AGC and limiter for audio

[Dean Longfield]

I agree Jim, I never had a problem with the stock mic on either a DSR 300 or 500 series camera, That’s why i tried that same mic on the EX1R – figuring it would work good on the EX1R also. It did not work well at the default settings (-41 trim..etc.).

As has been correctly pointed on this thread by others, the SPL on the stock DSR 300/500 mic (125-SPL) has the same 125-SPL as the recommended shotgun, (Sony ECM-673/9x), . for the EX1R. So after giving it more thought I decided to try the Rode NTG-1 rated at 139-SPL, which is also a Condensor mic with Supercardiod Pattern, but with the higher SPL.

So I’ll run my tests with that as the on cam shotgun mic, and see what happens.

Yes I also put a mic by the speaker and point it off axis, not directly into the speaker…..
Right now I’m just running tests with the on board built in mic and an on board shotgun, at non-critical times, on loud music type jobs.

Will let you know how the tests go.

[Bob Mark]

Start to raise your trim pad on the EX1(r) until the signal sounds clean and you have a volume control level around 4-5.

Bob

[Don Greening]

The moral of this story is that you can fix low audio volume in post but you can’t fix digital clipping in post. It’s sort of like a computer speed test: lower bars are better.

– Don

Don Greening
A Vancouver Video Production Company
Reeltime Videoworks
http://www.reeltimevideoworks.com

[Bob Mark]

That’s right. Remember when we made the hop from analog to digital and the audio on bars and tone on analog equipment at 0 VU became -20 or -12 db on digital gear? Analog can handle a certain amount of overload and not sound too bad, in fact recording studio engineers used to hit the analog tape recorders with a hot signal(+6 or more) to produce the fat sound of tape compression. No can do with digital.

Bob

[Brent Dunn]

crap in, crap out

Brent Dunn
Owner / Director / Editor
DunnRight Films
DunnRight Video.com
Video Marketing Toolbox.net

Sony EX-1,
Canon 5D Mark II
Canon 7D
Mac Pro Tower, Quad Core,
with Final Cut Studio

HP i7 Quad laptop
Adobe CS-5 Production Suite

[Dean Longfield]

Hi,

i tested the EX1R again, in a loud music from a DJ type scenario. I used the Rode NTG-1 on Channel 1 with the trim set to -32 and the (exterior knob on camera) manual audio level set to about 3-1/2 to 4. These settings seemed to work very well. (The Channel 1 music was recorded at an audio meter level of about -20).

Channel 2 was the internal mic. The INT MIC LEVEL setting in the menu was left at the
default setting of, ‘0’. the (external knob on the camera) Manual Audio level for Channel 2 was set at around 2- 1/2. Channel 2 was recording louder than Channel 1 but never peaked in the red. Now monitoring audio on a very loud dance floor is not easy but the sound appeared to be OK on this channel in the headphones. However upon bringing it back and loading it into the editing system, (the audio is recorded at an audio meter level of -12), and never peaks in the red but it sounds almost distorted. Not crisp and at times has some distorted crackling sound as if it is peaking in the red.

Re: Internal Cam Mic Levels:
Should I set the INT MIC LEVEL lower at say -6 ?

Also it appears the MIC AGC level is for both channels, (you can’t have one on high and the other on low). Has anyone tried the LOW setting and if so does that significantly alter the sound quality, (eg, muffled audio) ?

Thanks.

[Jim Stamos]

so are you saying i will be safe going with the rode ntg-1? i shoot a ton of receptions, but just started with my ex. never had an issue with the mic on my dsr300 for years.
you would think sony would have a recommended one for the ex1r that will give me good audio

[Dean Longfield]

Re: Jim’s question if we’re safe using the RODE NTG-1 in loud music environments:

I don’t know if we’re “safe” with the RODE NTG-1, but I do know that it worked well on the last shoot I did, which had a semi-loud DJ providing audio services / music in a nightclub. It appears that the
NTG-1, (with a maximum SPL rating of 139), coupled with adjusting the Trim Settings in the menu, and adjusting the Manual Audio Levels on the exterior of the camera itself, enables one to attain a desirable audio record level.

( BTW: The INTERNAL- built in – mic is something I have to test more in loud music environments before I find an acceptable setting.)

The recommended Sony shotgun Mic for the EX1R is the SONY ECM-673/9X which apparently works nicely with the camera, BUT only has a max SPL rating of 125, so being that I, like you, am often in loud music environments when recording, I opted to go for the RODE NTG-1, (with a max SPL of 139),
being it gives one that added padding – ( as others on the Creative Cow have so generously pointed out, and THANKS for doing so as that was very useful info ! )

My initial impression of the RODE NTG-1 as the shotgun mic on the EX!R:
so far so good, but I’ve only tested it once.

[Jim Stamos]

is the rode much longer than the sony? how did you secure it in the mic slot?

[Dean Longfield]

The Rode is 1″longer. I secured it in the mic slot by wrapping thin foam
around the mic where it’s in the mic holder.

I’ve heard that many people replace the mic holder with third party brands. You can find such attachments by searching the net.