Making the ML sub sound better
#32
Intermediate
Thread Starter
On the ML amplifier, the 24 pin connector nearest the rear of the car has a gray wire at pin 12. This is switched Accessory voltage that turns on the amp. Splice a thin wire to this wire, and run it to the remote turn-on terminal of the new amplifier.
#34
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anyone know how to remove the ML SUB from the 01 GS430?
looking through the trunk it seems, it has to come our from the inside the car, but don't want to damage the cover. reason being, the sub rattles and seems to be torn as a result of bad AMP.
can I just put in an after market SUB, since the exact replacement is close to $500.
thanks
looking through the trunk it seems, it has to come our from the inside the car, but don't want to damage the cover. reason being, the sub rattles and seems to be torn as a result of bad AMP.
can I just put in an after market SUB, since the exact replacement is close to $500.
thanks
#35
Lexus Fanatic
iTrader: (33)
quick questions.
Do you recall if the green or black wire from the ML sub was the -/+?
Also it looks like you took the +/- leads and turned them into 2 of each (4 total wires) at the amp? I know the ML sub is not dual voice coil like the oem Pioneer is. Just curious why you did this?
Thanks!
Mike
Do you recall if the green or black wire from the ML sub was the -/+?
Also it looks like you took the +/- leads and turned them into 2 of each (4 total wires) at the amp? I know the ML sub is not dual voice coil like the oem Pioneer is. Just curious why you did this?
Thanks!
Mike
#36
Intermediate
Thread Starter
quick questions.
Do you recall if the green or black wire from the ML sub was the -/+?
Also it looks like you took the +/- leads and turned them into 2 of each (4 total wires) at the amp? I know the ML sub is not dual voice coil like the oem Pioneer is. Just curious why you did this?
Thanks!
Mike
Do you recall if the green or black wire from the ML sub was the -/+?
Also it looks like you took the +/- leads and turned them into 2 of each (4 total wires) at the amp? I know the ML sub is not dual voice coil like the oem Pioneer is. Just curious why you did this?
Thanks!
Mike
I disconnected the wires right from the sub's terminals since I decided to run a new speaker wire from the Kicker amp to the sub. The loose speaker wires from the ML amp were then spliced into a wire to feed into the Kicker amp.
As you noted, the ML sub amp is a single voice coil. It is driven by a bridge amp. Both leads carry audio, in opposite polarities. Neither is ground.
The Kicker amp has two channels, each with opposite polarity. To run it as a mono bridge amp, I feed the L/R inputs of each channel in parallel. The Kicker's speaker level inputs are fine with bridge amp signal inputs. Since you are using the LOC, you'd have to consult its manual to see if it is happy with bridged signal inputs or not.
Last edited by DrexLex; 07-01-10 at 01:33 PM.
#37
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Drexlex,
Do you have a picture of the remote wire going to the factory ml amp? I want to make sure I have the right one, it looks like the grey wire has dots on it as well??
Do you have a picture of the remote wire going to the factory ml amp? I want to make sure I have the right one, it looks like the grey wire has dots on it as well??
#38
#39
Question on the short circuit
I was wondering why you had to run the short , I am assuming that you still have the ML amp running and as you said you only spliced into the remote turn-on and then run the wires out of ML amp to the Kicker amp. Could you just pull the input wires and turn-on wires and use them directly without going through the Sub amp, or does that cause the problems with the Fader and tone controls?
I read some stuff about summing devices and want to avoid that so my guess is that the amp contains not only the amplification but the eq functions as well, otherwise if this was performed in the head unit you could just kill the amp and go straight to the new amp-- ????
Your thoughts.
PS How does the short actually work, I have always believed that a short would shut the thing down, it sounds like it acts as an inductor in that circuit and if so does it work with other amps?
"I have just enough knowledge to screw things up"
Me.
I read some stuff about summing devices and want to avoid that so my guess is that the amp contains not only the amplification but the eq functions as well, otherwise if this was performed in the head unit you could just kill the amp and go straight to the new amp-- ????
Your thoughts.
PS How does the short actually work, I have always believed that a short would shut the thing down, it sounds like it acts as an inductor in that circuit and if so does it work with other amps?
"I have just enough knowledge to screw things up"
Me.
#40
Intermediate
Thread Starter
I was wondering why you had to run the short , I am assuming that you still have the ML amp running and as you said you only spliced into the remote turn-on and then run the wires out of ML amp to the Kicker amp. Could you just pull the input wires and turn-on wires and use them directly without going through the Sub amp, or does that cause the problems with the Fader and tone controls?
Cannot use input wires that feed the ML amp because it is where all the sources are selected and processed, and where the bass signal is extracted. It does not exist anywhere else but the subwoofer amp outputs.
