Just did the subwoofer mini amplifier upgrade (took me about an hour); bass sound much clearly and louder. However, the factory subwoofer seems to lack bass frequencies below 40Hz. Now that I have done both the dash speakers and subwoofer upgrade I would suggest that if you have money do the powered subwoofer enclosure (like Kicker 46HS10), if you don't do the mini amplifier upgrade. Then do the dash speakers upgrade if you have extra money to spend. But I think if you have the money and can get the ML you will be much happier. Before the upgrade I would rate the stock system as 7/10; after the upgrade I would rate it as 8/10. I spent around CAD$200 for the whole upgrade. I don't want to spend over CAD$600 for the Kicker 46HS10; but I think it would make the sound system a 9/10.

 

I thought I would clarify a few things. If you recall at the beginning of my post, the goal was the most bang for the buck and for about $100 these simple fixes to the system sounds worlds better in clarity and bass. I would rate the stock a 3/10 at best (muddy, no clarity and no bass. One of the worst I have heard in a modern car) and upgraded a 6/10 or 7/10 (The JL Audio a 7 and the Kickers/JBL/Infinity a 6). Adding a dedicated sub would bring it to an 8/10 at best, however without amping the main channels, it will never sound like the ML system. If you go to the trouble to amp and replace the main speakers and run it through a perimetric EQ, it can sound better than the ML system, but the cost would be similar. Plus changing your audio does not increase the resale value, but the ML does. Again, the goal is to fix the main shortcomings of the factory base audio. With each fix, brings to light new problems that can be refined... but at what cost. Any audiophile is aware that a $10,000 (or for that matter a $100,000 system) only sounds a little better than a $2000 home system. I have heard many at the CES shows in the +$100,000 range and quite frankly they are only selling these overpriced gear to the rich. There needs to be a point where it is sufficient, and people do have different expectations.

On to a dedicated sub or not. With the gas model, a dedicated sub requires wiring a high current lead to the battery which is a major pain and not easy for most DIYers. The hybrid is much much easier and I may have done just that if I had a hybrid. Or perhaps used a better higher power amp with the factory speaker box. The Taramps Bass 400 amplifier or Infinity PRIMUS-3000A are about the best reasonable cost sub amps that support bass boost and speaker level inputs. The obvious option is a dedicated sub with the lower end cost the Kenwood underseat style that does sound remarkably good, but costs a couple hundred more and only slightly better than this simple fix. Plus you lose storage space or more if you use a box. The Kicker sub is better, but also bigger and does not fit well into the cubby area below. BTW, as you use the sub, the sound quality improves as the driver starts to break in. Also, if you want lower bass, set the crossover point on the amp to 11am and not noon or 1pm. Perhaps bring up the volume to 1pm. I have not tested the distortion threshold so let your ears be the judge. It has become more obvious that the factory sub is likely tuned to ~80hz or so, but when I tested it, it is reproducing below this frequency. Run a sound wave generator and this is easily confirmed. Just keep in mind it is a small box with a small driver (8") with minimal xmax. This is the distance the piston, or shall I say speaker cone can move to produce more sound. Simply put, if you want killer bass, you need a big box, with lots of power and large expensive drivers. If the factory speaker does fry (unlikely) with this small 40w amp, a better replacement is the Polk Audio DB842 DVC put into the factory box with this baby amp. All I am saying, is to set your expectations realistically and test lots of music. Some sounds excellent and others (mostly due to poor mixing) sounds meh. But ALL of it sound much better than the stock system, and that was the goal. (And get rid of the center speaker or attenuate it or replace that one too. It muddies up the sound as well)

 

Hi Atomic, really appreciate your sharing of knowledge! It has helped me immensely building my project plan

 

It was not easy (mainly because of the two internal screws) to remove the subwoofer, but it was done. Some data: fs: 38 Hz, Re: 2.4 ohms, installation diameter 215 mm, depth 78 mm. The box can fit a speaker with a maximum diameter of 224 mm without conversion (e.g. Audison APS 8D). The plastic part is not actually a box, just a speaker holder, the resonator cavity is the rear body.

 

Not sure what method you found the Fs (free-air resonant frequency) unless printed on the speaker. We would also need the Vas, Qes and Qts to run a box plot program to determine the frequency curve, but it may get a bit complicated as I imagine the 2 chambers of the sub (box and rear body) act like a 3rd order network if the rear body is ported.

My thought was if a replacement was necessary, the Polk Audio DB842 DVC with a custom made adapter ring would be perfect. Drive both sides in Parallel and it becomes a 2 ohm subwoofer. The small external amp has no issues with a 2 ohm load. However, after using the factory sub with the baby amp this last month, the low bass is surprisingly good, and it improved as the speaker became broken in. No doubt that the Polk would outshine the factory sub, but may not be that dramatic.

As for your idea on the Audison APS 8D, this sub really wants more power than the little 40w amp I recommended can provide. If you are lucky with the hybrid (or don't mind running power wires to the front) a bigger sub amp should work well with it... unless the factory box is not rigid or sealed enough to drive that much air. Food for thought.

What made you want to remove the sub box in the first place? And since you have easy access, what are the bolt centers for mounting?

 

Yes, the factory construction looks like a special vented box. By itself, a speaker replacement probably does not mean a dramatic change - unless it involves an increase in size (10") - you also need a larger amplifier than the OEM with the frequency correction you mentioned earlier. The mounting screws are on a 215mm circle.

 

Don't believe Crutchfield, the 3.5 JL speaker will fit without any modification, it won't touch the factory grille! Before installation I did a simple mono A-B test: the difference was not big, the JL sounded clearer, and it was noticeable that the sensitivity of the two speakers was the same. BUT!..after I wired them in place in stereo, something magical happened, the stage opened up, a lot of new information, sounds, noises, effects were heard, the music became transparent and palpable. These little speakers are amazing! Thanks for the tips and especially to AtomicLexus for idea and the connector (Aliexpress) info!
Tomorrow I will continue with the subwoofer replacement, it is clear that the problem is with the band edges.

 

Damn, makes me wish I ponied up for the JL speakers.

 

JL is a smoother more natural sound, although 3x the cost of the Kicker/Infinity/JBLs. If I didn't already have my Kickers from my old Prius, I would have went that route too. Worst case, you dremel out the ridges on the inside of the cover if it did not clear.

You may be surprised on the bass with the simple amp fix for the existing sub. It is much easier than putting in a new sub and saves you storage space. Not the drastic punch of a higher power sub, but way way better than the totally absent low bass the system has now.

Glad I was able to help. It really is sad the crap audio Lexus passes off as "Premium", lol. Also, another big improvement is to attenuate the center channel. That poor center speaker is only adding to the lack of clarity.

 

Anyone have experience with the Kenwood Excelon KFC-X3C? I have a pair on order (when they return in stock)....

I still have time to change

JR

 

Crutchfield website has a sound comparison tool, and with good headphones (even earbuds), it is surprisingly accurate. Play around to hear what you like best.

 

If that comparison is to be believed then Morel Maximo 6 and Focal PC 165 FE are the most natural sounding speakers Crutchfield sells. Morel sounds almost exactly like the Focal which makes the Morel a steal. I have this Morel speaker in a 5 1/4" but it's at the back of my wagon so I don't get to fully appreciate it.

 

I tried this too, it's a very practical test! Of course, the question is to what extent practice proves it. (For example, the Pioneer TS-879 recommended by Crutchfield for the factory place sounded suspiciously dull in the test, even though Pioneer is more famous for its "Japanese" sound.)

 

It only "proves" that if you use the same amp in the same space you're getting a fair representation. You could find a sound you like in the test but isn't a good match for a particular amplifier and head unit. Or a factory system. Nakamichi uses speakers with very strong midrange the amp etc. is tuned for this. If you run the same speakers using aftermarket components it will be way too midrage boosted. From an engineering standpoint this makes sense it's easier to attenuate midrange than boost it in the amp/digital.

I'm running a Morel amp which is known to be mellow the JBL front speakers are quite sharp but it works nice with the particular amp. Rear is Hertz speakers which are also known to be sharp sounding. Bit of luck on my part. Driving a speaker like Focal IMO requires a very high quality source and amplifier otherwise the sound will be too muddy and mid heavy and lacking detail.

 

Here in Europe, they say that the two extremes in loudspeakers are Focal (sharp, detailed, "tiring") and DLS=Morel (smooth, rounded, "boring".) We absolutely agree that matching the character of the amplifier and speaker is critical.