I like my music loud, but not obnoxious or anything. My problem is that if I turn the bass to anything higher than -1 or -2, loud music will cause the stereo to cut out when I turn it up. This happens whether I am playing a CD or playing an mp3. Could I have a loose wire or something? Or is it just as sensitive for most here as well?

 

Something is not right. Two questions. What the fader position? Have you inspected the integrity of the door woofers?

 

Faders are equal all around. I haven't checked out the door woofers - not to certain what I'm looking for there.

 

Two comments, set the fader to rear only and then play the music how you'd prefer it. If it doesn't clip as you have described then we know the amp is good. If the same clipping occurs then there may be a problem in the amp. Chances of a "loose wire" are very slim since all connection points are modular ones.
Then fade it to only fronts and do the same test. The door woofer have a long and illustrious history of failure or being partially blown. The paper cone separates from the frame. There are many threads on the topic with many optional solutions.

 

Thanks so much for taking the time to help me out. I will give it a try this evening when I get in my car next and will report back with results!

 

OK just tried the fader with the music up loud.

If at F7, very little clipping if any at loud music, bass at 0. Increasing bass to +1 causes more cut outs.

Fader at R7, more frequent clipping.

Any combination of F + R = guaranteed clipping at high volume. With the bass at -2 the music never cuts out, no matter where the fader is at.

Seems to me that when the music is loud its fine, except when the bass hits a beat its likely to cut out if too loud.

Related note - what is ASL and what's the adv/disadvantage of turning it on? Thanks for the insight.

 

It is basically an automatic sound level adjustment that works off of a microphone in the vehicle that senses the noise level and will increase/decrease the sound level (mainly volume) accordingly to compensate. The high/mid.low settings are for how much adjustment you want it to make (sensitivity).

 

If you got stock speakers. That's the culprit. I had this problem to where I had to adjust the fader to the rears alittle more than the fronts in order to keep the clipping noise away. After switching speakers, no more problems. Worked for me.

 

That brings up a good point... Are all of your speakers OEM? If some have been replaced are they rated correctly.
The clipping yov've described could be your speakers, or could be an amp that's no longer driving efficiently.
Here are some thoughts from experts on this:

Before any speaker system can perform to its highest potential, it must be connected to an adequate amplifier, especially one with sufficient headroom. We don't mean how small a foreign car's interior is! Headroom is the amount of reserve level capability that the amplifier has above the long-term average level your ears hear as "loudness." In live music, 10 dB peaks above the average - of a few milliseconds duration - are common and are continuously going through the system. If the peaks can't get through, the sound will still be as loud but it will sound rough and distorted. This means that if you are playing at a 10-watt average level, you will need a 100-watt power amplifier to pass the peak levels (10 dB higher) without clipping (distorting) the amplifier. When the amplifier does go into clipping, you will know immediately because you will hear it through the speakers. Many times people say their speakers sound bad at medium-to-high levels when in reality it is their amplifier. The speaker has no choice but to reproduce the signal being fed to it whether it is clean or distorted.

This amplifier clipping is also a common cause of speaker failure. When clipping occurs, high-level high frequencies are produced which usually overpower tweeters and midrange speakers and result in smoke and no sound! Therefore, you need to be certain that the amplifier you use has enough power to give plenty of reserve over the average needed to give the desired sound pressure level.

Here's an example to help make the efficiency-versus-power issue more clear. Let's say you are running a 250-watt amp into speakers that are 2_% efficient. You're operating at 25-watts average, so there is headroom for the peaks. But it isn't loud enough (SPL too low). You could go to a 500-watt amp and get 3 dB more,' but that's expensive and still not very impressive in additional loudness. You could also go to a 5%-efficient speaker to get the same 3 dB; or you could use a very efficient speaker (maybe 25%) and get really loud but still be clean and have headroom. The point is, speaker efficiency is at least as important as amplifier power.


With that regurgitated ....I have not experienced the problem you described. Mine is an 02 and the AMP was replaced by a previous owner after some issues with it. Subsequent to that Lexus issued a TSB on amplifier problems. In my mind the next step is to do a physical inspection of the door woofers.

 

Wow thanks for all the responses guys. Yes, they are factory speakers. I recall having a blown speaker 2 or 3 years ago and getting it replaced via warranty. But since the warranty has expired I never got it checked out. The sound is still really good - no buzzing, very clear, sounds good. But the damned clipping is annoying I have to keep the bass at -2 all the time. I always leave all the levels at 0 otherwise - are there optimal settings for the levels?

 

If your opinion is the speakers are not damaged, and if clipping is going on as you have described, then it most likely a problem associated with the amp. They can and do fail and or degrade over time. And, this is just my opinion, when being driven, or overdriven over longer periods. There are a couple of physical signs to check for. Unfortunately the SC's ML amp is hidden in the trunk under the garnish and behind the NAV ECU. So to get to it you have to tear the trunk apart. Those symptoms are: excessive heat, a smell of burnt electronics (could be very slight, or obvious) and possibly a humming sound from the amp itself.
Sound is just another form of kinetic energy and energy, in the form of heat is produced in the conversion of electrical energy into sound. Heat does damage electonic components over time, especially when higher amounts are used/produced.
Pardon the pun, but it sounds like (from your description of clipping behavior and good speakers) your amp is wearing out, or failing when asked perform at higher levels. Ultimately the only way to determine if this is the case is to bench test the unit to known manufacturer's specifications.

 

Humming sound - definitely a humming sound. Heard it the other day when I was stopped at a red light, music was off. Heard it again one morning last week - stayed on for maybe 15 minutes or so as far as I remember. But, it does not happen all the time, again its infrequent. And obviously the only times I've heard it is when the stereo is off. Not an obtuse humming, low but definitely noticeable to me.

Anyone have any audio shop recommendation in DFW where I won't get hosed? Thanks for the help Bob!

 

If no one comes up with something in the DFW area, you might try these folks (I am not affiliated whatsoever) see comments 1 & 4 in this thread. But I think the mailing address zip code is incorrect...if you use them verify it.

 

If the sound goes muddy or just sounds bad, it would most likely be a speaker problem. If the sound actually cuts out (goes quiet), then it is most likely to be an electronic problem (most likely the amp in your case).

You might call the dealer and ask what they would charge to diagnose the problem, however, more than likely it won't be less than $100 but that is just a wild guess. OTOH, I'd speculate that you have a 90% chance of an amp that needs to be replaced.

 

Harold offers so good info there and he holds a BSEE.