I did fast rings and some road kill sound deadening in the doors and it made a big improvement. There are some bad frequency issues without it. I went with the Kenwood dsp and infinity speakers with a kicker 12" enclosure. Huge, huge improvement. I used an rta and a mic to tune, without doing this it will still sound mediocre. So even if going with the dsr1 you should study up and try to tune with a mono pink noise track. Don't jump to music and tune, stick to the noise track and reign in those frequencies. It will be worth your effort I know because the first time around I didn't understand crossover and slope very well and ended up jumping to music after a bit and it wasn't very good at all. Started over and now it just flat out kicks ass.I wanted to start a new upgrade thread for the Alpine 6-speaker amplified system (276 watt amplifier). This will contain lots of details that I either couldn't find in other threads or found conflicting information in other threads. At the very least, it will put all of the information in a single post. This is NOT an installation "how to" though - there are some other really good posts for that already. Although, I do include some noted about specific issues I ran into with the speakers I used and some solutions/work-arounds.
I wanted to get a few things out of the way before I start. First, as best as I can tell, the amplified Alpine system appears to be using a 6-channel amp. I believe that the radio feeds the amp with 4-channel audio and then the amp outputs 6-channel audio to 6 different speakers. The dash speakers only play mids/highs, the door speakers only play bass and the rear-deck speakers seem to play full audio. However, I cannot be 100% sure of this - this is just what I've gathered based on the Chilton wiring diagrams and the fact that there doesn't seem to be any "in-line" capacitors or crossovers.
First off, let's start with what speakers the systems comes with from the factory...
Front Dash: 3.5" paper-cone midrange/tweeters - ~2.5 ohm
Doors: 6"x9" bass speakers - ~2.5 ohm
Rear Deck: 6.5" midrange speakers - ~2 ohm
So all factory speakers are between ~2 ohm and ~2.5 ohm (measured with multimeter). The 3.5" dash speakers are the only speakers that use a cheap paper cone. All speakers are single-cone speakers. There are no actual tweeters or any 2-way speakers from the factory.
Before I replaced the door speakers, I bought a simple $12 speaker polarity tester. Since I was seeing conflicting information about which speaker wire adapters to use, I wanted to be 100% sure the polarity was correct as I replaced the speakers. For example, some threads said you needed the Metra 10-050 adapters while others said they used the Metra 72-6514 adapters. Both of these adapters will "fit", but they are reverse in terms of polarity.
So after I replaced the first door speaker using the 10-050 adapter that Crutchfield sent with them, I tested the polarity and found that it was reversed! So then I checked the other door, which still had the stock speaker and is was normal polarity. That tells me that the 10-050 is the wrong adapter to use for the doors in the Challenger - we should actually be using 72-6514 for the doors.
Then, before I went any further, I tested the polarity of the dash speakers - and found that both the stock speaker with no adapter and the aftermarket Infinity speaker with adapter were reverse polarity! So is seems that the dash speakers come from the factory setup for reverse-polarity.
Then I checked the stock rear-deck speakers - they were normal polarity. However, the door and rear-deck speaker wiring is "flipped" - so you actually need different speaker adapters for the doors and rear deck in order to keep the polarity correct on both (this is all confirmed in the Chilton wiring diagrams as well).
Here are the correct speaker adapters needed for my 2018 Challenger (in order to retain the polarity of all speakers as they come from the factory):
Dash: Metra 71-039c (old) or 72-7902 (new)
Door: Metra 72-6514
Rear-Deck: Metra 71-050
I went with the following replacement speakers:
Front Dash: Infinity Reference REF-3032cfx - 3.5" two-way speakers - ~3.5 ohm
Doors: Infinity Reference REF-9632ix - 6"x9" two-way speakers - ~3.5 ohm
Rear Deck: Infinity Reference REF-6532ex - 6.5" two-way speakers - ~3.5 ohm
The dash speakers installed without issue.
The door speaker would not fit in the stock speaker mounting bracket that Dodge uses to attach the speaker to the door - the Infinity speaker basket hits into indentations on the mounting bracket that appear to send water away from the speakers. I have seen that others have "modified" the mounting bracket with a dremel to work around that issue. Personally, I wanted to avoid hacking up the stock mounting bracket, so what I did was to install the included spacer on the back of the speaker instead of on the front of it like most people do. So there was the speaker, the spacer and then the stock mounting bracket (see pic below). This pushed the Infinity speaker out a little further and made it fit in the stock mounting brackets without issue. It also allowed the stock speaker mounting bracket to offer better "protection" of the speaker since the back of the speaker doesn't stick out any further into the door than the stock speaker did (normally, since the aftermarket speaker is "deeper", more of it would stick out of the back of the stock speaker mounting bracket - it would actually stick out past the end of the bracket a little). Only problem was that the screws included with the speakers weren't long enough - but I found screws that came with the REF-6532ex speakers that worked perfectly.
