auto gain control AGC” in XLite makes no difference.

Any idea what can be done? Should I use a different soundcard?
Amplified headset? Can something be done in Asterisk about the echo?

Thank you.

2 thoughts on - Volume too low + echo in *

  • Same headset model, or different headset model?

    Most computer mic inputs these days, are designed to work with
    mics and headsets using electret microphone elements. These
    microphone elements normally have a built-in FET buffer/amplifier,
    and have a respectably high audio output level. The FET amplifier
    requires some DC power to operate; this is normally provided by
    the sound card, as a resistor-coupled DC voltage applied to the
    mic input pin inside the jack (it’s usually in the 3-9 volt range).

    Some headsets use “dynamic” (electromagnetic) microphones…
    essentially little loudspeakers operated in reverse. These do not
    require DC power from the sound card to operate, but they have a
    significantly lower audio output level. They do require
    amplification in order to drive an input designed for electret
    microphones.

    Some sound cards have mic inputs which are switchable… the
    DC power feature can be enabled or disabled, and there’s a
    “gain boost” setting which switches in a preamplifier stage
    (often around 10-20 dB) for use with a dynamic mic.

    You may be attempting to use a headset with a dynamic mic,
    with a sound card whose mic input was intended only for use with
    electret mics and doesn’t have a preamplifier. If this is the
    case, switching to a headset with an electret mic and its built-in
    FET buffer-amp would probably be your easiest solution. If that’s
    what you mean when you refer to an “amplified headset”, then yes,
    that’s probably what you should do. You wouldn’t need a headset
    with a separate amplifier-box… the FET amplifier is usually
    build right into the microphone element.

    It’s also possible you have a bad PC sound interface… try
    using a different PC with the same headset(s) and see if the
    problem persists.

    You can probably buy or build a preamp for your existing headset
    (I recently built one for a similar purpose) but considering
    how inexpensive “A/V” comm/gaming headsets are these days
    it’s certainly cheaper to buy one.

    Another option would be to buy a USB-connected headset…
    these have all of the necessary gain electronics in them,
    as well as a “USB sound card” chip. There’s only one plug
    to plug in, and (once the necessary USB sound drivers are
    installed) you could be confident of having the same sound
    level and quality on any PC into which you plug it.

    How quickly after you speak, do you hear the echo? Is it
    near-instantaneous, or significantly delayed? What’s your
    outgoing voice connection (SIP, IAX, or an actual hardwired
    phone line with some sort of terminal adapter)?

    Does the caller at the far end hear an echo from what s/he
    says? Or does the echo affect only you?

  • On Tue, 07 Dec 2010 10:39:44 -0800, Dave Platt
    wrote:

    Different brand/model, but similar as they are both el cheapo,
    entry-level headsets. I tried using them on a laptop, and I get
    marginally better microphone output, even with its volume cranked all
    the way up + automatic gain control enabled.

    I guess those on-board soundcards by Realtek aren’t as good as a
    quality microphones. I’ll get a USB headset instead and see how it
    goes.

    Right after the connexion is made between the PC with the headset and
    a Siemens IP phone located on the same LAN. Both are using SIP. It’s
    light, but a bit noticeable. I’ll try again with a USB headset and see
    if it goes away.

    I noticed, something, though: While I only kept G11u on both the XLite
    and Siemens, I noticed that sound coming from the Siemens contains
    some reverb when running Asterisk (1.4.4) on an Atcom appliance
    (www.atcom.cn/IP01.html), while the reverb is gone when running
    Asterisk (1.6.2.5) on a regular PC with Ubuntu. I guess codecs sound a
    bit different depending on what hardware they’re running on.

    Thanks much for the education 🙂