How does the short actually work, I have always believed that a short would shut the thing down, it sounds like it acts as an inductor in that circuit and if so does it work with other amps?
I suspect this little trick may not work with other amps, nor is it really necessary if the amp's gain control has sufficient range. And in the rare case that it does not, a simple resistor attenuator can be added before the amp.
#42
Intermediate
Thread Starter
Not sure what you mean. I have no extraneous sympathetic vibrations in my car. If something is buzzing, it needs to be tightened up or glued down. In any case, this mod will not fix it. The main benefits of this mod are:
1) Reduce the muddiness of the bass to reveal deeper fundamentals
2) Offload the ML amp of subwoofer drive duty, reducing heat
3) Make it easier to tweak bass while driving if one installs the separate gain control. No menus.
4) Make it possible to swap the subwoofer for any other driver as may be desired in future
#43
Moderator
iTrader: (20)
Subwoofers are supposed to vibrate...
Not sure what you mean. I have no extraneous sympathetic vibrations in my car. If something is buzzing, it needs to be tightened up or glued down. In any case, this mod will not fix it. The main benefits of this mod are:
1) Reduce the muddiness of the bass to reveal deeper fundamentals
2) Offload the ML amp of subwoofer drive duty, reducing heat
3) Make it easier to tweak bass while driving if one installs the separate gain control. No menus.
4) Make it possible to swap the subwoofer for any other driver as may be desired in future
Not sure what you mean. I have no extraneous sympathetic vibrations in my car. If something is buzzing, it needs to be tightened up or glued down. In any case, this mod will not fix it. The main benefits of this mod are:
1) Reduce the muddiness of the bass to reveal deeper fundamentals
2) Offload the ML amp of subwoofer drive duty, reducing heat
3) Make it easier to tweak bass while driving if one installs the separate gain control. No menus.
4) Make it possible to swap the subwoofer for any other driver as may be desired in future
#44
Any suggestions before attempting this?
#45
Today I finished my project to improve the bass quality of the '06 GS ML audio system—and I didn’t replace the subwoofer. I'm very pleased with the result. Tighter, deeper bass. Much better bass detail. I can now hear the bottom octave notes rather than them getting lost in the muddle. All I did was add a new bass amplifier. This allows me to run the ML bass control clicked down 3 steps (suppressing midbass plumpness), then use the new amp's gain and EQ boost to achieve the low end boost needed to reveal the deepest notes.
I chose the Kicker ZX450.2, a stereo amp that can run in bridged mono mode. It had two features I wanted in particular. 1) It can accept speaker level signals, and 2) it includes a wired remote gain control for easy bass tweaking without messing with the ML’s touchscreen.
The bridged mode is useful because the ML sub has a higher voicecoil impedance than usual, 14 ohms, so I wanted plenty of voltage swing to be on tap.
Turns out that this amp was also very easy to match to the system due to the way the input stage is designed, as it has both speaker and line-level inputs. These are tied together with resistors, and it allowed me to use the line input jack terminated with a short to scale the input signal from the speaker input, which feeds into it with a series resistor. It might not have been necessary, but I’m now sure that the input cannot be overloaded.
Here are the steps I followed:
1) Unsolder the leads from the sub, and splice them to a length of thin speaker wire to run to the amplifier’s high level inputs. Feed both channel’s inputs in parallel. The trunk lining has to be removed of course, but it’s easy once you find all the clips.
2) Solder new speaker wires to the sub and run them to the amp’s outputs. In bridge mode, use the L+ and R- outputs.
3) On the ML amplifier, the 24 pin connector nearest the rear of the car has a gray wire at pin 12. This is switched Accessory voltage that turns on the amp. Splice a thin wire to this wire, and run it to the remote turn-on terminal of the new amplifier.
4) Run an 8 gauge power lead direct from the battery, thru a fuse block and then thru the firewall below the battery (alongside an existing harness), then under the door trim panels and into the trunk. The amp is grounded in the trunk. Need to also pull the trim panels in the passenger foot well to route the wire through.
5) Mount the remote gain control module near the driver. I put it inside the ashtray. It fits perfectly after ejecting the ashtray insert (I don’t smoke)—and the door still closes. The console panel is easy to pull up to facilitate mounting the control and running the wire out the bottom, but that’s already been detailed in other threads. Run the supplied phone cable from there across the passenger foot well, under the carpet, then follow the same path as the power lead into the trunk.
6) Purchase a pair of RCA phono plugs. Solder a wire across the signal/ground terminals of each plug, creating a shorting plug. Insert them into the low-level inputs of the amplifier. This attenuates the high-level input by 22 dB, but the amp has 36 dB of gain, so it lets me set the amp’s gain control to the second mark of 7 (about 10 o’clock position). Plenty of gain.