The rear-deck speakers come with an adapter plate that is used to mount it. The stock speakers mount via a 3-screw system, whereas most speakers mount with 4 screws. So basically, you attach the adapter plate to the speaker first via 4 screws - and then that whole adapter/speaker assembly attches to the rear deck using the 3 stock mounting holes on the rear-deck. However, this didn't work out so well... The screws that they give you to attach the speaker to the adapter plate are a little too long - so when you install the adapter plate onto the speaker, the pointy screws stick out on the bottom of the adapter plate, which then "interfere" with rear deck when you try to install the adapter/speaker assembly onto the rear deck (the tips of the screws hit the rear deck metal, not allowing it to sit flush on the rear deck)! You would actually need to drill holes in the rear deck to use things as-is. I ended up just "shortening" the screws with a dremel (all 8 of them), which allowed the adapter plate to sit flush on the rear deck for proper mounting. No idea how others have been handling this issue. Was very frustrating, to be honest - especially since Crutchfield lists these speakers as fitting properly. Between that and the wrong speaker wire adapters they provided for the doors, I was a under-impressed with Crutchfield. One of the reasons I buy from them is to hopefully avoid issues like this... I will let me know my findings though.
I also bought some "Fast Rings" to use for the door and rear-deck speaker install (first time trying them). Honestly, I'm not so sure they are worth it, at least for this car. They come with 3 parts - a "backing" part that is supposed to attach to the outside door panel behind the door speaker, a foam ring to use between the speaker and the door mount and a larger foam ring that goes around the whole speaker itself to "seal" the area between the front of the speaker and the door speaker grille. I didn't use the "backing" part since there was something in the way behind the speaker (and I was concerned about it retaining water). I didn't use the ring that is supposed to go between the speaker and the door (just didn't make sense in this install). I did, however, use the largest ring to help seal the speaker and the door panel so that less sound "escapes" into the door. Not sure how much of a difference it makes. I used that same larger ring for the rear- deck speakers as well, but again, no idea how much difference it makes. Not sure they are worth the $20 cost for each set of fast rings...
I did not buy all of the speakers at once. I bought them here and there when they were on sale and when I had the money.
I upgraded the 3.5" dash speakers first. The Infinity speakers had much higher-quality cone materials and were two-way speakers instead of a single-cone paper speaker. The dash speaker upgrades made a pretty noticeable improvement including much better highs. In my opinion, the stock dash speakers should have included dedicated tweeters from the factory.
A few weeks later, I upgraded the 6"x9" door speakers. I was expecting cheap paper-cone speakers based on what I found in the dash, but the door speakers were much better made and used a higher-quality (non-paper) material for the speaker cone. The door speaker upgrades gave me deeper, less-boomy bass. I even noticed that my side mirrors vibrated more with the Infinity 6x9's. However, I found that I had to turn the bass up a little more since they were less "boomy"- but the end result is deeper, more accurate bass.
Then, a few days later, I upgraded the 6.5" rear deck speakers. Again, I found that the stock rear-deck speakers were made with decent materials and had a decent weight to them. I actually think that the stock speakers weighed more than the Infinity speakers that I replaced them with - even the magnet was slightly bigger on the stock speakers. However, that being said, the rear-deck speaker upgrades provided the biggest difference of them all! The stock speakers were barely noticeable, even when I faded the sound to the rear a little. With the Infinity speakers, I had way more sound from the rear - and highs that just didn't exist from the rear at all before. I actually had to fade the sound towards the front a little to avoid having the rear-deck speakers overwhelm the front speakers! Huge, huge difference. They also seem to add to the overall bass a little as well.
After replacing all speakers, I had to adjust the EQ and fader settings substantially. Typically, I would have bass at +3, mids at 0 or +1 and treble at +2 or +3. With the Infinity speakers, I have bass +4, mid -2 and treble -2. However, I have only spent a small amount of time in the car since replacing the door and rear-deck speakers, so the EQ and fade settings may change over time as the speakers break-in and I spend a little more time with them. The overall sound definitely got way brighter - especially when the rear-deck speakers were replaced.
Honestly, I don't feel that I have enough control over the sound with simple bass/mid/treble and a fader control. I think that I will eventually be bypassing the stock amp and using some type of processor and external amp(s) in the near future. Right now, I'm leaning towards a Rockford Fosgate DSR1 w/t-harness and some external amps - not sure if I want to go with a a single 6-channel amp for speakers and a separate monoblock amp for a sub or multiple amps (such as a 4 channel amp for front speakers and 3 channel for rear speakers + amp). But ultimately, I want more control over each channel, such as being able to adjust crossover points for each speaker, better EQ and separate gain control for dash, door and rear-deck speakers. I think that the stock amp is EQ'ing based on the limited power of the stock amp and the limitations of the stock speakers - and that I can get MUCH better sound quality if I am able to modify the crossovers, EQ and gain on my own, separately for each channel. Of course, doing that is going to cost me lots of $$$ and time. A little at a time though...
I would love to get some input on peoples experience with the DSR1 and what amps you would recommend. Originally, I wasn't planning on going this far, but don't think I'd be happy with a simple 4-channel amp with only bass/mid/treble and fader controls. I need more control.
Chilton Wiring Diagrams:
Select Repair -> Wiring Diagrams -> Components -> Speaker to see speaker wiriing diagrams
Speaker Polarity Testing Tool (highly recommended!):
https://www.amazon.com/gp/product/B07MQ55QHL/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1 (available many places, but can get "free" 1-day shipping with Prime.