Reducing Audio Hiss in Captures

[JeromeERome]

I have a ATI AIW Radeon 7500 64MB that I use to capture with. I can capture the video perfectly through my S-Video input. I use AVI_IO with the Huffyuv codec capturing at 640x480. No problems with framedrops at all. My problem is the audio. I capture it at full 16 bit 48,000khz uncompressed PCM audio. Whenever I replay my files I have a significant amount of audio hiss. I am able to use Cool Edit to remove this afterwards but I am looking for a method to eliminate the need for that step. I am using the standard red and white rca jacks for my audio input. Is anyone else having this problem. What other methods can be used to solve this? My source is capturing from the digital satellite box so I know the input audio should be CD quality.

[BaronVlad]

It may help to set dowm audio to 44,1 cause your soundcard may have probs with 48

[Ookami]

also...

- try to change your recording quality (Win 9x MULTIMEDIA - AUDIO - Recording adv. properties)

- make sure your cables are OK

- possible but unlikely: try to change your soundcard driver or your capturing software

Cheers,

Mijo.

[droolian01]

Hi there.

Just a couple of points that may be obvious (but these are the sorts of errors which fox me for ages!)

- make sure you use the 'line in' not 'microphone in' jack on the soundcard

- are you sure the hiss is not there to start with? Try and connect your vhs video up with these inputs (video/scart red and white audio - you may need to buy an scart plug thing with jacks for video and audio) or connect to an amp somehow.

Good luck

[droolian01]

opps!

If your cables are poor quality(thin) and are very long you will lose quite a bit of signal strength at your sound card (due to resistance) which means that the card will try to amplify the signal up to acceptable levels and this can add noise. In this case use better (thicker=less resistance) cables.

[JeromeERome]

Thanks for the help. I tried a few other apps for capturing and also tried dropping the audio down to 44khz instead of 48khz. There was still hissing. (I cap at 48khz because I need to author these files to DVD and this removes the step of 44khz-48khz change) It must have something to do with the crappy quality of my audio cables. They are kind of thin and cheap. I will try using a higher quality cable like Monster Cable or something.

[Didée]

ATI AIW 7500 - What drivers ???

I had major audio problems when I started out with my AIW 8500DV - hissing, statics, - all captures have been CRAP.
All probs were caused by buggy drivers, and lenghty discussions were going on over at rage3d and others.
But ATI has fixed that for quite some time now. Be sure you use actual drivers!!

[JeromeERome]

Hey Didee, could you please explain further what you mean by "ATI has fixed that for quite some time now. Be sure to use actual drivers!!" Do you have any links or information you can share explaining how this issue has been fixed. I checked out the forums at Rage3d and the only REAL solution anyone came up with for eliminating the audio hiss problem was using a Turtle Beach sound card. I hate to spend $60 on a new sound card to fix this problem. The current sound card I have uses the C-Media chipset that seems to be causing all the trouble.

[Didée]

Hey JeromeERome, could you please provide a sample, so that we know what *exactly* your hissing sounds like ... ;)

Well, I meant exactly what I said.

For me, most pre-catalyst drivers caused audio problems - but there was a patch floating around, called "mono-patch" or something. Those days, I fiddled so much around, can´t remember every single key stroke I made - at least, my 8500D caused a couple of XP fresh-installs. At some point, I had everything up and running.
Since then, everything is stable - and up to now, I didn´t even get into installing the new Catalyst drivers (but I will, as soon as I [finally] may take my holidays!!!)

Could it be your incoming signal is too strong? Some people had success with an attenuator.

[Edit]
As far as sound cards are involved, my personal conclusion:
- Creative: Never, never again! (though I used one for a long time)
- C-Media: Uahahahaha - tried some of them, and kicked them all very quickly!
- Now I do own a Santa Cruz in fact - and I am a happy man, as long as we´re speaking of sound and capturing ...

[JeromeERome]

OK I cant provide a sample at the moment because I am on my PC at work. The hiss sounds like the same "white noise" that everyone else has described. I did upgrade to the new Catalyst drivers when they became available. This fixed the audio-synch problem I had prior to upgrading the drivers. However, it did nothing to resolve the hissing.

[aldonix]

I would suggest to follow the problem from start (sound source) to finish (youe PC).

Try to capture signal from reliably low-noise source like DVD player. Play some recent DVD using the same cables you used for you capture. If noise level is much lower, the problem - poor quality of your VHS tapes or you VCR. If noise is still the same, go downstream - replace cables. If it doesn't help, go after software, the last step - your soundcard.

