I love my 2010 RX450h that I bought a few months ago. But I thought the sound system was just awful, with boomy bass at about 100Hz. Since I am in the audio recording business this really grated on me to the extent that I manually cut the bass control several notches--with corresponding complete loss of low bass. So much for a "luxury" car's sound system. From Lexus no less.

Then today I came across some threads complaining about their ASL function also. On a hunch I turned ASL off. Wow! Now the audio sounds like it belongs on a Lexus! So appears that there is something way out of whack with many of these cars; on some the ASL works great, on others it either doesn't come on at all or it's on all the time.

I understand that the ASL circuit is supposed to key in on ambient noise. If background noise level rises it increases the volume and the bass. Is there some sort of adjustment the dealer can make? One user said there is a "microphone sensitivity" setting.

27 December 2016 UPDATE: Okay, so it appears that by turning the ASL off and then back on again, it seems to be working, in that the sound system appears to have a nice flat frequency response while I'm sitting in my driveway, and then yesterday I noticed that as I increased speed to maybe 30mph the volume and bass level increased, exactly as others had described. So why did it sound like the bass-boost was "locked on" initially? Does the ASL system need an occasional reset? I will see how it goes over the next few weeks.

What a nice car.

 

What is ASL and how do you access it ?

 

It's the Automatic Sound Leveler system. It's supposed to account for ambient engine/driving/city noise and turn your stereo up or down slightly to compensate for those noises. I'm not 100% sure if all trim levels get this option or not. The mic is located near the drivers right knee.

 

FURTHER UPDATE:

Well, now it's back to "all bass, all the time" mode. I've turned the feature off. I can increase the volume manually.