All right so I went ahead and bit the bullet and swapped the 2-ohm Infinity Kappa's into my Bose system. Wanted to leave my impressions here for others who are debating the same. Up front I installed a pair of 60.7cs 6-1/2" components, in the back I installed the 63.7i 6-1/2" 3-ways (retaining the Bose amp). This was in a 2007 GT hatch. Total cost ~$350 ($290 speakers new online + $60 in materials).
First, the installation. Very time consuming, probably 15 hours plus for all speakers. The major mistake I made was not buying the blank sail panels for the tweeters. Cutting and dremeling out the stock panels probably cost 2-3 extra hours. If you do this swap plan on spending a couple of hours making mounting brackets, the ones that come with the Bose are permanently attached. I used 1/4" MDF - if you use anything thicker the 63.7i's will likely not fit in the back due to the tweeter height.
Upon opening the first door panel I noticed that about 30% of the stock Bose speaker grille contains dummy holes i.e. they look to be open from the front but actually have solid plastic on the back of the grill. I'm no sound expert but it seemed to me that drilling the dummy holes out would result in much better sound dispersion (since part of the woofer would literally be firing into solid plastic otherwise). Very tedious and time consuming to do, probably 1.5 hours per door but in retrospect I think it was worth it. As noted in other walkthroughs, the plastic oval ring on the back of the door trim needs to be removed for a proper fit. A note about drilling out the speaker grille - the holes you drill will cause slight discoloration on the outside of the grille itself. I ended up using a couple coats of good old fashion black shoe polish to compensate.
Another step I took was to install a xtc foam baffle behind each of the speakers. I used the deeper version, cutting out the botton half of the foam basket. This protects the speaker from water (which I found does get inside the 3's doors) while allowing the speaker to still take advantage the door cavity for decent bass sound. The foam baffles also create vibration dappening surface between the speaker baskets and the MDF brackets. Additionally, I used modified speaker baffles made for 4x6 speakers to cover the front crossover units that I mounted inside the door (I installed the rear crossovers inside the plastic door cavity rather than inside the doors themselves).
Bose woofer autopsy - they are fairly cheaply made with paper woofers and foam surrounds. Not good materials considering the back two speakers were actually dripping wet from water that had drained down into the door during a rainstorm the night before.
So most importantly, how do they sound? Great. The highs, mids, & midbass are excellent. The midbass in particular is shockingly powerful and clean. These speakers are leaps and bounds above the Bose in sound quality. I'm still playing with the settings but so far I've settled on bass +4, treble +5, fade front +1. I'm more of a fan of the headphone type soundstage in a car and the fade front +1 will give you close to that. Volume wise I'd say the Infinity's are pretty much on par with the stock speakers. As far as the rumored custom EQ'ing done by the Bose amp - if I had to guess based on the sound of these speakers I would say they're boosting the mids. With this setup it almost works in your favor as it seems to compensate for the bass +4, treble +5 settings. Haven't played a whole lot with the tweeters, right now I've got them aiming just below the rear mirror and have been pretty happy with the staging. Another note about the tweeters - both the front and rear tweeters can be boosted by 3 db (at crossover for fronts, on tweeter itself for rears). I left them all at 0 db boost to avoid overly harsh highs. There is definitely a break-in period for both speaker sets, at least 10 hours per my ears.
The only complaint I have about my system after this install is a lack of serious low end punch. Don't get me wrong, the Kappa's are definitely punchy and provide very clean bass just not quite what you'd get from an external sub. The bass is actually strong enough that I'm debating whether a sub is necessary. If you listen to hip hop, you'll definitely want to add a sub. I'm more of a punk, industrial, heavy metal person myself and this setup may be adequate for that.
Overall, I'm very happy with the upgrade (especially considering it only cost $350). You won't believe how crappy the Bose system really sounds until you've swapped the speakers out. It's literally night and day different. Plus if you think the Bose amp isn't cutting it, the Kappa's are excellent speakers that could be paired with a more powerful 2-ohm stable amp later when you've got more time and/or money. If you're looking for a relatively inexpensive and technically simple way (i.e. not adding amps etc.) to make a serious improvement in your 3's sound this is an excellent option
.
