Bad audio with Sony cameras?

Al Min wrote on 12/5/2008, 11:08 AM
Please excuse me if I have posted in the wrong forum. I have a Sony T500 and a Sony HDR TG1 camera. When I record with them and download into Vegas Pro 8, there is a certain amount of background hiss with both cameras. I was expecting digital quality i.e. no noise at all. I can live with it and my Cinescore music masks it. I was just wondering if this is normal or is there a setting I can change.

Comments

newhope wrote on 12/5/2008, 2:38 PM
Hiss is generally caused during recording by the recording equipment if it is part of the recorded signal. It can also be a problem in the replay chain of the computer but, if so, would probably be noticed with other material.

How are you importing your files into Vegas? As both are tapeless cameras are you using any intermediate software to get the video/audio from the cameras before Vegas or are you importing directly from the camera to Vegas.

I don't have any first hand experience with your cameras but I can certainly verify that Vegas doesn't normally induce hiss into the signal so I'd be looking at your cameras as the source of the problem.

Can I recommend you fill out your system specs as it helps to know what equipment you are using when offering advice on the forum.

New Hope Media
Al Min wrote on 12/5/2008, 7:51 PM
Hi NewHope. I'm importing the files by downloading to a folder, then into Vegas. The HDR TG1 is AVCHD and comes with software to use. The T500 downloads directly as Mpeg4 files. I ran the files via HDMI cable into my TV and didn't notice any hiss then. So it must be in the transfer. I wonder what I can do?
newhope wrote on 12/6/2008, 12:35 AM
You don't need to use the software that came with the camera to import the files off the HDR TG1.
You can do this directly in Veags Pro 8.0c by using the File/Import/AVC Camcorder function.

This allows you to directly import off the camera without the need to use secondary software, though I don't think that s the source of your hiss.

Hiss is usually indicative of system noise if it is consistent. Alternatively it is often the byproduct of increasing the volume of low level recording in the analogue domain.
It may also be something that is being induced in your audio chain in the computer and is only noticeable when playing audio with backgrounds quieter than music files, which tend to be recorded at high levels.

If you can source some audio and/or video with audio from another source and import it into Vegas you can test if that causes the same problem. try downloading this small zip file (less than 1Mb) which contains a short piece of audio without hiss. It's a nail gun firing and the short section before it fires is quiet. If you system isn't producing hiss then you should not hear any playing this file which was recorded on a DV camera. http://www.newhope.com.au/RAMSET.zipRAMSET[/link]

Let me know how you go with it.

New Hope Media
Al Min wrote on 12/6/2008, 11:17 AM
Thanks for taking the time to help here.I played the Ramset sound in Vegas. There is some ambient noise in the background, not really hiss, but noticeable. It is almost the same as what I am talking about. So is there no problem really? I record audio with Cakewalk Sonar in my home studio, and I am used to pure digital quality with absolutely no noise except the instruments. Am I being too fussy?

I did a search on digital recorders and came up with several including the Sony PCM D50. It is resonably expensive but excellent at what it does. As neither of my cameras have audio inputs, I wonder if I should look at recording the audio into something like the Sony and syncing later. As long as it doesn't produce the same abient background noise that is! What do you think?

BTW - thanks for the tip on importing the ACHVD directly and bypassing the Sony cam software. I didn'y know that (or had forgotten!) I'm new to this game.
Al Min wrote on 12/6/2008, 11:35 AM
I've just conducted a test of my own. I recorded my voice into Sonar with talking, silence and then more talking. There was almost no noice at all, far less than the Ramset file and my camera files. I exported the file as a wave 44.1 x 16 bit. I imported this into Vegas and there was no induced noise at all and it sounded exactly as it did in Sonar. So it is the quality of the camera mics that is in question here.

Are you happy with your cam performance as demonstrated in the Ramset file? Do you just live with the noise that is produced? As I am going to produce professional DVDs of interviews of people telling their life stories, I will just have to use low level background music to mask it out (I have Cinescore also). However, this doesn't happen with interviews on TV. Please don't tell me I have the wrong cameras as I am delighted with the video they both produce and really enjoy using them.

