MrL

Hello, Well, you know what they say about opinions...... Could the speakers in the ML systems have been designed better in some cases? Absolutely. Should you avoid playing rock or rap on your Lexus ML system? NO, I never said that. What I said was that you would be best off listening to the music the way the engineers and artists who recorded it intended. I assure you their studio monitors don't have the bass bands boosted some 10 dB or more druing mixing. I'm not touting the limitations of any system as an asset. I'm just letting you know where the weaknesses are here so you can avoid the major headache of damaged equipment. It just so happens that I personally feel that maxing out the bass on a system that measures damn near flat from 20Hz to 20kHz before you even touch it is misguided to put it mildly. In this case (and lots of others at all price points for that matter) it also happens to be hazardous to your gear. You seem to be implying that natural frequency response equals sterile sound. If that were the case, then all live unamplified music would sound dull and lifeless, which is a ridiculous suggestion. Sounds to me like you're blaming some other system problem(s) on the fact that certain things are being done very well. We'll just have to agree to disagree on that one. MrL

It's probably a solder joint in the head unit or amplifier. Have the dealer use cold spray to isolate the issue or refrigerate each unit one at a time until they can reproduce the failure. This ain't rocket science, but it is beyond the usual knowledge base of auto mechanics. MrL

I disagree that this is likely to be a crossover problem. Most OEM premium car systems these days (including ML) use a separate amp channel for every speaker. The DSP acts as a digital EQ so crossovers aren't generally needed. There are some exceptions, but the crossovers rarely consist of more than a single capacitor in series with a tweeter. This sounds to me like an electronics problem, either in the radio head unit or the amp itself. Have your dealer try both, I would start with the amp. Intermittent noise in car electronics is usually caused by cracked solder joints which are pushed together or pulled apart depending on temperature. If warm weather or cold weather brings it on more, or if it only happens before or after the system is warmed up, this would suggest that as a prime suspect. Severe but intermittent noise in speakers is usually the result of debris inside the speaker which can get there any number of ways. The chances of this happening in multiple speakers in your car is very slim and would still not explain the low output from other channels. "Blown" is not a term that has any real meaning at all. There are lots of things that can cause a speaker to sound hideous or not work at all. "Blown" is a catch-phrase for all of them when one cannot be more specific. Good luck!

Hi all, I’m an audio hobbyist and have done work for a few friends on Lexus vehicles with Mark Levinson (ML) audio systems. After poking around on this site and finding numerous references to problems with speakers in these systems, especially the subwoofers, I’ve found that some people are making risky decisions when replacing these speakers due to lack of technical knowledge. I can’t stand to see a good system getting burned up, so I have written up a few guidelines and tips to help you replace your faulty speakers without risking further damage to these outstanding (and expensive) audio systems. PREVENTING DAMAGE IN THE FIRST PLACE. I have heard thousands of hours of live music, both acoustic and amplified. I’ve also heard dozens of audio systems, some costing tens of thousands of dollars. That includes close, critical listening to lots of car systems including several different ML systems (yes, I’m obsessed), and I can say unequivocally that the ML systems are by far the best OEM car audio systems I have ever heard, probably the best ever produced. Clarity, detail, and frequency response are all in a league with very fine home audiophile gear. Unfortunately, many people have become accustomed to grossly exaggerated, unnatural thumpy bass and feel that a system that does not deliver that kind of sound is “light on bass”. The ML systems are NOT deficient in bass, they are very accurate and “neutral”, a sharp contrast to much of what is out there today. However, some users are compelled to max out the bass controls and crank the volume to what I consider to be ridiculous levels, and as many here have probably noticed, this is probably the Achilles heel of many ML car systems. Probably the quickest way to damage an ML audio system is to play “superbass”-type techno and rap CD’s with the bass controls and volume very high or to use your vehicle to provide music for all your friends' beach parties. If you do this kind of thing regularly, it’s probably just a matter of time before the subwoofer fails. Even with less boomy pop/rock/country music, cranking the bass controls up is probably not a good idea. Frequency response in these systems is most correct with the tone controls all set flat anyway, so do yourself a favor and leave them like that or adjust lightly. REPLACING DAMAGED DRIVERS. Even the best systems experience a certain number of failures, even when the owner has done everything right. If your vehicle is still under warranty, I recommend always going with the factory replacement part. ANY other part is going to change the balance and character of the system at least a little bit simply because the speaker will not have the same design characteristics. Besides, the replacement should be free when under warranty. Go for that and hope it doesn’t happen again. AFTERMARKET SPEAKERS. If your vehicle is no longer under warranty and you (understandably) don’t want to spring for a pricey OEM replacement, aftermarket speakers are an option, BUT you have to choose carefully for a number of reasons. The single most important spec on any replacement speaker for an ML system is IMPEDANCE. Having measured a few of these parts with an Ohm meter, I have found that the impedance is usually between 8 and 12 Ohms (the LX 470 sub is 12 Ohms), quite a high number compared to most car audio speakers. I have also discovered that using 4 Ohm or lower speakers can cause the amp to cut out at moderate to high volume levels. Others on this forum have related similar experiences. THIS INDICATES A PROBLEM FOR YOUR AMPLIFIER. Amplifiers shut off to protect themselves. This kind of protection works for a while, but tells you there is a problem that can eventually damage the amp if not corrected. And if you think replacing a speaker is a pain….. If at all possible, use an Ohmmeter to measure the resistance of the coil on the speaker you are replacing. Disconnect the speaker and clip onto the tinsel wires just under the speaker cone when doing this—often the tinsel wires are where the problem is, so the less tinsel you go through for your measurement, the better. Add about 1 Ohm to the DC resistance measurement, and you have the speaker’s “AC impedance”. Choose a replacement speaker with an impedance as close to this value as possible. A 12-Ohm car subwoofer is difficult to impossible to find, but there are aftermarket subs with dual 6-Ohm coils by JBL and others out there. If you wire the two coils in series (tie the + side of one coil to the – side of the other and power the speaker through the unconnected ends), you now have a single 12-Ohm coil. An 8 Ohm coil is probably OK if you don’t listen at very high volumes, 4 and 2 Ohm speakers are out of the question in this case. As long as your amp isn’t cutting out on volume peaks, it should be safe from damage by your replacement speaker. HOME AUDIO SPEAKERS. Home audio speakers are not designed to withstand the environmental extremes seen in a car and most will literally begin to fall apart before long. I do not recommend using speakers designed for home use in a car—ever. POLARITY. Try connecting the new speaker with polarity connected both ways. The connection that yields the (slightly) louder sound is the correct one. Hopefully, this is enough info for most of you to find a safe and proper way to replace your problem speakers. If you don’t understand what is written here, enlist the help of somebody who does, or email me at garnetsandsilver@sbcglobal.net. Good luck and happy listening! MrL