2001 Ls430 Blown Ml Sub Woofer Quick Fix! (not Glue)

[Zett123]

Ok, I have a 2001 LS430 and already went though one blown, crackling, buzzing Mark Levinson Sub Woofer. I found a used one on Ebay at a used auto yard and convinced them to send it to me for $50.00 including shipping. (All you do is ask). I had Myer Emco install it for $75.00 and saved me the headaches of doing it myself. Unit worked perfectly for a few years Then the amp went, $250.00 Ebay for an .01rev ML Amp unit and installed it myself in less than 20 minutes. All is well... Then, the sub woofer blew again. Now, I personally keep the bass level low and do not blast the system. Being the inventive person I am, I took off the Sub woofer's grill and inserted some fiberglass insulation to suppress the speaker. It works great, took about 30 seconds and there is no more buzzing that I can detect. What is the harm is there in doing this?? The speaker is blown and awaits the hot glue gun trick if it gets worse. This repair (for a lack of better words) puts no strain on the stereo system whats so ever. Actually, I kind of like the deeper base that comes out now. Even if I do the glue gun repair, I will put the insulation back in the speaker. This causes less strain on the cone because it cannot snap back and forth (frequency response) as easily as it does without it, which causes the crack in the cone to begin with. About 3" of R13 does the trick. Why Lexus puts Mark Levinson in their cars is a mystery, for the price, it is crap for a lack of better words.

[curiousB]

Being the inventive person I am, I took off the Sub woofer's grill and inserted some fiberglass insulation to suppress the speaker. It works great, took about 30 seconds and there is no more buzzing that I can detect. What is the harm is there in doing this??

Are you saying you put fiberglass on the speaker cone in between the cone and the grill to act as padding against the cone?? I would expect that would likely create more damage than good. The voice coil currents will be higher if the coil is restricted from motion. Its equivalent to an electric motors current when you put more mechanical load on it. Current rises. It will also put a lot of stress on the cone where the voice coil is attached (i.e. the weakest point).

I'd be a little cautious recommending this as a solution to a problem.

[Zett123]

Being the inventive person I am, I took off the Sub woofer's grill and inserted some fiberglass insulation to suppress the speaker. It works great, took about 30 seconds and there is no more buzzing that I can detect. What is the harm is there in doing this??

Are you saying you put fiberglass on the speaker cone in between the cone and the grill to act as padding against the cone?? I would expect that would likely create more damage than good. The voice coil currents will be higher if the coil is restricted from motion. Its equivalent to an electric motors current when you put more mechanical load on it. Current rises. It will also put a lot of stress on the cone where the voice coil is attached (i.e. the weakest point).

I'd be a little cautious recommending this as a solution to a problem.

The fiberglass is not putting extreme negative pressure upon the cone as you might think. The voice coil will still move freely as it is supposed to and will not have to produce excessive current to pulsate. What causes a speaker to "blow" or "crack" the cone, is excessive movement of the cone to pulse or vibrate pass the point it has been designed to. I did this several months ago and it still sounds great, it has no increased distortion or buzzing.

[curiousB]

The fiberglass is not putting extreme negative pressure upon the cone as you might think. The voice coil will still move freely as it is supposed to and will not have to produce excessive current to pulsate. What causes a speaker to "blow" or "crack" the cone, is excessive movement of the cone to pulse or vibrate pass the point it has been designed to. I did this several months ago and it still sounds great, it has no increased distortion or buzzing.

OK if you think so. Any contact with the cone will restrict its travel. That restriction adds mechanical load to the solenoid (the electromechanical coil which is the basis of a speaker). An increase in mechanical load will increase current. This is just basic physics. Anyway I'm happy you feel it fixed things I just wouldn't want someone to think this has zero side effects or consequences.

[Zett123]

The fiberglass is not putting extreme negative pressure upon the cone as you might think. The voice coil will still move freely as it is supposed to and will not have to produce excessive current to pulsate. What causes a speaker to "blow" or "crack" the cone, is excessive movement of the cone to pulse or vibrate pass the point it has been designed to. I did this several months ago and it still sounds great, it has no increased distortion or buzzing.

OK if you think so. Any contact with the cone will restrict its travel. That restriction adds mechanical load to the solenoid (the electromechanical coil which is the basis of a speaker). An increase in mechanical load will increase current. This is just basic physics. Anyway I'm happy you feel it fixed things I just wouldn't want someone to think this has zero side effects or consequences.

Actually, suppressing the speaker does absolutely nothing to the amount of current flow to drive the Voice Coil. The flow of current to the coil is a given from the frequencies produced by the music or what ever you are listening to on the CD or radio. It is not like a starter "solenoid" where it is engaged as long as you are holding the key to start position and if held too long could overheat.

However, every computer Hard Drive has a Voice Coil to actuate the drive heads over the disc to read data. There is a starting point and a destination for that head to travel to read data. Current will be applied to the Voice Coil until it reaches its destination and if suppressed long enough, it will burn up the coil. Speakers are not like this because the radio in giving pulses + & - there is nothing within the speaker mechanics/electronics to tell what its orientation is in relationship to the coil.

[curiousB]

Actually, suppressing the speaker does absolutely nothing to the amount of current flow to drive the Voice Coil. The flow of current to the coil is a given from the frequencies produced by the music or what ever you are listening to on the CD or radio. It is not like a starter "solenoid" where it is engaged as long as you are holding the key to start position and if held too long could overheat.

However, every computer Hard Drive has a Voice Coil to actuate the drive heads over the disc to read data. There is a starting point and a destination for that head to travel to read data. Current will be applied to the Voice Coil until it reaches its destination and if suppressed long enough, it will burn up the coil. Speakers are not like this because the radio in giving pulses + & - there is nothing within the speaker mechanics/electronics to tell what its orientation is in relationship to the coil.