Regarding the Sony PCM D50 audio recorder I mentioned in the previous post, would you recommend that, or is there a cheaper, but just as good device that folks use?
rraud wrote on 12/6/2008, 3:41 PM
Ambient noise is everywhere. If you object to it that much, rent a high-end studio of soundstage.. Even then there will be some. A D50, SD788 or Cantar for that matter will not attenuate that kind of noise. Get real.
Al Min wrote on 12/6/2008, 5:35 PM
I am real. I have been working with audio for a few years now and I do know what I like. Hiss and a high background noise level are not what I like. The ambient noise I'm talking about is not just birds, wind, traffic etc, but is hissy as well. I'm just trying to find out whether the cameras should be doing this or not. Anyway, thanks for your input.
newhope wrote on 12/6/2008, 6:51 PM
The type of mics in the cameras you are using tend to be generalist style that captures everything that at which the camera is pointed .

The RAMSET audio was recorded using a Sennheiser 416 on the Sony PD 150 and the location was a small industrial factory unit. Heard in sync with the vision it was originally part of it is a natural background, no hiss, but certainly a normal level of ambient noise.

I rarely use the mike built into the camera unless I'm just recording landscapes and ambient backgrounds, even then I tend to use a specific mike. These days I would probably buy a RODE NTG-1 or Videomic as a cheaper alternative but I love my Sennheiser 416

By the way, my background is 30 years of professional audio for broadcast TV and film both as a location recordist and sound editor/mixer. A certain level of ambient noise is normal in all recording when not done in a sound studio, often even sound studios have a level of background noise from air conditioning etc.

The particular video content you have indicated you want to record, oral history, may be better suited to using lapel miking on the interviewees, either wired or wireless radio mikes. This gets the mike onto the subject but has other potential pitfalls that need to be avoided.... clothes rustle, mike in the shot if not hidden under garments, muffled response if not correctly positioned, the need for a mike for each interviewee in multiple interviewee shots.

Without having heard your sound I'd suggest what you are hearing is a combination of the cheaper quality mike on the camera and the background noise it is picking up.

The other quick suggestion I have is to check on the camera that any AGC is turned off as this WILL accentuate hiss and background noise in the quieter periods as the AGC tries to raise the gain of low level audio.

Try your voice recording again using the camera's mike with AGC ON and then set the AGC OFF and do the same thing. Turning AGC on and off probably won't be possible on the Sony T500 still camera but should be on your AVCHD camera.

http://www.newhope.com.auNew Hope Media[/link]
musicvid10 wrote on 12/6/2008, 8:44 PM
Al,
In addition to sharing your impression, why don't we try to quantify it?
Post, in the original captured format, 30 seconds of your audio, including representative program material and at least two instances of quiet, or noise floor audio. Don't post "normalized" audio, just the raw stuff will do just fine.

Also, let us know how you recorded the audio:
1) Onboard or external mics
2) If external, any devices between mic and camera
3) Manual or auto gain? If manual, the gain setting you used.
4) If on-camera audio, distance from camera to subject
5) How you captured the material -- firewire, usb, usb audio device, rca jacks, what?
6) Ambient noise description -- outdoors, indoors w/ air handlers, etc.

Finally, let some of the pros here listen and look at your waveforms and give their impressions and evaluate the S/N; you may gain a lot of insight. I've worked professionally in the live sound and recording industries for thirty years now, and my experience doesn't hold a candle to some of the people who have already responded to your post.

If you are truly interested in a solution, rather than just sharing your impression, you will make at least an attempt to objectify it by uploading an example of the raw audio for us to examine. If your assertions about two Sony cam models are true and can be duplicated, I'm sure it will give the pros here plenty to talk about . . .
Al Min wrote on 12/7/2008, 10:02 AM
Great idea musicvid. I'd be very pleased to have some expert advice on what I'm doing. How do I upload please? What format does it need to be in? Do you need video and audio, or just the exported audio?

Many thanks to all who have responded. I really appreciate your positive input.
Al Min wrote on 12/7/2008, 10:08 AM
ACG? Newhope, can you explain a little more about this please? I have dug into the HDR TG1 menu but don't recall seeing that as an option.

