Those with subs in their FRS.

[babydriver]

Originally Posted by AtlasMick

Tuning will also help a great deal. The stock door speakers work fine down till about 60-70hz so if you cross over your subs at 60hz low pass you eliminate an enormous amount of rattling just from that. (that worked for me, but my subs are connected to a baffle fiberglass'd directly to the sheet metal)

There is another advantage to crossing over at a higher frequency -- power handling. The excursion of a smaller speaker is limited; a subwoofer typically has a much longer available excursion. So if you cross over at about 80 Hz, you'll be able to play louder with less distortion.

The car cabin is not very big, so bass itself is coupled to the interior at a relatively high frequency (by high I mean in the low hundreds Hz range). Once you reach the point where the half-wave is longer than the longest dimension of the car interior, you are pressure loaded anyway. So cross over a bit higher and gain some dB's at no extra cost.

Added: A 100 Hz wave has a wavelength of 11.3 ft. Therefore a half-wave is 5.65 feet long. That is probably just short of the total cabin length of the FR-S. This becomes 22.6 feet at 50 Hz (1/2 wave = 11.3 feet, which easily exceeds the cabin length). Once the wave is coupled to the interior as a pressure wave, there is no directionality; the sound seems to come from everywhere. The higher the crossover, the less the door speakers will rattle because of greatly reduced excursion. You are limited by the upper frequency response of the sub of course.

Try this: change the crossover to 100 Hz. If you can tell where the bass is coming from, lower the frequency to 80 Hz. Keep lowering the freq until you can no longer tell where the bass is coming from. Bear in mind that you have to trade off the bass quality with the door rattle caused by those speakers. Good luck!

[quality_sound]

Originally Posted by Koa

I respect your apt name and agree foam is great. The rear deck has some items on it that foam may affect the deck's fitment.. if you ever get around to using foam to quiet that deck rattle hope it gets documented and shared around- could save people some moolah.

Sound deadener, when used in strategic places, can work to stop rattles 100%. Don't need to cover the whole thing in your choice of CLD. Just spots where washers, mounted objects (such as the key remote brain), pieces of trim are indeed rattling.

Same goes for license plates and other sensitive trim areas where the bulging foam is not feasible, but you can certainly add a layer of CLD over it

There are a number of FR-S/BRZ builds on diymobileaudio.com that show it. You don't need a lot and it doesn't have to be thick to be effective. When I get home I'll put up a few links. When I do my build I'll have a log here as well as on DIYMA for everyone to criticize.

Sound deadener can absolutely stop rattles, but it's much more expensive way to do it is all I'm saying. Trust me, mine will have PLENTY of deadener. Just not in areas that are rattling. Well, at least not by itself.

For my plate I used something adhesive-backed weatherstripping foam from Lowe's. Works beautifully and compresses very nicely. Only down side is that only have 2 holes instead of 4 to screw the plate down and that bothers my OCD.

[quality_sound]

Originally Posted by AtlasMick

Tuning will also help a great deal. The stock door speakers work fine down till about 60-70hz so if you cross over your subs at 60hz low pass you eliminate an enormous amount of rattling just from that. (that worked for me, but my subs are connected to a baffle fiberglass'd directly to the sheet metal)

I hadn't thought about this, but it's true. I redid my "tune" with the OEM EQ and the doors and midbasses sound SO much better. I'll try to remember to post the pic of the settings later.

Attachment 98446