Camcorder with Line Input

GarethWilliams79

Yeah, I used the main outs not the headphones out. I think those Stag leads are pretty poor quality too. It’s a pity Planet Waves don’t do M«»F jack cables. I think they do an M«»F adapter that you can stick on the end of a normal male to male cable, so I think with decent quality Planet Waves M«»M cables and a decent Planet Waves M«»F adapter there might be some improvement but not enough to be worth doing it.

The distortion was severe and most of it has got to be down to the attenuation and the camcorder mic in level. The Canon Vixia HF G40 is a completely different camera so I don’t think it matters if it can take a line signal in through the Movo. I’d like to know if anyone has fed a line signal into the NV-GS280 with the Movo. I doubt it based on today.

Terfyn

If you have one of these lying around:-
6.35mm Adapter 3.5mm 1/8 inch Female to 6.35mm 1/4 inch Jack Male Stereo Audio Headphne Adapter
then you could try Behringer Headphone out > Movo > camera before adding extension leads. You can monitor through the camera headphone out.
Please accept my apologies but you did have the Movo lead the right way round? I'm sure you did.

P.S. I carried out my own test. My TV has a Headphone Out with its own volume control.
I used a 5mtr. 3.5mm plug to socket extension lead, my SESCOM attenuator, my 750 camera and headphones.
I set the volume low on the TV Headphone out, connected from the TV, through the attenuator to the camera. Monitored through the camera headphone out. The camera mic level for the external mic socket was set to Auto.
The sound came through clearly and without distortion.
I increased the TV Headphone volume, the sound in my "heads" was too loud for comfort but still no distortion.
The connecting 5mtr. lead was a simple 3.5mm diameter wire with a stereo pair inside. I could not detect any hum or other distortion.

GarethWilliams79

Thanks again for your help Terfyn. I’ll keep that method in mind. Ok, I have tried it now and there is some good news and some bad news. I tried it with and without the Movo.

About your last post. The Movo was definitely the right way round. There is a label on it telling which end goes in the camera. Yeah, I might be better off sending from the headphones of the mixer with that adapter you described in the future. I tried it from the main outs today.

Right here’s what happened …

The bad news is without the Movo the signal is far too strong! The mic gain settings allow you to take it down to -30 which I did but even then the line level signal direct from the mixer was unbelievably distorted and it wasn’t even at full signal strength really. To monitor the level, my mixer has two green lights, one amber and one red. It was only at the level of constantly lighting the first green light with the second green light flickering at the loudest parts. It did not even engage the amber light which would be a full strength line level signal. Without the Movo at -30 was awful and totally unusable.

With the Movo and (still set at -30) it was a better. I can use this so that’s the good news! Also, I found it better with the 6m of cable than straight from the mixer with the two 1/4" mono male jack to single 1/8” stereo female Y adapter directly in the in mixer with the Movo attached and with the camera right next to the mixer. In that set up it sounded like it was just on the verge of distorting but when sending through the 6m of cable the level received in the camera seemed more comfortable. Maybe the 6m of cable weakened the signal a bit. Anyway this works so all is good.

I haven’t been able to import the footage into Premiere yet so I will now shift my focus to working that out. If anyone can help with that I would be grateful for any contribution but I think I might be better off posting that topic on the Adobe Premiere forum.

dosdan

A long audio connecting cable won't reduce the level of most of the signal. It might reduce the very top end of the frequency range if the cable has a lot of capacitance.  Long cable runs should be using a low-capacitance cable. But whether this was an issue would depend on the source material, load (cam mic input) and source (mixer line out). Generally, HF-loss in an interconnecting cable will probably not be an issue with modern electronics.

What is more likely to be an issue is hum or RFI pickup.

What Line Out level does the specs of your mixer indicate? -10dBV or  4dBV?  What about the level of the Rec Out? Mostly likely -10dBV.  (dBv is aslo known as dBu.)

As mentioned previously, if the headphone output has a volume control, you can use this to get a controllable reduced-level signal to the camera without affecting the normal mixer level.

Dan.

GarethWilliams79

You can turn the main mix down with the main mix fader knob (but then you won't be monitoring the input properly) sending from the headphones would allow you to still see the levels you input into the mixer while turning down the signal you are sending a bit. At present I don't have the adapter to send from the headphones socket but there is a control room out which is two mono jacks, (L and R) the same as the main out, which I think is sending exactly the same as the headphones. i.e. it's controlled by the headphones volume knob. I could use that will the cables and adapters I've got.

I'm not sure if I understand your meaning “What Line Out level does the specs of your mixer indicate? -10dV?” I would have to look that up. The lights system on the mixer indicates -20 for the first green light, 0 second green, and 6 for the amber light. Red just says clip. I'm not sure if that answers your question. Probably not!

dosdan

Audio electronic equipment for recording & PA generally have the zero on the meters set to indicate either a -10dBV (consumer) or  4dBV (semi-pro/pro) level.  If  4dbV , this is 14dB hotter than a -10dBv output.

"clip" here refers to the clipping of the mixer's output. The camera's mic input can clip a lot lower than this.

Dan.

