Amp is here under the subwoofer assembly above rear wheel well

https://www.clublexus.com/forums/gx-...l#post10814814

A Saturday project IMO

 

I had a blown subwoofer that caused very simillar issues. below 30 it worked fine, any higher and I lost all sound untill i restarted the car.

 

Was this resolved by replacing the OEM subwoofer?
I'm experiencing a similar issue where it seems I'm missing (or volume is very low) part of the lower frequencies ~35-60Hz. I don't know if this is normal or not. Doesn't seem like it should be for this higher end system. Also seems like the lower front door speakers are over working the lows as if it's not crossed over properly. Could be more noticeable since the sub is not putting out as it should.
When I get the opportunity, I'm going to test another GX with ML using my CD's to compare.

 

 

Thanks, I'll have to check the amp fans when I tear the drivers rear apart. (Not sure how this would affect a loss of low end frequencies range though.)
I did get a chance to listen to a 2022 GX460 with ML (assuming it's the same setup as the ML in my 2014) and it's definitely noticeable in the lows and sounds as it should.
There is definitely something wrong with my low end setup.

 

HELLO
I OWN a 2019 Lexus GX 460 not with ML audio what I done was change all 6 speakers for brand FOCAL that include the tweeter and add a power sub that fix under the driver seat and it sound excellent I had it done @BESTBUY so far I have not had any issue

 

Sorry to keep bringing this thread back up.
Finally got the time to remove the rear seat and panel to inspect the subwoofer and amp.
Amp and sub looks brand new. Fans work and are pretty clean.
Pictures below:




I'm still in confusion on why my setup is lacking (sound is there but low volume) a specific low frequency range. It just sounds like the subwoofer crossover point is at 35-40Hz range (or lower). Freq between 40-45 -> 55-60Hz is low volume compared to the rest around it. Also, the front woofers (front door lower speakers) seems to be doing a lot of work where I really only hear the rear subwoofer below 40Hz. Normal?
I noticed there is a newer ML amp part number than mine.
Looks like 86280-60700 superseded 86280-0W810 somewhere in 2019-2020? Does anyone know what has changed between the 2 (if any)?
When I listened to the 2022 model, I definitely noticed a difference (better in the 2022). I guess I need to listen to an older model to see if it behaves the same as mine.

 

Well, as an update, I found the issue.
After much investigation looking at wire schematics and sample listening to a 2022 and 2017 GX with ML, my issue was the +/- subwoofer wires were crossed from the factory.
I flipped the wires and now it sounds as it should and the same as the test 2022 and 2017 GX's. Since mine is a 2014, I guess they still didn't have the wiring ironed out or just maybe a batch of them were flipped.
So, if you have an earlier GX with ML and you don't think the lower bass frequencies are as it should or missing (or lower volume) between 40-50Hz, check your wires.
I still think the rear sub should be crossed over a bit higher and the front door woofers should cut out at a higher freq but I'm satisfied that is now matches what it's supposed to be.

This picture shows what wires are coming out from the amp to the sub. Pin 8 (white) for pos and 9 (black) for neg. But as you can see in the sub box area, both inputs show "+" for WF1 and WF2.





This pictures shows that pin 1 on the sub connector is pos and 2 (2nd position) is neg.


My factory sub wiring connector to the sub.
Clearly shows that black wire from amp pin 9 neg is connecting to pin 1 (green wire) position where it's supposed to be pos. And white wire from the amp pin 8 pos is connecting to pin 2 (black wire) position neg.


Right now, I just swapped the wires using posi-taps to test but eventually will try to replace the connectors (checking out ali-express) and wire them correctly.
If anyone knows how to extract the pins for either connectors, let me know. I tried with various pin extracting tools and could not figure it out.

 

I own a 2022 GX 460 with ML. Yesterday, I removed the seats and side panels to add sound deadening material to the floor and side area. To my suprise, I found the same exact crossed wires you were talking about. I haven’t tried to flip the wires yet, but this makes me wonder if this is done intentionally. Mine is a 2022 and yours is a 2014. If this was an error, Lexus would have fixed it by now.

I plan to test it tomorrow and will let you know if connecting the black wire with black fixes the low bass issue.

 

I listened to a 2022 and it sounds as it should. Since the color of wires has not changed, I'm not sure if they flipped the wires inside the box to the speaker or maybe made an adjustment in the amp.
Or maybe the wiring diagrams are inconsistent? Who knows.
If it sounds fine to you, no need to test anything.
If you do want to test, try running the frequency range test from YouTube before and after. Particularly in the 35-50Hz range.

 

The stereo in my ‘19 was outstanding. Full, rich, LOUD when called upon. After a day and a half, my impression is that it was better than my new Mark Levinson.

Yes I’ve played around with the three-channel “equalizer” and other settings. Not bad. Not at all. Just may not be better.

 

Hi MikeP1, I found the quality of input makes a difference in my 22 GX with ML. I stream from iTunes (and use a wired connection to the infotainment system) in my GX and have set cellular streaming & 5G quality to Lossless. That seemed to make a noticeable difference (to me) in the sound coming out of the ML.

Best.

 

Thank you. I was using wired connection and playing iTunes selections through CarPlay.

I’m asking the next question in case others may benefit. I cannot find a “lossless” selection in my controls. Can you advise?

Another note. Surround on/off makes a big difference and which one might consider better seems contingent on the individual music selection.

 

MikeP1,

In iOS, Settings, Music, Audio Quality. You should find an option for Lossless Audio (I have this turned "on") and Cellular Streaming, 5G & Wi-Fi Streaming and Downloads.

I have Cellular Streaming, 5G & Wi-Fi Streaming set to "Lossless"

Hope this helps.

Best