First, the installation. Very time consuming, probably 15 hours plus for all speakers. The major mistake I made was not buying the blank sail panels for the tweeters. Cutting and dremeling out the stock panels probably cost 2-3 extra hours. If you do this swap plan on spending a couple of hours making mounting brackets, the ones that come with the Bose are permanently attached. I used 1/4" MDF - if you use anything thicker the 63.7i's will likely not fit in the back due to the tweeter height.
Upon opening the first door panel I noticed that about 30% of the stock Bose speaker grille contains dummy holes i.e. they look to be open from the front but actually have solid plastic on the back of the grill. I'm no sound expert but it seemed to me that drilling the dummy holes out would result in much better sound dispersion (since part of the woofer would literally be firing into solid plastic otherwise). Very tedious and time consuming to do, probably 1.5 hours per door but in retrospect I think it was worth it. As noted in other walkthroughs, the plastic oval ring on the back of the door trim needs to be removed for a proper fit. A note about drilling out the speaker grille - the holes you drill will cause slight discoloration on the outside of the grille itself. I ended up using a couple coats of good old fashion black shoe polish to compensate.
Another step I took was to install a xtc foam baffle behind each of the speakers. I used the deeper version, cutting out the botton half of the foam basket. This protects the speaker from water (which I found does get inside the 3's doors) while allowing the speaker to still take advantage the door cavity for decent bass sound. The foam baffles also create vibration dappening surface between the speaker baskets and the MDF brackets. Additionally, I used modified speaker baffles made for 4x6 speakers to cover the front crossover units that I mounted inside the door (I installed the rear crossovers inside the plastic door cavity rather than inside the doors themselves).
Bose woofer autopsy - they are fairly cheaply made with paper woofers and foam surrounds. Not good materials considering the back two speakers were actually dripping wet from water that had drained down into the door during a rainstorm the night before.
So most importantly, how do they sound? Great. The highs, mids, & midbass are excellent. The midbass in particular is shockingly powerful and clean. These speakers are leaps and bounds above the Bose in sound quality. I'm still playing with the settings but so far I've settled on bass +4, treble +5, fade front +1. I'm more of a fan of the headphone type soundstage in a car and the fade front +1 will give you close to that. Volume wise I'd say the Infinity's are pretty much on par with the stock speakers. As far as the rumored custom EQ'ing done by the Bose amp - if I had to guess based on the sound of these speakers I would say they're boosting the mids. With this setup it almost works in your favor as it seems to compensate for the bass +4, treble +5 settings. Haven't played a whole lot with the tweeters, right now I've got them aiming just below the rear mirror and have been pretty happy with the staging. Another note about the tweeters - both the front and rear tweeters can be boosted by 3 db (at crossover for fronts, on tweeter itself for rears). I left them all at 0 db boost to avoid overly harsh highs. There is definitely a break-in period for both speaker sets, at least 10 hours per my ears.
The only complaint I have about my system after this install is a lack of serious low end punch. Don't get me wrong, the Kappa's are definitely punchy and provide very clean bass just not quite what you'd get from an external sub. The bass is actually strong enough that I'm debating whether a sub is necessary. If you listen to hip hop, you'll definitely want to add a sub. I'm more of a punk, industrial, heavy metal person myself and this setup may be adequate for that.
Overall, I'm very happy with the upgrade (especially considering it only cost $350). You won't believe how crappy the Bose system really sounds until you've swapped the speakers out. It's literally night and day different. Plus if you think the Bose amp isn't cutting it, the Kappa's are excellent speakers that could be paired with a more powerful 2-ohm stable amp later when you've got more time and/or money. If you're looking for a relatively inexpensive and technically simple way (i.e. not adding amps etc.) to make a serious improvement in your 3's sound this is an excellent option
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