I really enjoy learning about this car. I probably wouldn’t be putting in so much time if I thought my next car would be anything other than a Stelvio. But since I'm certain I'll eventually upgrade to a newer Stelvio, it all feels worth it - I’ll just transfer everything I've learned and set up to the new one

 

Finally finished my first amp rack! It took a lot of hours to get here. The empty space is reserved for a 3rd amp, but I'm still deciding whether to install a simple amp for rear fill or go with a better amp for the front stage while using a few channels from the P6 for rear fill. Any opinions on this?

 

yeah niiiice

 

Let’s cut some holes for the midrange speakers in the door panels!

The Gb25s are slightly larger than these holes were originally designed for, but these drivers are among the best you can buy in this size. For the grilles, I chose to use OEM ones from the higher-tier Harman Kardon system because of the uneven and asymmetrical surface. Although the outer diameter of the grille is 80mm, the inner opening is much narrower. This means I'll need to set the driver further inside, as there isn’t enough clearance at the corners to mount it close to the grille.

Now it’s time for custom 3D-printed adapters!

 

I need some advice on choosing the best approach for my 3rd amp setup. I’m considering several amps and configurations:

1. Helix M Four (using only 2 channels): This would drive the rear fill where I currently have OEM 2-way passive speakers.

2. Helix M Four (bridged to 2x200W @ 4 ohms): All power would go to the GB60 midbass, and I’d use the remaining channels from the P6 to handle the rear fill.

3. Helix P Two (2x280W @ 4 ohms): This would power the GB60 midbass, leaving the P6 to drive the rear fill.

Which option would you recommend, and why? Would it be worth paying 2.5x more for the P Two compared to the M Four if it’s going to be used to power the midbass?

 

I need some advice on choosing the best approach for my 3rd amp setup. I’m considering several amps and configurations:

3. Helix P Two (2x280W @ 4 ohms): This would power the GB60 midbass, leaving the P6 to drive the rear fill.

Which option would you recommend, and why? Would it be worth paying 2.5x more for the P Two compared to the M Four if it’s going to be used to power the midbass?

Absolute dream combination!

I have just sold one of my P Two, but only because I dont need 2 of them for my system

 

Nice work!! What's the purpose of running power through a solid bridge to then fuse outside the block?

 

Thanks! Since there's no low current rating mini ANL type fuse available, and using a high rating mini ANL fuse for just a few centimeters of cable before another fuse is pointless, I replaced it with a solid bridge and added a 1A blade type fuse externally for the Audison B-CON

 

Really enjoying this build!

 

Glad to hear that! 😊

 

yeah nice work with the mids

 

Thanks! 😊 Well, I'm not very happy with the driver placement - in my opinion it's a little too deep, they'll be quite off-axis from the listening position, and the grill itself is slightly narrower than the speaker. Unfortunately, there's not much I can do about it since installing a different, larger grill isn't an option due to the uneven surface and limited space there. I'm not expecting great RTA results, but we’ll see

 

I finally printed the custom 3D rings I designed for the midbass and midrange speakers in the doors and performed some initial fit checks and measurements. They fit perfectly, everything is aligned, and there are no issues. For anyone planning to install the GB60 in their Stelvio, I've checked the clearance at the back with the ring I made. Here are the details:

With a ring height of 23.5mm and the GB60 installed, you will have 1.5mm of clearance at the back. Therefore, 23mm is the bare minimum height leaving 1mm of clearance. I recommend to install the GB60 as deeply as possible to maintain clearance with the grill. Audiofrog suggests 12mm from the rubber to the grill, however, because the grill is uneven and tilted, I found that in one small section, the clearance reduces to just 5mm. Unfortunately, there's nothing that can be done about this limited clearance. A user from the Stelvio forum, who has been using the GB60 for some time, mentioned that the rubber never contacts the grill.

They're a bit deeper than I'd prefer. Unfortunately, there's not much I can do about it since I can't move them closer to the grill due to the narrower grill, uneven surface, and limited clearance in certain areas

 

Just want to say that's a very nice build! Nice to see someone else from around here doing stuff other than just big subs.

 

Very nice, please where did you find oem Harman amp female connector?

 

I bought a used wiring loom with a connector from a donor car. The part code is 50551829, and you can find it on eBay.

 

Just a simple question, Stelvio MY2020, base audio system, all speakers are 4 ohms?

 

I think the door speakers are 4 ohms, but I'm not sure about the tweeters. I'll update you on this

 

I've finally installed the P Two on the rack and redone some wiring. The tweeters, midrange, and rear are now on the P Six, while the midbass is handled by the P Two. I also changed how the P One Mk2 is connected - it's now using the analog mono (L/R sum), while the P Two is connected via SPDIF

 

Installing the Audiofrog GB60 & GB25 in the doors. I did this a while back but just now got around to sharing it.

