XA20 Zooming Noise

[Chuck Rich]

Has anyone experienced rapid multi-tone electronic noise during zooming (mostly slow zooming) while using the on board mic? It's somewhat faint and stops when zooming stops. The noise can be heard using headphones and does get recorded. I'm on my second xa20 with this problem, after returning the first one.

Thanks -
Chuck

[Jo Ouwejan]

As the inboard microphone is in the body, this is a problem, that can only be avoided by the use of a separate microphone.

[Chuck Rich]

After finding the second camera to have the same problem, I was beginning to assume this was an inherent problem and not an unusual defect. I have never had an handheld camcorder before; I wonder if they all have this problem?

I'm familiar with the servo motor noise of the larger cameras; that noise is easier to mask and is not as annoying. The good news is the noise does not get recorded with an external mic.

I really like the camera and will probably keep it.

Thanks for your response.

Chuck

[Jo Ouwejan]

The Canon HV series (recording on tape) even recorded the noise of the tapedrive.

[Don Palomaki]

Are you using AGC?
At what level is the noise recorded (e.g., how many dB below max digital record level)?
How is the camera powered?
Is the noise apparent and intrusive in a normal viewing environment?

As noted above, for recording important audio use an external mic, and placement close to the sound source is generally better. Built-in mics are mainly suitable for recording ambient sound in relatively loud environments (e.g., normal speech levels and louder).

Also the close coupling of headphones to the ear tends to make subtle noise more apparent because they reduce the masking effect of ambinet sound in the listening environment.

And I would say that ALL with internal microphones, and some with external mics on the camera, have this problem to various degrees. Using audio AGC in a quite environment will make it more apparent.

[Chuck Rich]

Don, I don't know if AGC was on or not (probably was since I left everything at the default settings), and I don't what level the noise is being recorded at. I'll check these things out and report back.

However, I used the battery for power, and the recorded noise is apparent and intrusive (as far as I'm concerned) in a normal viewing environment. But as you suggest, the noise is more apparent with the headphones on.

Again, regular servo motor noise is not as high pitched as the noise I'm talking about, so it's more easily masked and not as annoying.

Thanks -
Chuck

[Don Palomaki]

Can you post a sample of the noise, a few seconds, as a .WAV file.

[Andy Urtusuastegui]

I just picked my new XA20 up a few days ago.

I only get a barely audible sound when zoom FAST. When slow, I have not noticed it.

[Don Palomaki]

A strange noise, a bit like a teletype sound in sort of random burst

I extracted the audio from the .MOV file (received via PM) to a .WAV file.

The average sound is mainly a steady noise comprised of a combination of hiss and hum at an average 51 dB below max digital record level. It is about what I would expect to hear if audio AGC is enabled in a quiet environment. You hear the noise floor of the mic (condenser mics have a noise output) and the preamps.

Embedded in this noise are occasional bursts of noise pips, sometime stronger in the left channel (~570 Hz), some times stronger in the right channel at as lightly different center frequency (~760 Hz)., but they are a bit below the background noise level in all but the last scene so they do not stand out in the waveform, and it is not directly tied to zooming in that it is absent during parts of the zooming.

This noise reminds me a bit of some cell-phone hand shaking with local cell towers, or perhaps blue-tooth hand shaking noises I've seen leak into othe electronics gear (e.g., telephones). I wonder if something like that was going on near or with the camcorder that is bleeding in.

In any case I should have my XA20 inhand this weekend and will run some tests to see whether or not I can find a similar noise.

FYIW the 51 dB is better than the typical S/N of vinyl LPs, turntables, and most consumer tape recorders of bye gone days. Using manual gain control and external mics should help a lot, as will having actual normal ambient sound present if using AGC.

[Don Palomaki]

Made a quick test this am.

In a quiet room, but not a sound booth, in full automatic mode, including audio agc, the noise floor was about 53.5 dB below max record level Normal speaking voice art about 6" was peaking at about -10 dB

When zooming I could barely hear the fluttery sound, but it was below the overall hiss level on monitors, and at this level voice would probably have blown the drivers. Overall I would say the performance with the internal microphone is as expected and adequate for ambient sound and not critical events (e.g., the kids birthday party).

Setting it to manual audio level control the noise floor was perhaps 1 dB better for roughly the same voice levels. Note that the threshold of normal hearing is around 0 dB, a quiet room does have an ambient noise level, typically around 20 dB. and normal conversation is around 55 dB

Setting the audio input to XLR, with no mic connected the noise floor was down at about -72 dB and no zooming noise detected.. - just the expected hiss of the electronics. This is in line with the S/N performance of typical mid priced condenser mics such as the AT875R.

For better sound with ANY camcorder, use an external microphone located near the sound source.