Topic: CA-14 Omnis - "cracking" sound in left channel with loud bass

[jagraham]

So I think I overloaded my CA-14s for the first time at floydfest saturday night.  It's odd though because the left channel has a "cracking" or "scratchy" artifact and the right channel sounds fine.  Source: CA-14s(Omnis/1' spread) > STC-9000 > DR-05(LineIn), Center/FOB/~7.5' high.  The pre was set @ about 65%.  Hoping I can salvage this, any ideas?

[fmaderjr]

Source: CA-14s(Omnis/1' spread) > STC-9000 > DR-05(LineIn), Center/FOB/~7.5' high.  The pre was set @ about 65%.  Hoping I can salvage this, any ideas?

STC-9000 has gain settings of 0/+10/+30. Do you mean you had it set to +30 with the volume control at 65%? If so, the preamp might have brick walled. The volume control effects the level that the recorder sees, but will not prevent the preamp itself from brick walling, and +30 gain is too much for a loud show.

[jagraham]

^ No, I guess I didn't clarify that.  I meant the volume knob was @ 65%.  Gain was set to 0 as I knew it would be a loud show.  I see how you might have thought I meant 65% of the recorder's power.  It's strange because it's in one channel.  Also, I have taped a ton of shows with them at indoor venues that were equally boomy.

[jagraham]

I'll also add that I taped another show that night and another show the next day with the same rig that were quieter shows and had no similar issues.  That's why I assume it was due to the loud bass and overall volume.  Usually I would try the noise removal in Audacity but I can't isolate the artifact by itself since it only occurs during the music, at the peaks in particular.

[F.O.Bean]

Maybe cell phone interference Weird that its only 1 channel

Just copy/paste the other channel and it will be a mono recording

[jagraham]

It's throughout the recording at the peaks so I ruled out phone interference, but I don't really know that much about that topic so I guess it's possible.

[F.O.Bean]

Doesnt sound like thats what it is Crazy weird tho

[brad.bartels]

Just copy/paste the other channel and it will be a mono recording

That's what I've done when I had similar issues and only one channel is bad. You can play around with delay and EQ them differently, maybe add some reverb to one of them to make it sound more like a stereo recording. Wish I had some input on what caused it, but alas. Sorry.

[jagraham]

Good idea to use one channel but I got another source as well with cards so its not all bad.  I'm considering a matrix with the single omni channel mixed with the stereo cards.  Might not work though because the omni mic was a few inches over from the card pair.

[Hypnocracy]

Is it the channel that big blowup monkey landed on?

[newplanet7]

Humidity could be the culprit.
Have you tried to throw on a super bassy album at home and throw the mic about 4 inches from the speaker?

[adrianf74]

Can't really tell from the crappy speakers on my monitor at work, however, I would tend to think that humidity wasn't the culprit.  Omnis are a lot more weather tolerant than cards.

I don't think it's cell-phone interference, either, because that sounds more like "morse code."

I'm curious, were you wearing the mics or did you have them mounted (looks to be mounted from your description).    I had an experience once where the grounding pin inside the mini plug was "loose" and touching other metals inside the plug's housing which caused intermittent static on the one channel; I'd suggest you open the minijack and see if it's soldered correctly.

[fmaderjr]

^ No, I guess I didn't clarify that.  I meant the volume knob was @ 65%.  Gain was set to 0 as I knew it would be a loud show.  I see how you might have thought I meant 65% of the recorder's power.  It's strange because it's in one channel.  Also, I have taped a ton of shows with them at indoor venues that were equally boomy.

It looks like the preamp had nothing to do with the noise then, but for best signal to noise ration in the future I would always leave the preamp's volume control at 100% unless you need a bit of trim to keep the recorder from overloading. If set at 0/65% the preamp is actually attenuating so you are increasing the gain needed from the recorder's preamp. Chris Church recommends +10/100% for very loud shows and +30/100% for acoustic shows. I would tend to consider using +0/100% only when stack taping heavy metal.

[adrianf74]

^ No, I guess I didn't clarify that.  I meant the volume knob was @ 65%.  Gain was set to 0 as I knew it would be a loud show.  I see how you might have thought I meant 65% of the recorder's power.  It's strange because it's in one channel.  Also, I have taped a ton of shows with them at indoor venues that were equally boomy.

It looks like the preamp had nothing to do with the noise then, but for best signal to noise ration in the future I would always leave the preamp's volume control at 100% unless you need a bit of trim to keep the recorder from overloading. If set at 0/65% the preamp is actually attenuating so you are increasing the gain needed from the recorder's preamp. Chris Church recommends +10/100% for very loud shows and +30/100% for acoustic shows. I would tend to consider using +0/100% only when stack taping heavy metal.

^^ QFT.   Those settings are pretty much foolproof.

[Chuck]

Any chance the 9v battery in the STC-9000 is depleted? That would affect headroom and could cause clipping.