Terfyn

Adobe Premier is a video editor like any other video editor. It needs access to your video files at all times. This is why we all transfer the video files from the camera to the PC The video editor does not use the video files directly, instead it sets up a series of instruction files which act on the information in your video files when you render your final video. So the video editor needs access to those original video files all the time it is active. There are three stages, first you "import footage" to your editor. This creates links between the editor and the files but the original files are NOT moved from the folder or acted on in any way. Second, You edit the video. This creates a file of instructions. Third you Render the final video, this is the stage when the original files are accessed and the video copied to the final rendered file in line with the instructions. The original video files remain exactly the same as you filmed them.

See my post in your other thread on how to move the video files from your camera to your PC.

dosdan

It's been many years since I read up on this stuff and my old memory is getting weak. I now remember that what I've said above is wrong. Although it's probably above your head at this stage of your involvement with audio technology, for completeness I'll explain this correctly.

Decibels (dB), a logarithmic ratio, are used to indicate relative voltage and power levels. Sound Pressure Level (SPL) is another logarithmic ratio used to indicate how loud a sound is. Logs are used for 2 reasons:

The ear/brain's response to sound, (and to light level too), is logarithmic.  So a 200W amp will not sound 2x as loud as a 100W amp.When dealing with amplification/attenuation it's much more convenient to deal with logs as you can add/subtract instead of multiply/divide to show the level change from an amplification/attenuation stage. Anyone who does any audio engineering soon realises this.Decibels, being ratios, need to have 2 values:
Value_being_measured : Value_being_compared_against.

Often, a letter is added after "dB" to indicate the reference value.
In "dBV", the reference is 1V.in  "dBm", the reference is 1 milliwatt into 600 ohms. (An historical value originally used in telephony.) This is a voltage level of 0.775V.In "dBu" ("u" is "unit"). This is similar to dBm with a 0.775V reference level, but the load impedance is unspecified and assumed to be high.In "dBFS", the reference is whatever the Full Scale digital value is for the system.When comparing 2 voltages the formula is:
dB = 20 x log(V_measured/V_ref).

Note: "deciBels" are 1/10th of a Bel ("B")  (named after Alexander Graham Bell, the inventor of the telephone).  Bels are a bit too large a unit, so normally everyone uses dB.

With negative dB, the value being measured is less than the reference value. Positive dB values indicate that the value being measured is greater than the reference.

-10dbV, the typical metering-reference zero level for consumer audio is 20 x log(V_measured/1V) = 316mV.

4dBu, the metering-reference zero level of professional equipment, is 20 x log(V_measured/0.775V)  = 1.23V.

When comparing these two values, we are not using a standard reference value as a reference. Instead we are just comparing two values. So we don't include anything after "dB". 20 x log (0.316/1.23) = 11.8dB. Therefore,  4dBu is approx. 12dB hotter than -10dBV.

Using a -30dB attentuator on a -15dBV signal would drop it to -45dBV. This is much more convenient than saying "dividing 178mV by 31.6 = 5.6mV".

The reference value for "dB SPL" is 2 x 10^-5 Pa, supposedly the lowest pressure level the ear can detect. "Pa" is "Pascal" and is the unit of measure for pressure, here sound pressure.

dB SPL = 20 x log (P_measured/2 x 10^-5)

Working backwards to get the absolute pressure level for 95dB SPL
= 10^(95/20) x 2 x 10^-5 Pa
= 10^4.75 x 2 x 10^-5 Pa
= 5.6 x 10^4 x 2 x 10^-5 Pa
= 1.12 Pa

Note: 1 Pa is 94dB SPL. This is a common SPL used in the sensitivity spec for mics.  For example:  RØDE Microphones -  VideoMic Directional On-camera Microphone

Sensitivity: -38.0dB re 1 Volt/Pascal (12.60mV @ 94 dB SPL)  /- 2 dB @ 1kHz

The sensitivity can be restated as -38dBV/Pa. So, at 94dB SPL the output voltage level is -38dBV, which is 12.6mV.

Using this spec and increasing SPL levels, the voltage levels are:
104dB SPL ( 10dB) = 3.16 [i.e. sq-root of 10] x 12.6mV
114dB SPL ( 20db) = 10 x 12.6mV

At this mic's maximum SPL of 134dB SPL ( 40dB) the output voltage would be:
100 x 12.6mV = 1.26V.

This level is too hot for most mic inputs.  The mic comes with a 3-step pad: 0dB, -10dB, -20dB.  Even using the -20dB setting on this mic, 126mV at 134dB SPL may well be too much for many non-pro mic input circuits.

Dan.

Terfyn

Mentioned the Tascam DR-60D above. One feature is the direct feed out at low level to the camera mic input. This is obviously designed to supply a synchronising track to the camera so that the "quality" .wav recording from the DR-60D can be easily aligned in post production. This can be expanded to add any audio track to the video while recording, for example ambient sound effects such as wind or waves crashing, car sounds or background trains noise or crowd sounds.
The low level output has a volume control which makes it easy to match to the camera.
All this can be done in post production but could save a step during the editing.

rogs

Not quite right Dan ....0dBv is actually equal to  2.2dBu   (See HERE  for details)

Probably not too important in the grand scheme of things, but seeing as you've taken the trouble to go into quite a lot of detail....