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Discussion Starter #1
In one of the sub woofer discussions, I mentioned the possibility of replacing the rear woofer in the left quarter panel: has anyone had any success (better quality sound) just changing out existing speakers for something other-market, without changing the actual electronics? If so, got an assessment of the improvements in sound and any pictures or helpful instructions or tips?

I don’t really need a thumper, but would like a bit better sounding set of speakers.
 
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I would like to know too.
If only exchange the "speaker" located in the "sub" rear left quarter panel in the trunk area.

For me.. it lack of.. some extra kick "bass" sound.
I considered.. install underseat sub speaker... Any model.. plug and play... That will not interfered with factory car audio system?

Can it be done with « 2 under seat.. in under each front seat and remain the factory sub.. installed and enabled.
 

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Excellent! Thanks.
 

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If you do try to replace that factory sub with something in the same location, be careful.

That thing is a truly horrible design/install. There is not box or enclosure behind the carpeting, it is essentially a free air install with the rigid carpet used as the front baffle (a really bad, inadequate front baffle). The front baffle in a free air install exists to keep the front and rear sound waves from affecting each other, as they effectively cancel each other out. The carpet in the Stelvio will not do that properly...the sub with the system is cheap/underpowered enough that it really doesn't matter, but if you through a nice JL audio, or Rockford Fosgate in there without beefing up that baffle (making sure it is solid and air tight) or putting a box behind the carpeting there is a very good chance that you will wind up blowing out whatever sub you put in there after a few months (depends on how you listen to the music, louder = faster destruction), and it will just sound farty and nasty until then.


The best option is the type of install @ifly4fun did, a powered sub in a box under the floor board....


Seriously, the subwoofer all by itself is probably the single largest piece of money saving BS on the entire car (maybe on any car)....quite possibly the worst installed and cheapest subwoofer ever put in a factory audio system, which is saying a lot...
 

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In one of the sub woofer discussions, I mentioned the possibility of replacing the rear woofer in the left quarter panel: has anyone had any success (better quality sound) just changing out existing speakers for something other-market, without changing the actual electronics? If so, got an assessment of the improvements in sound and any pictures or helpful instructions or tips?

I don’t really need a thumper, but would like a bit better sounding set of speakers.
Yep. Just replaced all the speakers and added a sub, amp and processor without changing the stereo. Sounds amazing. Post all the pics as well.
 

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That thing is a truly horrible design/install. There is not box or enclosure behind the carpeting, it is essentially a free air install with the rigid carpet used as the front baffle (a really bad, inadequate front baffle). The front baffle in a free air install exists to keep the front and rear sound waves from affecting each other, as they effectively cancel each other out.
This is not true. The Stelvio sub speaker is enclosed in non ported box, which is good enough for 150W-200W. The OEM speaker is 100W.
 

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Have you looked at it? Pushed the carpet and watched the entier speaker move around? Put your mouth on the carpet and breathed through it? (Because it is not air tight. The 1st requirement of a sealed box)

Guess my definition of a subwoofer box and theirs are different. I use the one car audio people use for one type of subwoofer enclosure, they use the definition UPS uses for what the sub is shipped in. Both are sealed boxes..but very different types.

In car audio a box is made from either MDF or fiberglass generally, ALWAYS out of a rigid material that is capable of holding 100% of the air pressure generated by the back wave of the speaker (in the case of a sealed box) without releasing ANY of that pressure to the outside environment. It has an inflexible front baffle for the speaker to mount into so the cone itself can move freely without being affected by any inertia generated by secondary movement of the speaker assembly itself during use. Additionally a good box will be designed to control and absorb that back wave so as the pressure won't affect speaker cone movement. The entier purpose of a sealed speaker box is to contain both the air pressure and vibration of the speaker(s) contained inside.

The Alfa "box" is made out of a peice of stiff carpeting, that is nothing near air tight or inflexible. It is sealed by mounting the carpet to the side wall of the SUV with pushpins. It is not an actual seal and is in no way air tight, especially under pressure. It also allows the speaker assembly to move during use.

While that does create something that meets the technical definition of a "box" that is "sealed, which is obviously good enough for the marketing team at Alfa, it does not make a "subwoofer box." They arent the same thing.

...the sub is a bad joke. Better than nothing, but that is all.

Because the Alfa factory sub "box" is made from a flexible, porous material that allows air exchange...by accepted audio definitions...that makes it a moddified free-air install (and a bad one. With free air, that front baffle must be solid, and allow no air exchange between front and rear waves) not a sealed subwoofer enclosure (or box).

