Sennheiser G3 audio quality and can you plug a dynamic mic into the transmitter?

A

analogs

Well-known member
I am about to pull the plug on a Sennheiser G3 but I am wondering how best to use it for DSLR video.

I have read some people going direct into their camera with the +1 notch on the levels of the camera but they would have to boost the levels on the G3.

Are the gain on the G3 great?

I was considering plugging the G3 into my Tascam 60D and let the 60D do the boosting to go into the camera.

What methods will produce the best audio quality out of the G3?

Also is it possible to plug a dynamic mic into the G3 transmitter by using a cable instead of the lavalier?

Thanks!
 
"Are the gain on the G3 great?"
- Not sure what you mean. The G2/3 EK100 portable receiver's AF setting (output level) can range from mic level (typically -50dB) up to line (close to +4dB, though a little anemic with some device's +4 line inputs) It's also unbalanced, so long cable runs should be avoided

"I was considering plugging the G3 into my Tascam 60D and let the 60D do the boosting to go into the camera."
- Not sure what you're asking here either. Proper gain staging is the key. No compromises in physics.

"What methods will produce the best audio quality out of the G3?"
- When both transmitter, receiver and following devices are gain staged properly.
An interference free channel is necessary. Line-of-sight transmitter> receiver placement helps maintain a good RF signal.

"Also is it possible to plug a dynamic mic into the G3 transmitter by using a cable instead of the lavalier?"
- Yes, the input cable must be wired correctly> The butt-plug (plug in) transmitter is easier and better suited for H/H mics.

Note I would not use audio recorded on DSRLs is only good for sync purposes. But that depends of your (or your clients) expectations and needs.
 
Rick R said:
"Also is it possible to plug a dynamic mic into the G3 transmitter by using a cable instead of the lavalier?"
- Yes, the input cable must be wired correctly> The butt-plug (plug in) transmitter is easier and better suited for H/H mics.
Click to expand...

Regarding the above - Sennheiser makes an XLR cable to use a mic with the bodypack transmitter, the CM1.

According to Sennheiser, "The CM1 contains a DC voltage blocking capacitor to prevent damage to a microphone diaphragm." I assume this refers to the mic power that the transmitter outputs?

Is the capacitor necessary, or can you simply wire a mini to an XLR with the proper pinout?

And to the OP: keep in mind that the G3 doesn't supply phantom power - you'll need a self-powered mic or a phantom supply for most of the mics you would want to use on set.

 
Thanks people for the replies!

Regarding proper gain staging.

Is this the correct procedure for getting low noise when recording into the camera?
- adjust the levels using input gain on the G3 transmitter to read about -18dbu when audio is coming in
- +1 notch on the cameras record levels input
- adjust the levels using the output gain of the G3 receiver going into the camera so that it reads on the camera to be about -18dBu disregarding what the levels read on the G3 receiver itself


Is this the correct procedure for getting low noise when recording into the Tascam 60D?
- adjust the levels using input gain on the G3 transmitter to read about -18dbu when audio is coming in
- adjust the levels using output gain on the G3 receiver to read about -18dbu on the G3 receiver itself
- adjust the levels of the input gain of the Tascam so that the reading on it is about -18dBu


Rick R said:
"Are the gain on the G3 great?"
- Not sure what you mean. The G2/3 EK100 portable receiver's AF setting (output level) can range from mic level (typically -50dB) up to line (close to +4dB, though a little anemic with some device's +4 line inputs) It's also unbalanced, so long cable runs should be avoided

"I was considering plugging the G3 into my Tascam 60D and let the 60D do the boosting to go into the camera."
- Not sure what you're asking here either. Proper gain staging is the key. No compromises in physics.

"What methods will produce the best audio quality out of the G3?"
- When both transmitter, receiver and following devices are gain staged properly.
An interference free channel is necessary. Line-of-sight transmitter> receiver placement helps maintain a good RF signal.

