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killmaster
07-16-2010, 09:34 PM
Hi There,

Based on recommendations from this forum I purchased a Canon T2i and Olympus LS-11. I'm very very happy with my decision. I've been experimenting with sound and am thoroughly confused however. I set up all my microphones and tried some tests to determine what setup I will use. I'm starting out doing interviews and acting so voice is the main concern.

When I plug my lavelier directly into the LS-11, it already sounds great, though I have to crank the record volume up to 8 or 10. If I go through my preamp, I get much more sound but also much more environment noise. I turn to volume down to adjust and its turns out that it sounds to my ears almost identical to cranking the volume up during recording. Another mic (Rode NT1A) sounds way better through the preamp while my Shure SM57 actually sounds much better not using the preamp. I'm really confused on how to think about this. I don't want to just trust my ear. I want to know I'm getting audio I can use and edit with successfully. I have a large variety of mic types and each seems to have noticeably different responses from each other. So how best to think about all this when you are starting out?

here are some basic questions that came up:
1) should I use a preamp no matter what?
2) if I use a preamp, should I still plug into the mic input or should I plug into the line input on the LS-11?
3) what's this about balanced and unbalanced? How can I know? I know the cables I got are supposed to be balanced.
4) I assume I should record PCM for best quality (shows up as WAV in the menu when I select PCM)
5) For my livelier (AKG CE10), should I use phantom power if the mic manufacturer says it can take phantom power or not? Sound about the same to me either way.
6) Is the Olympus "Plug-InPower" the same as phantom power? From what I can gather it is the same.
7) Is there any reason to try and record line in on my T2i instead or in addition to recording externally?
8) If I just record externally and don't shoot anything over 5 minutes in length, is sync going to be a problem?

If there is an article that spells this stuff out for newbies, I'd appreciate a link. I looked but couldn't find anything that was layman enough for me to understand...

thanks!!

greg

brunsona
07-17-2010, 06:34 AM
Greg,

While you said you don't want to trust your ears, that's actually the best thing to do. You can measure sound characteristics and aim for perfection but your ears should always be the ultimate judge.

That being said, you need to monitor the sound on high quality equipment or the differences in setups will be masked by the playback system. And you need to monitor in a decent environment or the sound of the room can affect what you hear.

I recommend a good set of headphone as a way to monitor sound consistently no matter where you are. I use Sony MDR-V6 but there are many phones as good or better. I just know these really well.

You need to check the noise levels of the mics with and without the preamp. The sound quality may vary some but the noise when no one is talking is likely to vary a lot. You didn't say what your preamp is but it's easy to check.

Play a piece of music or voice through a sound system so you can have a repeatable sound source. Do this in a quiet room with no fans, appliances, etc.

Put all your mics the same distance away from the system so you take out that variable. Then plug in a mic without the preamp and set the level near the top of the meters. Record some sound and record some silence.

Change mics (at the same distance from the sound source), reset the level to the same place on the meters and record some of the same exact sound and more silence. Repeat all of this with the preamp in the signal chain.

Then listen to all the recordings with a good set of phones at fairly high volume. Listen to the quality of the sound but pay a lot of attention to the level of hiss and noise in the silence. You want the best quality sound with the least noise possible.

To double-check your ears look at the waveform on your computer and you will visually see which has higher noise levels. You can also use your computer to make the volume of the samples consistent if needed.

Write down the results and you'll know which microphones work better with the preamp.

Check a wiki for information about balanced and unbalanced. Balanced is better for cable runs longer than 20' and it's less likely to pick up stray radio signals from outside sources. But the microphone and preamp have to be balanced or it makes no difference which cable you use.

Use PCM for recording. It will be a .wav file. Also use the highest bit and sample rates possible - with the Olympus that will be 24 bit/96Khz. If you want to create smaller files you can record at 24 bit/48Khz as that is what most video editing systems use and it should be more than good enough for voice.

Phantom power does not affect the sound. Some microphones require power to function and you either power them with a battery or through the mic cable from a preamp/mixer. You will likely damage your SM57 if you flow power to it so only use phantom power with mics built for it.

The T2i does not have a line in, just mic in. Unless you rig up some hack the audio is screwed up by the bad auto-gain system. Even hacked the audio quality is pretty poor. I use it for reference sound only.

The only reason to feed sound to the T2i is if want to record the sound from a mixer to match the sound on your external recorder. You'll see this done by pro sound operators who will feed a line to the cameras from their mixer so the reference is as clean as possible and matches the timing of the external track exactly.

