[jtrosky]

I have a 2018 Challenger with the Alpine 6-speaker amplified system.

Originally, I took the cheap route and went with a Rockford Fosgate DSR-1, which handles the OEM integration as well as the DSP aspect in a single box - and it's only ~$260. While it works and it a great price for the amount of functionality you get, the tuning app is mobile-device only and it pretty limited when compared to a "real" DSP.

I also originally replaced all 6 speakers with Infinity Reference speakers.

I've since replaced the DSR-1 with the PAC AmpPro for integration and a Helix DSP.3 for DSP. This combination is WAY better than the DSR-1 solution - but it's also WAY more expensive. Instead of ~$260 for the DSR-1, it's about $250 for the AmpPro and the Helix DSP.3 retails for $700. However, the Helix is a top-of-the-line DSP. I bought mine from an out-of-country Ebay seller for $535 shipped.

I also replaced the Infinity Reference speakers with Kenwood Excelon speaker - and what a difference they made! The Kenwood KFC-XP6903C component set is a "drop-in" set that is made for Dodge vehicles (and a few others with the same setup). It comes with 6x9 midbass speakers for the doors and a 3.5" coaxial for the dash. Once tuned with the DSP, the speakers sound fantastic. I also put the KFC-X174 6.5" coaxials in the rear deck. Again, MUCH better than the Infinity Reference speakers they replaced.

As good as the Kenwood setup sounds, I've been buying up some "high-end" speakers when I find good deals - and will be replacing the dash speakers with some Illusion Audio C3CX point-source coaxial speakers (~$900) and some CDT Audio 6x9 midbass speakers. Honestly, I probably shouldn't even mess with it, because the Kenwood speakers sound fantastic, but I like exploring some of the "higher-end" options. I'm deep in the car audio rabbit hole right now.

Lastly, I didn't want a "real" sub, so I went with a JBL BassPro 8" under-seat powered sub. Believe it or not, with the Helix and it's "Augmented Bass Processing", I have that little self-powered sub playing down to 35hz cleanly - pretty impressive for what it is.

I'm powering the dash, door and rear-deck speakers with the JL Audio XD600/6v2 (6x75W RMS at 4 ohms). It does an excellent job and the system gets louder than I can play it at.

I would NOT mess with summing and all of that crap. It's much easier (and you'll get significantly better results) with the PAC AmpPro 4 device. It basically just gives you clean line-level outputs from the stock head-unit. It also supports an optical digital output. I'm using that optical output going to my Helix DSP.3 and I can say that it's well worth it. Nice clean signal with no noise - all with a single, thin optical cable.

I have a thread on how talking about my install in detail (in the audio section). I have everything installed in the trunk spare-tire well. Picture below.

Amp board is secured to the spare-tire hold-down bolt - so I didn't have to drill into the car body at all. Worked out REALLY well. Again, more details in that audio thread.

Hope that helps - don't hesitate to reach out if you have any specific questions.


EDIT: If you want a "real" DSP, but don't want to spend the $$$ for a Helix, the Dayton Audio DSP-408 is the best on a budget. I think it's about $150 new. No digital input though.

 

[jtrosky]

With all that said, I will list my system that is more of an SQ setup but has a good amount of SPL. I do have a 2015 STR with the HK system not the Alpine so keep that in mind.

Pac from the head unit AP4-CH41
JL HD900/5
CDT HD 6x9 mid bass in the doors (playing 60hz up to about 800ish)
CDT Unity 7.5 in the factory dash location (800ish and up)
CDT Unity 7.5 in factory rear side locations but have turned them off (just running front stage)
CDT CH-2 2" center channel passive with volume control on crossover (combined with the front channels)
CDT MX-1000 crossovers for front stage
JL 8W7 in ported enclosure with volume knob next to gear shift. (super important)
Dynamat extreme everywhere but ceiling as it was too much to get to.(at least 2 bulk pacs)
Lizard skin spray sound deadening where I couldn't get to with Dynamat (wheel wells inside)
Street Wires cables
Host of Steve Mead products for setup and gain adjustments
Hours and hours and hours of adjusting crossovers to get leveled and blended

I'm curious what you think of the CDT speakers. I'm in the process of installing the CDT CL-69S midbass speakers in my doors today (replacing the 6x9 midbass speakers from the Kenwood Excelon KFC-XP6903C component set, which I have to say, provide some really good, deep midbass. With only an under-seat sub, I'm playing the midbass speakers pretty low (I'm running fully active) to help compliment the under-set sub - and I'll tell you what, those Kenwood midbass speakers are impressive. I'm currently high-passing them at 45hz (24db Linkwitz-Riley slops), believe it or not and they sound fantastic that way! Originally, I was high-passing them at 65hz - but found that running them down to 45hz works so much better in my setup.

However, I just wanted to try something else and CDT had a sale last month - only $99 for a pair of the CL-69S midbass speakers (slim, 2-ohm, carbon-fibre midbass speakers). I liked the idea of running 2-ohm midbass speakers as well to get a little more power to them from my amp (although, I really only gain 25W RMS by the switch from 4-ohm to 2-ohm speakers with the JL XD600/6v2).

Anyway, like I said, I'm curious what you think of the CDT speakers in general. I'm hoping they will handle the midbass as well as the Kenwoods, if not better.

Also - are you running a DSP at all? For me (my first DSP experience), a DSP just provides so many benefits - but does take a LOT of time to learn to tune properly. I learned Room EQ wizard and got a decent measurement MIC (MiniDSP UMIK-1) - I have learned SO much about audio while tuning the DSP. Such a rewarding experience.

Like I mentioned, for those on a budget, I think you'd be hard-pressed to find a better set of speakers than the Kenwood Excelon KFC-XP6903C - especially if you have a DSP. They were my first Kenwood speakers and I was really impressed with them. I'm crossing over the door 6x9's with the dash 3.5" speakers at 450hz (24db Linkwitz-Riley) and that really keeps the stage up high and with the DSP.3 tuned well, the staging and sound-quality is excellent.

 

[jtrosky]

Yeah, it's almost impossible to replace the head-unit in the 2015+ Challengers (while still retaining all functionality). Luckily, the stock 8.4 head-units are actually pretty good in terms of functionality (supports all sorts of file formats (FLAC, WAV, MP3, etc), iPods, USB, aux-in, XM, HD radio, etc.

At least for now... However, five years from now, there will probably be some new "best" format and we'll basically be SOL at that point - without an upgrade path (since you can't just plop in an aftermarket head-unit) - unless someone comes up with an aftermarket unit that supports ALL stock features.

It is what it is, I guess. You really can make these stock head-units sound awesome with the AmpPro device, a DSP, an amp and some good speakers though. DSP is the way of the future. They are so powerful now - and easily obtainable now. You have almost unlimited control over the sound (phase, time alignment, EQ, speaker levels, etc). The Helix DSP.3, for example, has over 240 bands of parametric EQ (30 bands per channel). Compared to the 3-bands of "global" EQ with the OEM Bass, Mid and Treble control. HUGE difference. TIme alignment really makes a huge difference as well.... Good stuff.