"Also is it possible to plug a dynamic mic into the G3 transmitter by using a cable instead of the lavalier?"
- Yes, the input cable must be wired correctly> The butt-plug (plug in) transmitter is easier and better suited for H/H mics.

Note I would not use audio recorded on DSRLs is only good for sync purposes. But that depends of your (or your clients) expectations and needs.
Click to expand...
 
Michael Carter said:
Regarding the above - Sennheiser makes an XLR cable to use a mic with the bodypack transmitter, the CM1.

According to Sennheiser, "The CM1 contains a DC voltage blocking capacitor to prevent damage to a microphone diaphragm." I assume this refers to the mic power that the transmitter outputs?

Is the capacitor necessary, or can you simply wire a mini to an XLR with the proper pinout?

And to the OP: keep in mind that the G3 doesn't supply phantom power - you'll need a self-powered mic or a phantom supply for most of the mics you would want to use on set.
Click to expand...

The capacitor is needed to block DC voltage so, yes you need it. On some wireless there are a bunch of pins and you would chose with out the power the lav needs but with the Senn. I don't see how you could do that. Phantom power (in theory) should not hurt a dynamic mic since it's applied in a balanced way. The "plug in" power that lavs use is not balanced in that way and could quite conceivably blow the mic.

Also while correct about providing power the question started out as "is it possible to plug in a dynamic mic" and dynamic mics don't use phantom power.
 
I've used dynamic mics on these packs for years. Sticking 5 volts onto the diaphragm doesn't cause a problem because there's no return path and as long as the other connection isn't referenced to ground no current flows. The capacitor is a sensible feature because it stops the dc path. It's never caused me an issue, and to be honest, plugging in a balanced mic with phantom applied often causes a Big Bang because pins 2 and 3 touch at different times, sticking 48 rather than 5 onto the element. You shouldn't do it, but I've done it for years and dynamics are tough old beasts!
 
It states on the manual that it can receive a line in signal. Does that mean I can use a typical 1/8 jack to 1/8 jack cable and plug it into my iPod with a 3.5 jack adapter for example and it will run fine without damaging my iPod?

Let me get this clear. The CM1 cable is needed to plug a normal mic level signal into the body pack transmitter regardless of whether it is from a mixing board that sends mic level or a dynamic mic?

I have an AT351b lavalier that has a powerpack that has an XLR out and send out mic level signals +4. To connect it to the G3 transmitter, I would use the CM1 cable?

Also which would provide better audio quality
- a dynamic mic plugged into a plug-on transmitter
- a dynamic mic plugged into the bodypack transmitter using a CM1 cable?
Trying to see whether it is really necessary to buy the plug-on transmitter when you can just use the bodypack transmitter when using a microphone?
 
Last edited:
analogs said:
It states on the manual that it can receive a line in signal. Does that mean I can use a typical 1/8 jack to 1/8 jack cable and plug it into my iPod with a 3.5 jack adapter for example and it will run fine without damaging my iPod?

Let me get this clear. The CM1 cable is needed to plug a normal mic level signal into the body pack transmitter regardless of whether it is from a mixing board that sends mic level or a dynamic mic?

I have an AT351b lavalier that has a powerpack that has an XLR out and send out mic level signals +4. To connect it to the G3 transmitter, I would use the CM1 cable?

Also which would provide better audio quality
- a dynamic mic plugged into a plug-on transmitter
- a dynamic mic plugged into the bodypack transmitter using a CM1 cable?
Trying to see whether it is really necessary to buy the plug-on transmitter when you can just use the bodypack transmitter when using a microphone?
Click to expand...
No, a standard 3.5mm patch cable is not proper to send the output of your iPod to the G3 transmitter input. The plug for the transmitter input is a standard 3.5mm stereo plug but it is NOT wired in the standard stereo arrangement. The transmitter input is mono and uses only two of the three connectors in the stereo plug. If you are sending a mic level signal it uses the tip for signal hot and the sleeve for ground. If you are sending a line level signal (such as your iPod) it uses ring for signal hot and sleeve for ground. The unused connector is grounded in order to switch the transmitter's internal levels. You iPod puts the left signal on the tip and the right signal on the ring, totally wrog for the transmitter's input. Of course you could always build a custom cable to connect the two if you really wanted. The tip and ring on the iPod end would both connect to the ring at the G3 end, the sleeve of the iPod end would connect to the sleeve at the G3 end, and the tip of the G3 end would be shorted to the sleeve.
 
