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Old August 30th, 2017, 09:31 AM   #1
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Audio "clipping" without passing 0db

I often get clipping when I plug into someone else's equipment despite setting levels low. I try to mic the person but often for events with multiple people talking it's not an option.

For my theatrical work its more straight forward you get line level feed and if the recorder or camera was set to mic it be obvious during the sound check the clipping is being caused by incorrect level.

The dj at my last gig told me to plug into his speaker and it was ok for the parts I needed but there are sections clipped despite being well below 0 db, like when he is shouting into his mic or the music in general.

It must being getting clipped before it reaches me. Maybe there isn't anything I can do. Seems like I get this more when plugging into these portable PA systems
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Old August 30th, 2017, 11:10 AM   #2
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Re: Audio "clipping" without passing 0db

Welcome to the wonderful world of gain structures.

You're absolutely right, the audio is getting clipped before it hits your recorder, so it's either in the mixer's preamps, or in the wireless transmitter's preamps (if it's a wireless mic.)

This is why I don't rely on DJs to give me a good feed.
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Old August 30th, 2017, 11:26 AM   #3
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Re: Audio "clipping" without passing 0db

Quote:
Originally Posted by Pete Cofrancesco View Post
The dj at my last gig told me to plug into his speaker and it was ok for the parts I needed but there are sections clipped despite being well below 0 db, like when he is shouting into his mic or the music in general.
You plugged a speaker output into a line level input?
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Old August 30th, 2017, 11:38 AM   #4
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Re: Audio "clipping" without passing 0db

All true! There is one more possibility to consider, if you're having to set to line level and still set your recording gain below 1/10th of the scale of the control, you may be getting a hotter signal than your recorder/camera can handle, even though you've chosen line level at the input.

It does seem more likely the signal is clipped before it gets to you, but if you suspect your input is overloaded by a hot signal the solution is to get an in-line attenuator of perhaps 15 or 20db on the line you receive from the DJ. Audio-Technica, Shure, Whirlwind are some of the US manufacturers. I'm sure there are others.

This one's nice, because you can select -10, -20 or -30db.

Another useful bit of kit to carry for these situations is a DI, aka. Direct Box, especially when a DJ gives you an unbalanced signal on 1/4" TS. A good one will have selectable attenuation, and a transformer to convert to balanced mic level. A good one will tame a really hot signal...

Something like this.

And, some assorted adapting cables to deal with RCA/Phono, 1/4" TS/TRS, XLR barrel turnarounds, etc.

PS. This has come up a few times over the years, Search is your friend!
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Old August 30th, 2017, 11:42 AM   #5
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Re: Audio "clipping" without passing 0db

I have a ProCo AV1B which takes line, mic, or speaker level and pads it to XLR and 1/4" line- or mic-level output. It's saved me more than a few times when I could only get speaker-level outputs.
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Old August 30th, 2017, 12:05 PM   #6
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Re: Audio "clipping" without passing 0db

The dj directed me to plug my Zoom H5 into a PA speaker with xlr out. I asked if it was line or mic level, he replied both. That confused me so I plugged in my H5 and did a sound check set it to 5 which sounded fine so I didn't look at the level setting.
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Old August 30th, 2017, 12:07 PM   #7
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Re: Audio "clipping" without passing 0db

Haha, "both."

As I suspected, he probably had self-amplified speakers, like the ubiquitous JBL Eons. They take a mic or line level input and loop it through the output. He was probably clipping the mic inputs at his mixer, which is why your recording was clipped.
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Old August 30th, 2017, 12:14 PM   #8
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Re: Audio "clipping" without passing 0db

I know both.

Yes eon/loop through sounds familiar. So in hind sight what would have been the best approach?
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Old August 30th, 2017, 03:33 PM   #9
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Re: Audio "clipping" without passing 0db

Yes, many of the self-powered speakers have through-puts and/or mix outs if it has multiple input channels like some of the JBL Eon 500 and 600 series.

Speaker level into line level: I shutter just thinking about it. Some DIs can attenuate speaker level and output mic level. My old Countryman Type 10 had a separate speaker level input. It wasn't cheap though, even when I bought it back in the 1980s.
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Old August 30th, 2017, 05:41 PM   #10
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Re: Audio "clipping" without passing 0db

In all of the past discussions on recording live events the bottom line is always the same. Always go in self prepared to record your own quality audio independently of ANY other system that may be there, period. Then back that system up.

Then get your board feeds, and other systems that may enhance a good feed if everything works out perfectly. Don't put your success in someone elses hands you don't even know. You wouldn't ask the DJ to operate one of your cameras would you?

