SOLVED: Audio problem - HELP!

Rick R said:
Practically all mixer's outputs are XLR-M (male) (and/or 1/4" TRS jacks, and in many cases, RCA 'tape out' as well). Even with gender adapters, there's still no attenuation...
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But aren't the "Record Out" RCA's outputting at a lower dB level than the "Monitor" outputs?
 
David W. Richardson said:
But aren't the "Record Out" RCA's outputting at a lower dB level than the "Monitor" outputs?
Click to expand...
Typically yes, and this is what you want. However, even a -10dB output (typical for RCA) would require attenuation when feeding a microphone level input for optimal performance. And assuming your feeding an unbalanced input anyway, unbalanced pads (attenuation) are generally easier and cheaper to build/buy than balanced ones.
The main and 'monitor' outputs are usually +4dB (nominal) and would require about 10 or 15dB more attenuation than the RCAs.
 
Rick R said:
Typically yes, and this is what you want. However, even a -10dB output (typical for RCA) would require attenuation when feeding a microphone level input for optimal performance. And assuming your feeding an unbalanced input anyway, unbalanced pads (attenuation) are generally easier and cheaper to build/buy than balanced ones.
The main and 'monitor' outputs are usually +4dB (nominal) and would require about 10 or 15dB more attenuation than the RCAs.
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No no, I get that. I was just excited to see that connecting to the "Record Out" did have an effect on the hum level. So I feel like a good attenuation cable will do the trick.

I'm looking at 3 cables and am not sure which to get -- -25dB, -33dB or -50dB. Any thoughts?
 
My first choice would be ~40dB of attenuation, but maybe 33dB will work.

50dB seems like too much.
It would make the camcorder mic preamp "work too hard".
It would force the camcorder mic preamp into higher gain and make it more susceptible to picking up noise/interference.

33dB is probably a good compromise.
 
BTW you can get in-line XLR attenuators for not a heck of a lot. They usually have a couple of choices for attenuation.
http://www.bhphotovideo.com/c/searc...iJJ2PtiG6Z4fU-mPemi6i5mBCRozdhh8QsaAt_98P8HAQ

And you may also need a ground lifter
http://www.bhphotovideo.com/bnh/con...0oMfJWdFkkaAqlN8P8HAQ&is=REG&m=Y&Q=&A=details

Or an Iso box

http://www.bhphotovideo.com/bnh/con...sxTQ6QPCMgaArmI8P8HAQ&is=REG&m=Y&A=details&Q=

It can add up but you probably only need one. But you may want to have the others in your kit.
 
Noiz2 said:
BTW you can get in-line XLR attenuators for not a heck of a lot. They usually have a couple of choices for attenuation.
http://www.bhphotovideo.com/c/searc...iJJ2PtiG6Z4fU-mPemi6i5mBCRozdhh8QsaAt_98P8HAQ

And you may also need a ground lifter
http://www.bhphotovideo.com/bnh/con...0oMfJWdFkkaAqlN8P8HAQ&is=REG&m=Y&Q=&A=details

Or an Iso box

http://www.bhphotovideo.com/bnh/con...sxTQ6QPCMgaArmI8P8HAQ&is=REG&m=Y&A=details&Q=

It can add up but you probably only need one. But you may want to have the others in your kit.
Click to expand...

Where would this ground lifter go in the system? Between the XLR outputs and the camcorder?
 
Wow, I got a reply too short error! Not like me at all...

So yes that is where I would assume it would need to go based on what you have described.
 
I'm am not understanding why the attenuation is recommended. I listened to the second example and I hear the Reverend speaking with the hum at a level competing with the Reverend. If a pad is installed between the mixer and the recorder, it will drop the level of the Reverend and the hum equally. Won't the person operating the mixer (or the AGC) just raise the level and bring everything back to where it was? If the levels are too hot for the camera, wouldn't the Reverend be distorted?

What am I not understanding?
 
Paul F said:
I'm am not understanding why the attenuation is recommended. I listened to the second example and I hear the Reverend speaking with the hum at a level competing with the Reverend. If a pad is installed between the mixer and the recorder, it will drop the level of the Reverend and the hum equally. Won't the person operating the mixer (or the AGC) just raise the level and bring everything back to where it was? If the levels are too hot for the camera, wouldn't the Reverend be distorted?

What am I not understanding?
Click to expand...

