Canon XH-A1 line in levels: feature, not a fault?

[Petrus]

People have complained that Canon XH-A1 has very low levels when connected to a standard line device; you have to turn the audio level potentiometers all the way open to get a good signal. This has people worried as the conventional wisdom says you have to operate pots at the midrange for good results.

Maybe this behavior is not a fault but a feature: it makes setting up real easy!

I made some recording tests and found out that when feeding a signal from SD302 mixer and having the camera pots all the way open I got a perfect level match. Clipping level test signal from SD302 gave 0 dBFS peak levels on tape with no clipped samples!

Moreover, pink noise tests from a low noise mic gave -4 dBFS levels on tape when SD302 limiters started to kick in (set at +17 dBVU). Most amazing was the S/N ratio, pink noise and mic turned down the levels fell to -94 dBFS, which approaches the theoretical limits of 16 bit systems!

From now on I have no qualms using XH-A1 with line in and pots pointing south.

 

[Dionysos]

Sorry, but my knowledge on this subject is (still) limited, so maybe a dumb question;

Does this in practice mean that you can open the pots completely, without experiencing clipping? Only with a mixer in between right?
So, without mixer you still have to seek it somewhere in between, so actually no advantage? Thanks for clearing it up already, I'm learning on the audio side of filming, but I'm still a noob

Edit; Oh, and isn't it so that with the pots full open the chance on noise is larger?

 

[Petrus]

This means that with a standard line in levels the pots can and should be all the way open. If they are not, it is not possible to get maximum (optimal) levels.

Also my humble tests show that there is no need to be afraid opening the pots all the way, the sound quality is superb (over 90 dB S/N ratio) and the mixer-camera match perfect. If you want to use the camera pots at mid level and get high audio levels, you have to use mic levels for the inputs and this will cause about 10 dB drop in S/N ratio.

Of course you can use the line in levels only with line level devices like mixers, and then levels are manipulated by the said device (mixer, most likely).

 

[tigeba]

I have never touched one, but I remember seeing that it had XLR inputs. I downloaded the manual and the line inputs are 6dBV. It is a bit confusing since I would expect that the inputs would be +4dBu since they are XLR's (or maybe even -10dBV). I guess what I am saying is that the camera is probably expecting a +4dBu signal?