Wireless Shotgun Configuration

Ken Tanaka · January 22nd, 2003, 03:34 PM

(Jaime, I moved your latest post over here to prevent others' confusion.)

Yes, you basically have the configuration correct. The mic plugs into the MM-1 mic preamp. The MM-1 then connects to the wireless transmitter. The boom operator's headphones plug into the MM-1. The MM-1 also has facilities to attach a communication system, such as a walkie-talkie, to facilitate voice communication between director, camera operator and boom operator. In such a configuration the MM-1 sends the walkie talkie comm through one of the headphone's earpieces. (If you're envisioning the fully-loaded boom operator at this point, you may be thinkng that suspenders might be a good choice of attire.)

The boom operator can manage the signal sent to the transmitter by simply dialing the MM-1's level. The MM-1 also has a user-controlled 2-stage (80 Hz and 160 Hz) high-pass filter which enables it to eliminate excessive low-frequency rumble. Last, the MM-1 has a user-controllable limiter to prevent clipping under very loud consitions. So the gadget really packs alot of value into a small bundle.

Of course, if sending the signal back to the camera's audio ports, the camera operator (GL2, XL1s, et.al.) has the last word on signal level since he can dial it up or down. The camera operator can also monitor sound as it's coming in from the wireless receiver. At this end it's no different than using any other wireless configuration.

I should note that the MM-1 can certainly be used as a wired preamp inline with a hard-wired configuration to the audio deck or camera.

Jeff really turned me on to this MM-1. I think it's a great gadget that, although not cheap, belongs in many videographers' quiver of arrows.

Jaime Valles · January 22nd, 2003, 05:11 PM

Thanks again, Ken! I'll be doing some more research on sound recording, but right now I'm pretty much sold on the MM-1 wireless setup. It's cheaper than a DAT recorder and the MiniDisc recorder from HHB you got, plus the audio will be in sync with the video from the get-go!

Thank you for your recommendations, and for taking the time with a DV newbie. I'll keep everyone posted on the progress of my project this summer.

Jaime

Phil Reams · January 22nd, 2003, 06:45 PM

If you don't mind lugging around another piece of equipment, what I have done in the past is have my sound guy bring his ham radio handie talkie (it's tiny and frequency agile!), dial up the frequency of the wireless transmitter and patch it to his headphones.

That way, he can also monitor for interference if I happen to have my phones off for a sec. You can also do the same thing with a police scanner (that has wide-FM mode) with a belt-clip.

Although I am certain that audiophile purists might disagree, it's a good alternative if you happen to have a scanner sitting around and don't mind carrying an extra item on your belt. Most (although not all) have an receive RF bandwidth of 20khz on wide FM, so there's little chance of clipping since most RF mic transmitters have a RF TX bandwidth of 15khz.

As an added bonus, I sometimes use that technique to "borrow" audio from the venue's wireless mics if I am doing a wedding video and I need an extra feed. I just use the appropriate balun and adaptors and jack it into my mixer.

That's just my opinion... I could be wrong... : )

-Phil

Jeff Donald · January 22nd, 2003, 09:37 PM

Just as a note of caution on using radios near prosumer cameras (pro cameras are usually better shielded) this link might be of interest. Radios can cause problems (RFI) when used in close proximity.

Jeff

Phil Reams · January 23rd, 2003, 01:11 AM

You have an excellent point, Jeff.

Near-field RF from a transmitter can certainly wreak havoc on lesser-shielded prosumer cameras. Everything from image-shift to wavy lines in the picture, up to and including total failure of the camera. Especially when the antenna is close to the camera in the scenario I mentioned.

Our HTs are capable of outputting several watts of RF when keyed-up in transmit mode-- more than enough to cause problems.

However, in receive mode, commercial and amateur transceiver gear emits no more RF than a camera-mounted wireless mic receiver. In fact, even *less* than some of the wireless receivers I've looked at on the RF spectrum analyzer while they were on my repair bench.

The only RF emitted on these items (wireless recievers, scanners and amateur/commercial gear in receive mode) is from the local oscillator and PLL circuit, and this is usually -60bB to -90dB. Merely microwatts in comparison to the average 50 milliwatt part-15 or 500mw part-90 wireless mic transmitter.

Using gear in the above scenario, one will have to be prudent to *never* to accidentally key up and transmit (moot point using a scanner) lest you potentially fry your camera's delicate innards... Somthing we are very careful *not* to do!

Thanks for bringing that point up!