Aldonix

[GSz9z9z9z]

I have a Radeon 8500DV and I sometimes get the same hiss in the background. I've noticed the hiss appears when setting the volume above 50% of max. For me, setting the Line In volume (ie. the volume controlled by the slider bar on the TV) below 50% (even below 40% just to be safe) eliminates the hiss. This means of course you'll have to turn up your speaker volume to compensate but at least there isn't any hissing.

I think the problem arises from the crappy tuner components used. Just as switching to FULL SCREEN resolution results in unsightly blocks being visible, turning the volume up too high results in annonying backgroup noise made audible.

[waldok]

Hi,

I get some audio problems too with my AIW 128 Pro. It is not really hiss, but the sound captured sounds like some "distortion" was added, kind of "heavy-metal guitar effect" , like the input volume was too loud, which isn't the case. (I also have long thin cheap cables to connect my satellite receiver output to the analog input of my AIW, have to try better ones). Even when I set the line in volume to less than 40%, the "distortion " effect is still there, but a a lower volume.

So I'm really interested too in finding solutions on this kind of issue...

Waldok

[Swan]

@waldok
I had the exact same problem as you. Audio from the sat. receiver sounded distorted (like it was over-modulated) and changing the level on the Line-In audio volume in Windows did not help. I had the problem on some, but not all stations. The solution was to lower the outgoing audio volume *on the sat receiver*. Check if you can do that on your sat. receiver.

/Swan

[JeromeERome]

Just curious for all you guys having audio problems what kind of sound cards you are using. After I got my new Turtle Beach Santa Cruz card I have had no more problems at all. The audio is as perfect as the original source. Apparently from what I read over at the Rage3d site the problem with most cheap sound cards is that they don't support FULL duplex. This means there is not a seperate dedicated chip for recording audio and for playing audio. Most low end sound cards try to do these tasks with one chip and the results are often less than favorable. I can't say that this is the only solution to the problem but it is the only one that worked for me.

[waldok]

Well I have a SB Live 1024 card. I've been going through all sorts of problems with the association "SB LIve + ATI AIW 128 Pro", the latest being the famous PCI bus latency problem that caused crackles in every video capture (now solved thanks to a great latency patch from a guy named George I found ...somewhere... can't remember now, but if you're interested, I'll check for it).

For now, I don't really want to move to Turtle Beach (too expensive) and the only prob I have left is this "over-modulated" (thanks Swan for the appropriate words) sound problem on SAT receiver captures. And my sat receiver volume control doesn't affect the SCART output it seems, so no way to lower incoming volume on card input (I use audio from the Sat receiver scart output since RCAs are plugged into my home cinema receiver).

Anyway, let's agree on something : if someone here finds any possible solution to those sound problems, let's tell everybody else and have a beer or two :D

I don't have any idea for the moment.

Waldok (still :cool: )

[Swan]

I have a Creative Audigy Platinum, but I've not experienced any problems with it (in regards to capturing audio).

@waldok
Please, tell me more about the PCI Latency Patch. I saw it mentioned in regards to the "lines" that may occur when capturing and having a mobo with a Via chipset. What does it do? Is it safe to use since it's not endorsed by Via?

/Swan

[waldok]

@Swan

This great utility has been installed on my PC for a few months now without any single problem. It really solved my problem regarding audio crackles during capture. The patch comes with an install, so you can uninstall it anytime just like a regular application. It is absolutely reliable if you ask me.

Have a look here for the author's page :
http://www.networking.tzo.com/net/software/

Don't know about this solving your lines problem, though. I think it's worth a try, you can just uninstall it if it's of no use.
(By the way there are other nice utilities to try there if you are into optimizing every single bit of your computer for speed)

Good luck.

Waldok :cool:

[Didée]

Another thing

Times ago, when I got tired of audio problems, I tried the following:

With my AIW 8500DV, the recommended (LOL) audio connection is:

AudioInput -> GraphicCard/BreakoutBox -> SoundCard/LineIn

Driving into the sound card *directly* solved all of my problems regarding degraded audio quality :)

(I'm not sure about how this is handled by the 7500)

Additionally, I had [banging-my-head-against-wall] synching problems. Kind of "repeated audio buffers", which were parts of always 0.37 seconds that were "repeatedpeated", about 2-10 times per hour. Can you imagine the hassle going through the complete audio in 5-seconds-steps + spectral view in CoolEdit, just to search for those glitches and edit them out? Man, I was going crazy!

I tried several audio cards, and all showed the same problem!

In the end, it went away with ... a Santa Cruz ;)

[Latency patch was always running & PCI slot didn't share anything, not even the interrupt line -> a little adventure /w my ABIT KR133A-RAID]