Padding line down to mic level

[Steve House]

Originally Posted by Tripp Woelfel

Steve... Yeah, I see your point. I'll do some searching around on mixers and if I still have questions I'll start a new thread. I think a mixer's the way to go.

Even though it's a bit pricey compared to some, you could do far worse than a Sound Devices 302 or if you want to buy once and be completely future proofed, the SD442. I've got one and it's everything Ty said and more.

[David Ennis]

I agree that the most versatile solution is a good mixer.

But it is incorrect to believe that you can't pad down a line level signal without matching impedances. You can. I do it all the time. Other people on this board do it all the time. The only consequence of mismatched impedances to weaken the signal, and that's certainly not the problem you're having.

It does sound like the feed you're getting is on a fader rather than being a fixed output. Otherwise, -60dB of attenuation should work for you to take a standard -10dB or +4dBu line out down to mic in.

Buy or borrow a $30 or so digital multimeter (ROI all over the place) and check the ac voltage of the signal. True, it's not perfectly accurate to measure an audio signal with an ac meter, but close enough. You want a nominal value on the order of about 0.001V for a mic input. My Canon GL2's mic input starts to clip at about 0.016V

[Tripp Woelfel]

David... I'll take my digi multimeter to the track next week, or better, see if I can get them to take an hour with me during the week to see what's going on in the sound room.

From what's been said in this thread, the least I'll need is a DI. Simple pads won't work since I went down -80 and still got garbage with the camera's meter reading nominal input level.

If there is a cheap and cheerful (sub US$100) way to solve this problem, I'm all ears. Otherwise I'll probably get a mixer.

[David Ennis]

Tripp, the camera's meter doesn't read input level. It reads the recording level, which you can set. So a signal can be mangled by overloading the input and you can record the mess at a perfectly nice level. If you have the audio input control cranked down in order to get a good nominal recording level, that's probably what's going on.

If you're getting nominal recording level with the audio input control set mid range (an indication that you're at the designed in comfort level for the camera's circuitry), then something else is going on. You say you get good audio without the pads using line in. Besides using the multimeter, you could verify that the pads are doing their job by confirming that you get extremely low but otherwise undistorted signal with, say, -40 dB padding into line in. And does a mic still work fine in that mic input? Are you sure the distortion you hear is clipping and not induced noise?

Again, if you're in this for the long haul and especially if you're being paid, then you're going to need a mixer sooner or later. But purchasing anything before you know what's going on is not the right way ti start down the road IMHO. Any good clean output at any level can be simply padded down to a good clean input at any level.