Fix low volume audio overpowered by hissing?

[koberulz]

Halp?

I tried attaching a sample but I kept getting "connection reset" errors so here's a Dropbox link for now:

https://www.dropbox.com/s/5b8nzcxg2i...ample.wav?dl=0

[lordsmurf]

More info needed. VCR, capture card, software, etc.

Without even listening to the sample, description only, the most common issue is the tape hates the VCR. JVC S-VHS decks can have problems with badly recorded mono audio, a bit more than Panasonic AG1980/etc decks. But it's not always the case. The audio is muffled, hiss is amplified.

Mono doesn't have to be muffled. Clear mono is possible. But the recording VCR/camera is usually what harms it, not playback. But not always.

This is why having multiple high-end decks is helpful (Panasonic+JVC).

[koberulz]

But this is the restoration forum, not the capturing forum. I already have a thread there about not being able to get the HiFi track to work and the mono being awful.

I had one other tape like this, but it magically fixed itself. Not sure what if anything I did, but the mono ended up playing just fine eventually.

I got the same result in my Philips VR 1000 and my Panasonic NV-HS1000.

I tried Goldwave but it obliterates the actual audio without removing much of the hiss.

[lordsmurf]

Alright, got it, so this is what you have to work with. Well, at least now you (probably) know why it happened.

So on to the restoring...

- Goldwave is rough and powerful. Often too powerful. Like a really good axe. But you seemingly need a scalpel here.
- Audacity is decent, but often weaker, can add artifacts, and more involved.
I've not had either installed on my systems in years. I'm 99% using just Sound Forge these days. I use to do easier/cheat methods with a combo of Audacity and Goldwave and Sound Forge, but have since further honed my Sound Forge skills. And I'm still using version 9, no reason to upgrade, using Win7 as main video edit/restore/encode system.

BTW, such as small sample clip, 28mb, could have been uploaded to the thread. Site has 99mb max these days for attachments. Downloading now...

Ouch. There's no way to enjoyably restore that audio. Forensically, sure. Enjoyably, no. The audio is too low, and the hiss overpowers it.

I have another idea. The tapes is bad, VCR was fine. The recorded alignment path may be off. You can "break"/misalign a deck to match it. Since just audio, use a cheap deck.

[koberulz]

Quote:

Originally Posted by lordsmurf

BTW, such as small sample clip, 28mb, could have been uploaded to the thread. Site has 99mb max these days for attachments. Downloading now...

As I said, I tried that but I kept getting "connection reset" errors from the browser.

Quote:

I have another idea. The tapes is bad, VCR was fine. The recorded alignment path may be off. You can "break"/misalign a deck to match it. Since just audio, use a cheap deck.

I have no idea what this means.

Audacity just completely obliterated everything when I tried it, and I ended up with total silence. At least with Goldwave I got a horribly tinny hiss-filled mess that vaguely resembled sound.

[dpalomaki]

What can you tell us about the recording; e.g., how it was made, what gear was used, and what the content is? I tried a quick noise reduction in Audition, also garbage, but a hint that it may have been recorded at a venue with loud music in the back ground.

[latreche34]

Since you said the tapes magically started to work I'm guessing your VCR audio head is filthy and need cleaning.

[koberulz]

What?

This tape has never worked, only one other tape has ever been a problem, and it was only a problem once. I played it in a couple of different machines and it came good.

[latreche34]

Quote:

Originally Posted by koberulz

What?

This tape has never worked, only one other tape has ever been a problem, and it was only a problem once. I played it in a couple of different machines and it came good.

The VCR either plays the audio or it doesn't, It is not usual for a VCR to playback good sometimes and not playback good other times, If you are getting inconsistent results, clean the VCR/VCR's repair them or get a different VCR.

[dpalomaki]

From your other thread:

Quote:

It seems to have been provided to a sports club by the network broadcasting the game.

Read more: http://www.digitalfaq.com/forum/video-capture/10905-vhs-hifi-track.html#ixzz6VqlHl5hJ

Some speculation:

So the tape is a copy from a "broadcast professional" source, and as VHS it would not likely have been their original recording format. The machine used to make the VHS copy may also have been well worn/abused up over time, perhaps dirty or work HiFi heads or disconnected linear heads. Alternatively, professional/industrial VHS machines, like the AG-1980, allow the linear track to have a separate audio feed (or time code or over dub) and not contain a mono version of the HiFI track, depending on the recorder's configuration at the time.

This tape apparently has a weak HiFi signal on it, and a linear track that is not a valid mono version of what was on the HiFi tracks Either no audio, or phase cancellation caused by mixed reversed-phase mono left and right channels.

The linear audio track is generally low tech linear tape recording so if even if the heads were substantially misaligned you should hear something even if very poor fidelity. After all, the same head also provides the tracking signal, so gross misalignment would typically mean no tracking signal either.

Your best bet may be to try find a VCR that can read the weak HiFi track.

[hodgey]

Given the source it's also possible it was recorded on a broadcast VCR with linear stereo, if it's some phase cancellation issue or only one of the linear tracks were recorded to (Some of the Broadcast VHS decks linear stereo where one channel was often used for time code or similar.) maybe it would work better in a VCR with linear stereo, but I guess that may be a long shot.

Normally the mono audio head in most machines would pick up both linear stereo tracks, not really sure if only one stereo track having audio on it could result in lower audio or other issues in a normal VCR.

