Building an Audio Kit (wisely)

[Dan Brown]

I'm not sure.

The Beachtek can only attenuate the signal, so it's adjustable from 0 dB to -50dB. My Shure SM58 can drive the input of the DV852, but I've only used it as a narration mic, up close (12-24") to the person speaking.

The Shure SM58 has a sensitivity of -54.5 dBV, that's pretty low, about 1.9mV at 94dB sound pressure level. Now here are some sensitivities for other mics I'm looking at, all at 94 dB SPL (so called 1 Pa):

Shure SM58: -54.5dbV (1.9mV)
Oktave M012: -40dBV (10mV)
AT3031 Card.: -34dBV (20mV)
AT835B SG: -40 dBV (10mV)
AT897 SG: -40dBV (10mV)
AT873R HCard: -37dBV (14mV)
AT899 Lav: -43dBV (7mV)

So it looks like all the condenser mics have 10dB or more output signal than the SM58. I figure the Beachtek will be OK with a 'hot' condenser on phantom power.

I'll find out tomorrow when the Beachtek arrives and I plug the Oktavas into it. I plan on "planting" the Oktavas and video-ing the Christmas morning festivities. That should be an interesting test of this set-up.

Cheers...

[Dan Brown]

The BeachTek DXA-6 arrived and I have now used it some. It mounts under the DV852 fine, but shifts the center of gravity well forward of the fluid head tilt axis. That's kind of a pain, but OK as long as you tighten up the damping on that axis.

I set the attenuation knobs to 0 dB, switched on phantom power (I like that) and ran the Octavas into it. The audio level is high enough and seems to work just fine. I shot the Christmas morning festivities using this set up. It's a fairly large living room, about 20 x 24 feet. The mics were set on stands in opposite corners, moved into the seating area as close as possible. The audio quality was very good, and excellent for people sitting directly adjacent to one of the mics. Far, far better than using the in-camera mics.

I'm very happy with this set-up for now, I don't see myself breaking out the Behinger, if for no other reason than dealing with another box interconnected with cables and the need for AC power, etc. Nor do I seem myself getting the Marantz, unless I go to a Steadicam type of support, where cables are impracticle.

AGC functions whether I use the Behringer or the BeachTek. Audio is fine as long as there is something to record. When the 'talent' is quiet, then the gain ramps up and the ambience of the environment dominates the audio track. It isn't absurdley loud, but not as good as if audio levels could be set with a manual level and VU meters. Still, it should be OK, and I assume I can dial-down the ambience audio during post in FCE.

I'm going to add an AT897 mic with boom pole and shock mount soon, I'll report back on that. BTW, I'm going to try the new AT897 over the AT835b because the patterns are nearly the same, but the 897 is 3.5" shorter. That will let me use it on the camera, without intruding into the frame at the wide end of the focal length.

Cheers...

[Carlos E. Martinez]

<<<-- Originally posted by Dan Brown : The audio quality was very good, and excellent for people sitting directly adjacent to one of the mics. Far, far better than using the in-camera mics. -->>>

Camera mics are only good for incidental ambient. You will always get a better sound from external mics.

Pity you went for the Beachtek DX6, because for the same money you could have got one of our mic preamps. I also think the Beachtek unbalances the camera. That's why our preamp was designed for belt or tripod support.

<<<--AGC functions whether I use the Behringer or the BeachTek. Audio is fine as long as there is something to record. When the 'talent' is quiet, then the gain ramps up and the ambience of the environment dominates the audio track. It isn't absurdley loud, but not as good as if audio levels could be set with a manual level and VU meters. Still, it should be OK, and I assume I can dial-down the ambience audio during post in FCE. -->>>

As long as you don't have any new dialogue coming in you can do that. In order to do that you should do something specific. After you end or shoot or during it, do a specific ambien recording, at the top level the AGC gets to and stays there. Then use that as a background for your silent shots.

If you go in with a higher level, high-mic or low-line, you should be able to cheat the AGC for a longer time.

<<<-- I'm going to add an AT897 mic with boom pole and shock mount soon, I'll report back on that. BTW, I'm going to try the new AT897 over the AT835b because the patterns are nearly the same, but the 897 is 3.5" shorter. That will let me use it on the camera, without intruding into the frame at the wide end of the focal length.-->>>

You are getting to the point where, as I say on my location audio tutorial, you should seriously consider using a sound man.


