Kimafun wireless for measurement mic ???

Could this $US140 wireless system work for my live gig measurement rig? So I bought a kimafun system from amazon to try it out and thought this community might be interested in my findings. It has phantom power and I have successfully used it with my Behringer ECM8000 mic. I was concerned my measurements of a known studio monitor looked a little off, particularly the phase trace so I dug deeper.

I used Nathan's approach to "measure the wire" in Smaart v9 to plug transmitter directly into my interface output and the receiver into my interface input (no speaker/mic). I was careful to lower the interface output to "mic level" and to turn off phantom power. No surprise it was NOT flat and had a full wrap of phase shift. 1st screenshot below is this trace of the uncorrected transmitter/receiver.

Next I created a mic correction curve from my measurement and added that to Smaart. The next screenshot is another "measure the wire" measurement of the transmitter/receiver direct connection but with my self generated correction curve. Again, no surprise that magnitude is now flat enough to be useable BUT the phase trace has a full wrap.

I am interested in opinions if it is possible to work with measurements where this phase wrap is added by my the wireless transmitter/receiver.

Please let me know your thoughts?

Here is amazon link to kimafun (no benefit to me). https://www.amazon.com/KIMAFUN-Microphone-Transmitter-Condenser-Compatible/dp/B09QYQT7V3/?encoding=UTF8&pd_rd_w=Y8tk2&content-id=amzn1.sym.14ae7937-f413-4d1b-becd-7ba9e97b0c31&pf_rd_p=14ae7937-f413-4d1b-becd-7ba9e97b0c31&pf_rd_r=RAQQBKMKVZHFP10NSPCD&pd_rd_wg=Z8OX9&pd_rd_r=c4c77c8f-3570-419a-bac0-0955ad3a879a&ref=pd_gw_ci_mcx_mr_hp_atf_m&th=1

Smaart screenshots
1st = kimafun "measure the wire" NO correction curve
2nd = kimafun "measure the wire" WITH correction curve

Are you able to make this measurement in the LIVE mode of smaart?
If you align the reference signal with the measurement do you get 2.44ms of delay and does the phase trace flatten out?

You may be able to add some delay to flatten out the phase trace. Then you would have to be aware of the correction amount.

Does this wireless say it has a compander? The compander is what screws up wireless for measurement purposes.
As far as other options. I've been using the Line-6 xd-v75 model with great success for years. I don't know of anything else at that price that has similar quality.

Wow, thanks for running these tests Mark! Do you want to upload your measurements so we can play with them?
I believe in Smaart, mic correction curves only support magnitude values, but the phase can be correct in CrossLite, for sure, and maybe in REW. I suppose you could also forget about absolute values if you are taking measurements with a single mic because everything will have the same phase offset.

Hi Nathan – thanks for your comments.

I am appreciating your recommendation to practice measuring stuff at home. I had the time to say to myself – self this wireless stuff seems to be working but is a bit funky so I dug deeper. How else would I learn a subtlety that I have to export in ASCII to create my own correction curve and that it only affects magnitude and not phase.

I attempted to upload the TRF files yesterday and found your new community system only supports image files. I also tried to zip them and the UI rejected with same error message that only image files are supported. I may be failing the intelligence test here?

Please let me know how I could share these trf files with the community?

I am interested in your ideas on using a tool like crosslite to correct the phase shift introduced by using this wireless loop. I think it could benefit me and maybe others greatly if we can have an inexpensive wireless solution for say 3 measurement mics when under time pressure to get a rig in the air or align subs before a sound check.

I have been following youtuber Scott Uhl – you may find his videos on IEM and inexpensive wireless interesting … here is a link for his kimafun XLR wireless system review https://www.youtube.com/watch?v=mGETbUMKzG4

Hi Lou - thanks for your comments and info that your Line 6 xd-v75 system has worked well for you. I am familiar with Line 6 wireless as they bought X2 digital wireless in about 2008 and used their 2.4 Ghz digital wireless tech as the basis for the Line 6 wireless products. This tech was innovative at the time as it was 48khz digital and did not require the analog radio compander approaches for noise and dynamic range management that other pro wireless mic systems used at the time. In a former life as a bass player in a funk band I owned one of the X2 guitar wireless systems and it cost about $400 circa 2007.

