When it came time to add new front speakers to my Grand Prix, I did the research and determined that it was worth the hassle to install a 6.5” component set rather than the stock size of 5.25”. The extra cone area helps with midbass and this reduces the tendency of low notes to sound like they’re coming from the rear of the car where the subs are.
Of course, installing larger speakers meant developing custom mounts. My original idea was to make a wood replica of the stock mounts. However, as dl1030 pointed out, there isn’t much room and whatever u use must be both thin and strong. So I elected to use his method of cutting and reshaping the stock mounts. However, I soon discovered that, while his method produces excellent results, it must be done with precision to fit in the car. And the fact that I was using European (also known as “6.5S” or 6.75”)-sized speakers meant that there was even less room available. As I tried to make everything fit together, I started getting a lot of small gaps that would have leaked air and hurt performance. Then, as I was trying to get them crammed into the car, the putty I was using crumbled and my mounts fell apart. Giving the lackluster results I had obtained so far, it wasn’t worth rebuilding the mounts. I decided there had to be a better way.
The concept I came up with was a combination of dl1030’s design, Phil G’s design, and my original idea. I started by using a Dynamat door kit on the mounting surface – this reduces the metal’s tendency to flex and rattle, thereby improving bass response:
Then I bolted the stock pods back in. This created an imprint in the Dynamat, which I used to make a cardboard template. Then I took the mounting ring from my component set and cut out a hole for the speaker. I put the template back on the door and reached thru the hole so I could push nails thru the screw holes to mark them accurately. Then I put my plastic baffle in place to make sure everything fit, check window clearance, etc (although, as u’ll see in a minute, we’ll actually have slightly more window clearance w/ the wood mount):
The plastic baffle is necessary becuz it protects the speaker from water and prevents bass-killing air leaks from the back of the speaker. I used the cardboard template to cut out a wood mount from ¾” particle board. I was lucky enough to have access to a bandsaw and a stationary belt sander, so I cut the mount on an angle so it was thick at the bottom and thin at the top. Then I used the sander to even it out. With more work, u can achieve the same angle w/ a jigsaw and sandpaper. This allows it to sit flat against the door while providing a bit of the angle of the stock speaker pod:
NOTE: I did this a few years ago, and I recently took the door panels off. I discovered that, over the years, water has wicked into the wood and softened it. I suggest spraying them w/ rubberized undercoating or at least spray paint to provide some water protection.
And in the car… note the speaker wire for the tweeter sticking out thru the indentation in the door that creates a gap between the door and the mount. Also note the bottom screws… becuz of the thickness of the wood at the bottom, the stock screws weren’t long enough and I had to use longer screws. :
When I installed the mid, I noticed that the bottom screws for the mid would hit the metal skin of the door. I cut them so they were about as long as the mount was thick, so they wouldn’t stick thru.
When I put the door panel on, it looked as though I might have problems w/ the cone hitting the door panel. But it worked ok… however, it does underscore the fact that the top of the mount has to be thin. I believe mine were about a ¼” at the top. It’s also a good idea to keep the mid as far towards the bottom of the mount as possible while still getting it to fit in the hole in the door.
As for the tweeter, I knew I didn’t want to use the stock location becuz it sux. There was plenty of room to use a piece of metal strapping material to suspend the tweeter over the mid, but I wanted them to be ezily accessible for adjustments. Besides, high freqs are more susceptible to being blocked by grill cloth (and I doubt GM used high-quality grill cloth!). So I bought a couple spare grills and used an air grinder to make a hole in them. Then I used a file w/ a rounded edge to make the hole big enough for the tweeters to mount to:
Here they are in the car:
I’m really happy w/ how it turned out… I’ve barely had a chance to tweak them yet, but they already sound way better than the stock speakers. And what’s really funny is that the soundstage is higher now than it was, even though the tweeters are lower in the door! That just goes to show much the stock tweeter locations suck. Oh yeah, I mounted the crossovers in the center console… they’re ezily available for adjustments and they’re protected from water and shock from slamming the door.