Front mounted sub

[P.Kelly]

How's it sound?

I'm happy with it. It hits relatively hard, and is pretty tight, but also fills out the range between about 100-150hz that the 5 1/4" speakers can't do very well. For the price (all in ~ $150) of the woofer and materials I can't complain. Plus, it's for my vert so stealth is a big win.

[Gregs///M]

How is the sound of the woofer going to escape into the cabin in the car? Through the thick carpet?

[Jean]

OP - nice!

Gregs///M how does the sound of bass travel through walls ?

[Gregs///M]

OP - nice!

Gregs///M how does the sound of bass travel through walls ?

Walls lined with thick carpet? There will be huge output loss if so, therefore how much loss does the OP have relative to if the sub was firing through the ski pass?

And furthermore, if you are trying to replicate live sound stage, wouldn't muffling the sub woofer set you back? I've installed many woofers up front and even competed in IASCA and never seen front subs muffled with carpet.

[Jean]

We don't know if he removed all behind the carpet and it's just a thin layer of carpet over the woofer? There is still a huge benefit of it being upfront, meaning it can be crossed over higher and help with a strong front midrange vs coming from the trunk.

[P.Kelly]

According to my ears, the carpet makes only a minimal impact on the sound level and quality. Check out Luke's vert box and you will see he ports the sealed bandpass into the back of the rear seat foam.

The physics of low frequency sound wavelength effectively means that super low frequencies <125Hz are effected very little by obstacles with low or medium mass and only moderately by high mass (dense solid) objects. Here is a diagram from Crutchfield that speaks to this concept:



You'll notice that 125Hz sound is only absorbed about 8% by carpet with padding. A small price to pay for stealth in a convertible to keep someone from trying to steal it with the top down.

[Gregs///M]

According to my ears, the carpet makes only a minimal impact on the sound level and quality. Check out Luke's vert box and you will see he ports the sealed bandpass into the back of the rear seat foam.

The physics of low frequency sound wavelength effectively means that super low frequencies <125Hz are effected very little by obstacles with low or medium mass and only moderately by high mass (dense solid) objects. Here is a diagram from Crutchfield that speaks to this concept:



You'll notice that 125Hz sound is only absorbed about 8% by carpet with padding. A small price to pay for stealth in a convertible to keep someone from trying to steal it with the top down.

PKelly, give us a review when you have some time. My concern is the carpet will also inhibit the movement of air which is essential to bass wave generation. A sub firing into such a carpet has got to generate some cancellation.

Also, the carpet in the E30 is pretty thick, at least the foam section with some areas over 1 inch thick. Did you perform any modifications to the carpet? If so, did you hear significant difference?

[P.Kelly]

PKelly, give us a review when you have some time. My concern is the carpet will also inhibit the movement of air which is essential to bass wave generation. A sub firing into such a carpet has got to generate some cancellation.

Again, to my ear, the difference between having the carpet in front and not was minimal.

The maximum excursion on the pioneer shallow sub is about .15" which is pretty minimal IIRC. I believe that this particular sub is very inefficient as the output between a sealed box, ported box and bandpass were all VERY similar and the subwoofer can be used in an infinite baffle configuration. That said, I'm talking a little out of my butt right now, but I believe that this woofer doesn't move a ton of air, and therefore is effected less by the limited air movement than some other designs might be (since it is already highly inefficient).

I have the subwoofer crossed at 200Hz, and have the P-EQ set at the woofers sweet spot of 85Hz. It adds ton to the low end of the music as well as providing a nice "bump" that can be heard clearly on the freeway with the windows down. If time and money aren't an obstacle, and Luke finishes his power top vert box, I may be inclined to get his setup to add to my car and retune this shallow 8" just for musicality.

Again, for ~$150 all-in, I'm very happy with the results.

Also, the carpet in the E30 is pretty thick, at least the foam section with some areas over 1 inch thick. Did you perform any modifications to the carpet? If so, did you hear significant difference?

In order to install this box, I had to remove the bowling ball sized foam piece that fills the foot well in the vert. There is minimal backing to the carpet in this area over the woofer, but the carpet is relatively dense.

[Mad Chemist]

Thanks for the idea. Started the project this past weekend. Going to use a 12" sub, which is going to be problematic.

[P.Kelly]

Thanks for the idea. Started the project this past weekend. Going to use a 12" sub, which is going to be problematic.

I don't think you'll find enough depth without cutting into the passenger space.