Need good ears to tell me if my mic is "broken"

Battle Vaughan · June 26th, 2009, 03:50 PM

The sample on the right is clearly a maxed-out preamp. That's my message you quoted, and when I've overloaded my XHa1, the sample on the left has looked like the sample on the right, just with a lower amplitude. You have a very heavy waveform but with some amp headroom, as there is clearly preamp response in the spikes. My guess is you're right, the Rode mike is overloading. One of my collegues has an NTG2 with which he has experienced mike overload at a sporting event with thousands of loud-cheering fans, so it may be that this particular mike is sensitive to overload. In that case the in-line attenuator mentioned earlier wouldn't help (although it's a great thing to have in your kit -- we issue the Audio-Technica 10/20/30 db model, about $35, markertek sells). I use the Sennheiser ME66 and with some good luck have only maxed out the mike once, and that was in an extremely loud venue....might be worth an a/b trial if you can borrow one to compare with, might define the problem....best wishes/ Battle Vaughan/miamiherald.com video team

Vito DeFilippo · June 26th, 2009, 04:45 PM

Hey Battle,

Quote:

Originally Posted by Battle Vaughan

The sample on the right is clearly a maxed-out preamp.

I think my image sample was misleading, as that's the default waveform height I see in Avid. If I reduce the waveform view, I get this sample (attached), which clearly is not clipped. It's the same recording and waveform, just the view is reduced. But if you listen to the audio, I'm sure you hear the distortion in the bass. And the distortion is still present at -18db trim.

So from your test suggestion, I think my trim is post preamp since I'm getting the same result, and it's the mic that's overloading, and not the preamp.

Looks like I need a mic for loud events...

Thanks again for your time. You guys are the best.

Battle Vaughan · June 26th, 2009, 08:49 PM

Yes, the first waveform would clearly have been a maxed-out preamp -- in digital audio, 0dbFS is where you run out of digits and everything just bangs up against the brick wall. Clearly you have some headroom, even with a very heavy track (which may reflect the source if it's one of those heavy-metal constant-noise things that doesn't have a distribution of loud and soft sounds). So, again, I think you are correct and your mike is maxed out. Usually the preamps load up before the mike as most have an upper limit somewhere around 130dB, but not the case here. I don't know the venue you are working, but perhaps a shotgun isn't the answer in that case, maybe a wider cardioid with a 10 or 20 db pad would help here. Or even a dynamic mike, like a Shure Sm87, which has a lower output than a condenser mike by far...that's a standard instrument mike that every band owns, and they cost about $100 new....good luck! / Battle V.

Rob Morse · July 2nd, 2009, 08:56 PM

Quote:

Originally Posted by Battle Vaughan

I use the Sennheiser ME66 and with some good luck have only maxed out the mike once, and that was in an extremely loud venue

I had a problem with loud venues and the ME66 but I sent it in to Sennheiser and they adjusted the sensitivity.

I'm in the same boat as Vito right now. DJ's think if they play the music louder, somehow magically, more people will dance. I'm using an AT835ST and it has made a big difference in my audio but it's still not everything I'm looking for. I've spent the past few hours looking through these threads and while the sound guys are extremely knowledgeable, most don’t have to deal with a one man show. As videographers we have to get the best audio sometimes creatively. It would be easy if I stood in one place all night but of course my video would then be garbage. With that said, can I use a drum mic wirelessly set up in front if the DJ speakers with fair results? Does anyone do anything like that? If anyone has some other suggestions, I would appreciate the feedback.

Battle Vaughan · July 2nd, 2009, 09:37 PM

Oops, I meant SM57. But see my answer in other thread about a high-headroom mike from AGC....bv

Vito DeFilippo · July 19th, 2009, 08:49 PM

Hey guys,

I wanted to update with my solutions, but have posted it here to bring it together with a similar thread to avoid crossposting:

http://www.dvinfo.net/conf/all-thing...ud-venues.html

Thanks to all for your help.

Paul R Johnson · July 20th, 2009, 10:45 AM

Rob asked about using a drum mic - I assume he means a kick drum or snare drum mic (like the 57). The 57 works fine in loud situations and sounds pretty ok, However, proper kick drum mics are very strange sounding - after all, they're stuffed inside a drum and beaten to death! They have a good low frequency response, but not much up the top. Ok for maybe a double bass, but not much use for anything else!