Cause the box isn't actually sealed.

Love Alfa...however the audio system could (and should) be improved greatly by just giving the sub a better installation. Put it in a fiberglass pod..under the carpet. Done, same sub, 100% improved sound probably.
 

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To install a trailer wire harness I had to remove the left panel were the sub is to access the rear taillight. It was plastic and looked all in closed and mounted to the side of the car with 4-5 screws. I wish I took a picture. It looked more engineered and substantial. Never the less it still sucks.
 

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19329

This is the OEM sub. Plastic is ~2-3mm thick and it is not flexible in any way! I've changed the stock AMP and I can say the sub is more than adequate if the OEM speakers are not replaced. The OEM amp is very under-powered (and generally, that is why it sucks), I've replaced it with 8x70W amp and currently with the stock speakers, I am maxing out the AMP and the speakers are holding quite well. I am planing to replace them (and since I have 3 spare channels on the AMP) to create active front line (use the AMP DSP to cross over the speakers), and replace the sub with 2 coil one, so I can use 2 channels on the AMP to drive it. I am not sure if I am going to modify the sub box, probably I will see how it sounds and then decide if I will modify it or leave it as is.
 

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Glad you posted that, it is better than I thought for sure.

And worse in some ways (two speakers grills? Really Alfa, you really need TWO speaker grills on a subwoofer???). But fixable pretty easy...which is far better than expected.

And here I was being all pessimistic thinking it would take a full reinstall. Nope, just needs a poor install fixed. Should be possible with minimal cost and effort. Still pretty inconceivably bad factory install/design though...

The problem isnt a nonexistant box, the problem is a cheap box as well as the sub not being coupled directly to the airspace in the cabin. Instead it is coupled to the airspace behind the carpet...with a hole in the carpet for the sound to get out...sorta.

2-3mm thick plastic doesnt even make a decent speaker box for a portable radio. However, add a layer of dynamat or any of it's competitive products and you'll kill the box vibrations (of which there are alot, this will magnify and tighten bass alot) which are a problem. Doing that would probably be more of an improvment in quality (not volume) than replacing the speaker, especially with fast transients.

Now you have to deal with 2 speaker grills and the gap between the grill on the speaker and the carpeting/grill on carpet..which is the single biggest issue. The speaker grills are minor, but removing the one on the speaker would be good if it can be done without damaging anything.

The empty space between the speaker and the carpet, is basically creating a resonance chamber and is the part that is making the sub sound like a joke. It's essentially like the factory decided to install a sealed box in another room, but perforate the wall so you can hear what's happening inside.

The sound waves generated by the sub are not having an easy time getting out of all that, makes sense why it sounds like the sub is so muffled. I thought it was wave cancellation.

So we need something that will not vibrate easily to fill the gap between the speaker and the carpeting. I'm thinking a solid spacer and/or fiberfill.

The best way to install it would be to glue (or good double sided tape if you want it removable) the spacer to both the speaker and the carpet so the attachment is solid at both ends (again kill vibrations which cancel and/or dampen bass tones). You want a dense material that doesn't vibrate easily, MDF wood works well and is cheap. After that fill any remaining airspace around the spacer with fiberfill. Another possibility may be to glue or use double sided tape to attach the carpet more solidly to the weatherstripping the factory provides on top of that second grill. That wouldn't be optimal but may be enough to get the sub actually coupled to the cabin.

The goal is to make it so the air moved by the subwoofer cone goes directly into the cabin with nothing in it's way, and no empty chambers or anything else creating any sort of vibration or resonance. Which kills the sound, volume and quality.

Turth is, possibly just adding some fiberfill behind the carpeting to fill any airspace back there may be enough to help tighten things up, might not need the wood spacer or dynamat. That's something I'm going to play with for sure. It wouldnt be optimal, but might be a super easy and cheap fix that gives major improvments.

Thanks again! Was just waiting for my warrenty to expire before taking anything apart, but shoving some fiberfill in is an easy non invasive experiment...
 

