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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Audio Measurement and Testing => Topic started by: Chris Delcambre on November 21, 2017, 11:32:27 pm

Title: Wireless microphone setup for smaart
Post by: Chris Delcambre on November 21, 2017, 11:32:27 pm
What's everybody using for wireless setups for smaart? Shure, senn, lectrosonics?

Thanks
Chris
Title: Re: Wireless microphone setup for smaart
Post by: Ivan Beaver on November 22, 2017, 08:45:59 am
What's everybody using for wireless setups for smaart? Shure, senn, lectrosonics?

Thanks
Chris
The SINGLE most important thing is a NON COMPANDING system.

Most wireless mics have companding-so search carefully.  It will screw up the results of a measurement system due to the compression and expansion of the signal.

We us a lectrosonics system that was first eveloped for wireless interface (as far as I know-maybe it was another reason)
Title: Re: Wireless microphone setup for smaart
Post by: Christian Ekren on November 22, 2017, 09:37:58 am
Lectrosonics TM400 (http://www.lectrosonics.com/US/TM400-wireless-test-and-measurement-system.html) would probably be your best bet. Purpose built for measurement and calibration.
Title: Re: Wireless microphone setup for smaart
Post by: Nathan Riddle on November 22, 2017, 01:45:41 pm
Line-6 XD-V35L is an option as well.

http://forums.prosoundweb.com/index.php/topic,165485.0.html

http://forums.prosoundweb.com/index.php/topic,165241.0.html
Title: Re: Wireless microphone setup for smaart
Post by: Dave Garoutte on November 22, 2017, 05:55:34 pm
The SINGLE most important thing is a NON COMPANDING system.

Most wireless mics have companding-so search carefully.  It will screw up the results of a measurement system due to the compression and expansion of the signal.

We us a lectrosonics system that was first eveloped for wireless interface (as far as I know-maybe it was another reason)
Is the problem the companding or the resultant delay?
Title: Re: Wireless microphone setup for smaart
Post by: Peter Morris on November 22, 2017, 06:32:32 pm
Is the problem the companding or the resultant delay?

The problem is companding (TX compression - RX expansion)  - that's the advantage of the Line 6, its signal chain is basically straight into a 24bit A/D with no companding.  Delays in the measurement system are easily accounted for.
Title: Re: Wireless microphone setup for smaart
Post by: Ivan Beaver on November 22, 2017, 07:35:49 pm
  Delays in the measurement system are easily accounted for.

Agreed.

And if the same mic is used, any delay is simply not an issue.  Whatever is "common" doesn't matter.  It is the DIFFERENCE in the measurement that matters.
Title: Re: Wireless microphone setup for smaart
Post by: Lyle Williams on December 09, 2017, 07:25:34 am
I thought the line 6 model 35 had an inbuilt high-pass filter.
Title: Re: Wireless microphone setup for smaart
Post by: Don Boomer on December 10, 2017, 06:38:34 pm
The problem is companding (TX compression - RX expansion)  - that's the advantage of the Line 6, its signal chain is basically straight into a 24bit A/D with no companding.  Delays in the measurement system are easily accounted for.

Digital systems that use data compression will also be problematic. Some do, some donít.
Title: Re: Wireless microphone setup for smaart
Post by: Langston Holland on December 17, 2017, 06:33:53 pm
Don is exactly right. Digital wireless is no guarantee of the absence of artifacts that can make the system unusable for measurement applications. Iíve found that wireless systems of any type that are capable of fairly high channel counts generally cannot be used as a mic cable replacement for acoustic measurement. The Lectrosonics Hybrid system is a rare exception.

I recently tried a MIPRO ACT-818 receiver with TA-80 plug-on transmitter. It is a digital system that is advertised "to eliminate compander noise" and to be suitable for "acoustical measurements". I beg to differ. :)

Measurements

I set the TA-80 transmitter to its 24dB gain setting (reasonable for many measurement mics) and found the 1kHz clipping/limiting threshold and made log swept sine and Maximum Length Sequence (MLS) measurements 1dB below that threshold. Then I repeated those measurements 20dB below that threshold. I included MLS measurements because that process is extremely sensitive to non-linearities and time variance (LTI violations). Swept sines are the most forgiving of the non-LTI behavior present in almost all real acoustic systems to some extent. MLS freaks out if LTI is violated even slightly and makes a great blood hound when youíre looking for imperfections. Green and pink traces are MLS.

(http://soundscapesweb.com/files/PSW/WirelessTests/TF_MIPRO.png)

I made the same tests on the Line 6 XD-V75 receiver with TBP12 beltpack transmitter. The cable for the beltpack: XLF pin 2 to TA4F pins 3-4. XLF pins 1-3 to TA4F pin 1. TA4F pin 2 unconnected. The big downside is no phantom power like the MIPRO plug-on has. Green and blue traces are MLS.

(http://soundscapesweb.com/files/PSW/WirelessTests/TF_Line6.png)
Title: Re: Wireless microphone setup for smaart
Post by: Hayden J. Nebus on December 21, 2017, 12:51:54 pm
Glad to see you back here Langston!
Title: Re: Wireless microphone setup for smaart
Post by: Lyle Williams on December 31, 2017, 03:12:32 am
Gee, battery operated phantom power supplies are expensive (for what they are...)
Title: Re: Wireless microphone setup for smaart
Post by: Lyle Williams on January 09, 2018, 01:32:00 am
I made the same tests on the Line 6 XD-V75 receiver with TBP12 beltpack transmitter. The cable for the beltpack: XLF pin 2 to TA4F pins 3-4. XLF pins 1-3 to TA4F pin 1. TA4F pin 2 unconnected. The big downside is no phantom power like the MIPRO plug-on has.

I built the above setup with an XD-V55/TBP12 today, and it seems to work.  I'll run some better tests over the next few days.

The only battery phantom supplies available locally were serious brand name offerings that were $400+, so I am using a simple circuit with 2 9v batteries.  My measurement mic is the dayton emm-6.

I am using the Studio Six package on an iPad as a single channel TF rig.  This has worked fine for me wired.  Wireless should be a nice enhancement.
Title: Re: Wireless microphone setup for smaart
Post by: Jelmer de Jong on May 17, 2018, 08:29:35 am
Gee, battery operated phantom power supplies are expensive (for what they are...)
I'm using the iRigPre. It costs $30.- and makes 48V from a 9V battery. Only downside is the minijack connector, ive replaced it with a TA4F.
http://www.ikmultimedia.com/products/irigpre/
Title: Re: Wireless microphone setup for smaart
Post by: Kevin McDonough on May 17, 2018, 04:32:47 pm
I recently tried a MIPRO ACT-818 receiver with TA-80 plug-on transmitter. It is a digital system that is advertised "to eliminate compander noise" and to be suitable for "acoustical measurements". I beg to differ. :)


Thats unfortunate!  I had recently been talking to our local MiPro distributor about some other stuff in their range, and had saw this plug on transmitter and thought it'd be great for measurement. While I hadn't done any extensive research myself the frequency response chart they'd sent me looked promising.  A shame that's not really the case  :(

k
Title: Re: Wireless microphone setup for smaart
Post by: Tim Hite on May 18, 2018, 01:46:52 am
Any of the currently available wideband Lectrosonics units will work. It's all compandor free. Generally, folks are using a plug-on HMa TX and either an LT or R400a RX, but you can set it up with Venue2 if you needed multiple channels.

If anyone needs a demo you're welcome to get in touch with me.

Lectrosonics TM400 (http://www.lectrosonics.com/US/TM400-wireless-test-and-measurement-system.html) would probably be your best bet. Purpose built for measurement and calibration.