Topic: What caused this? (distortion sample)

[divamum]

Hi all!

Loved the results w/the Jecklin disk - had a ball taping and got MOSTLY a great tape. (Although I must say it's a bit weird to be your own roadie/sound engineer AND be the performer - jeez lugging makeup case, gown and... mic stand?!)

HOWEVER despite being mostly happy with the sound... in one or two places I got distortion,  even though there's no clipping per se and the level doesn't go up into the red zone on any playback I've tried.  What's going on?

(This isn't me, btw! One of the other singers.  This was the only voice that seemed to cause, this also - other voices in the cast are "bigger" than this - although don't go quite as high -  and didn't have the same problem)

In any case, here's an example - would be curious what y'all think, and how I can go about correcting it for the next performance which is tomorrow.  It seems that since it isn't a "volume" issue, knocking the level back won't help (or will it?)  This is unretouched, btw - exactly as it came off the jb3, without even so much as tweaking the gain.

http://home.earthlink.net/~divamum/data/peakclip.wav

Rig:  CMC8s on 7" jecklin disk >Reactive pre>JB3
Location:  wide-but-shallow school auditorium; mics sited in emptygallery balcony about 35-40 ft back from performers (no seats - just a walkway - the front of the balcony is actually the BACK of the auditorium).    Strings and piano on floor in front of stage; singers on stage.  Space relatively live (wood floors, plaster walls), although not echo-y.  There was a low overhang where everything was sited.  Actually, easier than describing: pix attached (bad pix, but pix!)

[Roving Sign]

Sure sounds like Brickwalling...which is different than clipping...

Brickwalling distorts the signal on input - rasing and lowering the levels will not change it...

Using a -10, or -20db pad should work - or a preamp with more headroom...

(This isn't me, btw! One of the other singers.  This was the only voice that seemed to cause, this also - other voices in the cast are "bigger" than this - although don't go quite as high -  and didn't have the same problem)

Perhaps the frequency content of their voice is the most resonant relative to your recording position in the room...

[divamum]

Interesting. I wondered if that's what this was, but it's very different from the only time I've faced brickwalling before - when using AT831's with an SP fixed-level preamp when I got the classic brickwalling shape in the waveform.

Anybody else have any insights into this and/or how to avoid it?

What are "pads" (sorry - I'm enthusiastic and leraning, but still basically a n00b!)

[kfrinkle]

I had this problem with the JB3.  When I was running CSB > JB3, for shows that were not UBER loud, i would barely get a signal.  So I decided to buy a preamp battery box from sound pros.  For taping quieter shows, things were working great at first.  Then I started noticing a similar distortion/crackling in my recordings for certain types of sounds.  In particular, female (or higher octave) vocals.  It got to the point where I refused to use the CSB > spsb-1 (with preamp) > JB3 setup for any concert like that.  I do not have an answer for you, as I now use CMC-8 > spsb-3 > MT, and I never have a reason to 'boost' the sound before it gets to the MT, but I am sure, like the others, that it has something to do with the pre part of your rig.

[divamum]

The weird thing is this is the first time it's happened with this rig, which I've used in a variety of situations and venues (from small, live rehearsal spaces to huge opera theaters), recording all KINDS of voices, including ones much more overwhelming than this one.  This gal - a high light soprano -  is the first one who's caused this!

I just swapped out the battery on the pre, but it was a drugstore brand and not an energiser or duracell. Could that be a contributing factor?

[divamum]

I had this problem with the JB3.  When I was running CSB > JB3, for shows that were not UBER loud, i would barely get a signal.  So I decided to buy a preamp battery box from sound pros.  For taping quieter shows, things were working great at first.  Then I started noticing a similar distortion/crackling in my recordings for certain types of sounds.  In particular, female (or higher octave) vocals.  It got to the point where I refused to use the CSB > spsb-1 (with preamp) > JB3 setup for any concert like that.  I do not have an answer for you, as I now use CMC-8 > spsb-3 > MT, and I never have a reason to 'boost' the sound before it gets to the MT, but I am sure, like the others, that it has something to do with the pre part of your rig.

yes, this was the reason I had to abandon the SP pre and go with the Reactive, which has adjustable gain instead of the fixed levels.  This has been the weakest link in my rig since the get-go, but because I didn't have the money for a modded AD20 it was pretty much the only solution at hte time and, if I'm honest, the REactive has done REALLY well in a variety of situations - this is the first time I've hit a snag with it!

BTW, due to the acoustic nature of opera, I have to use a preamp - can't go with just a battery box, as the ambient sound simply isn't loud enough for line in without gain.

[divamum]

BTW, where would I get attenuators, and how much would I need?  Would radio shack have something like that (the mics are 1/8  mini) or would I hvae to order from somewhere? I presume teh attenuators go between teh mics and the pre?

[Craig T]

I just swapped out the battery on the pre, but it was a drugstore brand and not an energiser or duracell. Could that be a contributing factor?

YES.

[kfrinkle]

I just swapped out the battery on the pre, but it was a drugstore brand and not an energiser or duracell. Could that be a contributing factor?

YES.

Agreed, that could easily be the problem.  When i gave up the pre, i let a friend use it, and even with a fresh knock off battery, he got a totally shitty ass recording when it shouldnt have brickwalled before... I hope that is your problem..

[divamum]

doesn't the jb3 have a mic attenuator?

But would that actually help? If the problem is between the mics and the preamp rather than the preamp and the JB3?  I'm all confused now......

[Roving Sign]

doesn't the jb3 have a mic attenuator?

But would that actually help? If the problem is between the mics and the preamp rather than the preamp and the JB3?  I'm all confused now......

No mic pad on JB3 anyway!

[divamum]

No mic pad on JB3 anyway!

Didn't think so, but figured I should get the "chain of command" right before I moved on to that!!

Moke, thanks  and please don't apologise! You are the great guru and I learn from everything!!

Ok, so will try a diff battery (the one in question was brand new, but only Eckerd's own brand) will record tomorrow in the same venue and see if it doesit again (to be honest, this is all purely in the interests of recording learning, cause thankfully MY stuff came out fine!!), and then will record on Sunday in a different venue and see what we get. Fascinating stuff, even if it proves that getting "a perfect tape" is somewhere between knowledge , experience and a black art........