Audio from mixer distorted but levels not clipping on Zoom H4n

[bodressler]

Hello,

I attempted to record audio of a loud musical performance tonight from the venue's sound board, and came across an issue where the levels were maxing at -24db and the audio was very distorted. The waveform looks like it's clipped, but it clips/flattens out at -24db.

Would this be a case of the output level of the board being too high, and my Zoom recording the distorted audio at "acceptable levels"?  The input level on my device was below 1.

Thank you in advance for your help.  Luckily this is not a catastrophe, but would like to know if this was an error on the part of the venue's sound guy and what can be done to avoid this in the future.

 

[Taranis]

I think the waveform speaks for itself. It seems you recorded an already clipped source at a lower volume.

[andrew berekdar]

Out of interest what were your settings on the input your recorder? Did you set the input to line-in, rather than mic / mic+48?

[bodressler]

Out of interest what were your settings on the input your recorder? Did you set the input to line-in, rather than mic / mic+48?

No, and I think therein lies my problem or that I didn't use an attenuator. 

I had success the previous night recording off of the board at a different venue but I think it was because I had a competent sound guy helping.

Will be purchasing this attenuator later today for our more important performance tonight.  

http://www.bhphotovideo.com/c/product/68600-REG/Shure_A15AS_A15AS_In_Line_Attenuator.html

Thank you!

[andrew berekdar]

No, and I think therein lies my problem or that I didn't use an attenuator. 

I had success the previous night recording off of the board at a different venue but I think it was because I had a competent sound guy helping.

Will be purchasing this attenuator later today for our more important performance tonight.  

http://www.bhphotovideo.com/c/product/68600-REG/Shure_A15AS_A15AS_In_Line_Attenuator.html

Thank you!

Changing to the line-in input should solve the problem.

Microphones have a low output, which is why they need to be boosted, but if you boost an amplified signal (i.e. from a mixing board) you can distort it, which appears to be the case here. Try to monitor the sound with headphones from the Zoom H4n you'll here the distortion but you won't necessarily be able to tell by the levels on the visual display.

Good luck for tonight and let me know if changing the input to line-in sorts the problem out or whether you need to use the attenuator. 

[Taranis]

Changing to the line-in input should solve the problem.

Microphones have a low output, which is why they need to be boosted, but if you boost an amplified signal (i.e. from a mixing board) you can distort it, which appears to be the case here. Try to monitor the sound with headphones from the Zoom H4n you'll here the distortion but you won't necessarily be able to tell by the levels on the visual display.

Good luck for tonight and let me know if changing the input to line-in sorts the problem out or whether you need to use the attenuator. 

If you boost a signal and it clips then yes you can distort it, but the waveform shows -24dB loudness, so I guess it was not the Zoom H4N that clipped it. The line in signal must have been already clipped.

[andrew berekdar]

If you boost a signal and it clips then yes you can distort it, but the waveform shows -24dB loudness, so I guess it was not the Zoom H4N that clipped it. The line in signal must have been already clipped.

The meter is referring to the signal in the NLE, not what was going in to the recorder. If you distort the signal as it goes in to a recorder, dial the recorder to 1, you'll end up with a weak (-24dB ) but already distorted signal. 

[Taranis]

The meter is referring to the signal in the NLE, not what was going in to the recorder. If you distort the signal as it goes in to a recorder, dial the recorder to 1, you'll end up with a weak (-24dB ) but already distorted signal. 

Okay I'm not familiar with the Zoom H4N. Are you saying that it's possible to overdrive an otherwise clean signal inside the recorder and record it at an attenuated level?

[andrew berekdar]

No, and I think therein lies my problem or that I didn't use an attenuator. 

I had success the previous night recording off of the board at a different venue but I think it was because I had a competent sound guy helping.

Will be purchasing this attenuator later today for our more important performance tonight.  

http://www.bhphotovideo.com/c/product/68600-REG/Shure_A15AS_A15AS_In_Line_Attenuator.html

Thank you!

Apologies, I forgot the H4n doesn't have a line-input option to by-pass the mic preamp, so you'll need an attenuator...

Okay I'm not familiar with the Zoom H4N. Are you saying that it's possible to overdrive an otherwise clean signal inside the recorder and record it at an attenuated level?

Yes, here's a video showing that happening with the H4n 

https://vimeo.com/38171316

Which is why you need an attenuator of some kind to prevent it. Other recorders allow for a line-in.

This explains what is happening to the voltage difference between line & mic

http://geoffthegreygeek.com/audio-levels/

 

Hope this helps 

 

[Taranis]

Apologies, I forgot the H4n doesn't have a line-input option to by-pass the mic preamp, so you'll need an attenuator...

Yes, here's a video showing that happening with the H4n 

https://vimeo.com/38171316

Which is why you need an attenuator of some kind to prevent it. Other recorders allow for a line-in.

This explains what is happening to the voltage difference between line & mic

http://geoffthegreygeek.com/audio-levels/

 

Hope this helps 

 

Okay I get it now, thanks for the clarification. Yeah, he will need an attenuator.

[Serious Steve Thomas]

The manual  (you need a magnifying glass to read it) states that the maximum input on the H4n Pro xlr sockets is -6dBu. I found that I had to set my board output to around -25dBm to stop the input lights flickering  (they flash off to indicate clipping). There recording level control has no effect on the input gain. You can use it to set the level of your clipped signal wherever you want,  but it'll still be clipped. So I've invested in a pair of 20dB fixed attenuators to add to my arsenal