-Phil

Ken Tanaka · February 5th, 2003, 01:52 PM

For anyone following this thread, I inquired earlier about a "XLR-to-mini XLR adapter". This is a short cable that has a 3-pin male XLR connector at one end and a much smaller 3-pin female XLR plug at the other. I found these cables, which are technically called XLR to P3 adapters for sale at Samson's site.

Jaime Valles · February 5th, 2003, 04:05 PM

<<<-- Originally posted by Ken Tanaka : For anyone following this thread, I inquired earlier about a "XLR-to-mini XLR adapter". This is a short cable that has a 3-pin male XLR connector at one end and a much smaller 3-pin female XLR plug at the other. I found these cables, which are technically called XLR to P3 adapters for sale at Samson's site. -->>>

Is this needed for the MM-1 Mic preamp and wireless setup discussed in the last few posts? Or does the MM-1 use the regular XLR cables?

Thanks!

Ken Tanaka · February 5th, 2003, 05:25 PM

Good question Jaime. Here's how the configuration looks.

Mic --(XLR)-->MM-1 preamp--(XLR-->XLR to P3)-->Samson UHF 32 transmitter

Some brands of wireless transmitters might not require this P3-style connector.

Rob Wilson · February 14th, 2003, 09:46 AM

The MM1 looks like a great piece of gear but $$$$$. Any thoughts on using a splitter out of the mic, one leg to the wireless transmitter, and a much less expensive mic pre-amp that would just feed the headphones? In my case, where I'm most worried about the sound guy aiming for maximum sound level, I'm thinking it may be more cost effective. Just not sure what impact feeding two sources with the mic would have.

Brian M. Dickman · February 14th, 2003, 10:16 AM

The "on the cheap" solution I'm looking at using is a Rolls PM50sOB portlable headphone amp. It just has a straight-thru mic connection (XLR in, XLR out), and pulls off and amplifies a headphone signal for monitoring. Can be powered by a 9V. B&H has them for $65.

http://www.rolls.com/new/pm50sob.html

Rob Wilson · February 14th, 2003, 10:47 AM

Brain, THANKS! Exactly what I had in mind. Just ordered it so I'll let you know how it works. As it always seems, if you can imagine it, someone else has and has already built it. This list is GREAT.

Ken Tanaka · February 14th, 2003, 12:07 PM

The Rolls looks like a good inexpensive solution! Much less expensive than the MM-1. Well, I guess you can always spot the 'pioneers' by the arrows sticking out of their chests and their pockets turned inside-out.

Bryan Beasleigh · February 15th, 2003, 12:59 AM

When I bought my Sennheiser evolution kit I opted fot the one that included the butt plug mic transmitter. It works out to be $100 more.

Nick Kerpchar · February 15th, 2003, 06:57 AM

And if you are going to use Ham radio gear you need to be licensed to transmit with it. You can listen without being licensed, but you definitely need a license to transmit. A scanner is probably the safer route to go so as to not accidently key the transmitter.

Nick

Jaime Valles · February 21st, 2003, 03:04 PM

About interference...

I am seriously considering the wireless shotgun configuration described above (with mm-1 preamp). I just realized that a lot of the scenes in my upcoming project take place inside a computer lab, with about 30 real computers turned on at the same time.

Do you think that the ammount of electronic equipment and cables in that room will create any kind of interference with the wireless system? Or does regular computer equipment not create interference on audio recording? Would I just be safer recording my audio to a separate device (such as the HHB Portadisc) that is not wireless? I've budgeted about $2000 for all my sound recording equipment. Obviously, cheaper is better, but not at the expense of quality.

Any advice would be greatly appreciated!

January 22nd, 2003, 03:34 PM	#16
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	(Jaime, I moved your latest post over here to prevent others' confusion.) Yes, you basically have the configuration correct. The mic plugs into the MM-1 mic preamp. The MM-1 then connects to the wireless transmitter. The boom operator's headphones plug into the MM-1. The MM-1 also has facilities to attach a communication system, such as a walkie-talkie, to facilitate voice communication between director, camera operator and boom operator. In such a configuration the MM-1 sends the walkie talkie comm through one of the headphone's earpieces. (If you're envisioning the fully-loaded boom operator at this point, you may be thinkng that suspenders might be a good choice of attire.) The boom operator can manage the signal sent to the transmitter by simply dialing the MM-1's level. The MM-1 also has a user-controlled 2-stage (80 Hz and 160 Hz) high-pass filter which enables it to eliminate excessive low-frequency rumble. Last, the MM-1 has a user-controllable limiter to prevent clipping under very loud consitions. So the gadget really packs alot of value into a small bundle. Of course, if sending the signal back to the camera's audio ports, the camera operator (GL2, XL1s, et.al.) has the last word on signal level since he can dial it up or down. The camera operator can also monitor sound as it's coming in from the wireless receiver. At this end it's no different than using any other wireless configuration. I should note that the MM-1 can certainly be used as a wired preamp inline with a hard-wired configuration to the audio deck or camera. Jeff really turned me on to this MM-1. I think it's a great gadget that, although not cheap, belongs in many videographers' quiver of arrows. __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

