Two AT Pro 88W questions at DVinfo.net

Jim Schweer · August 6th, 2006, 12:48 PM

1. I would like to use other mics such as an AT897 shotgun with the Audio-Technica Pro 88W wireless transmitter. A BH audio person told me it can’t be done. An AT support person said it can using a cable like this:

http://www.audio-technica.com/cms/ac...230/index.html

and an 1/8"-stereo-to-mono adapter like this:

http://www.radioshack.com/product/in...entPage=search

Does anyone have actual experience using such a setup? If so, how well does it work?

2. If, when scouting a location, I carried only the 88W’s receiver and monitored its output on headphones, could I determine what kind of interference I would encounter shooting in that area with the 88W?

Thanks.

David Ennis · August 8th, 2006, 10:55 AM

1. There is a piece missing from the puzzle. I don't see where the two devices join together to go into that mono to stereo plug.
2. Even if the puzzle were complete, chances are that it wouldn't work well due to large differences in ouput between the two devices, as well as the potential impedance mess of each device being connected to two others.

To do this properly you need a mixer or an XLR adaptor such as found at beachtek.com

Jay Massengill · August 8th, 2006, 12:20 PM

Mechanically it would work if you want to use the AT897 with internal battery as the "mic element" for the AT transmitter that has a mini-jack, but as Fred said there are potential issues. It would depend on exactly how the AT cable is wired, as well as how the input jack on the transmitter works. This includes whether the jack passes a voltage to the normal lavalier mic element, which I think it does.
The AT cable may have a voltage blocking capacitor since it says it's for hooking to a stereo-mini camera input, but I doubt it.
I know this can be accomplished, but these unknowns would have to be solved for sure, like with a custom-made cable. With the parts you've listed you'd have to experiment and see if it works. That AT cable would be a good one to have in your inventory even if it doesn't work for this purpose.

Jim Schweer · August 8th, 2006, 02:19 PM

Thanks for the responses. I brought up the issue of the jack voltage with the AT person, since the included condenser lav has to get its voltage there. He responded, as one of you did, that I'd need to run the AT897 with a battery since the jack didn't provide phantom. I have ordered a Hosa cable that terminates in a mono male mini plug, eliminating the need for the adapter. Is there a potential to damage the transmitter or 897 by trying this?

Jim Schweer · August 8th, 2006, 02:39 PM

Fred, I reread your response (again). I have a Beachtek, the passive kind. If I understand your suggestion, you'd be using the Beachtek between the microphone and the transmitter as an impedence-matching device. So I'd still need that stereo-to-mono adapter to go from the Beachtek's output mini plug into the mono jack of the transmitter. Am I understanding this correctly?

Jay Massengill · August 8th, 2006, 02:56 PM

I can't say for sure, but I don't think it's likely to cause damage. Anytime you're experimenting there is some risk involved.
Two other things to consider, in addition to the transmitter jack supplying an un-needed voltage to the mic which can cause loud crackles and pops.
That transmitter also uses the mic element cable as part of the antenna. This can either cause interference in your mic or it can reduce your transmitting range if you substitute parts.
And the cable you get from Hosa has to be wired correctly for taking the balanced mic down to mono mini without having cancellation of the signal. If you can test it ahead of time with a multi-meter that would be helpful. Pin 2 of the XLR female should go to the mini tip. Pins 1 and 3 should go to the sleeve. Or if that's too much signal into the transmitter, then disconnecting pin 3 would reduce it by half, but the 897 isn't a hot mic. If pins 2 and 3 both go to the tip, you won't get any signal.
I forgot to answer the first time about using just the receiver to test for interference. That won't necessarily tell you the whole story. It depends on how the receiver reacts when the transmitter isn't on and it depends on how many transmitters you will be running.
Some receivers totally mute when the transmitter isn't on, so you might not detect interference.
Any time two radio signals mix together they create a byproduct on another frequency. This "ghost" frequency could fall right on one of your other wireless frequencies. For example you could have only two wireless sets but there is strong interference present from an outside source that acts like a 3rd transmitter. The intermodulation byproduct could end up on one of your wireless sets if you're unlucky. The same could be true if you're in a clean zone but you're using 3 wireless sets of your own. So until you're operating everything for real, at least a real test, you won't know for sure.
Plus VHF interference tends to be less predictable than UHF because more VHF sources are mobile. Add to that you have limited frequency choices on this model of wireless. I'm not trying to be negative, just pointing out potential problems and I hope it works out.