Carlos

[Arthur John]

Reading the fine points of this post has really been informative and I've used it as a basis for putting together my own audio kit:

1. Samson Mixpad 4, portable mixer $159
2. Rode NT3 Mic $152
3. Shure SM93 Wired Lavalier $146
4. Sony MDR-7506 monitoring headphones $98
5. 8 foot Aluminum BoomPole $11

I used to have a window cleaning gig and used aluminum extension poles, and there's a nice 8 footer available at a nearby hardware store for cheap!

I decided on the Rode NT3 mic for boompole work because of the great reviews it has and it may have a better sound than using a similarly priceranged shotgun.

I wish I could find a portable mixer with 3 XLR inputs around the same pricerange, but the Samson has 2 and runs off of a few 9 volt batteries and should work well.

The SM93 seems like it will be a great Lav for recording voices or for hiding in props close to the actors. It's a lot smaller than some of the less expensive lavaliers, although I came close to choosing a schriber acoustic SA-345 instead. I'm hoping paying a few extra dollars for the Shure will be worth it though.

I should say that I did a lot of extra research on closed ear headphones after reading a few other articles on gear recommendations, and I came to the conclusion that the MDR-7506 is about the best you can get for the money. I haven't found any negative posts about them, and found plenty of other negative posts and reviews about seinhieser and AKG around the $100 range. I personally think that choosing a good pair of headphones for your sound man is vitally important if you want to catch good sound while filming.

I hope this info helps!

[Bryan Beasleigh]

"Pity you went for the Beachtek DX6, because for the same money you could have got one of our mic preamps. I also think the Beachtek unbalances the camera. That's why our preamp was designed for belt or tripod support"

I've checked this thread and there is no mention of "your" preamp until now. Considering your location , buying through you would be inconvenient.

The beach with phantom is pricey but it 's quality gear and fills a need for portability. There is a greater chance of camera damage with a belt mounted adapter than one that securely attached to the camera base.

[Carlos E. Martinez]

<<<-- Originally posted by Bryan Beasleigh :
I've checked this thread and there is no mention of "your" preamp until now. Considering your location , buying through you would be inconvenient.-->>>

That company is mine and is located in the USA, not in Brazil. I design the stuff here and build it there. There's a sales rep in Florida. We are moving address within Miami, that's why there's no address at the moment, but there will be next week. Holidays seemed like a good time to do that.

That preamp was designed at first to attend my needs here, as I own an audio rental house in Brazil and Argentina, and in the late '90s there were people doing more serious DV jobs using my pro audio gear. That interface was far from easy, so at first I tried to modify what was around, like the Beachtek.

Then decided it was better going for a whole new thing that was also affordable for amateurs. The idea was to do something simple, that anyone could use, with professional touchs.

Passive units, like the Beachtek, were limited. To start with they didn't improve on the camera preamps, and on my findings with my Hi8 camera (which had AGC as the majority of home cameras back then) I saw that you could "fool" the automatic level if you fed a higher signal into it.

The next question was control, which even now prevails although prosumer cameras have or internal manual level control. It's much more practical to set your levels as you go.

There were also design decisions that may have been too personal, like perhaps make it too simple. There are no headphone outputs on it, to force people to use the camera output, as you should. The output is line level, but can be padded with a cable or even with the pot itself, as the gain is on the first stage and the pot in-between.

<<<--The beach with phantom is pricey but it 's quality gear and fills a need for portability. There is a greater chance of camera damage with a belt mounted adapter than one that securely attached to the camera base. -->>>

Then why do you think the majority of camera preamps around (not passive adaptors, which I don't think cut it) can't be camera mounted?

Except for the PSC (very good) and the Glennsound (no phantom or battery power), absolutely ALL active preamps should be used separately. Cameras get too unbalanced because the housing needs to be large and heavy. There are a lot more reasons to go for it, but of course you may disagree with.

Our unit is now retailing for the same price as a DX6, with an active output.

In any case, the reason I never talked about these things in these forums is because I thought it was not proper. Still don't think it is and I maybe reprimanded by the moderators for it. Let's hope not, because I have always been trying to help with my advice. I wish more designers listened to users on these Forums, like Panasonic and Sony with their new cameras.


Carlos

[Bryan Beasleigh]

Carlos
If you have a product, what is it and where can we get information about it.

[Matt Gettemeier]

Yeah Carlos, now I'M intrigued! Email me if you can't post.

[Dan Brown]

I also bought the Sony 7506 headphones, to replace an old set of Aiwa phones had. The differnece is immense, and the Sony phones really let me hear the audio. Great investment for sure.