Before I installed GB60, I used speaker foam tape on both sides of the midbass mounts

Now the Audiofrog GB60 drivers are in the doors. You can also see a cable with an XT60 connector ready for the midrange in the door panel. I really like these XT60 connectors and highly recommend them. By the way, I have to mention that I really dislike the Audiofrog terminals. They pinch the cables at the very end, making it tough to attach them securely. Instead of using ferrules, I decided to solder the cable ends to make them thicker, especially at the ends

Here’s the other side

I used foam rings to fill any gaps between the door panel and the speakers. These rings are from the Stinger Road Kill RKFR6 set.

I also added some CLD and CCF material in flat spots, especially behind the midrange in the door panel.

I also made some changes to the door panel for the midrange installation. I used thread inserts for a better fit and cut away any extra plastic that was blocking the foam ring

Here’s the GB25 ready to go with a foam ring and XT60 connector

And here’s the Audiofrog GB25 installed. I made sure there are no gaps around it thanks to the foam ring

Overall, I’m really happy with how it turned out!

That's it for now! Just a quick update: I ordered the Stereo Integrity SQL 12 subwoofer last December and I'm currently waiting for it to arrive. While it's on the way, I’m collaborating with a local audio shop to create a custom fiberglass enclosure that looks fantastic, complete with a custom grill and other features. Stay tuned for more updates!

 

Great job, thanks for sharing, greetings from Crotia.

 

Can you tell me how you got the audison bcon to work with the helix amplifiers. Are the only wires you used remote, power and ground? And of course optical?

 

Yes, you're correct. These are the only wires you need. Additionally, you'll need a Conductor for volume control because you want to use Bcon in absolute volume mode, with attenuation occurring on the DSP side, not your mobile phone.

 

Made a custom 3D printed case to fit the Conductor perfectly in the 12V socket. The white ring and the black surround you see were both reused from the OEM 12V socket, which originally featured white illumination. I designed a custom 3d printed casing to hold everything in place and fit to the panel. The 3d casing has "pockets" for led lights so they emit the light only in small sections to acrylic glass I reused from that 12V socket. Additionaly there's another smaller 3d printed ring insert inside to cover remaining acrylic glass surface to prevent from lighting from behing the knob. Very happy with the result.

 

Looks so much better than the normal knob

 

looks very clean indeed I hope you enjoy the new setup

 

A few weeks ago, I finally got my SQL 12. This thing is huge and much heavier compared to my current 8" JL Audio sub. The new sub is already in the shop, and they've started working on a custom enclosure. I can't wait for the custom box to be finished and installed - I have a feeling it's going to be insane!

And here's a small hint of how the subwoofer grille is going to look.

While waiting for the sub, I did a system tune using the old JL Audio 8" in an MDF box just to check how the front stage sounds and confirm that everything is working properly. The system already sounds amazing and hits hard - it's a night-and-day difference compared to what I had before. The 3-way setup makes a huge difference, and those Audiofrog GB60 midbasses are just unbelievable, delivering insane midbass even while installed in the doors. Looking back, the Focal Flaxes were a joke, to be honest. Even the OEM speakers had better midbass than the Flaxes.

What also surprises me is how the GB25s are delivering such a linear response despite their installation location - completely off-axis, especially on the left.

 

What do you have the LPF set to for the GB25s? Based on measurement data, they are omnidirectional up until around 5k.

 

@alfaowner, could you please tell me how hot the P-ONE MK2 gets compared to the P-TWO? Is it just as much of a “flat iron”?

 

The P One Mk2 always stays cold, it doesn’t even get warm, no matter how long or how loud you listen. The P Two gets slightly warmer, but it still only reaches a maximum of around 30C (not reaching human body temperature for sure)

The P6 also stays completely cold, just like the P One Mk2. Of course, this might change if the P One Mk2 is used at 1 ohm with an SQL 12.

 

Hmm… My P-Two has always heated up to a level where it’s difficult to keep my hand on the case for more than 5 seconds since I bought it. Pretty much the same thing happened with my P-ONE MK1, but I ended up selling it

 

Interesting. I had similar overheating issues with my previous Audison Forza amplifiers to the point where they were unusable, and I eventually had to return them.

I was surprised that these Helix amps don’t even get warm.

What speakers did you use with the P Two and P One?

 

I love this build so much. How much for a copy of that sub adapter?

 

It's been a while since my last update. I've done quite a few upgrades but didn't have time to post them. I'll try to share everything over the next few weeks

Let's start with the Conductor. This one was tricky. The 3D printed mount I initialy made was too deep, so the panel wouldn't fit back into the console - it was hitting the console structure.

After tweaking the design and reprinting a few times, I finally got it to fit

This was honestly one of the most painful parts of the whole build - super tricky and frustrating to get right.

Since the center console was out again and again, I took the chance to run the optical cable from the back to the armrest where I have SMSL PO100 converter. Since I don’t notice any difference between LDAC and optical, I mainly use it for measurements now.

Btw, the P6 Ultimate has only one SPDIF input, but the B-Con has another optical input, and while it's not streaming, it passes that optical input through to the P6. That way, you can effectively have two optical sources instead of one.