Senn G3 as Wireless Hop HELP!

[lvignola]

I'll start off by saying I am very new to all of this, so I apologize in advance if the nature of my question seems very basic...

I've rented a G3 wireless system as a wireless hop into a Sony F55. I'm using a rental house provided XLR to TRS to go out of one of the XLR main outs from a SD 633 into the Senn Tx, the input level on the Tx is set to -48. The Rx is set to output level of 0 and going into the F55 as Mic level. The F55 has a manual volume of 0 and it's db reference is -60. When I send tone from the 633, the Tx meter peaks to where it should, then drops down very low, I'm not sure if this is just the specific ballistics on this Tx... But the tone into the F55 looks at the right level.

All that to say, I recorded on the 633 and on the F55, and the results are troubling. The 633 sounds fine, however the F55 sounds phasey and very hissy. I've attached two audio clips to help show what I mean. 

I was reading up on this workflow and I know that a special line level cable must be used to allow for this specific signal flow to work. I haven't yet called the renal house to ask if perhaps they provided me with the wrong cable going into the Rx, but I was wondering if someone here would be able to identify it immediately by listening to the audio clips?

Any advice is greatly appreciated!!

 

CAM_audio.mp3

SoundDevices_audio.mp3

[Eric Toline]

I would bet that the TX input cable is NOT wired for line level into the TX. Feeding a line level signal into a mic level input is wrong in so many ways. That's why you have the TX set at -48 and the RX set at "0". It's all about gain staging. You need to either get the correct wired cable or set the 633 output to mic level out. Then you can raise the TX input level to -18 or so and adjust the RX output to about the same if you have a mic level setting on the camera. The cable you need will have the positive feed connected to the ring of the 3.5mm TRS input connector and a ground connection going to both the sleeve and the tip.

[Rick Reineke]

I think the rental house gave you the wrong input cable.. These are specialty cables, so a generic off-the-shelf XLR>1/8" could cause problems.  FYI, for mic level, the hot (XLR pin 2) is wired to the input plugs tip (ring tied to shield/ground); for line level, the hot (XLR pin 2) is tied to the ring w/ the tip tied to the shield. SD recommends floating pin 3 on the XLR output for unbalanced operation on 633. Your G3's receiver AF out setting is 'about' normal for a mic level input, but the transmitter sensitivity setting is abnormally low. Feeding the G3 SK100 Tx mic or -10dB line would be recommended as a +4dB signal can clip occasionally.

[edward chick]

Several years ago when I was running G2s for hops I had a custom cable made from Remote Audio for line level. I never had any issues once I had my gain structure dialed in. 

[Derek H]

Yes as these very smart guys have mentioned you need to know exactly how that transmitter cable is wired. 

 

Im not sure what would cause phasing. You're not using a y-cable with two female XLR into a single 3.5mm into the transmitter are you?

 

Is this a single channel wireless hop setup you're attempting or do you have two sets of G3s?

 

I use G3s pretty often for sending a scratch track to dslr cameras. My setup is line level cable and full line level output setting on the 633 menu. Transmitter sensitivity is set to around -50ish. Sounds fine to me. Tone barely registers on the G3 meter it's a strange ballistic thing on the G3. 

[Philip Perkins]

Maybe jump online and look at the Sennheiser docs if you want a diagram for wiring the G3 TX--as was said, a normal XLR etc> mini won't work correctly.  Since the rental house kind of hosed you I would feel no compunction about rewiring their cable so you can get through your job.

[Eric Toline]

16 hours ago, Derek H said:

Yes as these very smart guys have mentioned you need to know exactly how that transmitter cable is wired. 

 

Im not sure what would cause phasing. You're not using a y-cable with two female XLR into a single 3.5mm into the transmitter are you?

 

Is this a single channel wireless hop setup you're attempting or do you have two sets of G3s?