Jon Fairhurst · July 20th, 2009, 11:21 AM

Quote:

Originally Posted by Paul R Johnson

R...proper kick drum mics are very strange sounding... They have a good low frequency response, but not much up the top...

Surprisingly, a good kick drum mic has a strong high frequency response, as well as a low response, with little in between. The high frequency response is to capture that snap of the beater when it hits the head.

The SM57 is just the opposite: lots of mid response with little in the lows, and a nasty, falling curve after a 6 kHz peak.

My son and I have mic'd things with both mics side by and mixed to taste. The results are excellent on electric guitar. The BD mic gives a scooped, metal sound, but it's too extreme. Mix in the 57 and you can get exactly the balance you want. As you decrease the BD mic, you get more of a '70s or '80s midrange guitar sound. The BD mic really helps with extreme drop tunings and 7-string electrics.

Here's the frequency response of the Sennheiser e902:

July 19th, 2009, 08:49 PM	#21
Vito DeFilippo Trustee Join Date: Mar 2006 Location: Montreal, Quebec Posts: 1,585	Hey guys, I wanted to update with my solutions, but have posted it here to bring it together with a similar thread to avoid crossposting: http://www.dvinfo.net/conf/all-thing...ud-venues.html Thanks to all for your help. __________________ . http://www.nosmallroles.com

June 26th, 2009, 03:50 PM	#16
Battle Vaughan Trustee Join Date: Nov 2008 Location: Miami, FL USA Posts: 1,505	The sample on the right is clearly a maxed-out preamp. That's my message you quoted, and when I've overloaded my XHa1, the sample on the left has looked like the sample on the right, just with a lower amplitude. You have a very heavy waveform but with some amp headroom, as there is clearly preamp response in the spikes. My guess is you're right, the Rode mike is overloading. One of my collegues has an NTG2 with which he has experienced mike overload at a sporting event with thousands of loud-cheering fans, so it may be that this particular mike is sensitive to overload. In that case the in-line attenuator mentioned earlier wouldn't help (although it's a great thing to have in your kit -- we issue the Audio-Technica 10/20/30 db model, about $35, markertek sells). I use the Sennheiser ME66 and with some good luck have only maxed out the mike once, and that was in an extremely loud venue....might be worth an a/b trial if you can borrow one to compare with, might define the problem....best wishes/ Battle Vaughan/miamiherald.com video team

June 26th, 2009, 08:49 PM	#18
Battle Vaughan Trustee Join Date: Nov 2008 Location: Miami, FL USA Posts: 1,505	Yes, the first waveform would clearly have been a maxed-out preamp -- in digital audio, 0dbFS is where you run out of digits and everything just bangs up against the brick wall. Clearly you have some headroom, even with a very heavy track (which may reflect the source if it's one of those heavy-metal constant-noise things that doesn't have a distribution of loud and soft sounds). So, again, I think you are correct and your mike is maxed out. Usually the preamps load up before the mike as most have an upper limit somewhere around 130dB, but not the case here. I don't know the venue you are working, but perhaps a shotgun isn't the answer in that case, maybe a wider cardioid with a 10 or 20 db pad would help here. Or even a dynamic mike, like a Shure Sm87, which has a lower output than a condenser mike by far...that's a standard instrument mike that every band owns, and they cost about $100 new....good luck! / Battle V.

July 2nd, 2009, 09:37 PM	#20
Battle Vaughan Trustee Join Date: Nov 2008 Location: Miami, FL USA Posts: 1,505	Oops, I meant SM57. But see my answer in other thread about a high-headroom mike from AGC....bv

July 20th, 2009, 10:45 AM	#22
Paul R Johnson Inner Circle Join Date: Nov 2005 Location: Lowestoft - UK Posts: 4,045	Rob asked about using a drum mic - I assume he means a kick drum or snare drum mic (like the 57). The 57 works fine in loud situations and sounds pretty ok, However, proper kick drum mics are very strange sounding - after all, they're stuffed inside a drum and beaten to death! They have a good low frequency response, but not much up the top. Ok for maybe a double bass, but not much use for anything else!