I just did a similar upgrade to my 2017 QX70 limited. Used the Cerwin Vega spare tire sub and tried the Infinity Reference speakers mentioned. I ended up pulling out the Infinity's in favor of the JBL Stadium series. Here's what I ended up with:
JBL GT0620 6.5 coaxial in rear door
JBL GT0600C component 6.5 in front door and 3/4" tweeter in the upper door trim (near mirrors)
JBL GT020 in the dash corners
I extended the corner dash wires to the door panels so I could mount the crossovers that came with the 600C and set it to 3-way mode to use the "Mid" output to then use the GTO20 crossover for the new dash mids.
-----------------------------------------3-way-crossover----->woofer-out----->not connected
---Dash-wire-extended--->3-way-crossover(in-door)------>mid-out-------->-GTO20-bandpass-filter/crossover--dash-GTO20
-----------------------------------------3-way-crossover----->tweeter-out---->upper-door-tweeter
What did I notice and why did I end up with this?
What:
The factory dash mid-range drivers are 3.5 ohm, the JBL 2" driver is 2.5" and noticeably louder. I temporarily threw on a 1ohm 10w resistor to mildly attenuate the JBL mids.
The CV sub fills in the missing lower octaves decently well, though not fully flat like the studio systems that I'm used to. 8-gauge wire MUST be run directly from the battery.
Why:
I'm a music mix engineer/studio owner (www.cleartrackstudios.com) and rely on my car for final QA before I send mixes and masters to the label or artist. I had a 2018 Q50 with the Bose Performance speaker that I just got rid of, which is objectively the most accurate audio system in any Infiniti car to date. My wife has a 2019 QX50 w/Bose P.series which is a tad less accurate than the Q50 w/Bose P.series.
The QX70 and any non Bose P.series speaker systems are sonically a mess and initially there was no way I could judge mixes without this massive speaker upgrade. Now I can confidently use the QX70 for listening purposes.
BTW, I don't believe in spending big on car stereos as you'll never reach professional accuracy, not to mention it's just a listening environment not a working environment: the noise floor is too high in a car, there is no sweet-spot in a car seat and there are too many speakers spread throughout the vehicle.
In the music industry the car test is supposed to be a "real-world simulation", which I find works best when you can hear all frequencies reasonably well. Then you go back into the control room where acoustic perfection and all of the tools are in their right place.
This may or may not help anyone but I just wanted to put it there in case someone else is seeking similar results.
JBL GT0620 6.5 coaxial in rear door
JBL GT0600C component 6.5 in front door and 3/4" tweeter in the upper door trim (near mirrors)
JBL GT020 in the dash corners
I extended the corner dash wires to the door panels so I could mount the crossovers that came with the 600C and set it to 3-way mode to use the "Mid" output to then use the GTO20 crossover for the new dash mids.
-----------------------------------------3-way-crossover----->woofer-out----->not connected
---Dash-wire-extended--->3-way-crossover(in-door)------>mid-out-------->-GTO20-bandpass-filter/crossover--dash-GTO20
-----------------------------------------3-way-crossover----->tweeter-out---->upper-door-tweeter
What did I notice and why did I end up with this?
What:
- The Infinity Refs. were a little muddy in the low end and a tad too harsh in the highs, especially in the rear doors.
- The JBL's are a better built speaker that can reproduce the low end more accurately. The JBL tweeters are smoother on both the coaxial and the components.
- The JBL midrange is VERY detailed and is one of the rare speakers that can drop in where the corner dash drivers are. The screw holes don't fit but can be hot glued or held by the force of the speaker grill. The 6.5" drivers need the "7400" speaker adapter as the JBL's are quite deep. Most websites say they don't fit out cars but that's not true.
The factory dash mid-range drivers are 3.5 ohm, the JBL 2" driver is 2.5" and noticeably louder. I temporarily threw on a 1ohm 10w resistor to mildly attenuate the JBL mids.
The CV sub fills in the missing lower octaves decently well, though not fully flat like the studio systems that I'm used to. 8-gauge wire MUST be run directly from the battery.
Why:
I'm a music mix engineer/studio owner (www.cleartrackstudios.com) and rely on my car for final QA before I send mixes and masters to the label or artist. I had a 2018 Q50 with the Bose Performance speaker that I just got rid of, which is objectively the most accurate audio system in any Infiniti car to date. My wife has a 2019 QX50 w/Bose P.series which is a tad less accurate than the Q50 w/Bose P.series.
The QX70 and any non Bose P.series speaker systems are sonically a mess and initially there was no way I could judge mixes without this massive speaker upgrade. Now I can confidently use the QX70 for listening purposes.
BTW, I don't believe in spending big on car stereos as you'll never reach professional accuracy, not to mention it's just a listening environment not a working environment: the noise floor is too high in a car, there is no sweet-spot in a car seat and there are too many speakers spread throughout the vehicle.
In the music industry the car test is supposed to be a "real-world simulation", which I find works best when you can hear all frequencies reasonably well. Then you go back into the control room where acoustic perfection and all of the tools are in their right place.
This may or may not help anyone but I just wanted to put it there in case someone else is seeking similar results.