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There is no gap. The outer grill sits very tight on the sponge like surrounding of the speaker. The two grill design is by my opinion to look good and stop the carpet lining from vibrating. If there is only inner grill there will be a gap, which will fill with dust/dirt overtime. If there is only outer grill it is more dust unfriendly, but it does bot matter, because the inner grill is more of a protection during transport than a real grill. They’ve had their reasons, but again just by changing the AMP I’ve made at least 300% improvement. The OEM amp is very very underpowered. Also again the box is very rigid, it can take a layer of dynamat or so, but if the results after changing the speaker are not satisfactory, I will make a box out of proper material, using the OEM one as a template. In reality the OEM setup is not bad at all, the amp is the only weak point. For comparison against HK my current setup makes more SPL, has more pronounced “scene”, the midrange and high end is more crisp and the woofers is the doors have more kick mainly because I’ve allowed them to go lower than stock (HPF is at 65hz).
 

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In my car I can push the carpet piece back as far as it will streach and not feel any resistance. Might as well be empty space. Part of why I assumed it was a free air install. There is at least an inch of flex. At the subwoofer cover there is more movement at the edge toward the front of the car than the rear. So guarantees I am losing sound pressure from that, given production tolerances it could be yours fits tight enough not to be a problem I guess.

Must be a particular issue with my carpeting, but it is not tight at all. Feels like nothing but empty space behind it. I know theres a sub there because I can hear it, and watch/feel the carpet move around while it plays.

Regardless not arguing the differances you hear with your amp, or that the factory amp is not great. It isnt, none of them are.

Glad you like the setup from the factory. Would be interested in hearing your opinions if you left the system at the factory crossover. Giving the front speakers more low end, could very well be negating the wave cancellation happening at the rear, allowing the system to fill in the sounds being lost to the bad sub install. Since it sounds to me like he frequency dip is around 80-60hz which is what you added to the front. Regardless changing the crossover frequencies has a massive effect on soudstaging and tone.

Did you hear the system with the new amp, but setup like factory?
 

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Did you hear the system with the new amp, but setup like factory?
Yes I did, but didn't like it. There was a gap in 80-110hz, because the sub (currently HPF at 25hz, LPF at 100) was not able to fill that. There was a lot of low bass < 65-70hz, but nothing substantial in the range 70-80-100hz. I've changed the crossovers config to 25-100 at 24db/oct and played with the filter algorithm until I was satisfied (using Linkwitz). The main issue is not the sub itself, its location, sound proofing or whatever. It is the setup of the OEM system. It is good when listening to rock or Italian music (Adriano Celentano, Peppino Gagliardi and etc), but is not good at all if you want to listen something like Three Six Mafia, Wiz Khalifa, 50 cent and etc. It is just not setup that way and unfortunately you can do nothing about it. My car was not with HK system to begin with, but I've had 2 Stelvios with HK around, so I was able to play with the sound setup for quite some time. I've also swapped the amp in one of them with HK system with mine and bypassed the rear mids (in the site columns behind the rear seats), because i didn't have enough channels and it started to sound great as well. At the moment my car, with standard speakers (from the base sound system), sounds at least twice as good as the OEM HK system. The choice of speakers in the HK system is also very strange to me - the woofers in the door on the HK are 25W, the base audio has 50W spekers, also the tweeters and the mids on the HK are 25W and 12ohm ones, while base has only tweeters that are 25W 4ohm ones ... they knew what they were doing, but maybe the engineers that did the setup, were not fans of bass ... who knows :)
 

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My suspicion is some of the issues with the audio have to do with the vehicle being designed and prototyped so fast. Willing to bet the audio system was designed and tuned in virtual reality using simulations and mathematics, then never really checked over for variations between the digital world and reality. Which works fine but can leave issues, like not taking into account the flexibility and production variations in the carpeting fit and how large of an impact that can have to certain frequencies. Not the biggest deal, dont mind that the factory test drivers paid so much attention to tuning the chassis they forgot to turn on the stereo.

The system is designed well overall, solid drivers (for factory). High resistance tweeter is common in HK systems as well as most high end separates. The ohm rating you see listed as spec is actually the resistance at the passive crossover, pretty commonly. The differance between the base an HK woofer power handling is strange but there is alot that goes into sound besides power handling. Could be the HK woofer is twice as efficient,so it needs less power to output the same ot greater volume.

The dip in frequency response, I thought was due to frequency cancellation from the back wave intersecting the front, in addition to cancellation from driver movment. Which I stupidly convinced myself would require a full reinstall with some box fabrication, better just replace everything since adding a box is so easy.

But it turns out it is just an incredibly compromised sub install, which should be easy to fix with fiberfill and some double sided gorilla tape. Might need a small wooden spacer.

We'll see...
 

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It can be from cancellation and wave fronts intersecting, I can check that, because the first thing I did was to time align the speakers. I can remove the time alignment and check.
 
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