Contour Enthusiasts Group Archives Forums Modifications Audio Widening the rear deck hole.

Has anyone purposefully widen the rear deck hole to fit a driver larger than a 6.5" driver like an eight or ten inch model. I have read post where an eight or ten inch would be mounted below the deck attached to a cutout board which itself is attached to the rear deck directly with carpeting or felt sealing the air gap preventing whistling; yet I have read that this sometimes induces unwanted rear deck vibrations due in part to the fact that some long throw drivers *8mm to +13mm or higher. So this vibration excitement issue within this mounting technique is why I am looking to read about others posters experience with widening the rear deck hole to fit an eight or ten inch driver.

Without the adaptor plate I suspect that the deck would rattle even worse as the Rigidity of the metal would be lower than that of the 3/4" wood.

My 8" driver has 8.7mm one way Xmax and I used a 3/4" MDF adapter. As Dave said, that metal is very thin and would vibrate like crazy. You can see the driver and adpter here . I don't think a 10" would fit, or most tens I looked at wouldn't work. I suppose with a more custom adapter plate, it might work. I guess it depends on what you want to do with it. I'm pretty impressed with my single 8".

To complete one sentence: some long throw drivers might have their cones actually hit the bottom of the rear deck. So Dnewma04 let us say that I wanted to mount an Audio Bahn AW800x with _+ 12mm of excursion or their aw831x with _+ 7mm of excursion would I not need to make sure that there is enough clearance, at least the xmax distance, between the rear deck and the highest point of the woofer cone area? Are there any eight inch woofers out there when at max positive excursion the highest point of the cone does not go beyond the mounting ring of the driver basket when in there would be less of a need for a 3/4" mdf sub mounting driver plate?

I am almost finished with my sub box that I will mount under the rear shelf. Go here to see a picture in it's current state.

The weird shape of the box is because it had to go around the center seatbelt anchor.

An 8" driver will 12 mm of exursion would only get to within a 1/4 of the metal at full excursion. I don't know of an 8" with the 18mm of excursion needed to hit the hole. Besides, the piston area of an average 8" driver is about 6.5 inches. If you wanted to be extra safe, go with a 1" adapter. There are very few drivers in existence with a 25mm xmax, and none with an 8" diameter, unless you can find an 8" TC Sounds driver from the Sunfire 8" sub which is highly unlikely.

How do you plan on fastening this box to the car?

I had thought about trying something similar. The only good solution I could come up with is to remove the package tray cover and suspend some bolts from the top using some large washers to distribute the weight, and then bolt the sub box to the screws. I just wasn't sure of how much weight it could handle.

Plus pretty much any drilling has to be done from below because of the rear glass.

I bought some steel angle brackets from Wal-mart, and I plan to bolt/screw into the rear deck from below. The box will extend to the rear to about 1" from the trunk light. Also, it seems there are two layers of sheet metal toward the rear of the shelf with about an inch of space in between, so that will aid in mounting.

I will attach to the box using T-nuts. I will use plenty of brackets, because this thing weights about 35 lbs! But I believe it will hold the weight with no problems.

I got it all assembled tonight, and gave it a test run. It sounds awesome. The sound is exactly what I was wanting (great SQ). I am driving it with a JBL 150.1 amp. Now all I have to do is figure out how I am going to hold it in place while I attach it. *sigh*