Guy Bruner · August 8th, 2006, 02:57 PM

All you need is the Hosa cable. I made my own using an XLRM connector and mono miniphone plug from Radio Shack. It (the AT897) works with the AT88W transmitter fine. I have also used a RODE Videomic as an input. Just about any mic you can feed to the unbalanced mic input will work.

Jim Schweer · August 9th, 2006, 09:17 AM

This is great. I received solid answers to both questions. Guy's actual experience can't be bettered for advice, and Jay helped me understand the complexities of interference, a lesson in itself (I'll have to reread it early one morning when the greatest number of my brain cells are firing).

This will be my first experience with wireless. I have begun micing objects within shots and this will make it easier to hide the equipment in plain sight.
Also I like the possibility of connecting the shotgun to it so I can boom a mic without necessarily having the camera nearby when I'm recording to the camera. Thanks again for the input. Dvinfo.net is an invaluable resource.

David Ennis · August 11th, 2006, 07:01 AM

Quote:

Originally Posted by Jim Schweer

Fred, I reread your response (again). I have a Beachtek, the passive kind. If I understand your suggestion, you'd be using the Beachtek between the microphone and the transmitter as an impedence-matching device. So I'd still need that stereo-to-mono adapter to go from the Beachtek's output mini plug into the mono jack of the transmitter. Am I understanding this correctly?

No Jim, I'm afraid I misread you initial post, interpreting using the 897 "with" the Pro88 as putting the output of one in the left channel and one in the right.

But I'm glad you got your answers. Like Guy, I frequently use the Rode VideoMic as input for my wireless transmitter, which happens to be a Sennheiser G2.

August 6th, 2006, 12:48 PM	#1
Jim Schweer Regular Crew Join Date: Sep 2003 Location: Kansas City KS Posts: 60	Two AT Pro 88W questions 1. I would like to use other mics such as an AT897 shotgun with the Audio-Technica Pro 88W wireless transmitter. A BH audio person told me it can’t be done. An AT support person said it can using a cable like this: http://www.audio-technica.com/cms/ac...230/index.html and an 1/8"-stereo-to-mono adapter like this: http://www.radioshack.com/product/in...entPage=search Does anyone have actual experience using such a setup? If so, how well does it work? 2. If, when scouting a location, I carried only the 88W’s receiver and monitored its output on headphones, could I determine what kind of interference I would encounter shooting in that area with the 88W? Thanks.

August 8th, 2006, 10:55 AM	#2
David Ennis Fred Retread Join Date: Jul 2004 Location: Hartford, CT Posts: 1,227	1. There is a piece missing from the puzzle. I don't see where the two devices join together to go into that mono to stereo plug. 2. Even if the puzzle were complete, chances are that it wouldn't work well due to large differences in ouput between the two devices, as well as the potential impedance mess of each device being connected to two others. To do this properly you need a mixer or an XLR adaptor such as found at beachtek.com __________________ "Nothing in the world can take the place of persistence..." - Calvin Coolidge "My brain is wired to want to know how other things are wired." - Me

August 8th, 2006, 12:20 PM	#3
Jay Massengill Trustee Join Date: Jul 2003 Location: Burlington Posts: 1,976	Mechanically it would work if you want to use the AT897 with internal battery as the "mic element" for the AT transmitter that has a mini-jack, but as Fred said there are potential issues. It would depend on exactly how the AT cable is wired, as well as how the input jack on the transmitter works. This includes whether the jack passes a voltage to the normal lavalier mic element, which I think it does. The AT cable may have a voltage blocking capacitor since it says it's for hooking to a stereo-mini camera input, but I doubt it. I know this can be accomplished, but these unknowns would have to be solved for sure, like with a custom-made cable. With the parts you've listed you'd have to experiment and see if it works. That AT cable would be a good one to have in your inventory even if it doesn't work for this purpose.

