PD-170 Auto or Manual for Audio In?

[Craig Seeman]

Wondering what people say about using manual vs. auto for Mic In on the 170?

I'd always used manual in the past because I don't like AGC circuts that compress the audio. Apparently the 170 "AGC" is really only a hard limiter.

With Auto on you clearly get better Signal to Noise ratio.

In Auto, apparently if you back off the input level from a wireless mic receiver so you don't let the limiter kick in, you have less noise and can keep the dymaic range. Is this true?

In auto, if you have a wired mic input or use the onboard shotgun you otherwise have no audio level control. Wondering if people have experience going this route vs manual?

[Mike Rehmus]

Craig,

Welcome to the forum.


Lots of posts on this forum about that. A brief search will give you all the various ways forum members attack this problem.

[Craig Seeman]

Hi Mike (et al),

I did search. There are posts on various audio issues with the 170 but If I do search on 170 and Limiter, nothing shows up.

Certainly there are posts about 170 and AGC but one thing I'm trying to determine is whether it's simply a limiter or there's actuall compression going on. I don't see any posts relating to that.

It's clear that when the audio is set to autio, there's less noise. I'm curious what, if any "cost" there is.

I was told from someone (without confirmation) that it's simply a limiter so one can simply "back off" on the input, avoid the limiter, and not have any compression and get a better s/n ratio to boot.

I know in many circumstance one can "split" the audio and go with "agc" (or is it a limiter) on one channel and manual on the other.

Problem is on many of my shoots I have on channel on wireless and use camera shot gun for ambient sound on the other so I can't really split the signal in those circumstance.

My own gut and practice has me fearfull of using a wireless only (and splitting it) since I seem to get occassional RF "crash/crunch" sound (being in NYC, the RF capital of the world doesn't help).

Just to recap, I've seen your other post on the 170 audio and Don's and others on the forums.

I'm still fuzzy (or a least trying to avoid fuzzy audio).

[Don Bloom]

One reason I avoided AGC with my SennME66 on cam mic was I felt the circuit and mic combo on the 150 was too hot and I had to "ride the wheel". After many conversations with Mike R on this subject I finally got a PROCO 10db attenuator. Well all I can say is that it is the cats meow (all pardons to my dog). Now at wedding receptions where the DJ forgets that his volume can be less than that of a 747 at take off power, I can use the add on attenuator and not go to MICATT on the camera which I always felt took the level a bit too low, but IF I need to I can. NOW, I use the oncamera mic on AGC on Channel 1 with Channel 2 on manual at about 50% just to give me a bit of a choice. For me the 10db attenuator made all the difference and was the reason I made the switch to AGC on channel 1. So far other than 1 braindrain on my part my audio has never be better with the 150's and frankly is one less thing I have to watch like a hawk while shooting.
My suggestion is to do what I did and take 1 tape and try all the different combos. I used a VERY LOUD stereo system to kinda duplicate a DJ at a reception and made note of everything I did. It took a bit of time but was well worth it.
Hope that helps a little,
Don B.

[Mike Rehmus]

Include the 150 on your search.

If you are inputting two sources and not splitting one, then you do have to (I think) go to a more conservative approach.

I normally use wireless only for the ceremony and for that I split the one-channel audio into the camera because I always use a MD recorder as a backup one way or the other. A second or third camera will also be capturing room tone so I don't worry about that too much. Strangely, my PC-110 which I frequently use as a pulpit cam always gets the best room tone.

In receptions, I have more time to work things out. Normally I place a wireless on the DJ's speaker rather than trying to get a feed. Then I have another wireless or a wired microphone for obtaining voice input during the reception.

I don't like to use a shotgun because I think they don't sound as good as a Beta58 or a small diaphram cardiod and they are just a bit too directional and require too much management for my tastes.

The PD150's AGC has a hard limiter that sounds just like a clip as far as I am concerned. I still use it but I'm not normally using a super-sensitive microphone on the input. And Channel 2 is normally set around 40% which gives me lots of headroom in most cases. 25% is the lowest I've ever had to set it.