January 22nd, 2003, 06:45 PM	#18
Phil Reams Regular Crew Join Date: Jan 2003 Location: Clearwater, Florida Posts: 60	If you don't mind lugging around another piece of equipment, what I have done in the past is have my sound guy bring his ham radio handie talkie (it's tiny and frequency agile!), dial up the frequency of the wireless transmitter and patch it to his headphones. That way, he can also monitor for interference if I happen to have my phones off for a sec. You can also do the same thing with a police scanner (that has wide-FM mode) with a belt-clip. Although I am certain that audiophile purists might disagree, it's a good alternative if you happen to have a scanner sitting around and don't mind carrying an extra item on your belt. Most (although not all) have an receive RF bandwidth of 20khz on wide FM, so there's little chance of clipping since most RF mic transmitters have a RF TX bandwidth of 15khz. As an added bonus, I sometimes use that technique to "borrow" audio from the venue's wireless mics if I am doing a wedding video and I need an extra feed. I just use the appropriate balun and adaptors and jack it into my mixer. That's just my opinion... I could be wrong... : ) -Phil __________________ Phil Reams Timeless Studio Productions Clearwater, Florida FCC Licensed Electronics Technician (GROL) Amateur Radio - KC4UVU Life Member of the PSHA - Pinnacle Studio Haters of America

January 23rd, 2003, 01:11 AM	#20
Phil Reams Regular Crew Join Date: Jan 2003 Location: Clearwater, Florida Posts: 60	You have an excellent point, Jeff. Near-field RF from a transmitter can certainly wreak havoc on lesser-shielded prosumer cameras. Everything from image-shift to wavy lines in the picture, up to and including total failure of the camera. Especially when the antenna is close to the camera in the scenario I mentioned. Our HTs are capable of outputting several watts of RF when keyed-up in transmit mode-- more than enough to cause problems. However, in receive mode, commercial and amateur transceiver gear emits no more RF than a camera-mounted wireless mic receiver. In fact, even less than some of the wireless receivers I've looked at on the RF spectrum analyzer while they were on my repair bench. The only RF emitted on these items (wireless recievers, scanners and amateur/commercial gear in receive mode) is from the local oscillator and PLL circuit, and this is usually -60bB to -90dB. Merely microwatts in comparison to the average 50 milliwatt part-15 or 500mw part-90 wireless mic transmitter. Using gear in the above scenario, one will have to be prudent to never to accidentally key up and transmit (moot point using a scanner) lest you potentially fry your camera's delicate innards... Somthing we are very careful not to do! Thanks for bringing that point up! -Phil __________________ Phil Reams Timeless Studio Productions Clearwater, Florida FCC Licensed Electronics Technician (GROL) Amateur Radio - KC4UVU Life Member of the PSHA - Pinnacle Studio Haters of America

February 5th, 2003, 01:52 PM	#21
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	Follow-Up For anyone following this thread, I inquired earlier about a "XLR-to-mini XLR adapter". This is a short cable that has a 3-pin male XLR connector at one end and a much smaller 3-pin female XLR plug at the other. I found these cables, which are technically called XLR to P3 adapters for sale at Samson's site. __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

February 5th, 2003, 04:05 PM	#22
Jaime Valles Major Player Join Date: Aug 2002 Location: New York City, NY Posts: 316	Re: Follow-Up <<<-- Originally posted by Ken Tanaka : For anyone following this thread, I inquired earlier about a "XLR-to-mini XLR adapter". This is a short cable that has a 3-pin male XLR connector at one end and a much smaller 3-pin female XLR plug at the other. I found these cables, which are technically called XLR to P3 adapters for sale at Samson's site. -->>> Is this needed for the MM-1 Mic preamp and wireless setup discussed in the last few posts? Or does the MM-1 use the regular XLR cables? Thanks!

