Audio Signal-to-Noise Ratio not that great on HMC150

[Averdahl]

I use two pads from Audio Technica, one for the left and one for the right channel, to avoid clipping when recording live bands.

I can set it to either -10dB, -20dB or -30dB. -20dB provides the best result and i have never had problems with clipping audio thanks to those two pads: Audio Technica AT8022

The microphone i use is a Audio Technica AT825.

/Roger

 

[8string]

So there you have it...

So there you have it...

Richardh, I think that you can start by taking your camera to a dealer or someone in the area that has one, if one is around, and make sure you don't have a hardware problem with it. If not, then you now have a bunch of easy to try stuff, from low end with the attenuators to higher end stuff. Best of luck.

 

[Denwa]

2) The HMC has a pretty low INPUT clipping threshold. This is clipping that occurs before the preamp, and before the limiter. This is what explains the clipping sounds that occur when the meters indicate no clipping. The HMC needs pads for inputs that the HVX/DVX handles without a problem. Somewhere, I posted the actual input level that makes the HMC clip regardless of gain settings... but I'm in too much of a hurry now to hunt it down. IIRC, keeping the gain dial at 1 dot below 12 o'clock is the safe position... that is, wit that or a higher gain setting, a line-level input will clip at the OUTPUT (and on the meters, etc) before it clips at the input. Any lower level and you're in danger of the input clipping without any indication. So: the HMC needs to be fed lower input levels than you may be used to, and you need to think of input clipping as well as output clipping.

I don't generally use the HMC for any critical audio; I make sure to use the HVX for almost any situation where the camera will be the only audio recording device (and in general, I record double system).

If using a field mixer with adjustable output gain stetting, lower the output gain. (note that this is independent of what the meters say or what the master is at).

 

[ronedee]

I don't have the noise problem you describe on my 150. The headphone jack noise is a known issue, but it doesn't translate into noise in the recording. I have also had XLR feeds directly into the 150 from a sound board, with no noise level problems. An example you can listen to is at http://www.youtube.com/watch?v=eWHMfy38XwU. This concert was earsplitting, way too loud, well over 100 decibels, but the feed of the board was fine, as you can hear. I've also just recently shot a live concert off the board and you can see/hear the results at www.centrum.org front page. While I could have mixed it better, there's no noticeable noise I can hear. Other examples of 'wild' sound off live speakers are at 8stringthing on youtube, which includes recordings of bands at Wintergrass without use of the sound board. Given a good solid sound man, you should be able to record wild stuff just fine. The real problem is trying to record ear splitting noise thats marketed as music. But there are ways to get it done, since even jet engines can be recorded. I just use earplugs and miminize my time in these concerts, as you go deaf from the low end stuff and the high end. There's no hiding from the ear damage.

I've recently bought a mixpre and love it. It feeds me a 1 kHz tone so I can properly balance my incoming sound, and have yet to have it clip on me at the camera. It was well worth the money, IMHO. I also have a Zoom and can feed the Zoom with the MixPre while recording onto the 150. And you can put headphones into the Mixpre if you don't like the noise on the 150 jack. This all allows me maximum flexibility in post. But even the Zoom is a 'low end' recording device, and has known problems which you can find by Googling it. You might step up to a higher end field recorder, like from SD, edirol or Sony. And remember to record at 48 kHz!

Thanks for the info!

At live events with a 2 camera shoot, I use an older Sony for the wide, "stationary" footage. I use the HMC for the close-ups and general hijinx. So attaching cables and/or devices is out of the question. Unless I want to bring down half the band on a stage sweep! I need to be as portable as possible to get action shots.

I have had great results from the Zoom! The only negatives I've read are the feature laden menus. Which some say are cumbersome. I was using the menu easily the minute I took it out of the box! The sound is great, and very precise. I actually add color and noise to some recordings because it's so clean! One big reason I got it was the 4ch simultaneous recording. I don't think there are many portables on the market that will do that. I use two condensers in a spread pattern, and the onboards in their XY configuration.

I still have the HMC sound levels on. But not enough to have to worry whether I'm saturated or not. And if there is a dropout on my other recording devices, I can always use the HMC as a backup once run through Soundbooth.

All-in-all, I don't believe there is a reason to use the 150 onboard sound for rock music. I could fiddle with it, but there's no point. It's also directional, so I need to be cognitive of levels standing in front of massive columns, and bumps, etc. It's a little more work but I'm getting great sound recordings now w/o the 150, and peace of mind.

 

[Allen Ellis]

Just since skimming this thread I don't see it mentioned, the headphone jacks send out considerable noise which isn't present in the recordings. So do all of your tests with footage played back on a computer for accuracy.