What -db of System hiss do YOU get?

Comments

Grazie wrote on 11/19/2011, 2:56 PM
Welcome to the horror that is mobo audio. On the mobo you have digital signals at 5V radiating noise over a wide spectrum of frequencies. On the same board you have unbalanced anaog signal lines that carry a signal of 1/1000 of a volt.

Well, Bob, thank you! That's clear enough. So there really isn't a point to isolating "other" devices if I'm stuck with the MoBo. Would this ALSO be the case for a separate Sound card?

Cheers Bob for the guidance. I'll stop banging my head against this particular brick wall.

- g

pwppch wrote on 11/19/2011, 3:10 PM
Have a look at this. Lots of myths busted.




Peter
farss wrote on 11/19/2011, 3:46 PM
"So there really isn't a point to isolating "other" devices if I'm stuck with the MoBo. Would this ALSO be the case for a separate Sound card?"

With separate sound boxes or cards you get or should get physical controls over your recording and playback levels. You can turn thing on and off either in the hardware or via the device control panel and drivers. You also gain the benefits of using ASIO and low latency.


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One thing to know, with Win7 MS changed how audio is handled. I don't know how much impact that has on this discussion but I've read a lot of people who are not happy about the loss of Direct Sound in Win7. From Wiki: "Because of the architectural changes in the redesigned audio stack, a direct path from DirectSound to the audio drivers does not exist".

Bob.


Grazie wrote on 11/19/2011, 3:53 PM
No Bob, I do understand about using separate BOXES, and maybe even a card.

So MS have done something to stop us getting at the Devices in the way we once were able to do.

- g

farss wrote on 11/19/2011, 4:27 PM
"So MS have done something to stop us getting at the Devices in the way we once were able to do"

So it would seem, searching the Win7 help I can find no reference to the old mixer panel that was available up until at least XP.

Bob.
Grazie wrote on 11/19/2011, 4:33 PM
I wonder if John Meyer is aware of this? I couldn't locate the devices he was advising I should Mute.

Cheers

- g

john_dennis wrote on 11/19/2011, 4:34 PM
I think I remember that you are using an ASUS P8-Z68 VPro motherboard. If so, the diagrams of the physical motherboard connections are on Page 2-2, 2-25 and 2-27 of the motherboard manual. There is a potential for a mic cable to run from the motherboard to the front panel. (I couldn't find a header for CD-ROM.) This would snake through the computer and probably should not be hooked up. You can use the mic (pink) connectior on the rear tailgate.

I can't speak to the default mixer in Windows 7 as my sound card manufacturer provides a mixer application to support their hardware. Sound options can be found in Start>Control Panel>Sound> Recording. Options for your hardware can be set there.
johnmeyer wrote on 11/19/2011, 5:18 PM
I wonder if John Meyer is aware of this? I couldn't locate the devices he was advising I should Mute.I seldom used Vista 64, but nonetheless upgraded to Win 7 -64 bit a week ago. So far I have found zero reason to boot to that drive, so I still normally use Win XP. In this ancient O/S, and in all other previous versions of Windows, there is a mixer control. This is the generic XP mixer:



As you can see, I have muted everything except WAV audio. You need to go to the Options->Properties and make sure that every device in your computer is enabled to be displayed in the mixer, and then mute them. I realize that this is showing the playback, and not the record settings for the device, but this is where I have found the crosstalk, hiss, and other gremlins can creep in.

Now while the problem you may be having in not being able to find the mixer may perhaps be a Windows 7 issue, it can also be related to what "sound card" is embedded on your motherboard. Lots of sound systems, including the ubiquitous sound chip sets sold by Creative Technology, get installed with a proprietary mixer control. While this should still be available via a systray control or from the Start --> Programs list, it may be true, as others have already suggested, that you'll need to go to the Audio settings in the Control panel to get to the full list of devices that are controlled by the mixer. I am quite certain that you still have a mixer control and that you can mute each individual device.

The dialog above is from my old laptop, and it has very few devices. My main computer has close to a dozen different devices shown, and you can have even more if you have capture cards.