This new Kimafun wireless XLR system piqued my interest due to the phantom power, price and good form factor. This Kimafun is also 48khz digital so it doesn't have the compander. It works in the 902-928Mhz band free from the problems of busy 2.4Ghz environments.

On the delay - YES I did make the measurement in Smaart Suite v9 LIVE transfer function mode and I did add delay. I worked with the delay finder to get the flattest trace I could.

Question - have you "measured the wire" for your Line 6 transmitter/receiver loop with direct connection to your measurement rig? Could you share your trf file?

Please let me know how I could share these trf files with the community?

Right! You'll need to share a Dropbox or Google Drive link or similar. There are a bunch of other free file sharing sites out there. I've been using https://filedoge.com/

Sharing trf files for "measure the wire" direct connection of Kimafun XLR wireless system. https://filedoge.com/download/33bfb1601db6e521881af29b6831afc36a8f5ab8620a878f436dd2e29f81f8bce98c8dae81a5bd3a54de

Next , I exported above file as ascii and imported to Smaart as a mic correction curve. Here is trf file for same "measure the wire" direct connection of wireless trans/xcvr but with correction curve. Smaart corrects the magnitude to flat but does not correct the phase.

https://filedoge.com/download/1a1fd11227d15422585a6828306e1c7ed337a89b3bfd10e4edf54e862cd6ef1bbc5e9ad028b7e0c17c6e

Seeking Opinions - with phase wrap still on corrected curve, can this wireless system be usable for an onsite rig tuning?

Question - I've heard of people using Lectrosonics and Line 6 wirelesss - has anyone "measured the wire" for those wireless systems - can you share trf?

Hey @mark-emerson you might also reach out to Rational Acoustics and ask them how they would recommend that you handle this situation. They might just tell you that you shouldn't use that mic, but there might be some feature in Smaart that can help.

Taking a closer look at your RF system measurement, it's not as bad as I thought. Once I inverted the polarity and add a few microseconds of delay, it looks mostly flat. You have less than 45º of phase shift above 100Hz. Totally usable, especially if you've got the correction for the magnitude trace. Later, if you need to get some critical bass measurements, you can connect an XLR again.

Finally got around to measuring my Line 6 as a wire.
It's not as flat as I'd like but this is my field rig. I don't do super critical measurements while on a gig. Mostly just seeing what the speakers are doing and trying to match them. When the measurement system is constant even if slightly off, you can do comparative measurements.
Like time aligning a delay speaker or matching subs to mains.
When you are in "lab" conditions you can plug a mic in with an xlr to be sure you have a more precise measurement.
Anyway,
Here's the link to the Line6 as a wire trf file.

https://drive.google.com/file/d/1mRRto3yvItZndCcrsKEymZnMaVFSwQyu/view?usp=share_link

Hi Lou - thanks for sharing "line 6 as wire". My use case is similar to yours - wireless mic for comparative measurements for aligning system (line array, subs, fills) onsite at a a gig to save time. Use a cable in the shop for more critical measurements. Your line 6 trf for the "rf" wire looks quite workable …

Further to my original post … on this kimafun wireless. I made up an XLR pin 2/3 polarity invert cable and repeated the process …

1. measure the "rf" wire
2. export as ascii correction curve
3. re-measure the "rf" wire with the correction cruve (hoping for flat)
   Atttached images are my results for step 1 and step 3.

My opinion: with this XLR invert cable, this Kimafun XLR wireless system is acceptable for onsite rig alignment. Let me know your thoughts?

I recently purchased Crosslite which has both magnitude and phase (Smaart is magnitude only) correction curves. I was measure the Kimafun "rf" wire with my self generated correction curve and xlr pin2/3 invert cable to achieve flat magnitude and only my phase shift above 3k5. I think this is quite acceptable for onsite rig alignment purposes.

Your rf measurements look better than mine. I'd say you are good to go with this setup.
Even if it's not 100% ruler flat having a wireless measurement mic actually allows you to get some real work done and quick.

Glad to see there are more options for wireless measurement.

Nice work on this Mark!