January 22nd, 2003, 05:11 PM	#17
Jaime Valles Major Player Join Date: Aug 2002 Location: New York City, NY Posts: 316	Thanks again, Ken! I'll be doing some more research on sound recording, but right now I'm pretty much sold on the MM-1 wireless setup. It's cheaper than a DAT recorder and the MiniDisc recorder from HHB you got, plus the audio will be in sync with the video from the get-go! Thank you for your recommendations, and for taking the time with a DV newbie. I'll keep everyone posted on the progress of my project this summer. Jaime

January 22nd, 2003, 09:37 PM	#19
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	Just as a note of caution on using radios near prosumer cameras (pro cameras are usually better shielded) this link might be of interest. Radios can cause problems (RFI) when used in close proximity. Jeff

February 5th, 2003, 05:25 PM	#23
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	Good question Jaime. Here's how the configuration looks. Mic --(XLR)-->MM-1 preamp--(XLR-->XLR to P3)-->Samson UHF 32 transmitter Some brands of wireless transmitters might not require this P3-style connector. __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

February 14th, 2003, 09:46 AM	#24
Rob Wilson Major Player Join Date: Dec 2002 Location: Flagstaff, AZ Posts: 473	The MM1 looks like a great piece of gear but $$$$$. Any thoughts on using a splitter out of the mic, one leg to the wireless transmitter, and a much less expensive mic pre-amp that would just feed the headphones? In my case, where I'm most worried about the sound guy aiming for maximum sound level, I'm thinking it may be more cost effective. Just not sure what impact feeding two sources with the mic would have.

February 14th, 2003, 10:16 AM	#25
Brian M. Dickman Regular Crew Join Date: Sep 2002 Location: Portland, OR Posts: 148	The "on the cheap" solution I'm looking at using is a Rolls PM50sOB portlable headphone amp. It just has a straight-thru mic connection (XLR in, XLR out), and pulls off and amplifies a headphone signal for monitoring. Can be powered by a 9V. B&H has them for $65. http://www.rolls.com/new/pm50sob.html

February 14th, 2003, 10:47 AM	#26
Rob Wilson Major Player Join Date: Dec 2002 Location: Flagstaff, AZ Posts: 473	Brain, THANKS! Exactly what I had in mind. Just ordered it so I'll let you know how it works. As it always seems, if you can imagine it, someone else has and has already built it. This list is GREAT.

February 14th, 2003, 12:07 PM	#27
Ken Tanaka Retired DV Info Net Almunus Join Date: Dec 2001 Location: Chicago, IL Posts: 6,943	The Rolls looks like a good inexpensive solution! Much less expensive than the MM-1. Well, I guess you can always spot the 'pioneers' by the arrows sticking out of their chests and their pockets turned inside-out. __________________ Lady X Films: A lady with a boring wardrobe...and a global mission. Hey, you don't have enough stuff! Buy with confidence from our sponsors. Hand-picked as the best in the business...Really! See some of my work one frame at a time: www.KenTanaka.com

February 15th, 2003, 12:59 AM	#28
Bryan Beasleigh Trustee Join Date: May 2002 Location: Barrie, Ontario, Canada Posts: 1,922	When I bought my Sennheiser evolution kit I opted fot the one that included the butt plug mic transmitter. It works out to be $100 more.

February 15th, 2003, 06:57 AM	#29
Nick Kerpchar Major Player Join Date: May 2002 Location: Texas Posts: 211	And if you are going to use Ham radio gear you need to be licensed to transmit with it. You can listen without being licensed, but you definitely need a license to transmit. A scanner is probably the safer route to go so as to not accidently key the transmitter. Nick

February 21st, 2003, 03:04 PM	#30
Jaime Valles Major Player Join Date: Aug 2002 Location: New York City, NY Posts: 316	About interference... I am seriously considering the wireless shotgun configuration described above (with mm-1 preamp). I just realized that a lot of the scenes in my upcoming project take place inside a computer lab, with about 30 real computers turned on at the same time. Do you think that the ammount of electronic equipment and cables in that room will create any kind of interference with the wireless system? Or does regular computer equipment not create interference on audio recording? Would I just be safer recording my audio to a separate device (such as the HHB Portadisc) that is not wireless? I've budgeted about $2000 for all my sound recording equipment. Obviously, cheaper is better, but not at the expense of quality. Any advice would be greatly appreciated!