7) Set the Crossover switch to Low-Pass.
8) Set the Bass Boost control on the amp to the same 10 o’clock position—this gives 5 dB boost at 36 Hz—clarifying the deep notes. This control has a maximum boost of 20 dB , so watch out!
9) Set the amp’s crossover control to max (200 Hz). It is not really needed. Setting it to a lower corner will cause certain midbass notes to disappear.
10) Set the bass control of the ML system to 3 clicks below mid point.
11) Mount the amp as you like. As I seldom use the trunk for anything, I tied each end of the amp to the chrome hold-down loops in the floor of the trunk, using large cable ties.
All of the above adjustments of course can be tweaked to obtain the sound as preferred, but these are good starting points.
I chose the Kicker ZX450.2, a stereo amp that can run in bridged mono mode. It had two features I wanted in particular. 1) It can accept speaker level signals, and 2) it includes a wired remote gain control for easy bass tweaking without messing with the ML’s touchscreen.
The bridged mode is useful because the ML sub has a higher voicecoil impedance than usual, 14 ohms, so I wanted plenty of voltage swing to be on tap.
Turns out that this amp was also very easy to match to the system due to the way the input stage is designed, as it has both speaker and line-level inputs. These are tied together with resistors, and it allowed me to use the line input jack terminated with a short to scale the input signal from the speaker input, which feeds into it with a series resistor. It might not have been necessary, but I’m now sure that the input cannot be overloaded.
Here are the steps I followed:
1) Unsolder the leads from the sub, and splice them to a length of thin speaker wire to run to the amplifier’s high level inputs. Feed both channel’s inputs in parallel. The trunk lining has to be removed of course, but it’s easy once you find all the clips.
2) Solder new speaker wires to the sub and run them to the amp’s outputs. In bridge mode, use the L+ and R- outputs.
3) On the ML amplifier, the 24 pin connector nearest the rear of the car has a gray wire at pin 12. This is switched Accessory voltage that turns on the amp. Splice a thin wire to this wire, and run it to the remote turn-on terminal of the new amplifier.
4) Run an 8 gauge power lead direct from the battery, thru a fuse block and then thru the firewall below the battery (alongside an existing harness), then under the door trim panels and into the trunk. The amp is grounded in the trunk. Need to also pull the trim panels in the passenger foot well to route the wire through.
5) Mount the remote gain control module near the driver. I put it inside the ashtray. It fits perfectly after ejecting the ashtray insert (I don’t smoke)—and the door still closes. The console panel is easy to pull up to facilitate mounting the control and running the wire out the bottom, but that’s already been detailed in other threads. Run the supplied phone cable from there across the passenger foot well, under the carpet, then follow the same path as the power lead into the trunk.
6) Purchase a pair of RCA phono plugs. Solder a wire across the signal/ground terminals of each plug, creating a shorting plug. Insert them into the low-level inputs of the amplifier. This attenuates the high-level input by 22 dB, but the amp has 36 dB of gain, so it lets me set the amp’s gain control to the second mark of 7 (about 10 o’clock position). Plenty of gain.
7) Set the Crossover switch to Low-Pass.
8) Set the Bass Boost control on the amp to the same 10 o’clock position—this gives 5 dB boost at 36 Hz—clarifying the deep notes. This control has a maximum boost of 20 dB , so watch out!
9) Set the amp’s crossover control to max (200 Hz). It is not really needed. Setting it to a lower corner will cause certain midbass notes to disappear.
10) Set the bass control of the ML system to 3 clicks below mid point.
11) Mount the amp as you like. As I seldom use the trunk for anything, I tied each end of the amp to the chrome hold-down loops in the floor of the trunk, using large cable ties.
All of the above adjustments of course can be tweaked to obtain the sound as preferred, but these are good starting points.
1. How did you determine the impedance of the sub? It looks like the RX has two subs: front left and front right. If my setup has a similar impedance then bridged mono will make sense.
2. I have no idea why you do this:
Turns out that this amp was also very easy to match to the system due to the way the input stage is designed, as it has both speaker and line-level inputs. These are tied together with resistors, and it allowed me to use the line input jack terminated with a short to scale the input signal from the speaker input, which feeds into it with a series resistor. It might not have been necessary, but I’m now sure that the input cannot be overloaded.
3. Why does this occur at 36Hz given that the spec for the amp (http://www.sonicelectronix.com/item_...11ZX450.2.html) says 40Hz, and how do you determine how much is safe to boost by?
8) Set the Bass Boost control on the amp to the same 10 o’clock position—this gives 5 dB boost at 36 Hz—clarifying the deep notes. This control has a maximum boost of 20 dB , so watch out!
Last edited by nadz23; 06-23-14 at 07:12 PM.