After many attempts to tune the system, I decided to upgrade by installing a separate, powerful monoblock amplifier specifically for the subwoofer. I now believe that DSP amps should not be used for subwoofers, regardless of their power ratings. The EQ on this thing was too "hot," making it impossible for the sub to be effectively integrated into the system.

I chose the Audison M1D to match the setup. After installing a separate amp, I plan to bridge channels for the front midbass. Additionally, I purchased a B-CON streaming device to bypass the limitations of the car's infotainment system. I am also waiting for the DRC AC so I can retain volume control after installing the B-CON.

So stay tuned, more update to come..

 

2024-08 DRC AC Install

The DRC AC fit perfectly in my car. It's quite a coincidence that the shape of the 12V socket perfectly matches the DRC AC knob. I just had to make the mounting hole slightly bigger with a Dremel. It was quite a challenge to access the panel and run the cable to the back, requiring me to remove the entire center tunnel and rear seats. It was one of the toughest parts of the project, but I'm really pleased with the result.

Before:

After:

 

That's worked really well

 

Cleeeeean brother nice job

 

maybe the most stealth look I have come accross so far looks fanstastic

 

Did you have any issues with the radio being load sensing? Did it need to see a resistance to output sound?

 

No, I don't have any issues because Audison includes a circuit on the high-level inputs to simulate the speakers. Afaik, Helix DSPs have that too. In my car, resistance isn't required for sound output. However, without the proper resistance, the car detects a fault in the sound system, which triggers an annoying error on the dash. However, as I mentioned, this issue is addressed in the DSP, and no errors are thrown.

 

I'm not sure where to start. The recent road trip with my car, and dealing with the constant overheating both Audison amplifiers - along with the distortion and cutting off of channels - was the last straw. This is definitely going to be the end of my journey with Audison. I've already spent too much time trying to make them work, but it's clear that they’re just not made for this.

If you're interested, I've shared more details about the issues with these amplifiers here: https://www.diymobileaudio.com/posts/6297646/

And here are some last photos of the installation that I didn't have time to share:

What's next? The plan is to switch to Helix P 6 Ultimate, Helix P One Mk2, and Conductor (yeah, it's quite disappointing that I spent so much time installing the Audison DRC AC). I'll probably keep the B-CON, as it's the only product from Audison that works well.

 

I am doing the same. Getting rid of my F8.9 Bit and moving onto a Helix M Four DSP. Audison software interface is very lackluster. You gain so much more tune ability with the helix line.

 

Well, I have to say that their new software BitDrive for the Forza DSP amp line is quite good, especially the latest version. You're probably referring to bit One.

 

I think the trial and error/learning session is also alot of fun for the hobbiest of this field, just part your way as you stated and dont even look back I can highly praise for Helix and especially the Helix P Six for being a ballsy,durable and dsp wise capable monster I think it is definatley a good pick.

 

While waiting for Helix, here are some updates from the past. One major problem with my system was the front tweeters installation, as I decided to use the OEM locations to maintain an OEM appearance, which was a compromise. Previously, the tweeter was installed about 1.5-2 cm deep from the top, sitting under the factory grill. This caused strange cancellations, likely due to the distance to the grill and the thickness of that grill (2-3 mm), which resulted in a bad top-end.

To address this, I decided to buy some second-hand spare tweeters I could modify. I cut the grill out, moved the tweeter as close to the top as possible, and used some speaker grill cloth for a proper look. Please take a look at the process:

I used a silicone to glue the tweeters to the mount

1 - after, 4 - before (from the top)

 

The Helix amps should arrive next week. Last week, I received the 9L sealed MDF box for the sub, made by Basser specifically for my car. I decided to completely replace the OEM flimsy plastic enclosure with the MDF box. The only thing I'll need to replace in order to install it is the trunk trim, using the trim from the base model instead (which didn’t have a factory subwoofer)

 

That looks very nice! How do you like those tweeters?

