SC300/400: 6.5" rear deck speakers with no modifications necessary
09-27-14, 03:05 PM
#1
SC300/400: 6.5" rear deck speakers with no modifications necessary
When I bought my SC400, the OEM 4" rear deck speakers were blown and it had some upgraded 4" Pioneer speakers in the doors. I replaced the rears with the newer version of the Pioneers up front. That sounded pretty good, but the rears were a lot better than the fronts (higher sensitivity, probably), so I figured it would be worth moving the rears up front and then upgrading their old spot to 5.25" speakers in the factory mounts, as some people have done with minor modifications.
However, if going to that trouble, why not go a step further and install 6.5" speakers?! Several people have said they fit with a bit of opening up of the factory cutout. So, I picked up a set of Pioneer TS-A1675R 6.5" and, to my surprise, they fit perfectly with no modifications! Amazingly, they drop into the cutout with room to spare and line up perfectly with the factory mounts. You just need to use some washers to clamp down on them, since they'll be ever so slightly inside the bolt holes.
Run a strip of speaker gasket tape around the lip on the bottom of the speakers and they fit snug against the deck. I popped one of the wire loom plugs out of the deck from below and used that to feed the wires down to connect to the speakers from the bottom. In the picture below, I hadn't done so yet.
The only thing that doesn't fit is the Pioneer grills, as they hit on the bolts. You could get around that by carving out part of their backing, but that seems unnecessary when the 6.5" size fits nicely within the factory grill and sits a lot lower than the stock speaker mounts.
The sound improvement is somewhere in the neighborhood of 100x better than what they replaced, complementing the aftermarket subwoofer nicely to fill out the midrange that a 4" can't hope to produce very well. I expect it will sound several times better still when I move the better 4"ers up front to the doors.
However, if going to that trouble, why not go a step further and install 6.5" speakers?! Several people have said they fit with a bit of opening up of the factory cutout. So, I picked up a set of Pioneer TS-A1675R 6.5" and, to my surprise, they fit perfectly with no modifications! Amazingly, they drop into the cutout with room to spare and line up perfectly with the factory mounts. You just need to use some washers to clamp down on them, since they'll be ever so slightly inside the bolt holes.
Run a strip of speaker gasket tape around the lip on the bottom of the speakers and they fit snug against the deck. I popped one of the wire loom plugs out of the deck from below and used that to feed the wires down to connect to the speakers from the bottom. In the picture below, I hadn't done so yet.
The only thing that doesn't fit is the Pioneer grills, as they hit on the bolts. You could get around that by carving out part of their backing, but that seems unnecessary when the 6.5" size fits nicely within the factory grill and sits a lot lower than the stock speaker mounts.
The sound improvement is somewhere in the neighborhood of 100x better than what they replaced, complementing the aftermarket subwoofer nicely to fill out the midrange that a 4" can't hope to produce very well. I expect it will sound several times better still when I move the better 4"ers up front to the doors.
09-27-14, 04:43 PM
#2
One more pic, showing the completed deck. I added some dynamat to the sections between the speakers, since that's the most open area with the sub amp cutout and corresponding cutout on the other side with just a thin metal insert clipped in. Trying to get at all the other little contours didn't seem worth the effort.
09-27-14, 07:06 PM
#3
Sweet I got to get around to doing this 
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