johngooch Posted May 21, 2008 Report Share Posted May 21, 2008 Ok, here is the situation and i am a little confused. I have heard this problem before but on a recent job it was magnified a great deal. I had five characters in the back seats of 12 passenger van. The characters were wired with a variety of Lecto UM-400, SM and SMD transmitters-Sanken COS-11. Blk 26 and blk 27. I was recording to PD-606 loaded up with Lectro-411As. Recorder powered by internal batts and the 411s powered by BDS system. Shotgun, CS-3e. All good solid canare star quad cable. Nothing exotic here. I heard it before on a different job driving slower with less characters and recording to my PD-6. I was hearing loud pops in my audio that were in time with hitting potholes in the road as we drove. These increased with speed(65-70mph). All audio was affected including and especially my boom. No amount of moving the recorder boom or my cabling changed anything. My theory(Hi Larry!), The seats in these vans are not well equipped with much padding and shoddy springs. I am guessing the springs create a static discharge that is released with every pothole. The boom was much worse and was more of a constant-pothole or not. I am guessing that also combined with bad contacts on the distributor cap(ford econoline style van), that is what caused some of my problem? It was a pretty humid day if that is factor. I do not know the dew point or the moon phase:) In past jobs(in the VHF Vega Dynex days) where i had to wire actors who had to interact on a bed, i have heard horrible discharges. So hot that they bled into adjacent audio channels. That was the only time i have heard it outside of a vehicle. Thanks! John Gooch. Quote Link to comment Share on other sites More sharing options...
taylormadeaudio Posted May 21, 2008 Report Share Posted May 21, 2008 could it be a grounding issue? Quote Link to comment Share on other sites More sharing options...
soundtrane Posted May 21, 2008 Report Share Posted May 21, 2008 i think it is the L - the LC or the LCR. the inductance components. best -vin (Watson, that's not so elementary, you know, it is actually.... ) Quote Link to comment Share on other sites More sharing options...
johngooch Posted May 21, 2008 Author Report Share Posted May 21, 2008 HI Vin, thanks for your response. Inductive components. Which inductive components? I am sorry i do not understand. john Quote Link to comment Share on other sites More sharing options...
Rob Lewis Posted May 22, 2008 Report Share Posted May 22, 2008 My only understanding of vehicle mechanics is that with todays electronic ignition systems is that they put off quite a bit of electromagnetic interference. Spark plugs with resistors in them are the only way to solve it. That being said, I have had issues with static interference with my Lectro 211's in some vans where stepping on the gas would caus it as the RPMS on the engine raised. I think it has to do with a bad alternator ground. I'm wondering if this is being magnified through the vans seats like you mentioned and being transfered to the transmitters. My only thought for a solution at the moment is anti-static material on the seats to see if it goes away. Just a guess ! Quote Link to comment Share on other sites More sharing options...
soundtrane Posted May 22, 2008 Report Share Posted May 22, 2008 thanks for your response. Inductive components. Which inductive components? I am sorry i do not understand. john in the Rx? best -vin Quote Link to comment Share on other sites More sharing options...
Eric Toline Posted May 22, 2008 Report Share Posted May 22, 2008 My only understanding of vehicle mechanics is that with todays electronic ignition systems is that they put off quite a bit of electromagnetic interference. Spark plugs with resistors in them are the only way to solve it. That being said, I have had issues with static interference with my Lectro 211's in some vans where stepping on the gas would caus it as the RPMS on the engine raised. I think it has to do with a bad alternator ground. I'm wondering if this is being magnified through the vans seats like you mentioned and being transfered to the transmitters. My only thought for a solution at the moment is anti-static material on the seats to see if it goes away. Just a guess ! It's not the seats or the springs. It's from the ignition/electrical system in the van. Eric Quote Link to comment Share on other sites More sharing options...
johngooch Posted May 22, 2008 Author Report Share Posted May 22, 2008 Thanks for your replies. If it has to do with ignition/electrical system, why is the problem amplified by hitting potholes and physical shock. I honestly think it has to do with the combination of problems. The electrical system combined with some sort of static discharge. I have heard this before when i wired talent in a bead. But really, i am still just guessing what the problem is and i still welcome all theories! john Quote Link to comment Share on other sites More sharing options...
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