Michael Carter said:
Regarding the above - Sennheiser makes an XLR cable to use a mic with the bodypack transmitter, the CM1.

According to Sennheiser, "The CM1 contains a DC voltage blocking capacitor to prevent damage to a microphone diaphragm." I assume this refers to the mic power that the transmitter outputs?

Is the capacitor necessary, or can you simply wire a mini to an XLR with the proper pinout?
Click to expand...

The capacitor is essential as it prevents the plug-in power getting to the micrphone. You could damage a dynamic mic. if you directly plug without the blocking capacitor.



Michael Carter said:
And to the OP: keep in mind that the G3 doesn't supply phantom power - you'll need a self-powered mic or a phantom supply for most of the mics you would want to use on set.
Click to expand...
Thsi is misleading as there are G3 transmitters that supply 48V phantom power. IE: SKP 300 G3 and SKP 2000.
 
"adjust the levels of the input gain of the Tascam so that the reading on it is about -18dBu"
I'll assume you mean -18dBFS.. Is this a calibration tone or program audio? OK for a calibration tone.. low for program audio peaks unless one needs excessive headroom. It would likely sound ok though, especially at 24 bits.
As I stated, if you desire clean audio, a DSRL ain't it. .. FWIW, The REDs ain't much better.
 
paulears said:
I've used dynamic mics on these packs for years. Sticking 5 volts onto the diaphragm doesn't cause a problem because there's no return path and as long as the other connection isn't referenced to ground no current flows.
Click to expand...

With out a balancing transformer very odd stuff would happen plugging a balanced mic with a straight through to the G3. So I'm not sure how you are wiring it. The way to cheat it is to ground one of the hot legs so then you would have a path to ground. At the least it seems that you would end up with a sizable DC offset, which would really hurt your dynamic range and cause problems in post unless they do a DC removal on all the clips.
 
I phrased that pretty poorly, didn't I - tip to pin 2, pins 1 and 3 linked as usual - I've not noticed any damping effects on SM58s, but fully agree there should be - the one I have laying around in the 'get out of trouble' box works fine. I'm assuming the Sennheiser's 5v is current limited which probably prevents the usual blocking. The DC offset would be important if hard wired, but isn't evident on the radio link. Good design by Sennheiser preventing a problem created by less sensible users!
 
Good point, the wireless link would probably eliminate that. I was thinking hard wired.

The senn. probably has current limiting because wiring it like that would give a dead short to DC coming in on the hot leg.
DC will run through the windings like so much copper wire and show up at the other side so other than the resistance of the windings all of your plugin power will show up at pin 3 and be shorted to ground.

What this should do is bias the voice coil away from it's normal 0 resting place. So the amount it can move in one direction is greater than the other. As long as you don't exceed the shorter sides travel the only thing that would be a problem would be the offset of the center (DC offset). But you do loose some dynamic range because you will clip in one direction sooner than you would have. With not a lot of current and a fairly low voltage that loss may not be noticeable with what you are doing.

IF the OP decides to go that route I would urge him to clearly label the cable as for use with "dynamic mics to the G3 transmitter" only. There are a lot of people who will assume that if you can make the connectors connect it should be good, and having voltage on the hot leg and the cold leg shorted to ground could cause problems/ damage to some devices. Having a un labled nonstandard cable lying around can be an unpleasant surprise when you can least afford it.
 
Rick, I just bought my Sennheiser G3 and just waiting to receive it in the mail.

What step by step recommendations do you have for gain staging program audio properly on the G3? Most likely the program audio will be speech like in an interview setting.

