Beachtek DXA 5D - distortion problems
 

Last week, I tested two Beachtek DXA-5D adapters using a stereo setup employing two Sennheiser MKH 20 omnidirectional mikes. When I enabled the 20 kHz tone (which is intended to tame the automatic gain control in the 5D MII), I detected high frequency distortions in the left channel which includes the loud tone.

I could clearly see these distortions when I made a sonogram of a recording of myself talking. They are high-pitched clicks, loudest up around 20 kHz (inaudible), but extending down to 5 kHz and sometimes below.

I have severe high frequency hearing loss, therefore I could not hear these distortions. But a friend with youthful hearing heard the clicks instantly and found them annoying.

When I turned the tone off, the clicks instantly disappeared.

To find out if the recording circuitry of 5D Mark II was at fault, I ran a signal directly out of the Beachtek and into my Sound Devices 722 recorder . . . and detected the same distortions. So the distortions are unrelated to the 5D Mark II. They are coming directly out of the Beachtek adapter.

This problem occurred with two Beachtek units, proving that it was not a bad unit (I have since returned both units to B&H in order to get my refund).

I immediately notified Beachtek about this problem. The owner, Harry Kaufmann ran some of his own tests but said he could not duplicate the problem. Perhaps the problem is peculiar to my setup, or perhaps Harry could not hear the distortions, which is likely for someone over 50 years of age. He told me he notified his engineers, but none of them contacted me.

My test audio file and a sonogram of that file are posted here:

Beachtek DXA 5D Audio Test

In the sonogram, look for the distortions in the upper (left) channel. The clicks show up as vertical lines, loudest up around 20 kHz, but extending down as far as 5 kHz. Although the clicks soften at lower frequencies, they should be audible to anyone with good HF response.

If my tests are correct, I conclude that the Beachtek adapter is not suitable for professional work.

I advise others to perform a similar test to determine if the distortions (clicks) are of universal occurrence when the AGC disable tone is enabled.

Lang Elliott
NatureSound Studio

Lang:

I experienced the same clicks using my 15,400 hrz tone runing into the camera through my old Beachtek, DXA-4. As I reduced the volume of the mp3 player going into the Beachtek, at a point, I am able to eliminate the clicking, and sitll have a pretty good recording. I am not a sound engineer, but I thought it might have something to with a limiter of some type on the Canon cycling on and off.

I don't know if Beachtek can change tone volume levels, but that may help if it does.

I just bought my dxa-5d and tested it on my 7d..

o my gosh... it is terrible!!!!!!

this is my email to harry
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Hi there,

I just recently purchased the dxa-5d to be used on my 5d and 7d cameras.

I tried connecting my ntg-2 mic and g2 wireless mic.

- The audio meter doesn't work properly, it doesn't move as I speak.I have to scream on my wireless g2 in order to get it coming up.

- The audio from the ntg2 is very very soft...

- THe wireless g2 is not so bad, I can still hear my voice speaking on the headphone and stuff but I still can't monitor the levels on the lcd monitor properly.

- The auto gain control disable is causing a high pitch tone continuosly...


Please advice if I have done something wrong with it.

Kind regards,

Santo

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any ideas??

Santo