August 8th, 2006, 02:19 PM	#4
Jim Schweer Regular Crew Join Date: Sep 2003 Location: Kansas City KS Posts: 60	Thanks for the responses. I brought up the issue of the jack voltage with the AT person, since the included condenser lav has to get its voltage there. He responded, as one of you did, that I'd need to run the AT897 with a battery since the jack didn't provide phantom. I have ordered a Hosa cable that terminates in a mono male mini plug, eliminating the need for the adapter. Is there a potential to damage the transmitter or 897 by trying this?

August 8th, 2006, 02:39 PM	#5
Jim Schweer Regular Crew Join Date: Sep 2003 Location: Kansas City KS Posts: 60	Fred, I reread your response (again). I have a Beachtek, the passive kind. If I understand your suggestion, you'd be using the Beachtek between the microphone and the transmitter as an impedence-matching device. So I'd still need that stereo-to-mono adapter to go from the Beachtek's output mini plug into the mono jack of the transmitter. Am I understanding this correctly?

August 8th, 2006, 02:56 PM	#6
Jay Massengill Trustee Join Date: Jul 2003 Location: Burlington Posts: 1,976	I can't say for sure, but I don't think it's likely to cause damage. Anytime you're experimenting there is some risk involved. Two other things to consider, in addition to the transmitter jack supplying an un-needed voltage to the mic which can cause loud crackles and pops. That transmitter also uses the mic element cable as part of the antenna. This can either cause interference in your mic or it can reduce your transmitting range if you substitute parts. And the cable you get from Hosa has to be wired correctly for taking the balanced mic down to mono mini without having cancellation of the signal. If you can test it ahead of time with a multi-meter that would be helpful. Pin 2 of the XLR female should go to the mini tip. Pins 1 and 3 should go to the sleeve. Or if that's too much signal into the transmitter, then disconnecting pin 3 would reduce it by half, but the 897 isn't a hot mic. If pins 2 and 3 both go to the tip, you won't get any signal. I forgot to answer the first time about using just the receiver to test for interference. That won't necessarily tell you the whole story. It depends on how the receiver reacts when the transmitter isn't on and it depends on how many transmitters you will be running. Some receivers totally mute when the transmitter isn't on, so you might not detect interference. Any time two radio signals mix together they create a byproduct on another frequency. This "ghost" frequency could fall right on one of your other wireless frequencies. For example you could have only two wireless sets but there is strong interference present from an outside source that acts like a 3rd transmitter. The intermodulation byproduct could end up on one of your wireless sets if you're unlucky. The same could be true if you're in a clean zone but you're using 3 wireless sets of your own. So until you're operating everything for real, at least a real test, you won't know for sure. Plus VHF interference tends to be less predictable than UHF because more VHF sources are mobile. Add to that you have limited frequency choices on this model of wireless. I'm not trying to be negative, just pointing out potential problems and I hope it works out.

August 8th, 2006, 02:57 PM	#7
Guy Bruner Major Player Join Date: Nov 2003 Location: Ashford, AL Posts: 937	All you need is the Hosa cable. I made my own using an XLRM connector and mono miniphone plug from Radio Shack. It (the AT897) works with the AT88W transmitter fine. I have also used a RODE Videomic as an input. Just about any mic you can feed to the unbalanced mic input will work.

August 9th, 2006, 09:17 AM	#8
Jim Schweer Regular Crew Join Date: Sep 2003 Location: Kansas City KS Posts: 60	This is great. I received solid answers to both questions. Guy's actual experience can't be bettered for advice, and Jay helped me understand the complexities of interference, a lesson in itself (I'll have to reread it early one morning when the greatest number of my brain cells are firing). This will be my first experience with wireless. I have begun micing objects within shots and this will make it easier to hide the equipment in plain sight. Also I like the possibility of connecting the shotgun to it so I can boom a mic without necessarily having the camera nearby when I'm recording to the camera. Thanks again for the input. Dvinfo.net is an invaluable resource.