BeachTek DXA-2S

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Bryan_Lawler

Well-known member
I have an older BeachTek DXA-2S and was wondering if it would be okay to use it with my 7d. Has anyone else trying using one? What are the issues and limitations?

I am going to be doing a series of interviews with one person on camera and a translator off camera. My mics are XLR's and was wondering if it would sound okay without to much AGC issues with the interview mic on ch 1 and translator on ch 2. The translator audio most likely will not be used in final edit. It is there more as a instant reminder of what was said.

thanks!
 
I wouldn't do it. I think the AGC noise would be unacceptable. I have the DXA-5D which holds down the AGC noise to acceptable levels. You should do dual sound or get a unit which defeats AGC.
 
You can try the "hack" and run a mp3 player playing tone into one channel on the adapter, that way you get XLR input, and no AGC
 
Another option... I do have another wireless mic that has 1/8" connection. I could connect it straight to the 7d and don't worry about the translation. How would that differ than hooking up my Rode VideoMic?
 
Bryan_Lawler said:
Another option... I do have another wireless mic that has 1/8" connection. I could connect it straight to the 7d and don't worry about the translation. How would that differ than hooking up my Rode VideoMic?
Click to expand...


It wouldn't. You need to defeat the AGC by running a tone or noise into one channel or do dual sound.
 
Direct or mixer audio feed to 7D

Direct or mixer audio feed to 7D

I made a cable that sends one wireless Letrosonic output directly to both channels via xlr to 1/8 stereo connector.

If I need two channels I have another cable that sends output from two Letro units to separate channels, again via xlr to a 1/8" stereo connector.

Another option is to use my ProMix6 mixer and feed un-balanced mic output from the mixer to both channels of the 7D.

An on-camera Rode or Sennheiser is only good for run and gun on-the-fly audio where you have to live with the AGC - never depend on an on-camera mic for a good interview.

As with any good Broadcast or top quality Doc shoot, a good sound tech with a mixer and boom and bag full of Letro's is the way to go.
 
snp said:
An on-camera Rode or Sennheiser is only good for run and gun on-the-fly audio where you have to live with the AGC - never depend on an on-camera mic for a good interview.
Click to expand...

Well I've been using the Rode VideoMic boomed and run through the BeachTek DXA-5D with good results...in fact shooting another interview tonight with it. You simply have to hold down the AGC with a tone like the DXA-5D does and it works fine.
 
Avoid Tone...

Avoid Tone...

Bryan_Lawler said:
Thanks snp - So, would my stereo 1/8 wireless do the same?
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Works for me. The last thing I want is to waste a channel with a bleeding tone. Using a mixer or wireless with a fixed output to both channels produces the best audio I've heard.

No disrespect to Boulder but trying to defeat AGC with a tone wastes one channel and risks the tone bleeding into your one good live channel.

As long as you are supplying an even signal from a wireless receiver or mixer, AGC has all it needs. It's only an open mic directly fed to the camera pre-amp that causes the AGC to seek a higher level.
 
I guess I'm being dumb, but how exactly are you defeating the AGC?

Are you saying that during gaps or pauses in the conversation the noise level wont rise and what is this constant signal you speak of? Not trying to be annoying but I just don't understand and have never heard of this from anywhere else.

I mean if this is true it solves the AGC problem, just use wireless into both channels...I guess I'd really like to hear an example of a pause with no noise
 
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Test result...

Test result...

Here's a simple audio test. 30 sec of a stereo Sennheiser 200 shotgun mic attached to hot shoe and plugged directly into 7D, followed by 30 sec of Letrosonic 200c UHF lav wired to both channels and clipped to the front of the shotgun foam windscreen.

The 7D was stationary 1' from my iMac hearing only a clock ticking in the background and the hum of drives and cooling fan.

The shotgun peaked @ -6db at my voice and settled to -24 db noise level with no speaking. The Letro peaked at -6db at my voice and settled to -30db with no speaking.

http://www.vimeo.com/11170080
 
Well I must say the Letrosonic vas very good. So tell me once more what is the constant signal that is being output from the Letro? It is obviously inaudible so exactly what is it? Not quite understanding how this is working.
 
I've got my Letro set at -40db output. I convert the balanced output to un-balanced by shorting pins 1&3 to ground and pin 2 stays hot. I then send pin 2 to 1/8 stereo mini tip and ring (effectively sending the signal to both channels). Pins 1&3 go to 1/8 sleeve or ground. It's an setup learned years ago from a broadcast tech.

If I'm running two Letro's then I send separate Pin 2 sigs to Tip or Ring and sum the two grounds to sleeve, giving me two channels of wireless mics. I pre-adjust the two UM200 audio levels on the xmitter, giving me a constant output from the receivers.

My understanding is that the constant output of the Letro can not be influenced by the AGC, as an open mic can.
 
Is this something unique to Lectro or is this something that is true about any wireless? And what exactly do you mean by "open mic"?...sorry not familiar with audio speak
 
Not sure about others, though I would suspect that any wireless would have a constant output. I'd refer to any wired mic connected to the camera directly as an 'open mic' vs. one going thru a mixer or wireless.
 
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