Rick R said:
"adjust the levels of the input gain of the Tascam so that the reading on it is about -18dBu"
I'll assume you mean -18dBFS.. Is this a calibration tone or program audio? OK for a calibration tone.. low for program audio peaks unless one needs excessive headroom. It would likely sound ok though, especially at 24 bits.
As I stated, if you desire clean audio, a DSRL ain't it. .. FWIW, The REDs ain't much better.
Click to expand...
 
I am getting a little confused here regarding connecting my dynamic mic to the G3 transmitter.

I would like to build a cable to allow my dynamic mic to be plugged into the G3 transmitter and will not affect the audio quality. My main objective is to obtain the best audio quality. Can someone please provide a drawing or instructions of some sort that will enable me to build one.

Thank you.
 
analogs said:
I am getting a little confused here regarding connecting my dynamic mic to the G3 transmitter.

I would like to build a cable to allow my dynamic mic to be plugged into the G3 transmitter and will not affect the audio quality. My main objective is to obtain the best audio quality.
Click to expand...

Well.... I've actually done it. That is, I ran my Electro-Voice RE50N/D-B through a Sennheiser SK 100 G3 transmitter. And it almost works. Almost.

But it certainly does not give you "the best audio quality" you seem to want. Why? Wrong tool for the job. When I tried this, I had to max out gain on both the transmitter and the receiver, and ended up with a low dynamic range hissy mess. And this is with the high output version of the RE50N. If the talent would eat the microphone and talk loudly, it would almost work (but they looked moronic on camera). If they used the mic normally, the sound quality was so poor it was unusable.

This is why Sennheiser sells the SKP 100, and why Audio-Technica sells AT8314. Because they are the right tools for the job.

I know, I know, you don't believe me. And why should you? You want to bang your head against the wall. Why the heck not? Well, there is a cable you can use, you don't have to build one. I don't remember anymore what I used, but it's all documented in old posts where I asked this exact same question on this same set of fora quite some time ago. The search tool is your friend.
 
OK, I understand what you mean. The dynamic mic is too low for the transmitter or the transmitter is not sensitive enough and it needs a preamp by the sounds of it to feed the transmitter.

Is it possible that the cable you used was not wired correctly to Steve House's comment about the ring, tip and sleeve configuration?

Does anyone know if the G3 line input on the transmitter normally +4 or -10?

Bruce Watson said:
Well.... I've actually done it. That is, I ran my Electro-Voice RE50N/D-B through a Sennheiser SK 100 G3 transmitter. And it almost works. Almost.

But it certainly does not give you "the best audio quality" you seem to want. Why? Wrong tool for the job. When I tried this, I had to max out gain on both the transmitter and the receiver, and ended up with a low dynamic range hissy mess. And this is with the high output version of the RE50N. If the talent would eat the microphone and talk loudly, it would almost work (but they looked moronic on camera). If they used the mic normally, the sound quality was so poor it was unusable.

This is why Sennheiser sells the SKP 100, and why Audio-Technica sells AT8314. Because they are the right tools for the job.

I know, I know, you don't believe me. And why should you? You want to bang your head against the wall. Why the heck not? Well, there is a cable you can use, you don't have to build one. I don't remember anymore what I used, but it's all documented in old posts where I asked this exact same question on this same set of fora quite some time ago. The search tool is your friend.
Click to expand...
 
analogs said:
Does anyone know if the G3 line input on the transmitter normally +4 or -10?
Click to expand...

You own it... There is this thing called a manual.

I would be worried about your making a cable considering the questions you have asked. Have you ever soldered small electronic connectors? The XLR won't be too bad but the 1/8" is a bit of a pain. And you are going to need to fit some components in one or the other unless you are doing a straight through.

If you don't have the manual then you should download the PDF version.
 
The G2/3 SK100 bodypack transmitter can handle -10dB (nominal) when the input cable is wired so, (the 3.5mm 'Ring' is the hot terminal, the 'Tip' is tied to shield/ground.) However.. the input stage can be over driven inputting a +4dB (regardless of the sensitivity level setting), which can have peaks of around +20dBu.
 
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