 

They sound nice and natural as long as you don't compromise on their location. Based on my distortion tests, they should handle down to 2.5kHz without any issues. Since my front setup is 2way, I'll try to set the crossover as low as possible

 

Thanks. I have some Focal speakers in my Atlas and was thinking about putting a set in my Mercedes E550 and was looking at the FRAK tweeter.

 

2024-10-15 update. Preparing the subwoofer for install

I decided to replace the terminals with something more reliable, as the existing ones were poorly made and the spade terminal barely made contact with the metal

Before:

After:

After putting the terminal cup back I sealed it from the inside to prevent any leakage

To secure the subwoofer in place without worrying about damaging the MDF, I decided to use threaded inserts instead of screws. This will also allow the subwoofer to be removed as many times as needed.

And here's fully assembled sub ready to be installed

Obviously, I checked how it fits in the trunk with the new trim I recently purchased

The only concern left is figuring out how to secure it in place. I already tried using Velcro, but for some reason, it won't stick to the subwoofer lining.

Another potential issue is that I might still need a bigger subwoofer, as this one may not provide enough output. However, I'll wait and see how it performs with the new amp and this new, more rigid enclosure, which is closer to JL Audio's volume requirements.

I already have some ideas for a 10" subwoofer and have found someone who can help me make it from fiberglass.

 

Finally got my Helix amps and Conductor. More updates coming soon. Sneak peek: I decided to go 3-way!

 

very nice, lot of grunt in that P One for the 8" !!

 

I no longer want to make compromises because in the end you just hit a wall just like I did with all this Audison gear. I wanted it to be future proof, keeping in mind that I might eventually upgrade the sub to a 10" or even a 12". By the way, this JL sub isn't performing well and isn't delivering the proper output with the recommended amp power of 250W

 

yeah IMO you're into a 12 or pair of 10s in a car like that.

My alfa QF had a JL 12TW3

 

Yeah, now I know! 😄 How was it? Did you like it?

 

Yeah it was decent enough, run it in my Cayman now which it's more ay home in.

seen this build?

 

I saw this build, but installing midrange speakers by removing two air vents and blocking access to the car battery with the amp rack on top seems a bit odd. They also forgot to add supports for the trunk floor on the rack (or the amps serves as the support?). By the way, I'm currently working on my own amp rack, but I plan to leave a cutout for easy access to the battery.

 

The custom amp rack is finally finished, and now the fun part wiring everything together is left. The result turned out better than expected, especially since this was my first time doing upholstery work.

 

Nice work.

 

Since I decided to go with a 3-way setup in the front, and I'm not satisfied with my Focal midbass, I decided, after extensive research and measuring clearances, to go with the Audiofrog GB60 and GB25. Later on, I might upgrade the tweeter to the GB10 if I feel it's necessary.

For the midrange, options were limited because my plan is to install it in the OEM dedicated space in the door panel, which only fits 2.5" drivers. The GB25 is probably one of the best 2.5" options on the market.

It was a bit challenging to buy this Audiofrog set here in Europe, but with help from Audiofrog, I managed to purchase them from a dealer in Germany and have them shipped over.

I'm very excited to install them, but I still need to finalize measurements before sending the 3D model for custom print. I’ve already made some progress and I’ll provide an update very soon.

 

Preparing cables for the 3-way

I was about to run cables for the midranges throughout the car, but after some investigation, I discovered there were still "unused" cables in the connector at the back of the trunk. After reviewing the Alfa’s service library, I found that these cables are for the midranges in the doors of higher trims with the Harman Kardon system. They run from the back of the car all the way to the door connectors. The only difference is the harness in the doors, where those cables are missing. So, all I had to do was pin a few cables into the door connector, and that was it!

 

love seeing things done right, adding real pins to connectors vs when people cowbox it and just ram a cable through the holes so you cant actually decouple the plug

 

It's a hassle to search for and find the right pins for various harnesses, but it's the right way to do it. You'll almost never find a shop willing to go to this length unless it's a vehicle they do over and over again.

 

yeah the closest you'll see if someone like MusicarNW with their porsche kits