I started with a BMW 4X6 to 6X9 speaker adapter. If this link dies, just to a search for those terms. http://www.amazon.com/BMW-Series-Rear-Speaker-Adapter/dp/B0081IC506
The challenge was coming up with an orientation that aligns as many of the BMW screw holes, or some of the places that aren't technically screw holes, or a good flat spot to make a screw hole, with the stock screw holes. The best I could do is 3 screws, but it's plenty secure:
1 = the only normal hole used. 2 = the approximate spot where a hole must be drilled. 3 = a c-shaped tab re-purposed as a screw location.
A tab on the other side should be cut off so it doesn't interfere when mounted:
The adapter after being mounted I used M8 sheet metal screws, but you have to be careful with the length. There is some room for tilting the adapter so it's hard to give an exact recommendation for screw length. IIRC screws #1 and #2 were 1.5", while screw #3 was 2". You can't rely on the screw holes in the OEM speaker mount to bottom out and stop you...you WILL screw right through the grill with ease. Ask me how I know. The #3 screw location is the weakest point used so don't over-torque there.
End result after the speakers were mounted. I was able to reuse the stock speaker screws to secure the speakers to the adapter. They were just long enough. The screws included with the speakers would have been too long. The intrusion into the cargo area is mostly inconsequential to me. I don't carry a ton of stuff in this car and even if I did, the intrusion is off to the side. The left side needs adjusting. The #1 screw isn't in deep enough and #2 probably can be backed out a bit.
Top down shot showing how far the speakers intrude into the cargo area...and a teaser of the handy spot I found for the Kenwood sub I'll be getting around to later:
Earlier I had installed Kicker 4" speakers in the front. They improved clarity, but not bass of course. So what does it all sound like with the 6X9s? Not that impressive, honestly. Maybe it's their location. Maybe it's the adapter. Maybe I need more time tweaking the "EQ" settings. I've only taken one quick drive and it did admittedly begin to sound better after starting over at zero on the sound settings and adjusting from there. Upping the bass enough to be heard from the 6X9s causes the fronts to pop. Fading things to the rear helps, but then I get too much high frequencies from the rears and the fader on this head unit sucks...it sounds like it's doing more than just fading. The best results were fading a bit to the rear and cranking the treble down quite a bit. I have bass-blockers in hand to try to deal with any low-frequency issues front or rear, but I wanted to listen to every step before just throwing everything in at once.
Next comes the Kenwood sub. It fits snugly in the spot vacated by the charger with only minor tweaking of one of the foam corners. I only have access to 110v so the charger stays in the garage. The sub does stick up a little above flush - maybe .5". I'll listen after that is installed and decide which speakers get bass blockers. The fronts will almost certainly end up with them.
The challenge was coming up with an orientation that aligns as many of the BMW screw holes, or some of the places that aren't technically screw holes, or a good flat spot to make a screw hole, with the stock screw holes. The best I could do is 3 screws, but it's plenty secure:
1 = the only normal hole used. 2 = the approximate spot where a hole must be drilled. 3 = a c-shaped tab re-purposed as a screw location.
A tab on the other side should be cut off so it doesn't interfere when mounted:
The adapter after being mounted I used M8 sheet metal screws, but you have to be careful with the length. There is some room for tilting the adapter so it's hard to give an exact recommendation for screw length. IIRC screws #1 and #2 were 1.5", while screw #3 was 2". You can't rely on the screw holes in the OEM speaker mount to bottom out and stop you...you WILL screw right through the grill with ease. Ask me how I know. The #3 screw location is the weakest point used so don't over-torque there.
End result after the speakers were mounted. I was able to reuse the stock speaker screws to secure the speakers to the adapter. They were just long enough. The screws included with the speakers would have been too long. The intrusion into the cargo area is mostly inconsequential to me. I don't carry a ton of stuff in this car and even if I did, the intrusion is off to the side. The left side needs adjusting. The #1 screw isn't in deep enough and #2 probably can be backed out a bit.
Top down shot showing how far the speakers intrude into the cargo area...and a teaser of the handy spot I found for the Kenwood sub I'll be getting around to later:
Earlier I had installed Kicker 4" speakers in the front. They improved clarity, but not bass of course. So what does it all sound like with the 6X9s? Not that impressive, honestly. Maybe it's their location. Maybe it's the adapter. Maybe I need more time tweaking the "EQ" settings. I've only taken one quick drive and it did admittedly begin to sound better after starting over at zero on the sound settings and adjusting from there. Upping the bass enough to be heard from the 6X9s causes the fronts to pop. Fading things to the rear helps, but then I get too much high frequencies from the rears and the fader on this head unit sucks...it sounds like it's doing more than just fading. The best results were fading a bit to the rear and cranking the treble down quite a bit. I have bass-blockers in hand to try to deal with any low-frequency issues front or rear, but I wanted to listen to every step before just throwing everything in at once.
Next comes the Kenwood sub. It fits snugly in the spot vacated by the charger with only minor tweaking of one of the foam corners. I only have access to 110v so the charger stays in the garage. The sub does stick up a little above flush - maybe .5". I'll listen after that is installed and decide which speakers get bass blockers. The fronts will almost certainly end up with them.