Finally, I second Bob's advice about using an external box. That is clearly the way to get the best possible audio because you get all the analog stuff completely out of the hostile inside of the PC and into a nicely controlled environment. Once digitized externally, you shouldn't get any hiss or static, although having said that, I have actually come across digital problems, usually related to sampling, that introduce artifacts that sound a little like bad S/N analog hiss.

Chienworks wrote on 11/19/2011, 7:09 PM
"Actually, I am not sure whether it would even be possible to play an audio CD unless there IS a connection between the CD/DVD and the sound system. Since the audio on a red book CD is not in digital format, the device cannot simply transfer bits through the IDE or SATA cable.

I think you're a bit off on this. The data stored on an Audio CD is digital. It's in PCM format, which is basically a stream of the same data found in .wav files without the .wav header. This is much the same as how the signal on a DV videotape is a stream of the same DV data found in a DV .avi file without the .avi headers.

It's very possible to play an Audio CD in a a computer's drive without an analog audio cable. Any version of Media Player in the last 20 years will play Audio CDs and *none* of them use the Analog output of the drive. It reads the digital audio stream from the drive and feed it to the sound card the same as if it was playing a .wav file.

The analog cable was used primarily with older computers that weren't fast enough to do the digital transfer and feed the sound card and still have enough processor power left to run other programs. In these cases the CD-ROM drive handled all the playing functions itself just like a stand-alone CD player. I can remember many of the older drives having play/pause/ff/rew buttons on them in addition to the eject button. Some even had volume control knobs and headphone jacks. In this situation the only thing the sound card in the computer did was act as a power amp to feed the speakers. Somewhere around the introduction of the 16MHz 386 this whole kludge was no longer necessary. Computers could handle the digital transfer without impacting system performance. Drive manufacturers dropped the extra buttons to save costs. Lots of them are losing the analog connector as well.

Ripping is nothing more than copying the PCM data stream from the disc and wrapping it in a .wav file. As in the case of a DV capture, it's exactly the same as copying the DV stream from the tape and wrapping it in a .avi file. There's no analog->digital conversion going on.

There really is no such thing as an analog CD.
Chienworks wrote on 11/19/2011, 7:17 PM
With my recording signal maxed just below clipping, the SoundMax on the motherboard has about a -55dB noise floor. When i use my USB M-Audio Transit it's about -80.

I generally record a few seconds of the noise floor with no input signal to use as a noise reduction sample. I can generally get the SoundMax recordings' noise floor down to about -85 and the Transit recordings' noise floor down to about -95 this way with no noticeable affect on the signal.
LReavis wrote on 11/19/2011, 7:30 PM
Frankly, I'm shocked that some sophisticated Vegas users are utilizing the MOBO sound system for input, and more than a little surprised to learn that sometimes the S/N ratio might not be so bad. My experience always has been that the on-board sound system is just not usable.

Being pretty tight with a coin, instead of buying special equipment, I now simply am relying upon the camera with the best audio performance when used with my ancient wireless mic 2-channel system. Now that tape no longer is used in my cams, the digital file is easy to drag into Vegas. The old mic system itself has a pretty sorry S/N ratio, so I don't need cameras with outstanding audio performance - they are not the limiting factor for my audio.

The result is that I rarely get total hiss and noise lower than about -54 db on the Vegas VU meters. After setting the peak record level to around -6 db, that means a S/N ratio of about 48 db, which many would consider to be unacceptable.

But for my voice-over work, it's really not so bad, for I can use a noise gate that gets rid of all noise during intervals of silence between words, without making the voice sound in any way unnatural. True, the noise still is present when the voice is heard, but few seem to notice unless they know what to look for. So generally, I don't try to use very aggressive band-pass filters to get rid of the remaining hiss/digital noise, lest I damage the quality of the voice itself.

