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2kHz is what most people call "ringing" when they hear feedback at a concert as this is the most common xover point in large scale sound reinforcement so all the drivers in the top boxes are contributing to the problem. So I'd start with 1 / 1.6 / 2.5 range and if that's not the problem then download a frequency generator on your phone and use it to sweep the spectrum till you find the offending frequency.
 

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Fair enough...how much do you think I should drop them to become effective? Also, what app would you recommend?
+/- 3dB requires 10x more power or a 10x cut in power so start there with one band at a time

Any frequency generator will be fine.
 

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Plus or minus 3db is double or half the power not 10x

to sound twice as loud needs 10db
Thank you again for correcting this and why do I always get that backwards?

3dB is Double Wattage
10dB is Double Volume
Yes...only source of music...android - Amazon Music & YouTube
Which android device are you using and which OS is it running?
 

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Oh boy...now I am really confused.

Pixel 5...12.

When I was tinkering around with my O-Scope and the lowering/raising the freq level, the total output wattage changes as I lowered/raised the levels. So my 150w going to my mmats was 127 when I dropped everything from 4k up to -4. Does that mean that once I find the sound I like, I need to turn gain up again to hit target voltage?
The Pixel 5 had volume problems back when it came out in 2020 - hope that's not part of your issue.

The volume limit and red bar on the volume slider is mostly with Samsung phones and they have a "Media Volume Limit" - not sure about Pixel phones...
(Settings > Sound and Vibration > Volume > [expand the 3 dots in the top right corner] Media Volume Limit) that can be set but this only needs to be done if you're using the headphone jack and IIRC the Pixel 5 doesn't have one so as long as you're using BT then this is probably a non-issue.

EQ / Gain / etc.
The last bagger I setup was similar to yours except it had a HiFi-4250 feeding quad MMats 6.5 in the fairing and CDT 2ohm 6x9 in the bags with a pair of tactile transducers on the seat pan. Owner wanted as much SQ as we could eek out of his setup at maximum volume so we started out ignoring the tactile transducers and with pushing the 6x9s to their limit on bass and setup a HP on them at 60Hz, then did the same with the fairing and set the 6.5s to 90Hz, then tuned the setup (me with earplugs) as much as we could to give as flat a response as possible at maximum volume. We got a fairly consistent setup on 1/3 octave smoothing from 100Hz - 10kHz and had him test ride to gather his thoughts - he came back in 10 minutes and said it wasn't nearly loud enough. So we raised the HP to 100Hz on the 6x9s and 150Hz on the 6.5s and retuned (MiniDSP 2x4 w/RF HU) with a target of flat from 250Hz-10kHz and by this point I was wearing ear plugs and over the ear hearing protection as well - we managed to get what he wanted but by this point any semblance of SQ was gone and after doing A/B comparison of tuned vs bypass we eventually determined that a few narrow cuts on frequencies that were really harsh from the fairings (comb filtering was horrible) and letting the rest of the system run WFO was what he wanted.

All of that to say that my suggestion is to wear hearing protection along with your normal gear (helmet and do you wear ear plugs when you ride?) and figure out the offending frequencies at your max volume (likely due to driver interaction) sitting still. Once you've applied the necessary cuts then reset your gains at the point you start to hear distortion (likely clipping or cone breakup) and then back it off a notch or two to give yourself a safety margin. The actual wattage you measure on the oscope is not important - you are simply trying to get the absolute maximum you can from the drivers you have installed regardless of wattage.

Running a system like this WFO for an hour (or two) long ride on the open road will likely generate a lot of heat and you'll get into what's known as power compression due to increased impedance in the voice coils as a function of thermal rise. If you do notice that the volume starts to diminish after some time, then turn the volume down and let the system cool (did you know most touring acts that push the volume limits have their set list designed to comply with OSHA exposure limits and equipment cooling?) If your sled is anything like the bagger that we tuned he could easily hit 130dB at the riders ear and that puts the system at the "Instantaneous" hearing damage level for dBA exposure:
Font Number Circle Screenshot

My suggestion to the gentleman who brought his bike in to be tuned was to save WFO for the songs he really likes or moments when he felt the need to impress (or disgust as the case may be) and to find a happy 2/3 volume for the rest of the time so there was some reserve for those special moments. His bike cruising at 70 was over 120dB at the riders ear from the short shot staggers he was running so I don't hold out much hope for his hearing in the long run (he refused to wear ear plugs or helmet - not mine to judge.)
 
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