Travis Prater Posted April 5, 2012 Report Share Posted April 5, 2012 While on set the other day, I had something very perplexing happen. I was using my brand spankin' new COS-11D with a Senny G3 set I had recently picked up on the used market. After about 11hrs of uneventful use, I set down my bag, powering off the mixer and recorder(302 &702). When I came back about 10min later and powered everything up(RX and TX remained "on" throughout this power cycle) I found that my lav was significantly quieter. I double and triple checked that nothing had changed with the mixer/recorder, and found nothing out of place. I ended up increasing the sensitivity on the TX and everything was fine for the rest of the shoot. After doing some research, I came across this on the Sanken website in regards to the "2-wire" wiring method... "(1) This method can have approx.10dB gain because of FET DRAIN output. (2) It might have unevenness in output level because of FET gm difference. It may have a negative phase output signal when it has a positive sound wave." My questions are... 1. what does the above quote mean exactly? Will a COS-11 in 2-wire mode have a potential to swing 10dB in one way or another? 2. If the answer to 1 has no relation to my issue, has anyone had this happen, or know what might be the culprit? Thanks in advance for all your help. Best, -Travis Quote Link to comment Share on other sites More sharing options...
OmahaAudio Posted April 5, 2012 Report Share Posted April 5, 2012 After about 11hrs of uneventful use, I set down my bag, powering off the mixer and recorder(302 &702). When I came back about 10min later and powered everything up(RX and TX remained "on" throughout this power cycle) I found that my lav was significantly quieter. I am NOT the most knowledgeable about all this audio stuff but... 1) Batteries in your G3 receiver? 2) A re-set of the entire system including the Sennheiser wireless components? I've found that it's usually it's the simplest thing that's the problem and, as with most computer problems, try a re-boot. Quote Link to comment Share on other sites More sharing options...
Travis Prater Posted April 5, 2012 Author Report Share Posted April 5, 2012 Thanks Jim, forgot to mention, when I got home that night I did a factory reset on the TX & RX and it didn't make a difference with the issue. Batteries were in the units with 2/3 power on both TX and RX. In other news, I did notice that my G3's are on Firmware V1.2.2 and the latest on the Senn website is 3.6.0. Could that have something to do with it? Also, how would one go about updating that? Quote Link to comment Share on other sites More sharing options...
OmahaAudio Posted April 5, 2012 Report Share Posted April 5, 2012 In other news, I did notice that my G3's are on Firmware V1.2.2 and the latest on the Senn website is 3.6.0. Could that have something to do with it? Also, how would one go about updating that? I couldn't find anything on the Sennheiser website about updating the firmware on G3 wireless TX/RX so I'd also be interested about instructions on doing an update. Quote Link to comment Share on other sites More sharing options...
John Blankenship Posted April 5, 2012 Report Share Posted April 5, 2012 While on set the other day, I had something very perplexing happen. I was using my brand spankin' new COS-11D with a Senny G3 set I had recently picked up on the used market. After about 11hrs of uneventful use, I set down my bag, powering off the mixer and recorder(302 &702). When I came back about 10min later and powered everything up(RX and TX remained "on" throughout this power cycle) I found that my lav was significantly quieter. I double and triple checked that nothing had changed with the mixer/recorder, and found nothing out of place. I ended up increasing the sensitivity on the TX and everything was fine for the rest of the shoot. After doing some research, I came across this on the Sanken website in regards to the "2-wire" wiring method... "(1) This method can have approx.10dB gain because of FET DRAIN output. (2) It might have unevenness in output level because of FET gm difference. It may have a negative phase output signal when it has a positive sound wave." My questions are... 1. what does the above quote mean exactly? Will a COS-11 in 2-wire mode have a potential to swing 10dB in one way or another? 2. If the answer to 1 has no relation to my issue, has anyone had this happen, or know what might be the culprit? Thanks in advance for all your help. I don't have time to answer all your questions, but the short answer is, it's quite doubtful that your mic rewired itself during your downtime. Your real answer to issues like this is proper trouble-shooting technique -- a step-by-step process, narrowing down the possibilties as you go. Quote Link to comment Share on other sites More sharing options...
ShubiSnax Posted April 5, 2012 Report Share Posted April 5, 2012 To update your G3's, it looks like you need the EM100 G3 rackmount receiver.. It has an ethernet port on the back. You can connect it to your computer through your network, then use Wireless Systems Manager to configure. Quote Link to comment Share on other sites More sharing options...
LarryF Posted April 5, 2012 Report Share Posted April 5, 2012 Hi Travis, Here is more than you probably wanted to know: "(1) This method can have approx.10dB gain because of FET DRAIN output." LEF- This just means that the source output which is normal for the COS-11 has no voltage gain, i.e., a gain of unity or 1. When you come off the drain of the FET the voltage gain is very dependent on the resistor load. The Sennheiser has a 4k (?) resistor and you will have 10 dB more output (two wire) than when using the COS-11 three wire wiring. No big deal and it won't change form one moment to the next. (2) "It might have unevenness in output level because of FET gm difference." LEF- Some Fets have more gain than others. The three wire setup forces the FET to have unity gain. The two wire setup will vary with the Fet gain but not over time. If the Fet is higher gain today, it will be the higher (the same) a month from now. Again, this is not your problem. (3) "It may have a negative phase output signal when it has a positive sound wave." LEF- There is no "may" about it; it will have a reversed phase. You can ignore it if the mic is used by itself or flip the phase in the receiver if it has that function or flip it in the mixer. My questions are... 1. what does the above quote mean exactly? Will a COS-11 in 2-wire mode have a potential to swing 10dB in one way or another? LEF- Absolutely not. 2. If the answer to 1 has no relation to my issue, has anyone had this happen, or know what might be the culprit? LEF- It is not the wiring method of your COS-11. As the mymecologist said, "Shitake happens!" Best Regards, Larry Fisher Lectrosonics Quote Link to comment Share on other sites More sharing options...
Travis Prater Posted April 6, 2012 Author Report Share Posted April 6, 2012 Thanks Larry, that was exactly what I was looking for. So from what you're saying, it's a pretty safe bet that the Lav is not the problem in this scenario... I'm going to look into updating the firmware, and do some more troubleshooting. I'll report back if/when I figure this all out. Thanks again for all your input. -Travis Quote Link to comment Share on other sites More sharing options...
studiomprd Posted April 6, 2012 Report Share Posted April 6, 2012 " it's a pretty safe bet that the Lav is not the problem in this scenario... " it's a pretty safe bet that the Lav wiring scheme is not the problem in this scenario... Quote Link to comment Share on other sites More sharing options...
.png.279748a58a2b862b7aa5f3b84126e232.png)
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.