Well I don't mean to offend you but you are entirely incorrect. You are confusing DC and AC characteristics of the voice coil. There are no pulses in audio. It is a random AC waveform with zero DC component. It is the absence of DC component is quite important or else your speaker coils would burn up (or at least heat up).

In fact the head of a disk drive is identical to the operation of a speaker. An electromechanical coil exists within the field of a permanent magnet. Applying a voltage to the coil causes a current to flow which in turn create a magnetic field. The fields interact and the disk drive head moves.

So we are talking about AC characteristics of the voice coil. It only stands to reason if you restrict the motion of a voice coil then the coil will have to work harder to move. The only source of energy to move the speaker and do work is the power applied electrically. If you restrict it mechanically you require it work harder electrically to overcome. It might seem like insignificant pressure but to a speaker cone weighing a few grams being accelerated quickly (especially for the higher frequencies) then the restriction (or equivalent mass) will be relevant.

This is why speaker designers go to such pains to make speakers cones rigid (to avoid distortion) but very light (to keep the m in F=ma small). This is the battlefield for speaker designers. If mass didn’t matter they’d make speaker cones out of steel with bracing ribs (this also whey keeping disk drive heads so small is important). Applying a restriction to the cone is effectively loading the cone with equivalent mass. As a result AC current increases. Again the same as if you watch current in a motor and apply mechanical load to the shaft, motor current rises in direct proportion to that load. If AC current =I and I^2*R=P(power in watts) where R is the DC resistance of the speaker cone the P is the heat given off in the voice coil. In other words increasing speaker current increased power lost as heat in the voicecoil to the square of that current. Not good.

[Zett123]

Actually, suppressing the speaker does absolutely nothing to the amount of current flow to drive the Voice Coil. The flow of current to the coil is a given from the frequencies produced by the music or what ever you are listening to on the CD or radio. It is not like a starter "solenoid" where it is engaged as long as you are holding the key to start position and if held too long could overheat.

However, every computer Hard Drive has a Voice Coil to actuate the drive heads over the disc to read data. There is a starting point and a destination for that head to travel to read data. Current will be applied to the Voice Coil until it reaches its destination and if suppressed long enough, it will burn up the coil. Speakers are not like this because the radio in giving pulses + & - there is nothing within the speaker mechanics/electronics to tell what its orientation is in relationship to the coil.

Well I don't mean to offend you but you are entirely incorrect. You are confusing DC and AC characteristics of the voice coil. There are no pulses in audio. It is a random AC waveform with zero DC component. It is the absence of DC component is quite important or else your speaker coils would burn up (or at least heat up).

In fact the head of a disk drive is identical to the operation of a speaker. An electromechanical coil exists within the field of a permanent magnet. Applying a voltage to the coil causes a current to flow which in turn create a magnetic field. The fields interact and the disk drive head moves.

So we are talking about AC characteristics of the voice coil. It only stands to reason if you restrict the motion of a voice coil then the coil will have to work harder to move. The only source of energy to move the speaker and do work is the power applied electrically. If you restrict it mechanically you require it work harder electrically to overcome. It might seem like insignificant pressure but to a speaker cone weighing a few grams being accelerated quickly (especially for the higher frequencies) then the restriction (or equivalent mass) will be relevant.

This is why speaker designers go to such pains to make speakers cones rigid (to avoid distortion) but very light (to keep the m in F=ma small). This is the battlefield for speaker designers. If mass didn’t matter they’d make speaker cones out of steel with bracing ribs (this also whey keeping disk drive heads so small is important). Applying a restriction to the cone is effectively loading the cone with equivalent mass. As a result AC current increases. Again the same as if you watch current in a motor and apply mechanical load to the shaft, motor current rises in direct proportion to that load. If AC current =I and I^2*R=P(power in watts) where R is the DC resistance of the speaker cone the P is the heat given off in the voice coil. In other words increasing speaker current increased power lost as heat in the voicecoil to the square of that current. Not good.

For clarity,

A loudspeaker (or "speaker") is an electroacoustic transducer that converts an electrical signal into sound. The speaker pulses in accordance with the variations of an electrical signal and causes sound waves to propagate through a medium such as air or water.

[Jonicat]

Ok, I have a 2001 LS430 and already went though one blown, crackling, buzzing Mark Levinson Sub Woofer. I found a used one on Ebay at a used auto yard and convinced them to send it to me for $50.00 including shipping. (All you do is ask). I had Myer Emco install it for $75.00 and saved me the headaches of doing it myself. Unit worked perfectly for a few years Then the amp went, $250.00 Ebay for an .01rev ML Amp unit and installed it myself in less than 20 minutes. All is well... Then, the sub woofer blew again. Now, I personally keep the bass level low and do not blast the system. Being the inventive person I am, I took off the Sub woofer's grill and inserted some fiberglass insulation to suppress the speaker. It works great, took about 30 seconds and there is no more buzzing that I can detect. What is the harm is there in doing this?? The speaker is blown and awaits the hot glue gun trick if it gets worse. This repair (for a lack of better words) puts no strain on the stereo system whats so ever. Actually, I kind of like the deeper base that comes out now. Even if I do the glue gun repair, I will put the insulation back in the speaker. This causes less strain on the cone because it cannot snap back and forth (frequency response) as easily as it does without it, which causes the crack in the cone to begin with. About 3" of R13 does the trick. Why Lexus puts Mark Levinson in their cars is a mystery, for the price, it is crap for a lack of better words.