Welcome to our community

Be a part of something great, join today!

Register Log in
  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Audio problems

James Brundige

James Brundige

Well-known member
Joined
Feb 11, 2008
Messages
856
Reaction score
0
Points
0
Location
Snowmass, Colorado
Website
firstlightfilms.tv
Feeding epic from three sources -

SD mix pre - line level out - w Female XLR to male 1/8 TRS hosa cable - results NG - very crunchy

Rode NTG-2 battery powered mic - mic level out - same cable - NG - only line noise

cheap Sennheiser mono mic w 1/8 mono plug - this works (but it's a lousy mic)

I've tried balanced and unbalanced input settings, many different gain levels.

ideas, suggestions?
 
I am not sure about this, but the Epic has two mini jack mono inputs, if you use a stereo mini jack in these it might not work as you hope.

I get very good sound quality from my Epics, but I spent I while figuring out how to get there, and in my case the issue was that all my adapters and all my mics had mini jack STEREO cables, once I exchanged those for mini jack mono, it worked. (That´s my best suggestion, hope it helps)

But i can tell you this: I do get great audio out of my Epics now.
 
Sd send line level only.

Brain accepts mic level only.

Need to attenuate the line libel to mic level and you'll be good to go.

David
 
Eirik Tyrihjel said:
I am not sure about this, but the Epic has two mini jack mono inputs, if you use a stereo mini jack in these it might not work as you hope.

I get very good sound quality from my Epics, but I spent I while figuring out how to get there, and in my case the issue was that all my adapters and all my mics had mini jack STEREO cables, once I exchanged those for mini jack mono, it worked. (That´s my best suggestion, hope it helps)

But i can tell you this: I do get great audio out of my Epics now.
Click to expand...

There is some confusion about jacks. A tip ring plug (and jack) is only mono. Is that what you are referring to?

The input to Epic is mono, but it is TRS (tip ring sleeve), which can be either stereo, or balanced mono. I am sending mono signal over TRS.

I'm curious why my crappy unbalanced mic . (tip ring) is working, and the others ( even at mic level) are not.

Thanks for your suggestion.
 
You need a 40db pad (approx) to attenuate a line level signal to mic level. You could make a cable with a few resistors that could do this. Or just buy a 40db pad.
 
Which Hosa cable are you using? There are at least two that appear to have to correct connections, i.e. female XLR to 1/8 TRS. One is dual mono, the other is balanced mono. Do you have model number or a schematic?
 
Steve Wake said:
Which Hosa cable are you using? There are at least two that appear to have to correct connections, i.e. female XLR to 1/8 TRS. One is dual mono, the other is balanced mono. Do you have model number or a schematic?
Click to expand...

Labeled "Pin 2 Hot", so I assume it must be balanced mono.
 
The wiring configuration for a balanced mono audio cable:
• XLR pin 1 to jack sleeve
• XLR pin 2 to jack tip
• XLR pin 3 to jack ring
 
James Brundige said:
I am using the hosa cables, wired as Keith suggests (pin2 hot)
Click to expand...

Have you checked the cables with a multimeter to make sure they are wired as Keith described and there are no cross-connections? Written descriptions can be deceptive and defective cables in that price range are certainly not unknown.
 
I can't tell at all from your posts what you are actually doing, but I can tell you that I am using Hosa cables with a Sound Devices Mix Pre-D and getting very good sound out of my Epic.

So here are some thoughts random thoughts about what I'm doing, and some guesses about what might be wrong with your setup.:
  • The cables I am using are XLR to TRS balanced cables. (Hosa XVS102F Right Angle 3.5mm M to XLR F 2 Foot) There is a wiring spec in the Epic manual; these cables conform to that. There is a wiring diagram on the packaging.
  • The Mix Pre-D can put out mic level audio. It puts out a balanced signal, and this setup works just as well if the camera is set to balanced or unbalanced.
  • Mono cables will not work if the camera is set to balanced input. They will work in some cases if the camera is set to unbalanced.
  • The camera does not supply phantom power. (The manual says it does, but the build notes say that phantom power is not enabled. It is not.)
  • If you have the camera set for unbalanced audio, an mono dynamic or self-powered mic might well work. Could this be why your cheap mic works?
  • Are the cables feeding from the Rode mic to the camera all good?
  • Steve's suggestion of checking all the cables is a good one.
 

Attachments

  • Screen shot 2012-01-31 at 11.18.32 PM.jpg
    Screen shot 2012-01-31 at 11.18.32 PM.jpg
    19.7 KB · Views: 0
I am using a Hosa XVM-102 F, which does not work. It appears that the Hosa XVS-102 F does work. I now wonder if the XVS is in fact a stereo cable with common ground to sleeve, which accidentally unbalances the signal.

I've just read in another thread that the balanced input on Epic does NOT work. I appears it only recognizes unbalanced signal (hot to tip, cold and ground to sleeve)

I also wonder is this is a spec which has changed in build 2.0.5.
 
James Brundige said:
I think I have a clue from another thread. Balanced cables do not work. Have to get an unbalanced Stereo Hosa cable - which is a total miswire, and contrary to Red's spec.

Audio still not ready for prime time.
Click to expand...


The stereo Hosa cable is a balanced cable. And it conforms to Red's spec exactly.

In fact, cables aren't really balanced or unbalanced at all. Inputs and outputs are balanced, and the cable has to be wired to pass those signals properly. The Hosa XVS102F (stereo cable) does that. Just to make things confusing, there is a mono version of that cable which is not wired properly to pass a balanced signal. (It's called the Hosa XVM102F - note the M in the product number for MONO.)
 
Steve Wake said:
Have you checked the cables with a multimeter to make sure they are wired as Keith described and there are no cross-connections? Written descriptions can be deceptive and defective cables in that price range are certainly not unknown.
Click to expand...

I tore apart one cable, and the wiring is not as specced. I'll order more tomorrow. Thanks for your input.
 
You must log in or register to reply here.
Back
Top