Can the Canon XH-A1 accept line-in from a mixer?

[John Whiteway]

First, thank you all for the help and answers you've given me concerning my questions about my XH A1 and Sound Devices 302 mixer. I've learned a lot.

I'd like to ask one more question.

Several of you have said that the Canon XH A1 can accept line-in. The trick is to open the mic levels on the camera fully. When you do and send the tone from the SD 302 you'll get a reading of -20dB.

I've been experimenting today alternating between line-out and mic-out. I agree that the sound I get with line-out/line-in is clearer. The problem is volume. When I play back on the camera the sound is faint. When I transfer to Final Cut the volume is barely audible. The sonogram shows that. Even when I raise the volume of the track on FCP to the maximum the volume is still too low.

Am I doing something wrong?

I have to use the equipment tomorrow so, if someone can help me here I'd appreciate an answer as soon as possible.

Thanks again.

John

[David Morgan]

John,
When u play back the tape on the camera, what do the meters show? Are they bouncing at the same level as when you were recording?

[John Whiteway]

I did a test recording the same dialogue first with line-in then with mic-in. I did that for a wireless then a boom mic. When I look back at the audio meters in the sequence captured in FCP I see that all the mic-in readings are in the proper range. The line-in readings are all below -25dB.

John

[David Morgan]

what I'm asking is BEFORE you ingest into final cut, do the line level recording levels playback at the same level you recorded them? or is it that you didn't notice your levels while you were recording?

[Petri Kaipiainen]

Originally Posted by John Whiteway

I've been experimenting today alternating between line-out and mic-out. I agree that the sound I get with line-out/line-in is clearer. The problem is volume. When I play back on the camera the sound is faint. When I transfer to Final Cut the volume is barely audible. The sonogram shows that. Even when I raise the volume of the track on FCP to the maximum the volume is still too low.

Am I doing something wrong?
John

What are your levels on the mixer? They should read something like +6 to +8 for dialog peaks and even +12 + 16 for absolute peaks. Even higher, if the limiter is engaged. Mixers show levels in old analog units which are 20 dB higher than digital dBFS units modern cameras use. If you keep the levels below zero on the mixer, camera levels will be 20 dB too low.

[Vinny Flood]

Has anyone else encountered a situation where they could get reasonable sound from a mixer when audio is set to automatic, but not when audio is on manual?

I'm hoping someone can point out that there was a setting/adjustment I missed.

[John Whiteway]

Hi,

Hope it works this time. Just wrote a long reply and it got lost in space some where.

First, thanks to all of you who have helped me figure out my problem, in particular to Patri Kaipianen.

I've now been able to figure it out. After setting the 302 to line-out and opening my camera's pot fully so that the tone setting was -20, I'd been applying the camera range of readings of -20 to -12 to the mixer. It's that that had been producing the barely audible signal in the camera. I now know what to do.

I do have a question though. If one is to read the meter such that mixer +6 equals camera -12, why do the LED light on the meter turn to yellow at 0 and red at +8? That just feed the confusion of a fellow like me, especially when the "caution" yellow begins precisely at 0, the beginning of the no-go area on the camera meter. I read the 302 manual and it says "the 302's scale is designed for digital recording devices". I understand now that the mixer has its analogue history but why not modernize it for its application to digital devices? It would sure have helped a fool like me.

I have one other question.There are times when I'll have to use a mic mounted on the camera along with the boom mic. On those occasions, since the XH A1 can only be set either mic or line in, I'll have to set the mixer at mic out. I can't remember where I read this, but I did read that in that case one should set the camera's level to -12 when sending tone. Is this correct?

Thanks again for all the help. My respect for the skills and challenges of taking sound has grown enormously.

John

[Petri Kaipiainen]

Originally Posted by John Whiteway

I do have a question though. If one is to read the meter such that mixer +6 equals camera -12, why do the LED light on the meter turn to yellow at 0 and red at +8? That just feed the confusion of a fellow like me, especially when the "caution" yellow begins precisely at 0, the beginning of the no-go area on the camera meter. I read the 302 manual and it says "the 302's scale is designed for digital recording devices". I understand now that the mixer has its analogue history but why not modernize it for its application to digital devices? It would sure have helped a fool like me.

Nice to be able to help.

Audio has a very long analog history. It is true that practically all recording now happens digitally, but most professional systems and great many audio professionals are still "partly analog", so to say. I quess that is the reason analog professional equipment is still made the analog way (metering at least), also presuming the user is professional who knows what VU metering means and how to connect analog devices to digital ones. It is only the new generation of people who have problems with these concepts, and it is a smaller risk to the company making devices like SD302 to make a few beginners confused and angry than make all the professionals angry by suddenly changing the whole system of metering audio.

Of course this change will happen within the next generation, when all analog recording is gone. Untill then we just must realize that systems which go to +20 must be analog, and systems where meters stop at 0 must be digital and do some arithmetic there.

Yellow band on SD302 meters actually marks the optimal, aim-for levels area, red area is a "watch it!" area. In digital recording nothing bad happens untill you hit zero dBFS (and then all is lost), so these colors do not have the same meaning they used to. On the camera -20 is really not a beginning of a "no-go" area, just a reminder to be more cautious. The beauty of digital audio is the fact that the quality stays the same, and in some respects gets better the "hotter" the signal recorded. But therein lies the danger of overdoing it, IF you hit zero, you are screwed. I try to keep levels at yellow, with one or two reds lighting occasionally. The most important light to keep the eye on is the limiter signal, that should not light too often. I have my limiter set at -3 dBFS (+17 dBVU) on the SD302.

Using the mic out levels out of the SD302 makes no difference to how the levels are set. If you want the levels to math between SD302 and the camera, 0 dBVU should give -20 dBFS and full level signal +20 dBVU 0 dBFS on cam, just like with line levels. The difference here is that you actually have to adjust the camera audio with the pots this time, not just turn them open, as that mic out level from SD302 is not a standard level (there is no such standard, all mic are also slightly different).

[Don Palomaki]

See http://en.wikipedia.org/wiki/VU_meter

VU (volume unit) meters were analog meters with a mechanical swinging pointer, and due to mechanical inertia and damping, they respond to an "average" short term level of the signal, not the peak values. Some have a percent scale and that refers to the expected level of modulation of an radio signal, if used in that application (More than 100% modulation is a no-no.) This calibration was based on typical program material during in the golden AM radio era (mainly before the mid 1950s). There is a standard for these meters as applied to professional gear; it was largely ignored for meters used on consumer gear.

As noted above, the advent of the digital era has made more precise metering easier, and the use of digital recording has enforced hard limiting of the recorded information because a 16-bit (or 10-bit or 12-bit or 24-bit or whatever bit depth you use) can only count so high.

Optimal audio recording happens when the input and output levels of all system in the signal chain are properly matched, and where options exist, the options are selected that provide the most faithful and noise free recording. That means understanding the capabilities and limitations of each item in the signal chain, and the sound environment you are trying to record.

Misapplication of any link in the chain can result in poorer sound, maybe even terrible sound; e.g., using a mic that saturates at a low sound level to record a rock concert, or using a mic with a high self-noise level (poor S/N ratio) to record soft sounds. When folks get zapped by this sort of misapplication they sometimes will blame the most costly link in the chain (the camcorder) when the difficulty lies elsewhere.

It is not brain surgery or rocket science, but it is a bit technical and some study is required to understand it, and experience to do it well, especially issues such as mic selection and placement.