As for syncing the external sound with takes of more than five minutes I use Plural-Eyes software when I have a lot of clips to match up. It's amazing. Otherwise I just match the sync up by hand on the timeline, lock the new audio track to the video and cut it up as needed.

You can get in the habit of starting and stopping the recorder when you start and stop the video recording. Or you can let the audio recording roll through the entire session. I usually let it roll because I've caught some great moments with the audio when no camera was recording and covered them later with b-roll.

Hope this helps.
-a-

killmaster
07-17-2010, 12:00 PM
this is fantastic! You answered all my questions very clearly. I'm very grateful...

I'm going to set up and run the test you recommended in the next few days. I've been reading about some headphones based on your suggestion and I've narrowed it down to these 4. If you have any positive or negative experience with these and have the time, it'd be great to know:

Sony MDR7506
AKG K240S
Sennheiser HD280 Pro

all around $100

this set sounds incredible but is $160:
Audio Technica ATHM50 Closed-Back

In any case, thanks again for taking the time. I'll post back with my microphone results in a few days.

killmaster
07-17-2010, 12:03 PM
actually 2 things I still wonder about. I think the "Plug-InPower" feature of the LS-11 must be phantom power, right?

And I'm assuming that once I pass the mics through the preamp, I should still route that to the recorder using the "mic" input as opposed to the "Line In" inut. Is that correct? Seems like line-in and mic are vastly different levels.

dlion16
07-17-2010, 12:10 PM
ditto what bruns said. your ears are the final test.

i have the 7506, you can't go wrong.

killmaster
07-17-2010, 03:33 PM
by the way, my preamp is an Art Tube Mic Preamp

brunsona
07-18-2010, 07:59 AM
Greg,
Any of the headphones you listed will be great. What matters more is that you spend time listening to them with a variety of material so you know what "good" sounds like. It's like calibrating your hearing to the phones. Mostly, though, you need them on location because there can be so many issues with the sound that are not visible by just watching the meters bounce.

I don't know what "plug-in power" is - seems to be an Olympus term. But they were clear that it was not phantom power. And they were clear that it should be off unless the microphone uses 'plug-in power'. Maybe their mics use it. I'd leave it off.

You need to connect to line-in from the pre-amp. The purpose of the external pre-amp is to bypass the mic pre-amp built into the recorder. That's why you're getting such a hot level when you use the pre-amp. Line-in will be much better and much less noise.

The Art Tube is probably higher quality than the one built into the LS-11. If nothing else you'll need it for XLR connections. Try it plugged into line-in and you'll likely use it all the time.

-a-

killmaster
07-18-2010, 12:05 PM
thanks Adriel!

I ordered the Sony heaphones and have turned off plug-in power. Yes, re-reading the manual I see that it explicitly says it is not phantom power. thank you for that...

I actually got a couple XLR to mini stereo cables thinking I'd go directly into the LS-11 :)

So thanks for the tip on going to line-in. It all makes sense now.

brunsona
07-24-2010, 01:05 PM
Greg,

I created a video comparing shotgun and lavalier mics on the Canon T2i and Zoom H2.

Here's a link. (http://dslrhd.com/2010/07/dslr-audio-lavalier-vs-shotgun-microphone/#more-1804)
-a-

killmaster
07-29-2010, 09:40 AM
thanks Adriel! very helpful to see...

brandondull
07-29-2010, 01:26 PM
how much did that audio stuff cost? Please provide B&H links if you could.

killmaster
07-29-2010, 08:30 PM
http://www.bhphotovideo.com/c/product/642526-REG/Olympus_142570_LS_11_Compact_Stereo_Field.html

got it for around $300 on amazon

preamp:
http://www.bhphotovideo.com/c/product/130518-REG/ART_TUBE_MP_Tube_MP_Preamplifier.html

cables:
Audio-Technica 25' XLRF-XLRM BALANCED MIKE CABLE - AUAT831425 1 $18.99
$18.99
Comprehensive STEREO MINI/M to XLR/M CABLE - 10' - COCSMMXM10 1 $14.99
$14.99
Comprehensive STEREO MINI/M to XLR/F CABLE - 10' - COCSMMXF10 1 $11.99
$11.99
(from B&H)

headphones:
http://www.zzounds.com/item--SNYMDR7506


is this what you were thinking of?