Cable Lengths, Beachtec, etc. at DVinfo.net

George Ellis · September 26th, 2004, 02:46 PM

Hi gang. Getting ready to do a band competition. My main camera will be in a mid-tier of the stands with a mic on a mast. I have a 5-pin 25' XLR running from the mic to the 5 -> 2 3-pin spliter cable. I then plan on running 2 100' 3-pin cables up to my Beachtec DXA-8. The camera is a VX-2100.

The mic is a A-T 835ST. Besides lots of tape to prevent trip overs, and a boat load of 9v batteries, what am I missing? Am I setting up for too long of a run?

Normally, if I had the camera within 50' of the field, I would run my attenuators at -10dB. I am thinking with that much cable, I can skip them.

What am I missing?

Bruce S. Yarock · September 26th, 2004, 03:42 PM

Is there a pa board you can also record from? It' s lot cleaner sound than an ambient stereo mic.
Bruce Yarock

David Ennis · September 26th, 2004, 07:18 PM

It's my understanding that no mic would need attenuators with the DXA-8, no matter how short the distance.

George Ellis · September 26th, 2004, 07:53 PM

I should have clarified that this is a marching band. There is no house sound.

George Ellis · September 26th, 2004, 07:56 PM

<<<-- Originally posted by Fred Retread : It's my understanding that no mic would need attenuators with the DXA-8, no matter how short the distance. -->>>
My mic is too hot when close to the bands. This has been the only way to solve it.

Bryan Beasleigh · September 27th, 2004, 04:01 AM

Do you mean the DXA-8 gain control or do you use an inline pad?

George Ellis · September 27th, 2004, 09:07 AM

I have to use inline pads (attenuators). The gain controls and limiters still let it through.

We discussed it in this thread.

http://www.dvinfo.net/conf/showthrea...threadid=26818

I am fairly sure that it was the mellophones and trumpets that were the main instrument that was causing the crackle. It is not like recording a normal band. There are about 10 each of trumpets and mellophones. These are not normal playing levels either as this is when it 'blasts'. The final result was -10dB being the best setting. It also takes a top 12 DCI Division I corps to tip it. I could do audio setup on other smaller corps while preparing, but our corps would always be louder. There are strict rules about recording, so staying there to test the setup was not an option. ;)

My high school band can over drive it too, but that is at a closer distance (20-40 feet). That band is 230 members, 100 more performers than a DCI corps.

David Ennis · September 27th, 2004, 02:54 PM

This all squares with the numbers, which always makes me happy.

Even with its gain set at minimum, the BeachTek can only take a maximum of 0.92 volts without clipping, but the 835ST can dish out almost 1.3 volts at its maximum acceptable input sound level (137 dB SPL). So the mic can cause clipping in the DXA-8 without working up a sweat.

I wouldn't bet on being able to skip the pad with 100 feet of cable. Its dc resistance is only about one ohm, compared to probably about 800 ohms of impedance in the circuit. So there won't be much voltage drop in the cable.

George Ellis · September 27th, 2004, 07:48 PM

Thanks Fred, and that is my answer too. I should not have an issue with the cable lengths then. Since I will be up in the stands by a bit, I might skip the pads. Maybe I should get an air horn to test with ;)

Edit - Duh, nah, leave the pads. The POINT of the cables was so the CAMERA can be in the stands, the mic is near the action. ;) jeez, long day, low pressure, rain, duh.

Jacques Mersereau · September 29th, 2004, 10:02 AM

You can run XLR balanced microphones up to 600 feet. At that length
there is considerable line lose. 100-200 feet should be no problem
considering the DXA-8 has mic pres built in (I believe). It's always wise
to use good cable.

George Ellis · September 29th, 2004, 10:16 AM

Thanks. I ordered 2 100' A-T cables yesterday (beating the B & H deadline by hours).

September 26th, 2004, 02:46 PM	#1
George Ellis Trustee Join Date: Feb 2004 Location: Suwanee, GA Posts: 1,241	Cable Lengths, Beachtec, etc. Hi gang. Getting ready to do a band competition. My main camera will be in a mid-tier of the stands with a mic on a mast. I have a 5-pin 25' XLR running from the mic to the 5 -> 2 3-pin spliter cable. I then plan on running 2 100' 3-pin cables up to my Beachtec DXA-8. The camera is a VX-2100. The mic is a A-T 835ST. Besides lots of tape to prevent trip overs, and a boat load of 9v batteries, what am I missing? Am I setting up for too long of a run? Normally, if I had the camera within 50' of the field, I would run my attenuators at -10dB. I am thinking with that much cable, I can skip them. What am I missing?