I understand your concern. Take a listen to last Sunday's service. Start at maybe the 2:33 minute mark, where the preacher is speaking in the pulpit. You will see that the buzz level is far lower than the voice. The other example was a visiting preacher, and his personal volume level may have been a good bit lower than our regular preacher's.

http://pisgaharpchurch.org/media_category/pisgah-arp-church-sermons/
 
There is a big difference between the 27th and your original posting. The buzz is largely gone. All I hear now is some room noise and a bit of hum that could be most anything (room noise or the gain being high). I do hear the AGC ramping up during non-speaking periods. That makes the 'silent' moments noisy. I don't see how a pad will help that. If the signals were low and you had to turn the gain up high in any section of the signal, then that would make it noisy. But the working theory is that the level is hot (which it plausible considering what we know). So the gain would be all the way down and things should sound good except during silence, when the gain goes up.

It actually sounds ok to me now. I hear a lot of room noise as thought the Reverend's level is low and the gain is up and we hear a lot of room noise. If anything, it sounds like the signal is low and the gain stages are all the way up rather than there being a hot signal that needs to be attenuated. What level is the fader on the mixer when the Reverend is speaking?
 
Paul F said:
What level is the fader on the mixer when the Reverend is speaking?
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You're going to make me show my general ignorance of audio terminology again. :-(

The slider on the pulpit mic is set to about -5. The gain on that same input is at 30 dB. That was the last one shot using the old mixer. I'm now uploading the video from today's service, which uses the new mixer. It also has the camcorder connected to the mixer's "Record Out" RCA jacks. I think that has improved the signal-to-noise ratio, and the thinking is that it's because the "Record Out" jacks are some 13dB lower than the 1/4" "Monitor" jacks. That's what's leading us to believe that an attenuation cable that would get the signal down more to mic level (which is what the camera's input needs) may improve the signal-to-noise ratio even more.

When today's video finishes uploading, I'll provide a link.
 
What kind of levels are you seeing on the mixer's meters during the service (when there's actual speech, not during the quiet parts)?

- Greg
 
Greg Smith said:
What kind of levels are you seeing on the mixer's meters during the service (when there's actual speech, not during the quiet parts)?

- Greg
Click to expand...

Oddly enough, the OLD mixer's LED meters rarely showed anything at all. The only time the bottom segments ever lit, that I saw, was when the preacher was in the pulpit and singing along to a hymn.

I can't answer about the NEW mixer. Today was the first service it's been used, and I was out sick so another guy ran the board.
 
David W. Richardson said:
Oddly enough, the OLD mixer's LED meters rarely showed anything at all. .
Click to expand...

The low reading on the mixer is exactly what the 27th sounds like; a low level signal. The audio experts here should be able to help you with that. That AGC is messing things up. You have a weak level and an AGC circuit that is bringing the gain up to try to compensate. You need to be able to bring a good level into/out of the mixer and then drive a proper level to the camera.
 
David W. Richardson said:
Oddly enough, the OLD mixer's LED meters rarely showed anything at all. The only time the bottom segments ever lit, that I saw, was when the preacher was in the pulpit and singing along to a hymn.

I can't answer about the NEW mixer. Today was the first service it's been used, and I was out sick so another guy ran the board.
Click to expand...

That's kind of what I expected. By running the mixer output well below its normal level, you are reducing the output into a range that the camera will accept -- but the signal-to-noise through the mixer will suffer,

You really should be seeing more than the bottom two or three segments of the meter light up during normal speech peaks. Certainly you don't want to be in the upper yellow/red range, but seeing nothing at all means you're running too close to the mixer's noise floor. You'll probably need to turn down the inputs on the PA amplifier or anything else attached to the mixer outputs.

I'd suggest about a 40 dB attenuating cable between the main line outs and the camcorder. Let me see what I have in the junkbox, and if you want to PM me about it, maybe I can make one up for you.

- Greg
 
Greg Smith said:
That's kind of what I expected. By running the mixer output well below its normal level, you are reducing the output into a range that the camera will accept -- but the signal-to-noise through the mixer will suffer,

You really should be seeing more than the bottom two or three segments of the meter light up during normal speech peaks. Certainly you don't want to be in the upper yellow/red range, but seeing nothing at all means you're running too close to the mixer's noise floor. You'll probably need to turn down the inputs on the PA amplifier or anything else attached to the mixer outputs.

I'd suggest about a 40 dB attenuating cable between the main line outs and the camcorder. Let me see what I have in the junkbox, and if you want to PM me about it, maybe I can make one up for you.

- Greg
Click to expand...

Sounds reasonable. No need to make up a cable. I'm happy to buy one, just needed guidance on which one to buy. From the replies, it sounds like the -33dB one would be a better option than the -50dB one.

Thanks all!
 
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