From owner-freebsd-current@FreeBSD.ORG Tue Feb 24 18:31:06 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 20128106566C for ; Tue, 24 Feb 2009 18:31:06 +0000 (UTC) (envelope-from mav@FreeBSD.org) Received: from cmail.optima.ua (cmail.optima.ua [195.248.191.121]) by mx1.freebsd.org (Postfix) with ESMTP id 7754C8FC0C for ; Tue, 24 Feb 2009 18:31:05 +0000 (UTC) (envelope-from mav@FreeBSD.org) X-Spam-Flag: SKIP X-Spam-Yversion: Spamooborona-2.1.0 Received: from [212.86.226.226] (account mav@alkar.net HELO mavbook.mavhome.dp.ua) by cmail.optima.ua (CommuniGate Pro SMTP 5.2.9) with ESMTPSA id 235697990; Tue, 24 Feb 2009 20:31:04 +0200 Message-ID: <49A43CE5.5030701@FreeBSD.org> Date: Tue, 24 Feb 2009 20:31:01 +0200 From: Alexander Motin User-Agent: Thunderbird 2.0.0.19 (X11/20090118) MIME-Version: 1.0 To: Ben Kaduk References: <1235218982.00077642.1235207402@10.7.7.3> <499FFC5F.3020903@FreeBSD.org> <47d0403c0902210949i74473bc5j57c923e13c85e89@mail.gmail.com> <47d0403c0902240939h317c0454qfa2b5246f60d42d3@mail.gmail.com> In-Reply-To: <47d0403c0902240939h317c0454qfa2b5246f60d42d3@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: FreeBSD Current Subject: Re: Annoying whitenoise sound coming from snd_hda enabled chipset X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 24 Feb 2009 18:31:06 -0000 Ben Kaduk wrote: > On Sat, Feb 21, 2009 at 12:49 PM, Ben Kaduk wrote: >> On Sat, Feb 21, 2009 at 8:06 AM, Alexander Motin wrote: >>> Garrett Cooper wrote: >>>> I don't know how else to describe it, but when I turn up my >>>> speakers enough (50%+) and don't have any sound playing, I hear a >>>> whitenoise hiss coming out of them. When I change webpages (nvidia >>>> driver is GIANT locked) or do something else kernel intensive it stops >>>> for a brief second, but apart from that it's an annoying trill sound >>>> almost like a mosquito humming around me waiting to be swatted. >>> I think it may be radio interference with disconnected microphone inputs. >>> Try to set all unneeded mixer volumes to 0, especially mic, monitor, speaker >>> and mix. Inputs often have too sensitive 20-30dB pre-amplifiers. Some codecs >>> have them on all inputs. >> It's hard to be sure, since I'm not sure that I could describe what I >> hear any better than Garret did, but I think I'm seeing the same sort >> of thing on my work desktop. I'll try setting unneeded volumes to >> zero the next time I'm in, and see if that helps. >> >> dmesg and pciconf are available here: >> http://stuff.mit.edu/afs/sipb.mit.edu/user/kaduk/freebsd/periphrasis/ > > I'm still getting the noise, even with these mixer settings: > periphrasis# mixer > Mixer vol is currently set to 25:25 > Mixer pcm is currently set to 25:25 > Mixer speaker is currently set to 0:0 > Mixer mix is currently set to 0:0 > Mixer rec is currently set to 0:0 > Mixer monitor is currently set to 0:0 > Recording source: You have set vol and pcm to 25. They are measured not in percents now, there are a logarithmic scales inside codec, so, depending on model, 25 may mean something like -30dB, when you will be able to hear codec's native noise margin, which can quite high cheap codecs and cheap boards. Set your mixer to 80-100 and reduce volume on you speakers/amplifier. > Now that I'm actually listening to the noise, I'm not sure that it's > really something > I would describe as white noise --- the frequency distribution is only > on a fairly narrow > band of relatively high frequency. > Setting the mixer entirely to zero does not eliminate the noise. > Things like switching between workspaces in KDE or scrolling up and > down in firefox > using the scroll wheel cause the noise to disappear during those actions. CPU or other system activity may influences audio in many aspects, like power converters operation modes, CPU/bus/memory/whatever idle power management and other. The only recommendation here is not to buy cheap components. > I just now tested switching back to hw.snd.default_unit=0 and using > the headphone > jack on the back of the machine (soldered directly to the motherboard), and the > noise is still present, though slightly quieter than using the front > panel headphones > jack. Depending on configuration, driver could activate additional Headphones amplifier on your front connector. It's also usually does not increase quality. PS: The only way to completely avoid system noises is to get good external digitally-connected AV-receiver. snd_hda driver now supports SPDIF (and I hope HDMI) output and after I have implemented such output on my laptop (just soldered one more connector to the existing codec), I can say that this the best solution, at least for me. Expensive PCI sound cards, like Audugy2 or X-Fi could give comparable quality even via analog connectors, but until I anyway have good AV-receiver/amplifier, there is no reason for me to use analog connectivity. -- Alexander Motin