HD vs. SD Audio..
 

I have been a wildlife videographer for many years and have been shooting in SD with good results. Natural "outdoor" audio has been very important to my Productions and the JVC DV-500 camera has served me very well when coupled with two Audio-Technica shotguns and about a 30 to 40 ft. left-right stereo seperation. The sound with this SD set -up has been literally incredible in the wild... I`m now ready to jump into the HD format and looking at the Canon XHA-1S but am concerned about the quality of the HD audio seeing that it is recorded differently than SD.
Could you please advise me on how much difference there is in sound quality between SD and HD if any when using the microphone set-up I described above? Thank You very much for any input.

Specification wise, there is no difference. The difference may be in the analog preamps which are frequently neglected in camcorders. Your JVC was a more professional camera than the Canon. Whether than translates into better preamps, I don't know. When dealing with quiet sounds, a good preamp becomes more essential.

I'd say try it out and see what happens. I suspect you won't have a problem. But if you do, there are external preamps available Sound Devices | Mixpre - Portable 2 Channel Microphone | MIXPRE

Or you may wish to use a separate recorder which, theoretically, will have better audio quality--double the same rate and more bits but may share the preamp issue. At $150, I'm sure the preamps in my Zoom H2 aren't spectacular but it works for me.

Sound didn't really change from SD to HD. You could go from stereo to 5.1 surround, but you can have surround sound with standard def DVDs too.

I can't imagine that the sound quality will be very different from the JVC to the Canon. If it is, you can always record sound into your JVC as you have always done and insert it in post. To get things to line up, point both cameras the same direction, walk in front of the camera, and clap your hands. Wildlife footage takes risk looking alike, so you might want a slate so you can tell the difference between clips.

Separate devices can drift over time. If you do long takes, use the clap/slate at the start and end of each clip, so you can match the durations.

Later, if you decide to do surround sound, I'd recommend recording four channels, rather than two. (The LFE channel is for booms, and the center channel is for dialog. No need for wildlife sounds there.) By keeping your JVC, you could get two additional shotguns, record two channels into each camera and end up with a four channel surround source. If you like the soundstage that you get from two mics spaced at 30 ft, four mics at 30 ft will sound even better.

Often, by spacing mics, you can get phasing errors, but with shotguns outdoors, that's less of an issue. Surround sound engineers really sweat where to place mics to get good sound at live events, like the Grammies and at football games. If you like the results of spaced shotguns, stick with what you like!

No fundamental difference: SD vs. HD sound
 

There is no fundamental difference in recording sound for HD vs. SD. The only difference will be the quality of the audio sections of the SD vs. HD cameras, and that is completely independent of whether it is SD or HD.

You have a very valid question, but the issue is the quality of the JVC DV-500 vs. the XHA-1S, NOT the quality of SD vs. HD.

When shooting SD on your JVC standard def camera audio will be 48k/16bit.
When shooting SD on the Canon A1 audio will be 48K/16 bit also.
When Shooting HD on the Canon audio will be MPeg 2.... 384Kbit/s.

So, the SD audio will be better on these HDV cameras. Canon preamps are good.
MPeg 2 fine for dialog. Maybe not for ambience or nature recording ... this is for you to decide.

Thank you for the insights, as I already knew it will take side by side testing. As stated, the JVC with the Audio Technicas did a fantastic job at recording the full spectrum of natural outdoor sound from fantastic highs (birds) to excellent lows (grouse drumming). I luckily still have very good hearing but the JVC was capturing sounds that I never actually knew were going on. I`m hoping that the Canon in HD will do at least close to the same....

If the A1 pre's are anything near the quality of the XL2 pre's I think you'll be fine. Being a car enthusiast, some of the best recorded exhaust notes I've ever heard came from our XL2 and a Senny shotgun. Full range, all the way from the bassy low RPM growl, to high and raspyness high RPM screaming.

I think you'll be pleased.

If by "HD" you mean "HDV" then the audio is much worse than the SD spec of many cameras. The HDV codec records audio equivalent to a 320kbps mp3 file. But my Sony VX2100 SD (NTSC) camera records uncompressed audio. My Sony EX1 records uncompressed audio 16/48 which is one of the reasons I got it.

Of course preamps, mics, hardware all play into it, but EVERY HDV camera is recording mp3 audio.

Actually, it's 385 but either way, that is sufficiently high to be 'perceptually loseless'.

I ain't gonna lose sleep over it. I've encoded my CD collection (in wma) in vbr around 135-215kbps and they sound pretty good to me.

If you've got golden ears, yeah, I'll grant you might hear some distortion or artifacting but for most of us...

Andy I think (somewhat) uncompressed PCM audio stands up better to processing. I mix my audio tracks as I would tracks in a song project, with compressors and maximization. When audio files that contain 10% of the original uncompressed signal (HDV) are processed you can hear the artifacts and loss of openness.

That being said, if you are just recording dialog it won't matter too much for ENG, but Denny is trying for nature sounds and birds. It's important to have all the fidelity possible for recordings like that. It may be better for him to buy an external recorder for the important sounds if all he has is an HDV camera. I suggest Denny get's an EX1 for great in-camera audio. Otherwise try a Sony PCM-D50, or an Oade Brothers Edirol R-44 with modified preamps. It's only about 100.00 more than the stock R-44, and records 4 channels of audio.

http://www.bhphotovideo.com/c/product/524130-REG/Sony_PCM_D50_PCM_D50_Professional_Portable.html
Ordering for Oade Brothers Audio: Edirol R44 Super

Plural Eyes software will automatically sync your audio/video files:
Singular Software

I concur. Best solution for Denny is to get a non HDV camera. That technology's on its way out anyway. There are a lot of attractive options these days. As this is for outdoor shooting, I guess you should research the best recording format and pick your best option from there. I would say that the audio on the EX1 as recommended here is exceptional.