[dpalomaki]

The stereo linear tracks recorded width was not as wide as mono, but still offered mono playback compatibility. There would be a somewhat lower output, perhaps 6 dB or so, and phase cancellation could apply if the left and right were phase-reversed.

Some folks using a single balanced output external mic with consumer camcorders faced this issue. They elected to use a simple XLR-to-Stereo mini plug adapter that feed the mic's + pin to the tip and the - pin to the ring and connected that to the external stereo mic jack on the camcorder. This resulted in phase reversed but nearly identical signals recorded on the right and left channels. Played on a stereo system the sound was OK (with perhaps a sound image but both channels were heard.)

When copied to a typical stereo VHS VCR the HiFI tracks were similarly usable, but the linear track, being a just a sum of the left and right channels) had phase cancellation and thus near zero usable output. (However the linear track noise floor was about normal.)

[koberulz]

Quote:

Originally Posted by dpalomaki

From your other thread:



Some speculation:

So the tape is a copy from a "broadcast professional" source, and as VHS it would not likely have been their original recording format. The machine used to make the VHS copy may also have been well worn/abused up over time, perhaps dirty or work HiFi heads or disconnected linear heads. Alternatively, professional/industrial VHS machines, like the AG-1980, allow the linear track to have a separate audio feed (or time code or over dub) and not contain a mono version of the HiFI track, depending on the recorder's configuration at the time.

This tape apparently has a weak HiFi signal on it, and a linear track that is not a valid mono version of what was on the HiFi tracks Either no audio, or phase cancellation caused by mixed reversed-phase mono left and right channels.

The linear audio track is generally low tech linear tape recording so if even if the heads were substantially misaligned you should hear something even if very poor fidelity. After all, the same head also provides the tracking signal, so gross misalignment would typically mean no tracking signal either.

Your best bet may be to try find a VCR that can read the weak HiFi track.

The linear track isn't silent, just incredibly quiet.

[dpalomaki]

FWIW: The linear track will never be silent, unless you have a noise gate in the system. The noise floor (tape hiss, system noise, and hum) will probably be around 40 dB below full record level even if nothing is recorded on the linear track. (Dolby or other audio noise reduction could drive it lower.)

If there is left-right channel phase cancellation it will not likely be complete due to minor differences in channel gain. A 1 dB difference in channel gain could result in a roughly -20 dB residual signal being recorded. A 0.1 dB difference could put it around the noise floor.

But that doesn't recover the audio for you. Is there any chance the station/network kept an archive copy of the original tale?

[koberulz]

This is the only tape I have access to.

[dpalomaki]

If this is a recording from the press box of a game, the sound may be largely crowd noise with some narration of the action.

Does the team have a copy of the recording?

What to do at this point depends on your ultimate objective/goal in this project, how much time and effort you are willing to spend on it.

For example, sound is essential for ambience and explanation of key events in the video. But detail such as "Smith heads the ball to Jones who passes to Peters" might not be for your purposes. If detailed accuracy is not, an approach would be to do as in the movie "Bull Durum" (a USA baseball movie) and in post mix in crowd noise with some voice over based on the action on the screen plus information from news reports and box scores of the game. For this you will need to create an audio script and arrange for some voice acting or maybe do it yourself. (You may be able to rip sound from other games for authentic crowd noise ebb and flow being careful not to include narration that does not fit your video.. And maybe add AM broadcast-like noise/static to help sell the new sound and mask transitions/cuts on the audio.)

Good luck with the project.

[koberulz]

I'm just trying to get the best possible digital version of what's on the tape.

So does anyone have any ideas, or more detail on the "break a VCR to match the tape" thing?

[dpalomaki]

"breaking" is something you do as a last resort and only if you have the necessary technical skills and equipment to restore the VCR (if it is worth anything).

If the video plays is OK, breaking the tape path alignment will not recover the HiFi track because it was fixed when recorded. The HiFi heads are on the spinning drum with the video heads - it is a fixed position and they share the same alignment.

Breaking the linear tape path alignment by adjusting the vertical position of the head might recover some audio, but only if vertical head alignment was the problem with the original recording, or if it was a (rare) stereo linear track with left and right channel recorded out of phase. I would initially try this on a throw-away cheap VHS VCR that still works for linear audio only output. To net essentially no linear audio output from a mono liner track it would have to have been about a linear track width out of alignment (about 1 mm, or about 0.5mm if an out of phase stereo linear track). A lot considering the tape is only 12.65 mm wide.

If you are not technically inclined I suggest you consider finding a video recovery service in your area that might be able to salvage the audio for you.

[koberulz]

I have three good VCRs, and a shitty hand-me-down that was stuck in a cupboard once I started taking this project seriously. So the hand-me-down is fine to trash, really.

FWIW when the HiFi does pop in, it's left channel only.

-- merged --

Tried capturing with the HiFi enabled to see how much of it got used, hoping it came good most of the time later in the tape. No dice. If I open that in Audition, I get this:
Screenshot 2020-09-02 01.08.32.jpg

[lordsmurf]

Quote:

Originally Posted by dpalomaki

If you are not technically inclined I suggest you consider finding a video recovery service in your area that might be able to salvage the audio for you.

My problem with this advice is that I'm not sure what they'd do any different than what we're doing here.