[keep_hope_alive]

The factory radio is comprised of two pieces – the screen that you see and the brains that you don’t see.

There is one harness to intercept these signals and it’s the PAC LPHGM72.



The factory amp here is buried in the dash. We want connectors X1 and X2


The adapter goes in-line and has removable bypass clips.


Of course, we want to wrap the connectors and cabling with fabric coating, like OEM.




The floorboard will need some treatment as well.

[keep_hope_alive]

Finshed a layer of Resonix CLD on the inner door skin, and then used Resonix Moldable Barrier to close up the openings. Using the barrier was a joy compared to my traditional methods of aluminum sheets with CLD and CCF.

[hrpiii]

wow, and wow. It will be the most quiet car to make a phone call in that I have ever seen. Did you replace the stock amp?

[keep_hope_alive]

Originally Posted by hrpiii

wow, and wow. It will be the most quiet car to make a phone call in that I have ever seen. Did you replace the stock amp?

This trim doesn't have an amp in the trunk, it has the standard radio/amplifier module under the passenger side of the dash. I have photos of the interface harness that allows me to snag the signal out of the radio/amp module and also intercept factory speaker wiring.

I am adding a sound system, yes, and it will be designed to be competitive in IASCA and MECA for sound quality competition - meaning it will be pretty darn nice and will sound amazing. Most of this effort is to make the sound system shine. Low road noise means you get to hear musical dynamics.

[SWRocket]

Looking forward to seeing more of this amazing work.
If you are inclined, maybe you can post the raw RTA for each of the drivers once the system is up? I'd love to compare and see if you see the same cancellations in the same spots.

[keep_hope_alive]

Originally Posted by SWRocket

Looking forward to seeing more of this amazing work.
If you are inclined, maybe you can post the raw RTA for each of the drivers once the system is up? I'd love to compare and see if you see the same cancellations in the same spots.

Certainly. I have 1/3 octave measurements of road noise before (fully stock) and will do a follow-up afterwards, with video and narrative on my YouTube channel. I will also have detailed videos of the entire install process on my channel.

I will be taking RTA measurements of the factory amplifier output (I use a LOC to convert the output to low level then run into a soundcard to see what the stock EQ curve looks like). Then I use the DSP to flatten that prior to doing any acoustical tuning. This is done by bringing the signal into the DSP and using that input channel for factory EQ shaping, then I run the signal out then back into another input so I have separate EQ for acoustic tuning.

Note that when taking measurements, I will likely use a microphone array to alleviate the nulls and peaks that occur with a stationary mic.

[keep_hope_alive]

Almost done with the door speaker brackets, they weigh about 10x as much now and are acoustically dead. Just need fasteners, will be using 6-32 bolts. This is also a view of the drivers being used. Hertz is my go-to speaker manufacturer and what we have here is a ML28 tweeter, HL70 midrange, and ML165 woofer for a front 3-way. The HCX-690 will go in the rear deck but will be turned off for windows-up SQ listening with an excellent sound stage, and the rear 6x9 will be engaged for windows-down louder listening without a focus on a sound stage. I'm excited to hear what the rears can do when they are that close to the rear glass. The challenge is that I'll need to build enclosures for the rear deck speakers so the subwoofer doesn't manipulate them. It's a lot of work for something that will usually just be off.




Ready to start treating the floor:

[The Zebra]

Very nice build log Keep, excellent photos and information. It's going to be an amazing sound system

[SWRocket]

Originally Posted by keep_hope_alive

Certainly. I have 1/3 octave measurements of road noise before (fully stock) and will do a follow-up afterwards, with video and narrative on my YouTube channel. I will also have detailed videos of the entire install process on my channel.

I will be taking RTA measurements of the factory amplifier output (I use a LOC to convert the output to low level then run into a soundcard to see what the stock EQ curve looks like). Then I use the DSP to flatten that prior to doing any acoustical tuning. This is done by bringing the signal into the DSP and using that input channel for factory EQ shaping, then I run the signal out then back into another input so I have separate EQ for acoustic tuning.