Re wireless - I do have an AKG headset with an extra lavallier mic that I use in a band (I'm a singing keyboard player.) However, I've been trying to keep the setup as simple as possible when I go to people's houses, that's why I was hoping the built in mics would suffice.
musicvid10 wrote on 12/7/2008, 10:42 AM
Upload in the original format (AVCHD?) so it won't be affected by recompression. Again, 30 sec. of representative footage is fine.

If you don't have your own webspace to upload to, I know that johnmeyer and others here use photobucket with good results. I understand it is free, but don't know the terms.

If you are not sure what AGC is, it was probably "on" by default on both of your cameras, and is likely the cause of all of your concerns, esp. if shooting at a distance with even a moderately weak audio source. We can easily confirm or rule this out once we see your clip. You see, it's not the quality of the onboard mics, but what you're asking them to do at even moderate distances, which is pick up all the audio so you can hear the source. I doubted we were getting the full story first time around.

Take some time to learn what the advantages and pitfalls of using Automatic Gain Control are, and strongly consider investing in some off-camera mic capability -- quality though, not cheapo stuff.
newhope wrote on 12/7/2008, 2:49 PM
Al

I've just downloaded the manual for the HDR-TG1.

So... it doesn't have any external audio inputs, which you mentioned earlier. This removes the possibility of using an external microphone with the camera. The only alternative would be to use a separate recorder as you also suggested earlier. The down side of this is syncing the audio to video, something that is the norm for large professional TV and Film productions where timecode can be employed to help the syncing process. Though this isn't impossible in your situation it will be a time consuming process and adds more hardware to control and monitor on location. All fine if you have a crew but as a one man band not so much fun.

AGC as explained by others is Automatic Gain Control and is a feature on most camcorders, which is usually able to be turned off on the higher end units. Having read the manual on the HDR-TG1 this isn't an option. In fact it isn't even mentioned as you also indicated. That means that, whatever gain control structure Sony have employed in the camera you don't have any option of changing, not even the record volume. The volume +/- appears to be only a replay level setting, not recording level.

You do have the option of choosing between 5.1 and stereo recording. In fact hearing the 5.1 summed into stereo from the Sony software that was supplied with the camera is probably accentuating the ambient sound you are objecting to even more.

However, if you import the video with audio recorded as 5.1 directly into Vegas you can isolate the centre (center for U.S. readers) channel and hopefully that will provide a more present sound and remove more of the ambient sound picked up by the surround and left/right elements of the microphone. I'd also try setting the camera to record stereo (2 channel) and listen to the difference in the quality of the audio then choose which mode best suits your recordings.

The position of the microphone on the camera does nothing to make me feel you'll get the kind of sound you want though. It's back mounted and not forward facing. Basically to achieve good interview sound you need to have a mike close to the subject and this camera doesn't cater for that type of situation.

In all I'd rate the camera as a great HD consumer camera but not something I'd choose, for the type of project you are embarking on, as the sole source of audio recording which is your initial concern.

New Hope Media
Al Min wrote on 12/10/2008, 10:46 PM
I thought I'd update this thread by saying that I have decided to buy a Sony PCM D50 audio recorder. It's had great reviews, uses two built in swivelling mics for stereo recording and is stand alone being battery powered. I've also bought a clapper board to use to line up the audio to the video. Many thanks for all those who offered suggestions. Its great to be able to ask Q's as a novice and then to get sensible aswers without smart comments.

One more thing if I may. Do the cameras I own (mentioned above) generate time code automatically? And if so, how do you use this in Vegas Pro to syncronise the clips from the cams?
newhope wrote on 12/11/2008, 1:06 AM
The AVCHD consumer cameras do timestamp their files with the equivalent of timecode but usually start each new file at 00:00:00:00 instead of sequential (record run), time of day or user preset.

This isn't particularly useful when trying to sync to another source.

Professional cameras allow you to sync the TC generators in the camera to each other or an external source as well as record run, free run, TOD and user preset.

The clapper is your best source of sync for these cameras.

New Hope Media