SMPTE sound bleed

[ssmith512]

Started dry fire testing my new Cobra system with SMPTE. I am getting very significant SMPTE sound bleed over into the sound system. During silent moments in my soundtrack, the SMPTE sounds are every bit 30% as loud as the music, so it is not "subtle". I have 10 seconds of silence at the beginning of my soundtrack (Cobra recommended "pre-roll"), and during that 10 seconds the SMPTE sounds are loud enough to make your ears bleed with the volume set correctly for when the music starts. Did everything by the book....compiled soundtrack in audacity, imported to Cobra Show Creator, added SMPTE timecode in Cobra Show Creator, using Cobra SMPTE Player on the laptop, everything is hooked up the way it should be. Anyone experiencing the same thing? Anyone know what can be done to eliminate the bleed over?

Thanks in advance.

Steve

[Rick_In_Tampa]

Have you tried contacting Cobra to see if they can help? That would be my first stop. I'd love to be able to help, but I don't have a clue what it could be.

[ssmith512]

Hi Rick,

Yes I contacted them first, but figured while I wait for them to get back with me I would post the same question here, maybe tackle the issue from two sides.

Thanks.


Steve

[WithReport]

Are you playing the audio (music track and time code ) directly from a computer, or ? If computer have use tried their USB audio card they provided? Have you tried just playing the audio from some other mp3 player/phone/tablet, etc. How are you splitting the L and R channels? These might help to determine if the bleed over is a HW issue with the computer or audio card.

FWIW, I've installed TC on my 18R2, but haven't used it yet. I have used TC many times on other systems and never had bleed over issues, but I would expect the bleed over to be from the player

[ssmith512]

Are you playing the audio (music track and time code ) directly from a computer, or ?

From my laptop.




If computer have use tried their USB audio card they provided?

Tried both. It is much worse using my laptop audio output (headphone jack), and I can not get a TC signal to the 18R2 using my laptop audio.




Have you tried just playing the audio from some other mp3 player/phone/tablet, etc.

I have not


How are you splitting the L and R channels?

I am using the Cobra supplied 3.5mm jack to RCA left and right cable.



These might help to determine if the bleed over is a HW issue with the computer or audio card.

FWIW, I've installed TC on my 18R2, but haven't used it yet. I have used TC many times on other systems and never had bleed over issues, but I would expect the bleed over to be from the player


I was playing around with it last night and did come up with a "fix" that solved my particular immediate issue. I exported the audio track from CSC after I used CSC to add the smpte timecode. I then imported that track into Audacity. In Audacity, it shows the audiotrack on the left channel and the timecode on the right channel as it should be. I then panned that stereo track to 80% to the left. Exported as a new mp3. Uploaded that new panned mp3 to CSC and used it as the audio track for my script. Success. No more smpte bleed into the left audio channel. Only "issue" is with the new audio track that is panned 80% to the left, for some reason when that audio track is selected as the track with my script in CSC, the Cobra SMPTE Player tab is no longer available on the left side of the screen. Doesnt seem to be a problem, I can still run the show directly from CSC. Did several dry runs of the script and audio and cue firing remains in perfect synch throughout the 23min script.

[WithReport]

I created a SMPTE track directly from Audacity yesterday - similar to what I have done in the past years. I pan the song fully to the left and pan the TC fully to the Right.

This video (focused on fireTEK, but good for creating any TC track), at the end, I show controlling the show with an MP3 player.


https://www.youtube.com/watch?v=IhCK27PgPwA



I would reach out to Cobra, maybe after the 4th, and try to figure out why CSC is crating some bleed (I've never used CSC, so I'm not much help with that application) .

[ssmith512]

I did more testing last night with a different laptop. using the Cobra USB sound card I got almost imperceptible SMPTE sound on the left audio channel. So, I am pretty confident it is a hardware issue specific with my (admittedly kinda old) Dell laptop.

But, there is a workaround as described above if anyone ever finds themselves in a similar situation.

Thanks.

[Scotty Rockets]

Sounds like a hardware problem, good thing you got it figured out. As far as stereo smpte a very slight bleed into the other channel is normal.

[WithReport]

FWIW, I've never had bleed problems - that I've noticed.

So, I just tested the TC track I made the other day. With headphones on and volume turned up - no bleed.

I have a 30 second pre-roll and it is 30 seconds of silence. Also during a few other breaks in the 20min soundtrack there is no bleed of the TC.

Here is the equipment:

Older Lenovo Legion Y520
3.5MM Male to 2 RCA Female Jack Stereo Audio Cable Y Adapter
Male RCA Cable to male 3.5mm (3.5mm plugs into headset)
Decent OTE Headset


Maybe running through an AMP might change things, but I was not picking anything up on the headset.