Over the years there are countless posts here that say "help I have no audio". Almost all of them blame the audio guy or DJ. When video recording a live gig quality audio is your responsibility, not anyone elses. Coming away with bad audio is inexcusable no matter what you did. If it is crap you own it. There are no second takes at live events. Get it right the first time or face your client with bad news.

Not trying to be a hard a**, just saying it the way it must be done.....

Kind Regards,

Steve
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Old August 31st, 2017, 06:00 AM   #11
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Re: Audio "clipping" without passing 0db

I figured out what happened I was actually lucky I got what I needed.

After reading up on the Zoom H5, I discovered it has an odd way of handling line and mic levels. There is no line/mic setting in the Zoom H5. The xlr inputs are only for mic level. There is a 20db pad in the menu , which I had on but that wouldn't prevent clipping because it pads after the mic preamp. The 1/4 trs inputs on the H5 are for line level.
In my situation I needed to either plug into the 1/4 input using a xlr to 1/4" adapter or use a xlr external attenuator to reduce the signal to mic level.
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Old August 31st, 2017, 09:09 AM   #12
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Re: Audio "clipping" without passing 0db

The H4n was like that, the 1/4" input (on the combo jack) was line level. Unfortunately it was unbalanced and -10dB as well. The H5's line in maybe +4/balanced though (?).

A 20dB pad is not enough for attenuating a true nominal +4dB (w/peaks approaching +20dB) to nomina mic level (-60dB). A 50 dB pad is typical for a line to mic level. One can usually get by with a little less though.

Last edited by Rick Reineke; August 31st, 2017 at 11:33 AM.
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Old August 31st, 2017, 11:35 AM   #13
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Re: Audio "clipping" without passing 0db

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Originally Posted by Pete Cofrancesco View Post
There is a 20db pad in the menu , which I had on but that wouldn't prevent clipping because it pads after the mic preamp.
Hi Pete, Let me see if I can help a little bit. I'm not quite sure what you mean here about the pad wont help? The -20db pad is Pre Fade because it is not a clip blocker like a limiter. It is going to knock 20db off of every signal going through it. Your meter will reflect that change. And, as Rick said, often that is not enough. Zoom makes a big deal out of claiming it will handle a pro line level of +4db because of that pad. In the real world that is flat out not true. Especially when you are tied into a system like a mixer with an operator behind it constantly changing gain and output levels.

This is how I run my H6 (which I am not crazy about) when taking a board feed. I engage the -20db pad. But between the H6 and the console I place an old passive bang box ( DI Box, kind of) with 4 buttons on it, I can select reduction from 0 to -30 with the buttons. That gives me a total of -50db if needed. In live reinforcement situations (especially if a band) I almost always end up engaging that pad. I don't set it and forget it ether. No matter what the audio mixer tells me his show level is going to be during rehearsal things change. Mixing FOH audio is a very dynamic operation.

This part is becoming a soap box. There are other things that can make audio sound bad even if your meters are not showing a clip. Zoom recorders really show their amateur side when it comes to their on board compressor/limiter. In a perfect world compressors and limiters should be a rack mounted device. Of course these days they are ubiquitous as a digital menu item in cameras and recorders. That is not a bad thing, the problem lies most often with user error. I see guys set them and forget about them all the time, that is a big problem. First, a limiter is something you do NOT want to engage. It is supposed to be insurance against clipping on peaks for properly set gain structures. When a limiter engages it damages the sound quality of the audio. Second, and the big problem is that camera and recorder limiters don't even tell you when they are engaged (gate active). You may be receiving a signal that is way over driven but your your meter will read 0DB (or less). If you are not monitoring properly or in a loud environment it may sound OK. Then you go to post and find out it is crap. I am probably going to sound like a broken record here.....When recording ANY audio signal always begin with ALL signal processing parameters turned off. How can you adjust or process something if you don't know what you are processing? I am not saying you did not know this Pete, I am saying it is a common problem among some video guys that do not understand enough about audio. Rant over......

Kind Regards,

Steve
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Old August 31st, 2017, 05:17 PM   #14
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Re: Audio "clipping" without passing 0db

With most of the budget recorders, the compressors, limiters, HPF and any other processing are after the input stag(not to mention the record volume), so over-driving that analog stage is common. Hence, we often read, "my record levels were low but the sound is still distorted."
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Old September 1st, 2017, 05:39 AM   #15
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Re: Audio "clipping" without passing 0db

Thanks for the replies. I have a better understanding now of both my recorder and of general audio principles behind it.

Your right theses consumer digital recorders are ill equipped to deal with hot signals and their various internal sound controls tend to lower lower the volume after its been clipped..

I guess these same issues crop up because we can't dedicated ourselves to the audio and these recorders gloss over these issues and their limitations.
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