Shooting from a green screen, I also use a lot of Foley sound, such as low-level automobile traffic noise if I am representing shooting in an urban area, bird chirping/dog noises for other outdoor scenes, etc., that effectively mask even that noise-with-voice problem. Even when a scene is shown inside a room, room-noise Foley such as HVAC-system noise, kitchen appliances, etc., can go a long ways toward enhancing a sense of realism and masking the limitations of my audio - without in any way sounding out of context.

I skip the wireless mic for music and instead pull out a better quality wired mic (usually an ancient Sony dynamic mic that I bought back in the '60s) and run it into the camera which seems best matched to its impedance, etc.. This gives a better S/N ratio and generally better overall sound. If the music is continuous, you might get by with lesser quality audio, but for music that includes a wide dynamic range or includes silence as part of the creative effect, you really are limited on how much you can do if you don't record it properly. Don't try to make life convenient with wireless gadgets - just bite the bullet and do it right. A good, used dynamic mic should be sufficient in most cases.

My recommendation for other misers or those on a really tight budget is to buy at least one good used microphone for music, pair it with a cam that has a tolerably good audio section, and fix voice recordings in post, editing the sound accordingly - if your subject matter permits.

All in all, I really haven't felt the need for top-quality gear. But I'd certainly entertain offers of donations - should anyone be interested in pampering an old miser . . .
johnmeyer wrote on 11/19/2011, 8:16 PM
I think you're a bit off on this. The data stored on an Audio CD is digital. It's in PCM format, which is basically a stream of the same data found in .wav files without the .wav header. This is much the same as how the signal on a DV videotape is a stream of the same DV data found in a DV .avi file without the .avi headers.Yeah, I think you are right. I was remembering the issues with "ripping" CDs, where with early CD-ROM units, you often got really bad audio, and also often didn't get the same results twice. Somehow I was taking that fact and then jumping (wrongly) to the conclusion that the audio was stored in analog format, like (some) laserdiscs. I was wrong.
Grazie wrote on 11/19/2011, 10:38 PM
Well, LReavis, what would say if I told you that I've got the same 54db on my MoBo audio? That's the same you're getting with your "canny" camera recording workflow. As to you being shocked at, if you are referring to me, any sophistication I posses is a result of asking questions here and seeking assurances. I'd rather shock you than remain in the dark and not ask. And, BTW, "others" will be reading this and too might glean some knowledge. It's all good.... It's all good....

John Meyer, you're not having it, are you? I can't see where what you're asking for can be found. I was looking exactly for the same screenshot you kindly posted. In the past I've used that control when needing to isolate inputs/outputs. So I did and do respond to your guidance. But here, MS has not made this straightforward in Win7. I've priced the boxes Bob refers to and here in the UK I could get the 610 for £120 plus TXs. For my needs, for V/O, I may just stay with what I have and can accept.

Kelso, your approach is exactly where I've gotten to. Even to the recording of the input-free sample 54db (for me) to adjust SONY NR. It works well indeed.

My experience of this thread is that what I've got with my MoBo seems the status quo. That to trace/track down the offending noise is not that straightforward as it was with XP Pro. That Chienworks has a workflow that parallels what I've done and that to improve matters I could go to record to camera and drag a file onto the Timeline OR purchase kit that would isolate "words" from background hiss. And, again, that to understand this craft the easiest thing to do is ask questions here, and risk, momentarily look a fool, rather that, than remain a fool forever by not asking in the first place.

- g



Geoff_Wood wrote on 11/19/2011, 11:38 PM
You could get a half-decent soundcard - the analogue inout stage and to a lesser degree D-A stage is the only thing 'internal' that can add noise to your recording.

