Re: [asterisk-users] [headset/mic] Volume too low + echo in * (Gilles)
On Wed, 08 Dec 2010 10:48:06 -0800, Dave Platt dpl...@radagast.org wrote: It does sound as if the mic-input gain is too low for those headsets. Disabling the on-board soundcard and using even an entr-level PCI soundcard solved the issue. If some customers complain about low sound when using the on-board soundcard, I'll tell them to try a real soundcard or a USB headset. I'm curious, though, about what settings, if any, are available in Asterisk to manage sound. Does someone know of a good article on the subject by any chance? Thank you. -- _ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- New to Asterisk? Join us for a live introductory webinar every Thurs: http://www.asterisk.org/hello asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] [headset/mic] Volume too low + echo in *
On Tue, 07 Dec 2010 10:39:44 -0800, Dave Platt dpl...@radagast.org wrote: Same headset model, or different headset model? 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. How quickly after you speak, do you hear the echo? Is it near-instantaneous, or significantly delayed? 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 :-) -- _ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- New to Asterisk? Join us for a live introductory webinar every Thurs: http://www.asterisk.org/hello asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] [headset/mic] Volume too low + echo in * (Gilles)
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. It does sound as if the mic-input gain is too low for those headsets. 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. Hmmm. The traditional cause of echo on analog phone lines is the presence of impedance mismatches... the electrical signal reflects when it hits a point where the impedance of the transmission line changes, and returns to the origin (where it is heard as an echo). This situation really shouldn't exist at all, in the digital stages of transmission (i.e. between the SIP endpoints). The causes would have to lie elsewhere. One source of echo I've observed on SIP calls in the past is purely acoustic... cheap handsets/headsets. It's possible for acoustic feedback to occur within such a device... the microphone picks up a fraction of the sound being generated by the speaker/earpiece, and is transmitted back towards the point of origin. I had this problem with a cheap little USB handset I use here at work... its case is mostly hollow, and channeled sound from the speaker to the mic. When I called my wife and home she complained of hearing her voice echoing. I opened the handset, stuffed the open areas with cotton wadding, and added a few small pieces of left-over car-door-damping sticky-sheet to the inside of the case. Problem gone - no more echo. So, once again, you may be having a headset/handset-related problem! 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. That's odd... the U-law codec is about as simple and deterministic as it gets, and really shouldn't have an effect on any echo behavior. Is it possible that silence detection settings were different in these cases? If a phone endpoint was configured to detect silence and stop sending RTP audio packets, it could have the side effect of suppressing low-level acoustic echo occurring within the phone handset/headset, since the level of this would fall below the silence-detection threshold. Thanks much for the education :-) Quite welcome! -- _ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- New to Asterisk? Join us for a live introductory webinar every Thurs: http://www.asterisk.org/hello asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] [headset/mic] Volume too low + echo in * (Gilles)
On Wed, 08 Dec 2010 10:48:06 -0800, Dave Platt dpl...@radagast.org wrote: (snip) I'll read up more about sound quality and Asterisk and see if something can be done about this. Thanks again for the help. -- _ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- New to Asterisk? Join us for a live introductory webinar every Thurs: http://www.asterisk.org/hello asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
[asterisk-users] [headset/mic] Volume too low + echo in *
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. -- _ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- New to Asterisk? Join us for a live introductory webinar every Thurs: http://www.asterisk.org/hello asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
Re: [asterisk-users] [headset/mic] Volume too low + echo in *
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 Same headset model, or different headset model? - Enabling Auto gain control AGC in XLite makes no difference. Any idea what can be done? Should I use a different soundcard? Amplified headset? 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. Can something be done in Asterisk about the echo? 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? -- _ -- Bandwidth and Colocation Provided by http://www.api-digital.com -- New to Asterisk? Join us for a live introductory webinar every Thurs: http://www.asterisk.org/hello asterisk-users mailing list To UNSUBSCRIBE or update options visit: http://lists.digium.com/mailman/listinfo/asterisk-users
