JBL Premium sound system problem

I've had the car beep for a notification of some sort, then just... Never turn off the sound attenuation mode.

On a base model prime.

The voice navigation on android auto also stopped working entirely. It would "play" but no assistant voice would play, and it wouldn't read messages out to me etc also and music was similarly lowered in volume.

Only restarting the car or resetting the head unit worked to resolve it.

Probably some weird software AA related glitch.

 

Is all sources of music! Is it same with FM radio? I use apple CarPlay with YouTube music! but if I get voice text lowers sound to 50% to hear text and resumes full volume!

 

I have the same issue as OP but with 2024 model. Sound was normal while driving, then level suddenly drops 50% ish. This has happened 3x since owning the car for 4mos. Normally a power cycle would solve it immediately, however, today I tried 2x power cycles and it won't return to normal levels.

 

Are the rear speakers 2 way?

If there are no clear highs then the JBL system simply gas more speakers front vs back, and the woofer is likely wired in the front and the software doesn't isolate it from fader/balance. Also if the front speakers are 2 or 3 way with crossovers, then the low end speaker cones in the door will be biased to be bass heavy, vs the rears if they're 2 way speakers in a single piece.

At some point I might upgrade the speakers in the Prius just because I spoiled myself in my old car (before the crossover broke on the driver side door somehow making the woofer speaker not work half the time). I'd swap the kicker KS over if the sizes match after fixing the crossover this summer, but theyre so old now, they probably have moisture related rust on the magnets now.

If they are in good condition when the old one dies, and if tweeters are easily accessible I'd consider.it though.

 

So if you're using android auto, there are a few quirks.

1. If you have the dolby atmos option on your phone enabled and you're connected via android auto, it can be weird on how/when it activates. When it does activate it's like the EQ gets bumped a TON for almost the entire range. Bass will really kick, etc. I disabled dolby atmos entirely because I didn't like having an option that would almost randomly via certain interactions (like my passenger tried to take a picture using my phone while I was on wireless android auto playing over spotify and dolby atmos decided to kick in and blast my speakers). This may very well be your issue, some software EQ/sound boosting quirk of the phone.

2. On a rare occasion a system notification which lowers the playback volume doesn't complete the routine of restoring the playback volume. Leaving you with muddied audio until you restart the phone or until you get another notification that completes the lowering/restoring routine. I doubt it's this since it also sorts itself out if you restart the phone and I'm sure you have since then.

So, how to test... Sirius/FM radio. That removes the phone from the equation. If the test you did with the dealer car was at the same volume level on the same xm/fm radio station sounds the same as yours, then the issue is with something on your phone that was boosting your music quality. Probably some EQ program. I turned off dolby atmos, turned off EQ stuff in spotify, I think I even went into my developer options on my phone and changed something. All to make sure that my phone and the software on it would not affect my audio output. Since I want a consistent source that I can tune at my headunit/amp/dsp.

 

I think the images would explain why using the balance/fader would make the rear sound really bad, since its so heavily tuned toward the low end and away from mid/high. That's really all I was trying to get at when it comes to the sound mix when using fader/balance to test things out.

Now, why the sound attenuated significantly one day to the next - that's probably a software bug as you point out. Maybe that weird "clarifi" or whatever tech they show on the JBL page is doing something wonky, or as someone else pointed out, its interacting strangely with a setting on your phone related to audio that got updated and introduced a quirky bug :/

 

I've experienced the same, the volume ducks out for a notification then doesn't recover. It's usually back to normal by the next drive though.

If it were a computer, I'd say reboot it, but rebooting a car on the highway might not be a good idea. Sometimes I appreciate some of my friend's views that a car shouldn't have anything more complicated than a carburetor in it.

 

If you experience volume ducking/loss of navigation audio until the media system reboots or the car is power cycled, then it sounds like a generic bug that is present in the standard media software at least with android auto (I don't have any apple devices so I can't confirm it's broken for both) that there is another thread about: restoring media volume after tss "warnings/dings" | PriusChat

It sounds like there may potentially be some overlap between that and what the OP described, but the other issue is not something that persists across reboots and I only have access to an XLE with the base audio so there's no way for me to test further.

Oh, and you can reboot the media system by holding the power button down for some number of seconds, though that's a bit annoying in a model with the larger display.

 

I've read that you can hold the volume button down on the head unit for 10 seconds to initiate a reboot of it while driving. Havent' tested it myself but it sounds like it'd work.

 

I think the issue OP has is more fundamental and isn't being fixed with a reset of the head unit. The resetting of head unit only works for a glitch that happens when navigation directions happen at the same time as a safety notification/ping sound - like when you signal early for a lane change and there's a person there, or if you have your blinker on in a turn lane next to another turn lane so the car beeps at you about your blind spot (since it doesn't know its two turning lanes).

 

That's interesting. HD Radio is a digital broadcast alongside the analog broadcast. It's entirely possible this is related to the car converting the digital signal to the analog one. Since you have an amplifier, I am going to assume that the task of processing that digital signal is happening there. Maybe there's something wrong with it, or there's a glitch in the tuning at a level that the headunit cannot communicate with the amplifier on to address.

As for the soundstage though - there is nothing you can do about the back seat audio. The fact the back 2 speakers are woofers, and the fact you have an amplifier means that the amplifier is going to be filtering the audio signal such that only the response range for the rear speakers is being sent there. You can put in whatever you want, a 2 way, or three way speaker - you'll still only get the low end frequencies that the amp is filtering for those speakers to pass through them. And to *some* extent, you should always expect the rear speakers to be at a lower volume as a result. Since low end of the spectrum is going to be quieter in terms of volume unless you're compensating through much more power. All this being said If they're tuned for super low frequencies, and the amplifier is filtering very low frequencies to them, the issue of an error in the signal processing could be exacerbating this. It could be that its filtering too high a frequency that the speakers have a poor response to, and the lowest frequencies they would have a good response to could be getting cut off. It's also possible that the amplifier is just not providing the appropriate power level at the same time.

If it works better when the volume is cranked, that's a sign to me at least that the amp is only really sending solid power at that higher volume. Often aftermarket amplifiers will have a gain setting which is related to their processing to apply a flat +X dB to all signals being pushed through the amp so that you can tune more effectively just how sensitive you want the volume knob to be. A really high gain means every notch on the volume knob will push way more power. If you tune it too high you can blow your speakers very easily. Too low and you have the issue you have where you have to CRANK it. Ideally it should be tuned such that 75% volume on the knob is very loud through the amp, but maxing out the volume doesn't introduce distortion and damage to the speakers. But at this level it should be comfortable to listen to music between 25%-75%. My previous experience with car audio was that an amp tuned in this way will often feel too quiet below 25% system volume on the head unit more often than not.

Maybe there's a way to check the amp, its connections, if it has physical gain knobs, or if there's some software setting that needs to be updated directly, or a poor connection?

 

I'm going to have to agree with the ones on here saying there's a problem. I finally got around to testing today and the rear door speakers are hardly getting anything compared to the front door speakers. And what's getting to the back is tinny and anemic. From what I can tell, the front and rear door speakers are almost identical in construction(if not completely identical), so there's no good reason for the fronts to be getting a full-range signal(including almost all of the bass) while the rears get hardly anything.

I think it's fair to say someone screwed up the settings in either the head unit or the amp. I'm not the guy to do this, but it would be interesting to see the raw F/R levels coming from the head unit and also the WF/R levels coming out of the amp. That would help pinpoint if it was a head unit programming issue or an amp issue.