Helmholtz resonator Help Needed

I need help figuring out what at length of pipe I need for a helmholtz resonator. My current setup on my 2020 V6 Tacoma is a Vibrant ultra quiet resonator before a Thrush welded muffler with an axle dump. Love the mellow tone I get around town but on the freeway while cruising at 75mph at 2,400 rpm I get a bad drone. I ran a spectrum analyzer app on my phone and it’s coming in at 125Hz. I really don’t want to change the muffler again or the resonator as it deepens the sound, I just want to cancel out the drone at freeway cruising speeds. Any advice would be greatly appreciated for the J Pipe length and diameter I should use, so I can take it down to a muffler shop to have to fabricated.

 

https://www.youtube.com/watch?v=z5SY5oUTEcc

 

That was a very informative video. Thank you for posting that. It looks like a need a J Pipe 34.44” long to cancel out my drone. Boy that’s a long one

 

How’d the j pipe results turn out?

 

Even using stainless tube I'd be concerned about condensation accumulating in the pipe from stagnant airflow not being able to burn/flow moisture out I don't care how hot it gets it still going to happen over time.

But i will say that guy knows his shit

 

I'm just curious if you had the drone with the stock exhaust. If not, why not just go back to that?