 

I use G3s pretty often for sending a scratch track to dslr cameras. My setup is line level cable and full line level output setting on the 633 menu. Transmitter sensitivity is set to around -50ish. Sounds fine to me. Tone barely registers on the G3 meter it's a strange ballistic thing on the G3. 

There's something wrong if your TX is set to -50. Either your cable is not wired for line or your sending too hot a signal from your 633. Not sure what you mean by "full line level" output. You should be using the "0" tone from the 633 as your reference tone and adjust the TX input to give you about 75% on the TX meter. The RX meter should be set to about the same level. The 3.5mm TRS connector should be wired with positive to the ring and ground to the shield & the tip. The connector to the 633 should be positive to pin 2 and ground to pin 1 & 3. Now you have an unbalanced connection that will drop the 633 output into the TX by 6db as compared to balanced wiring. The way your working is like driving with one foot on the gas pedal & the other on the brake at the same time. Look up unity gain & gain staging for more information on how to do it & the advantages.

[Rick Reineke]

"There's something wrong if your TX is set to -50."

I concur with Eric. The sensitivity setting on the SK100 transmitter does not actually adjust the input stage level, so a hot signal could still clip regardless. Similar to a budget recorder's 'record volume' setting, which is after the preamp.

[Derek H]

6 hours ago, Eric Toline said:

There's something wrong if your TX is set to -50. Either your cable is not wired for line or your sending too hot a signal from your 633. Not sure what you mean by "full line level" output. You should be using the "0" tone from the 633 as your reference tone and adjust the TX input to give you about 75% on the TX meter. The RX meter should be set to about the same level. The 3.5mm TRS connector should be wired with positive to the ring and ground to the shield & the tip. The connector to the 633 should be positive to pin 2 and ground to pin 1 & 3. Now you have an unbalanced connection that will drop the 633 output into the TX by 6db as compared to balanced wiring. The way your working is like driving with one foot on the gas pedal & the other on the brake at the same time. Look up unity gain & gain staging for more information on how to do it & the advantages.

 

I have to respectfully disagree here. In my experience 0dBu tone barely registers on the G3 transmitter meter but dialog with the usual +10dBu peaks completely fills the G3 transmitter meter. I've concluded that there's nothing wrong with running the sensitivity down at -50 or even less as long as you're fully modulating the transmitter during your mix. My cables are wired correctly for line level. Signal to ring, tip and sleeve to ground. Receiver output sounds perfectly fine and there's no clipping or compandor pumping or anything weird. I don't believe what Rick is saying to be true that the transmitter doesn't adjust the input stage when set below 0dB and Sennheiser's technical support has also confirmed this. You're clipping it when the AF peak light goes off and as long as you're not engaging that light any sensitivity setting that sounds good and gets the meter fully modulated is fine. Lectro transmitters work the same way. People think something's wrong if they're sending the SM a line level signal and only need the gain at '3' but in actuality this is not a problem as Larry and company have confirmed in the past. Any trim setting is valid as long as it modulates the transmitter fully. I'd be more worried about the opposite side of the coin where you're using all of the transmitter's available gain, in that case it would surely be better to increase the gain earlier on via a less noisy preamp. I understand gain staging but I'd say not all devices have a detent in the exact middle of the adjustment range where you should always be operating. At least not wireless mics.

 

My setup method for transmitters is usually to send full scale tone (+20dBu or 0 dBFS) and set the pack so it hits the clip light then back it off a notch or two. On the G3 this means I end up around -50 to -60. At this point when I send normal tone I find that it barely blips the meter. And then the human voice is not tone and it modulates a little differently so I often make another tweak after observing actual program levels. My conclusion is that the G3 meters are sort of zoomed in on the 0dBU to +20dBU area if you're comparing it to the meter on our mixers.

 

Not trying to start a war but this is what works for me. 

 

 

 

 

 

 

[Eric Toline]

As has been said, "there are many ways to skin a cat" and while your way works for you, that's not how I would do it.

[VASI]

dBFS metering scale EVERYWHERE for God sake.
Dear manufacturers, can you hear?