XLR - TRRS

[Jackingreen]

Hello everybody!
I need some help..I been searching on the web without success the schematics for a cable XLR to TRRS. I have a micro Rode NTG4+ and normally I use it with an Tascam DR100 MKIII, that I use to record bird sounds on the field. I have a XLR-XLR balance cable for this combo, but sometimes I am already carrying a camera with heavy lens, tripod and scope, so I would like to be able to use the NTG4+ with the android smartphone to record some of these sounds although without the same quality, still useable. I have found plenty information XLR-TRS but not XLR-TRRS.

I have found this very useful website from RANE, although no information for the TRRS:
https://www.ranecommercial.com/kb_article.php?article=2107

and I have found this information on RODE's website for TRS and the NTG2:
https://www.rode.com/faq/how-can-i-connect-my-mono-microphone-xlr-output-to-a-stereo-trs-socket

I still have 1meter of Van Damme 6.00mm Classic Starquad, I wonder if:
- I have to solder the shield from the XLR 1 and 3 to TRRS Ring and XLR 2 to the TRRS Sleeve? Like Rodes webpage, since the Mics for smartphones use the Ring as ground and Sleeve as Mic.
- Or like in RANES webpage with the scheme 2, but shield doesn't connect to TRRS plug and the XLR 2 and 3 go to the TRRS Sleeve?
- Ranes Scheme 3b, shield from XLR 1 to TRRS Ring (ground) and XLR 2 to the TRRS Sleeve (Mic)?
- Any other alternative?

I am sorry if this isn't the right place to ask, but I am getting quite confuse with the information I been finding.

Thank you in advance for your help

[Hugh Robjohns]

There is no simple cable wiring scheme which can be used to connect this mic to a smartphone. They have incompatible electrical formats and signal levels.

Instead, I'd suggest using a dedicated mic preamp that accepts a balanced XLR input and provides a suitable output format for the phone.

I've used and recommended Saramonic interfaces a few times now for this kind of requirement, with great success. The SmartRig II is the one you need with a TRRS output connector for an Android smartphone. It will set you back about £50. (They also do stereo/dual channel models, and models with lightening connectors for iOS devices).

https://www.saramonicuk.com/collections/smart rigs

[Jackingreen]

Thank you for your fast reply!
Buying a rig and have to carry it misses the idea of using just the smartphone and not carry the recorder..is one more thing to carry, one more weight on my backpack..for that I will just use my Tascam recorder. Because there are XLR-TRS cables, I thought it would also be possible to have XLR-TRRS. I know you have digital and analogue signal, but I also thought both TRRS mic and XLR had analogue signals.

[Hugh Robjohns]

Ah well... you live and learn...

[Sam Spoons]

Forgive me if I'm being thick but the NTG4+ has an onboard battery for power (as an option to spook power) so why is it not possible to make a suitable adapter to connect it to an analogue unbalanced mic input on a smartphone? I'm guessing it's to do with the smartphone supplying 5V 'plug in power' but not sure.

This article seems to explain how most TRRS connectors on phones and camcorders are wired https://www.cablechick.com.au/blog/understanding-trrs-and-audio-jacks/

Or this one https://www.provideocoalition.com/ts-trs-trrs-trrrs-combating-the-misconnection-epidemic/

[Hugh Robjohns]

Forgive me if I'm being thick but the NTG4+ has an onboard battery for power (as an option to spook power) so why is it not possible to make a suitable adapter to connect it to an analogue unbalanced mic input on a smartphone? I'm guessing it's to do with the smartphone supplying 5V 'plug in power' but not sure.

It's just not a very elegant solution. As you say, power isn't a problem as the mic can run from its internal rechargeable battery. And the presence of plug-in power from the phone won't be a problem either because the mic is already geared up to handle phantom power anyway.

But, the mic has an electronically balanced output which might well get upset if the destination isn't balanced -- with potential distortion and noise problems, as well as the likelihood of picking up interference. And although the NTG4+ has a relatively strong output level for a mic, it's still pretty low and so prone to noise and interference at the phone's input stage.

The physical connections are simple in theory, with pin 2 of the mic's XLR going to the lowest ring terminal on the TRRS, and XLR pin 1 to the sleeve terminal... XLR Pin 3 might need to be linked to pin 1 too, but might not, depending on the mic's output circuitry.

But having gone down this route a while ago for my niece who wanted a phone rig for recording birdsong, using the same mic, I was disappointed with the quality and it just didn't work very well...

Which is why we found the Saramonic to be a much better solution all round. It works happily with a long mic cable when necessary, and it sends a strong signal into the phone avoiding problems with interference pickup and noise. The sound quality is improved, the mic is happy, and it's actually quite a neat and very practical solution.

Using the Saramonic to provide phantom power eats through its PP3 battery rather quickly, but just as a preamp it has an acceptable battery life.

[Sam Spoons]

I'm very much in favour of elegant solutions...