Topic: Problematic rig

[travelinbeat]

Hey there folks, I'm not sure whether this post should be in Mic's or Pre's, so I figured I would put it here because the issue may well not be the fault of either.

I run Church Audio Card's with a CA-9100 Pre into a Rockboxed h120.  I saw a show last night and stealthed all three acts.  I set the Church Pre to just over half (approx +12dB), and the iRiver Pre to +20dB with AGC ON to Safety Clip mode.  I know that the iRiver AGC is not the annoying sort which raises, then lowers, then drops, and raises the levels all the time, but rather the sort which simply turns down the levels until the recording is no longer clipping, and I know I've had success with it before as a "set it and forget it" tool in high security / small venues.  The first two acts were on for a combined total of about 2.5 hours, and then my band cam on.  The first opener was a solo act with a guy and a bass doing experimental / low key stuff, the second act was rock, and the third act was definatly loud rock.  My recording came out slightly overloaded sounding at times though, and this brings us to my question... I am wondering what aspect of my recording is responsible for the overloading?  Do iRiver owners often complain about the AGC not turning down the levels enough?  Could +12dB on the CA-9100 Pre in a loud show have created a signal that was too hot for the iRiver AGC to adjust?  Could my brand new for this show 9V battery have lost enough juice during the opening acts to have rendered it unable to sufficiently powered the mics?  What, if anything, else could have cause some overloading in the recording?  Any and all input is, as always, highly appreciated.  Thanks so much!

EDIT:  I'm not sure if this helps, but in looking at the recording in Soundforge, the recording does not appear to be peaked out... Could I be mistaking some effect used by the musician(s) as overload?  Is it possible to have an overloaded recording which doesn't look overloaded?

[sml42]

Is it possible to have an overloaded recording which doesn't look overloaded?

Yep. If the SPL was too high for the mics, the waveform would look fairly normal, yet sound distorted. If there is no obvious brickwalling, that could be what happened here. Care to post a sample?

best regards,
stephen

[travelinbeat]

Thanks for that Stephen, here's a sample mp3 at 256kbps, I have a FLAC en route as well

http://media.putfile.com/The-Rentals---Friends-of-P-Los-Angeles-July21-2007

Also, would you happen to know how long a standard 9V battery (Duracell or Engerizer) generally lasts in a CA-9100?  I'm guessing I may just wait for Chris to poke through this thread, but I figure it's worth a shot =).

EDIT:  here's the flac:  http://www.megaupload.com/?d=6THH2GOA
   

[sml42]

No idea on the battery life, sorry, although I'd be amazed if it ran down in, what, a couple of hours?

Had a quick listen (and looked at the waveform in audacity), you're definately not brickwalled, so I can only assume the mics overloaded. Seriously loud bass? How did the other acts turn out? You could probably improve the recording a bit by filtering out some of the bass in post, although to be honest IMHO it's fairly listenable, if it were me I'd be tempted to just leave it as-is.

[Kindguy]

I set the Church Pre to just over half (approx +12dB), and the iRiver Pre to +20dB

This is somewhat off topic.

Wouldn't you get better/cleaner gain by not setting the iriver pre so high? And using more of the church pre gain.

I would guess the pre in the iRiver sucks. I don't own one so I'm not sure. Maybe you found out just how bad it is?

[travelinbeat]

No idea on the battery life, sorry, although I'd be amazed if it ran down in, what, a couple of hours?

Had a quick listen (and looked at the waveform in audacity), you're definately not brickwalled, so I can only assume the mics overloaded. Seriously loud bass? How did the other acts turn out? You could probably improve the recording a bit by filtering out some of the bass in post, although to be honest IMHO it's fairly listenable, if it were me I'd be tempted to just leave it as-is.

I was thinking the same thing with the pre battery life-- seems rather unfathomable to have a battery life of two-three hours.  Thanks for looking at the recording for me, I agree that the recording is still listenable, I just wanted to get some opinions on how to make sure that I don't encounter the issue again.

Wouldn't you get better/cleaner gain by not setting the iriver pre so high? And using more of the church pre gain.

I would guess the pre in the iRiver sucks. I don't own one so I'm not sure. Maybe you found out just how bad it is?

It's a fair point you make...  The reason I set my levels this way is I am pretty sure that the iRiver pre is okay up to 20dB (after which it goes digital), and I knew that in all likelyhood, the AGC Safety Clip feature would turn the iRiver pre WAY down anyways (as it did, I think it dropped the iRiver pre by about 16db in the first couple of seconds of the band).  I'm still pretty new to the world of external preamps, so I'm more familiar with flying my iRiver solo with mics than with a second pre.  I'm still learning, but I do feel that you're point's a very worthy one, probably one I'll be testing increasingly from here on in to see how we go.


+t's for both of you, thanks for the input so far!

[Brian Skalinder]

Could my brand new for this show 9V battery have lost enough juice during the opening acts to have rendered it unable to sufficiently powered the mics?

Yes.  And I'm guessing that's the culprit.  I've had more than my share of brand-spanking-new 9v batteries fail very quickly, in all sorts of applications.  Just because it's new, doesn't mean it's good.  How to tell?  Well...that's the trick, there's really no good way to know for sure when pulling it out of the pack.   

[travelinbeat]

really???  dang!  So what do people do to make sure that their recordings come out nicely?  I always thought just so long as I stuck with a brand name battery that I'd be okay... perhaps my best course of action would be to make a new thread asking people about 9V's =(

[junonato]

i have had similar problems with 9 volts, even brand new!  definately don't go with cheapo 9 volts!

[stantheman1976]

The recording's definitely not brickwalled, as stated before.  It sounds like it could have been a little loud and caused a little distortion, but running the CA cards I doubt that would be a serious issue unless you were very close to VERY loud stacks.  It probably was a power issue. 

The advice about using the gain mostly on the preamp is good.  The whole reason for using an external preamp is good quality amplification.  Get most of your gain from the preamp.

[drapes]

really???  dang!  So what do people do to make sure that their recordings come out nicely?  I always thought just so long as I stuck with a brand name battery that I'd be okay... perhaps my best course of action would be to make a new thread asking people about 9V's =(

Test your battery with a voltmeter before using it. I've had problems with power before as well with my Church Audio ST-9100 pre-amp and cards, and now I'm in the habit of checking it every time I go out.

I'm far from having completed a scientific study, but I've found that a 9v with less than ~8.3v in my system isn't powerful enough. Recently I measured a brand-new Energizer 9v at 9.3v and ran it a few nights at a festival for about 10-12 hours total before deciding to replace it with a new one at around 8.6v. I have no idea where between 8.6v and 8.3v the problems start.

drapes