my stock 07 tC with the factory hu has been acting weird for a few days now. with CD, aux, and FM, when I reach around 40mph, the volume increases. Nothing drastic, but enough that I need to turn the volume down. But the moment I hit a stop light, the volume comes back down. The volume control itself doesn't change, I keep it around 18 but have to turn it down to 14 when the volume gets too loud. It's nothing too major and works out pretty nicely when i'm on the freeway, but I just wanted to make sure that this isn't a sign of something that can bite me in the ___ later.

 

It's a function called ASL (Automated Sound Level... I think). It raises the volume when it notices a change in ambient noise - in this case road noise, or an increase in speed.

I didn't know the stock head unit had that, but I am pretty sure you can turn it off in the menu settings.

 

if you go through settings... hit the volume button... that will go through bass, trble... fade.... etc... asl should be last. put that on off.... to turn it ogg.

 

thanks guys, I didn't know that feature was there or how it even got turned on.

 

yea i hate ASL, it really bugs me out, especially if i am trying to talk to someone in the car while it decides to get louder

 

it was first implemented in the '06 tCs..

i don't think i remember the '05s ever having it. and the speed signal wire that goes to the headunit was part of the new plug used in the '06+ (which has the aux and steering wheel controls too)

but yeah... you should be able to turn that feature off

 

When recently working on the HU and having disconnected it, I found out the ASL is turned on by default, so you have to turn it off any time you remove the power, if you don't want it on. I hate it too, and always have it off, as it's so easy to adjust the volume yourself when you need or want to.

 

I have a quick question about ASL, if I turn mine off it cuts the bass completely out and it sounds like crap and I have to turn the volume way up just to hear it. Is there anyway to get around that?

 

i've never heard of that

 

If you turn off the ASL and the sound goes down, try to change the SSP function.

Look at this thread:
https://www.scionlife.com/forums/viewtopic.php?t=146063.

Hope that helps.

 

I've got it set to xA Feel, still the same. If I turn off ASL it's just flat sounding.

 

Isn't there a "loud" function on that stereo as well? Try that.

 

I haven't seen a 'loud' function. If there is one I don't know where it would be.

 

The ASL shouldn't do that, it shouldn't do anything other than vary the volume, basically by increasing it as you go faster, that's all. I always had mine off, but after disconnecting the radio and not knowing ASL was turned on by default, got quite a surprise when I went for a drive. Everything seemed the same when going slow, I had the stereo on very low only for some quiet background music, but then I hit the main road and by the time I was doing 50mph, the stereo was LOUD. Turned off the asl and all was back to normal volume, but it didn't sound 'flat' like you're describing. Maybe something is wrong with your HU.

 

Could be, I'll have to try turning it off in my wife's tC. She got hers first and never let me drive it so I went and got one of my own I liked it so much. I might just put an aftermarket HU in, but I don't want to loose the steering wheel controls.

 

Many after market radios have an added option that allows you to tie into the steering wheel controls.

 

nice, thanks.

 

yeah i've seen that before with the ASL function. It's because of the way the volume is controlled with the speed. ASL-low, med, high, will also change the way the bass sounds too. It's because of how it controls the volume based on speed, and asl mode chosen.

Without it on, the sound is lifeless and not as loud, and this is standing still. When moving, turning ASL on will end up raising the volume, but it seems to have most of the volume raised in the bass, mid-bass frequencies. So no you're not losing your mind, i've seen this as well.

 

I can also concur with this concurrence. (That is a great sentence, by the way.) I added an amp to the stock HU and ASL made the subs sound so much better when it was on, I left it on in "Low" and it wasn't very bothersome with the volume going up and down. No need to worry about it anymore though as the Avic-D3 has changed my life almost as much as puberty did...

 

I'm sure ASL is more advanced than just rasing the volume, which probably explains all your guys' observations of it changing a few of the dynamics of the audio rather than just flat out volume.

Makes sense, since increased road noise usually means drowning out certain aspects of audio more than other, usually bass.