I have plans to some way add more bass to default ML audio system. Now system is stock except OEM sub that I have changed to kicker CompC8 https://www.kicker.com/comp-c-8-dvc-subwoofer but bass is a little weaker than I would like. Okay let's say miserable to my taste.
So my plan is either A, B or C

Plan A is lineconverter and about 200W RMS amplifier (because of kicker specs) which I connect to existing 8" kicker sub.
Pros: cheaper
Cons: Is that combo sufficient enough? probably not

Plan B is lineconverter, 10" or 12" sub in sealed/ported box and more powerful amplifier
Pros: More bass
Cons: Of course more expensive but how about subwoofer box in trunk of sedan car like LS430?

Plan C is that I forget the whole thing and cry myself to sleep

And now I'm talking about small bass upgrade and I do not have plans to install more than 1 subwoofer.

About installing lineconverter to ML audio system is "normal" lineconverter ok or should I use more advanced device like Helix AAC.3

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Helix AAC.3

The integration of car hifi components into existing OEM sound systems becomes more and more
challenging as today's factory radios either lack of preamplifier outputs or incorporate intelligent
speaker diagnosis features. That's where the new Helix AAC.3 comes into play.

The smartest high-low converter in its class
Forget about error messages or loss of features (e.g. the fader) - the integrated ADEP.3 circuit
cleverly "bypasses" the speaker diagnosis in factory car radios. Distorted sounds and
increased THD which may occur with conventional high-low converters are prevented as well.
The good thing is that the ADEP.3 doesn't load the car radio's amp unnecessarily
and therefore reduces its current draw by up to 70%.

Smart signal detection
Its “Double Activation Circuit” generates a +12 V remote signal for turning on connected power
amplifiers in two different manners. Either it detects the DC offset on the speaker outputs of
the OE car radio or it utilizes an integrated, switchable signal detection with variable sensitivity.
Furthermore the AAC.3 incorporates Audiotec Fischers proprietary "Power Save Mode",
which turns off the remote output if no music signal is present for more than 2 minutes.
That's really a great advantage as many cars with "CAN" or similar bus architectures
keep the radio invisibly "alive" for up to 45 min. even if you have
already left the car meanwhile.

High Resolution-ready
The AAC.3 generates a high-quality preamplifier signal out of the speaker output signal of
a factory radio or amplifier and thus allows the easy connection of additional power
amplifiers. Its wide frequency response of 18 Hz up to 80,000 Hz warrants excellent
sound quality and makes this high-low converter ready for High-Res audio reproduction.

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And what is the best route to pull power cable from inside car to trunk? I have electric back seats so how to make sure that power cable not damaged when adjusting the back seat?

 

Why not just get a new head unit, amp, and speakers...why upgrade the old when new is so much better and less of a headache? There is a way to keep touchscreen/button functionality with a new radio unit btw

 

Which is why I should renew everything if everything works as should? Amp and all speakers are ok. I'm pretty happy with OEM door speakers.
I just want more bass

 

Now this small audio enhancement (more bass) project is complete. I ended up buying Audison APBX 10AS 10" active subwoofer http://www.audison.eu/products/apbx-10-as/
I take signal from OEM sub wires because that sub has also high-level speaker-in input. Sub has "Automatic Remote Turn-On" but sub signal is too weak so I take remote signal from the fuse box in the trunk.
First I install damping mats to trunk and here is couple of pictures.





As you know, pulling the wire from battery to trunk is not easy task.






And job done

 

That looks amazing. Hope that your bass is blasting now.

 

Now after just over a week of testing I would say that I am very happy with my choice. Of course, this is no earthquake bass but good choice for listening to normal music. That audison bass and 4AWG Amp Kit was 300e (~315 USD)

 

I to would like to up the level of bass in my car, without changing everything in the car. I currently have a stock ML system that is in perfect working condition. I recently purchased this vehicle from my local LEXUS dealer. It is a low mile, one owner, dealer maintained garage queen. I guess my real question is this. Do the Kicker, Polk or Dayton replacements produce more base than a good working ML sub when connected to the stock ML amp? I have been reading a lot of threads about the ML system but no one really makes this distinction. Thanks in advance, as I'm new here I hope that this is an okay place to ask this question.

 

By the way I like the Audison unit you installed but I don't want to put a sub box in my trunk, if I don't have to. I would like to stay with a freeair set up.

 

The stock ML sub was already broken when I bought the car so I don't know what it sounds like. But I think by switching only sub do not produce more base because power of the stock ML amp is something like 50-100 RMS (someone gets corrected if I'm wrong) and that free air set up is another problem.
If you do not want put a sub box in trunk you can consider to buy lineconverter + aftermarket sub amp and new 8" sub. That way you can hide amplifier behind trunk covers and you have nothing extra in the trunk.

 

Sorry, but you guys are driving me crazy.

It's bass... NOT base.

 

I replaced my busted ML Sub with the Dayton dual coil 8" Sub wired in series to give 16ohm.
Now I have to drop the bass setting in the equaliser by one notch to get optimum bass for me.
If you want more bass, try this Sub and increase the bass in the EQ.
The other advantage with this Dayton Sub is you are less likely to blow the amp as running an 8ohm Sub from a system expecting a 16ohm will lead to over-current and a blown amp.

 

Thanks, that is good to know. I have been a fan of the Dayton Audio products and Parts Express for a long time. I wasn't sure how the Dayton would work off the stock amp @16ohms instead of the @12ohms. I was thinking there would be slightly lees amp output because of the slightly lower impedance. The difference is small but would like to know from someone who has tried it. That sounds like a great option and good value.

 

The static resistance of the 2 coils in series on the Dayton is more like 12.5 ohms so is a very close match for the ML Sub which is 16 ohm nominal and 12.3 ohm static. Just make sure you wire red to black when linking the 2 coils. Otherwise the 2 voice coils will be working against each other.