Here it is, our first Project of the Month! Future projects will be drawn from actual sales at retail, but since this is our inaugural issue, I’m drawing from my own private stash of projects. Prices are estimated in this case (they’re what I would charge someone who wasn’t family), and install times are actual. This is a sale I would not hesitate to make at retail.

My sister and brother-in-law live in Hawaii, and they plan on taking some road trips around the Lower 48 now that the kids are grown. I recently helped them purchase a 2010 Toyota FJ Cruiser (they have one at home and really like it). They asked me to upgrade the tech and the sound, and after that, they plan to fit it for overlanding – lift kit, rooftop tent, solar panel on the hood, that sort of thing. I planned out the upgrade, and Pierce Barrett at Musicar Northwest in Portland, OR, made it all happen.

In-Dash Receiver

First, they knew they wanted CarPlay. This FJ lacked steering-wheel controls, so I wanted them to have a volume knob, and I also wanted them to have a rear USB so we could install the USB port out of the way (we put it into the top-dash glove compartment.

We used the Sony AX210 CarPlay CD receiver, paired with an iDatalink RR2 radio-replacement interface. The Sony has a rear USB and a volume knob, and the RR2 gave  us individual TPMS info for each tire, as well as gauges on the screen.

I am not a fan of any of the dash “kits” available  for this Toyota, so Pierce made a trim ring on the Musicar laser cutter.

The Toyota rear-view camera fed a tiny display in the rear-view mirror. Pierce intercepted the video feed on its way up the A-pillar, and re-routed it into the Sony’s back-up-camera input. The 6VDC power supply in the Maestro took over the duty of powering the camera as well as putting TPMS and DTC info on the screen.

This part of the project came out to around $1500, including installing some “customer’s own gear” 12-volt and USB power ports:


We looked at all the available add-on subwoofers for this vehicle. Even the sub enclosure for the factory JBL option takes up a lot of space – space the owners wanted to use for cargo and a 12V refrigerator. So we looked at the front-door speakers.

The OEM front door speakers look like they’d be 8” round woofers. Take off the door panel, though, and you discover the same undersized 6×9-class oval speaker from the Toyota Tacoma. Same for the dash speakers – there’s a 2”-class “middler” in each corner of the dash, just like the Tacoma.  The FJ was based on the Tacoma platform, so this isn’t surprising. Full-size 6x9s will fit, though, so we decided to go subwoofer-less.

We used the Audison AP690 woofers in 1” thick HDPE adapters, and we used Fast Ring gaskets – attached to the back of the door panel, they fit around the outside of the OEM oval tab – and we designed the HDPE spacer to line up with that gasket.

Then we treated the door with aluminim/butyl constrained-layer damping tiles, and replaced the vapor barrier with a large sheet of mass-loaded vinyl.

The dash speakers are 2-inch-class “middlers”. We replaced them with Audison AP2 widebanders in mounting adapters made on the Musicar laser-cutter.

This by-nine/middler front stage speaker arrangement is increasingly common nowadays from vehicle OEMs – especially in trucks. Chevy, RAM, and Toyota all use this setup. Ever wonder why? The off-axis orientations of those dash speakers prevent the near-side speakers from overpowering the far-side speakers. The near side is still a bit louder than the far side, because it’s farther away, but it’s not that much of a difference. Because both left and right dash speakers are off-axis from either front seat, they have similar frequency responses without EQ. This helps with a 2-seat presentation.

The premium systems usually use one set of channels for the dash middlers, and another for the door woofers. A carefully-chosen crossover point prevents the 6×9 woofer from operating outside its omnidirectional range, and that means (again) the left and right door woofers also have similar frequency response without EQ. Again, this helps with a two-seat presentation. This allows an unusual speaker arrangement (to us, anyway) work much better for both seats than our traditional 6-and-tweeter kits can.

Many systems – premium or not – are now using all-pass filters on the worst of the cancellations caused by the path-length differences (more below).

The optional JBL system uses the same 2”-class speakers from the dash locations in the D-pillars. We decided to use those locations for “ambiance” speakers, We ordered the JBL speaker brackets and grilles, and we installed speakers there and ran wire to them.

This part of the project came out to about $2200 (the customer supplied the OEM grilles).

Amplifier & DSP

In talking with my sister and brother-in-law about their planned use of the vehicle, they told me they’d both be in it 80% of the time. That means that 80% of the time, a one-seat tune will make the passenger seat worse (the seat my sister will usually be in).

I decided to do a two-seat tune for this project. I don’t think two-seat tunes sound  quite as good to me as great one-seat tunes, so I decided to do both.

Some of you are familiar with what happens in either front seat of a car when listening to door speakers – there are periodic cancellations caused by different arrival times (see above). If we use delay to correct this for the driver’s seat, we make things worse for the passenger.

If we use an “all-pass” filter on the biggest cancellation null – around 250 Hertz – it  helps both seats. Flipping the phase to 180 on one channel at that point puts both channels back into phase in either front seat. (Put your head in the center of the vehicle, where the distances are equal to either front seat, and that hole would reappear).

It was decided to use the JL Audio VX600/6i amplifier with DSP tuning inside. This amp isn’t intended for complex OEM interface, but that was OK, we were using an aftermarket head unit. The amplifier went under the driver’s seat. It has 75 watts into 4 ohms, and a full DSP tuning processor built in. It has two more processed preamp channel outputs, in case a subwoofer gets added later.

The VX series amps have an input wire that’s called “Valet” in the manual – but it’s really just another tuning preset. Rather than creating a “valet” preset with everything knocked down to 50%, we created a 2-seat tune accessed by triggering the Valet input. That 2-seat tune has the left and right speakers the same level, and applies the same EQ to left and right as well. A true  two-seat tune shouldn’t favor one seat or the other. (I am an advocate of something I call a “one-and-a-half-seat tune”, using OEM all-pass filters but optimizing EQ and level for the driver – but this wasn’t one of those). For that reason, this tune doesn’t use any delay (except on the D-pillar speakers). Instead, we used an all-pass on one door woofer to address that 250 Hz null, and then another on the 2” dash speaker to address a null caused when those speakers played the same note.

The standard preset is where the one-seat tune with delay and asymmetric EQ hangs out. The occupants select one tune or the other using an OEM-look dash pushbutton  (ordered from, using a pre-existing icon from their selection, and our custom text).

We high-passed the D-pillar speakers at 500, and delayed them about 12 milliseconds. We also created a “Left-Right” signal for those speakers, which cancels out any content occurring in both channels. That content is what happens in the center of the  stage, and with this arrangement, that doesn’t come out the rear speakers. No matter how loud these rear speakers are, they won’t “fight” the front speakers by playing center-stage content loud enough to draw attention. What remains is full-right-only or full-left only, and it is delayed a similar amount of time that it would be in a concert hall venue. The result is the “feel” of a larger and wider room than we actually have.


No sheet metal was harmed in the making of this picture – not only did we not need to cut any, we didn’t use any self-tappers anywhere, either.

This reasonably billed out at 23.6 hours of work, which means three business days. In reality, the physical installation was done in two long work days, and the tuning was done later. The mounting adapters for the dash and door speakers were made using templates for a Tacoma, which saved time. I give this job a utilization score of 10 out of 10.

That’s almost $2000 a day, which is not terrible – that’s a run rate of roughly $40k of revenue per installer if you sustain that all month. It’s 56% product and materials, and 44% labor and shop charges. High-volume shops often want a higher percentage of product than that – 75/25 used to be the goal, but I think that was before product prices dropped so much.  Many custom shops now operate at a 50-50 ratio, and this is better than that average.


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