September 26th, 2004, 07:18 PM	#3
David Ennis Fred Retread Join Date: Jul 2004 Location: Hartford, CT Posts: 1,227	It's my understanding that no mic would need attenuators with the DXA-8, no matter how short the distance. __________________ "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

September 27th, 2004, 04:01 AM	#6
Bryan Beasleigh Trustee Join Date: May 2002 Location: Barrie, Ontario, Canada Posts: 1,922	Do you mean the DXA-8 gain control or do you use an inline pad? __________________ Life's journey is not to arrive at the grave safely in a well preserved body, but rather to skid in sideways, totally worn out, shouting ".......holy smokin rubber lips...what a ride!"

September 27th, 2004, 02:54 PM	#8
David Ennis Fred Retread Join Date: Jul 2004 Location: Hartford, CT Posts: 1,227	This all squares with the numbers, which always makes me happy. Even with its gain set at minimum, the BeachTek can only take a maximum of 0.92 volts without clipping, but the 835ST can dish out almost 1.3 volts at its maximum acceptable input sound level (137 dB SPL). So the mic can cause clipping in the DXA-8 without working up a sweat. I wouldn't bet on being able to skip the pad with 100 feet of cable. Its dc resistance is only about one ohm, compared to probably about 800 ohms of impedance in the circuit. So there won't be much voltage drop in the cable. __________________ "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

September 29th, 2004, 10:02 AM	#10
Jacques Mersereau Trustee Join Date: Mar 2002 Location: Ann Arbor, MI Posts: 1,334	You can run XLR balanced microphones up to 600 feet. At that length there is considerable line lose. 100-200 feet should be no problem considering the DXA-8 has mic pres built in (I believe). It's always wise to use good cable. __________________ Jacques Mersereau University of Michigan-Video Studio Manager

September 26th, 2004, 03:42 PM	#2
Bruce S. Yarock Trustee Join Date: May 2004 Location: Pembroke Pines, Fl. Posts: 1,842	Is there a pa board you can also record from? It' s lot cleaner sound than an ambient stereo mic. Bruce Yarock

September 26th, 2004, 07:53 PM	#4
George Ellis Trustee Join Date: Feb 2004 Location: Suwanee, GA Posts: 1,241	I should have clarified that this is a marching band. There is no house sound.

September 26th, 2004, 07:56 PM	#5
George Ellis Trustee Join Date: Feb 2004 Location: Suwanee, GA Posts: 1,241	<<<-- Originally posted by Fred Retread : It's my understanding that no mic would need attenuators with the DXA-8, no matter how short the distance. -->>> My mic is too hot when close to the bands. This has been the only way to solve it.

September 27th, 2004, 09:07 AM	#7
George Ellis Trustee Join Date: Feb 2004 Location: Suwanee, GA Posts: 1,241	I have to use inline pads (attenuators). The gain controls and limiters still let it through. We discussed it in this thread. http://www.dvinfo.net/conf/showthrea...threadid=26818 I am fairly sure that it was the mellophones and trumpets that were the main instrument that was causing the crackle. It is not like recording a normal band. There are about 10 each of trumpets and mellophones. These are not normal playing levels either as this is when it 'blasts'. The final result was -10dB being the best setting. It also takes a top 12 DCI Division I corps to tip it. I could do audio setup on other smaller corps while preparing, but our corps would always be louder. There are strict rules about recording, so staying there to test the setup was not an option. ;) My high school band can over drive it too, but that is at a closer distance (20-40 feet). That band is 230 members, 100 more performers than a DCI corps.

September 27th, 2004, 07:48 PM	#9
George Ellis Trustee Join Date: Feb 2004 Location: Suwanee, GA Posts: 1,241	Thanks Fred, and that is my answer too. I should not have an issue with the cable lengths then. Since I will be up in the stands by a bit, I might skip the pads. Maybe I should get an air horn to test with ;) Edit - Duh, nah, leave the pads. The POINT of the cables was so the CAMERA can be in the stands, the mic is near the action. ;) jeez, long day, low pressure, rain, duh.

September 29th, 2004, 10:16 AM	#11
George Ellis Trustee Join Date: Feb 2004 Location: Suwanee, GA Posts: 1,241	Thanks. I ordered 2 100' A-T cables yesterday (beating the B & H deadline by hours).