To use a crappy mobo soundcard is equivalent to shooting your HD video on a crappy webcam.

geoff
Geoff_Wood wrote on 11/19/2011, 11:42 PM
Mute unused sources on the soundacrd mixer applet.

geoff
Geoff_Wood wrote on 11/19/2011, 11:45 PM
If you have a CD-ROM attached to thye soundcard, disconnect it and instead tick the box that say "allow D digital playback' or siumilar. AVoid 2 superfluous (and probably crappy) D-A and A-D conversion stages.
ushere wrote on 11/19/2011, 11:46 PM
well grazie old boy, you just saved me a lot of typing ;-)

now, bearing in mind my hearing is fubar'd, and that my poor old missus has to sit through some awfully boring crap listening for things i might have missed (page turning, off camera asides, mobiles, etc., etc.,) WITHOUT even listening for hiss. hum, etc.,etc., my own experience has led me to;

a. getting the best sound into the camera in the first place with my HARDWIRED senny me66 or sony ecm 66. (i've stopped using wireless due to break through and other extraneous noise sources / interference.)

b. i bought a xlr to usb adaptor (micpro port - bob's recommendation) which gives me great vo direct to pc.

and, as yet, i've never had a complaint (other than boring content!) from any client regarding audio quality. in fact i've often had students asking me how i achieved such clean / clear audio.
Geoff_Wood wrote on 11/19/2011, 11:52 PM
No. It's usually just less direct, in an attempt to make it easy for noobs a al mac !!!?

Control Panel, Sound and Audio Devices is a good place to start looking.

geoff
Grazie wrote on 11/20/2011, 12:33 AM
Mute unused sources on the soundacrd mixer applet.And again, where's that to be found?


If you have a CD-ROM attached to thye soundcard, disconnect itAnd if the CD-ROM ISN'T attached to the SC? Read above.


So, how would I:-

. . . and instead tick the box that say "allow D digital playback' or siumilar. Not so straightforward here?

AVoid 2 superfluous (and probably crappy) D-A and A-D conversion stages.Which is evidenced by what? I have V/O using my Senni ME66 mic, hard wired to a Analogue preamp going into the MIC input on the pc. Seems straight enough? Don't forget, I AM talking about already existing 54db hiss - that's without any mic/amp plugged-in.

Control Panel, Sound and Audio Devices is a good place to start looking. Yup, did all that yesterday. I also reported that I had gone down that route here. But, Geoff, you think I've overlooked something? Well, give me more of a route map for Win7 Pro and I'll follow your lead.

Cheers

- g
Grazie wrote on 11/20/2011, 12:59 AM
And just so that you all can see what I am seeing:-

This PRIOR to opening Vegas - just 3 visible controls:-


And this AFTER opening up Vegas:-


Any the wiser? Anybody?

- g

farss wrote on 11/20/2011, 1:24 AM
"Any the wiser? Anybody?"

Looks to me like you don't have any other inputs to worry about.
That said plugging a mic into a mic preamp and plugging the output of that into the mic input isn't really such a grand idea however as you say the mic input to the mobo has a noise floor of -54dB with nothing plugged in so you are kind of stuck by that fact alone.

One thing I guess you could maybe do it to turn the gain up on your mic preamp so you're getting as close as possible to 0dB, that would improve your S/N ratio a tad.

Bob.
John_Cline wrote on 11/20/2011, 3:24 AM
If you're using a mic preamp which outputs line level (and technically, that's what a mic preamp does) then you should plug it into the line input, which always has a better signal to noise ratio than the sound card's mic preamp anyway.
Grazie wrote on 11/20/2011, 4:00 AM
John, yup, done both.

I've now got line-in to the rear of the pc and tested that against mic-in on the front.

I'm now crawling about, headphones on, moving cabling and switching a single lamp on and off to hear if there are any RF-emissions I can neutralise.

I'm getting to the point of recognising what my limits are, why they are there, and just getting on with the rest of my life. Like looking for ANY sweet spot, there will be any amount of compromise. Same in life huh?

Cheers

- g

john_dennis wrote on 11/20/2011, 5:32 AM
"I've now got line-in to the rear of the pc and tested that against "

See page 2-45 of your motherboard manual. If you can plug your mic into the front panel of the computer, then you do have a cable snaking through the computer that's attached to a hi-gain mic pre-amp in the sound adapter. This is not good and not neccessary. The pink mic jack can be accessed from the rear of the machine. The mic cable inside the machine could be acting like a noise antenna. You should get the internal cable off the header on the motherboard shown on page 2-27.