Note that when taking measurements, I will likely use a microphone array to alleviate the nulls and peaks that occur with a stationary mic.

Would love to see the mic array measurements. I use moving mic method with a UMIK-1 so it will be very interesting to see the comparisons.
I find that the passenger side MB (GB60 for me) has a huge cancellation at around 520Hz and both MB have a cancellation at 110Hz and 400Hz

Following you on DIYMA as well

[Kamero6]

Originally Posted by keep_hope_alive

Almost done with the door speaker brackets, they weigh about 10x as much now and are acoustically dead. Just need fasteners, will be using 6-32 bolts. This is also a view of the drivers being used. Hertz is my go-to speaker manufacturer and what we have here is a ML28 tweeter, HL70 midrange, and ML165 woofer for a front 3-way. The HCX-690 will go in the rear deck but will be turned off for windows-up SQ listening with an excellent sound stage, and the rear 6x9 will be engaged for windows-down louder listening without a focus on a sound stage. I'm excited to hear what the rears can do when they are that close to the rear glass. The challenge is that I'll need to build enclosures for the rear deck speakers so the subwoofer doesn't manipulate them. It's a lot of work for something that will usually just be off.




Ready to start treating the floor:

Every time I look at this sealant applied on the floor / metal sheet of the car (by a robot most probably), I think the factory does it for acoustic reasons? Am I right? Or it's just my imagination?

[keep_hope_alive]

Originally Posted by Kamero6

Every time I look at this sealant applied on the floor / metal sheet of the car (by a robot most probably), I think the factory does it for acoustic reasons? Am I right? Or it's just my imagination?

You are correct, I believe it is to provide stiffening to break-up structural modes - it changes resonance so it is less offensive/problematic. It doesn't behave like "deadner" because has hardened and lacks viscoelastic and elastomeric properties. That said, I would expect some structural resonance to be reduced when compared with/without.

We saw the attempt at "deadener" in the doors along the outer skin (the stuff that I just peeled off).

[Kamero6]

Originally Posted by keep_hope_alive

You are correct, I believe it is to provide stiffening to break-up structural modes - it changes resonance so it is less offensive/problematic. It doesn't behave like "deadner" because has hardened and lacks viscoelastic and elastomeric properties. That said, I would expect some structural resonance to be reduced when compared with/without.

We saw the attempt at "deadener" in the doors along the outer skin (the stuff that I just peeled off).

Thanks for confirming. It would act as if thyou stick a weight in the cone of a speaker (roughly speaking). It would change the frequency and amplitude of the sound.

Isn't the dynomat effect also the weight that adds to the panel? the thicker and heavier the better?

I can imagine they might have equipment to measure a "sound heatmap" to be able to determine in which places apply the sealant.

[keep_hope_alive]

Originally Posted by Kamero6

Thanks for confirming. It would act as if thyou stick a weight in the cone of a speaker (roughly speaking). It would change the frequency and amplitude of the sound.

Isn't the dynomat effect also the weight that adds to the panel? the thicker and heavier the better?

I can imagine they might have equipment to measure a "sound heatmap" to be able to determine in which places apply the sealant.

Adding weight alone just changes the resonant frequency, but doesn't reduce the duration of the resonance. A constrained layer damping product works using two pieces - the elastomeric damping product (the soft, sticky stuff) is constrained from moving by the aluminum layer. The compliance of the damping product, when properly tuned with the constraining product, is what determines performance.

I have used acoustical cameras before, and am trying to build a 360 acoustical camera with low frequency resolution. I agree that they likely determined what and where, using as little product as possible.

[keep_hope_alive]

Been busy, but made a bit more progress getting the front door midbass speakers installed. Used 6-32 bolts and nylon locking nuts and washers, all stainless steel.

Gasketing options, I choose what makes the most sense for the application.





Ready for mounting to the door: