Gsr3is

I thought I will post this here if anyone needs this in the future.

As mentioned in the title, I have a 2016 IS350 non-ML with NAV audio system. So it has 8 speakers from the factory.

Main reason I did this is because my kids kept complaining they can barely hear any vocals and music in the rear seats. So I started researching this and realized the stock speakers are mainly to blame. But I wanted a project to take this further.

I initially wanted to just install a JBL4086 + few speakers and be done with it. But it turned more complicated than that. So before you proceed with such project on your own, read through this and it might help you decide if this is worth it.

1. The factory is Amp is heavily tailored to the stock speakers and has dynamic eq as volume changes.

2. Nav version of the cars have a co-axial cable going into the Amp. So there is just no way to bypass factory amplifier. Whatever you do, it has to be from the factory amp output. So things like RF DSR1 does not work on our cars. So crutchfield is not always 100% accurate.

3. Factory Amp has time alignment built-in. So if you simply sum the factory output using a LOC's it will not be ideal as they will be mis-aligned in time.

4. Frequencies going to front door/dash and Rear door are not full spectrum. They are completely missing Bass frequencies. So any kind of summing you do, it must include the stock sub signal.

5. Any kind of summing and tuning you want to do, you need to have a proper summing device. I did research into it and Audison AP 8.9 will not cut it unless you don't want to control any of the rear door channels. It has only 6 input channels. Also looked into Match PP 86DSP/ UP 8DSP but I think these only work on radio output and not on Amp output (higher voltage)

6. If you don't have any load on the factory Sub output, I think the stock Amp automatically cuts off those frequencies (not 100% sure but I couldn't hear any sub frequencies when I did that at first).

7. I ended up going with a JL Audio Fix-86 (8 channel input fed from factory Amp and outputs 6 low-level summed, de-eq'ed and factory alignment removed). Note that I am not using the factory center channel into this Fix-86. Below is a snapshot of frequencies (Blue -> Sub, Purple -> Front door, Red -> Dash L/R, Green -> Rear door ===== Orange is the converted low-level output signal).


Fix-86 Calibration from a 2016 Lexus IS350 Non-ML with Nav.

8. This pre-amp out from the Fix-86 is then fed into a JBL 4086 where I have setup the frequency crossovers for each speaker appropriately. The fix-86 turns ON when it detects a signal. It then has a remote out to wake up the JBL 4086. So no need for an explicit remote turn-on from factory AMP.

9. I use a PAC APH-TY02 harness to keep the factory wires intact. I did not have to tap into any wires at all due to this harness.

10. This speaker adapter works perfectly for dash and center channel :

As for the speaker upgrades, I did change front doors, dash L/R and Rear doors to mid-tier ones but nothing fancy. Yet the audio is super crisp and clear. I got the skar audio npx65-4 with neodymium magnets for front door as the speaker adapter (from car-speaker-adapter) is very light duty. I did not want to overburden the adapter with the vibrations and a heavy speaker. Get some foam rings esp for the front door.

The stock speakers were really missing a lot of the details especially in the rear doors. The center speaker can be disconnected. Get some 2-way or 3-way speakers for rear door if you want people in the rear seat to hear the music/vocals properly. The stock ones are totally 2 cent plastic cones. I got RF r165x3 for rear doors.

I have JBL Stage3 427F 4" speakers in the dash.

Bought used (but pristine) Fix-86 from facebook marketplace at half the price. The JBL4086 was also purchased open-box for $200. So I didn't pay MSRP for any of them.

Coconut

Great write up and I think this will be very useful for people looking into upgrading the non-ML systems. Another thing to mention is if you’re only wanting to add a sub by tapping into the factory sub, it really won’t sound that great. As Gsr3is mentioned, the signal from the sub is heavily eq’d, time delayed and the level drops when you turn up the volume to protect the speaker. Yes, you’ll get more bass but delay and lack of quality signal (nothing <50hz) will make things sound muddy.

If you’re doing a full aftermarket system with amps, speakers and sub(s), it’s almost required to get a quality DSP like a Mosconi, Helix or Mini-DSP with at least 6 inputs and 8 outputs (if sticking with 2-way fronts) or 10 outputs if going with 3-way fronts). The best way to pull a “flat” signal would be to sum the front L/R dash/door speakers and sub, then take that “flat” stereo signal and distribute it to the front 2-way or 3-way speakers, rear speakers (if you want rear fill) and sub(s). It’s not recommend sum or even have a center channel as this will destroy imaging. The beauty of this is that you will run all channels active, so no need for crossover controls on the amp or hardware crossovers at the speakers. Another benefit of a full on multichannel DSP is that you can bypass the OEM amp and run a pure source from either Bluetooth, aftermarket head unit (through RCA) or an optical or digital (coaxial) source if your DSP supports it. For sure this is the best method to get cleanest sounding system.

kkid

I have an NX 300, I'm using the same amp/dsp as you, instead of using the JL Fix-86 you can just use the amp as a pass through of the factory signal and eq that to get the sound you want. I passed through everything except my rear door signal since there are only 6 inputs (dash L/C/R, door L/R and sub), you can recreate the rear signal using the dash and door woofers.You can still match to a house curve by EQing the factory Lexus signal for each speaker. Just use REW and a calibrated mic as an RTA to verify the changes.

I ended up adjusting the crossover for the Sub and Door woofers, the doors were crossed over very low from the factory, it sounded great at lower volume but not when you cranked it. Then I used a few EQ bands for the Dash speakers and made minor adjustments and matched everything to the Harman house curve.

The benefit of doing it this way is you don't have to mess with the factory all-pass filters which Lexus already took the time to figure out for you and you get to maintain the stock 2 seat tune from Lexus (if the IS has a true center channel like the NX does).

Gsr3is

Following up on this after my initial post. I completely gave up on Fix-86 method. Not all songs that we listened to were being enhanced the way I had hoped. I tried around a lot with DSP settings on the JBL4086 as well but to no avail. In the end, I removed the Fix-86 and using the JBL4086 in AMP only model. Just boosting the frequency to front and rear door speakers along with the stock sub. I just have better cutoff than what factory Amp did and it takes care of most of my use cases.

So long story short, unless you are an audio expert or have a shop that can do this for reasonable price, dont both with it. Instead just install better speakers and Amp the audio to door speakers/sub.