Why are we not using infinite baffle woofers

[Brian-bmw]

I tried it a long time ago, and it really did not work that well in a car. The two main issues were: 1) the trunk of a hatchback is really is not sealed well enough, and 2) the drivers really do need the benefit of a tuned enclosure.

For my credentials, I used to be a high-end car audio installer. And, I had studied audio engineering as a specialty within my Electrical Engineering degree. Back in the day, I had designed and built tuned subwoofer enclosures having access to the best knowledge, equipment, and training.

First, I found that I could never seal the hatch area well enough. So, too much air leaked around the baffle, and that canceled-out a significant portion of the output. You can correct this with more power and more drivers, which helps to some degree.

Second, there was no tuned enclosure to help control the speaker's resonant frequency. So, the sub system tended to sound boomy and non-linear.

Third, there was no tuning to help the driver extend below its natural low-end roll-off frequency, so the subs tended to lose their impact and sound muddy on the low end frequencies.

When you add power to compensate for #1 and #3 above, the non-linearity of #2 really comes to haunt the system. It just sounded like a big, loud mess.

I did achieve the goal of creating more room in the trunk. But it came with significant audio sacrifice.

[DocMike]

I think a lot has changed over the past 15 years with woofer design. I think for SQ systems, which most of us want it may be a no brainer. Additionally I am not so sure a BSW stealth box would look any cleaner than a 8 inch with a grill in the lateral trunk wall. Infact, after hearing a friends M3 with kicker compVT in the deck, 2 6.5 subs will probably out perform it.

Originally Posted by Brian-bmw

I tried it a long time ago, and it really did not work that well in a car. The two main issues were: 1) the trunk of a hatchback is really is not sealed well enough, and 2) the drivers really do need the benefit of a tuned enclosure.

For my credentials, I used to be a high-end car audio installer. And, I had studied audio engineering as a specialty within my Electrical Engineering degree. Back in the day, I had designed and built tuned subwoofer enclosures having access to the best knowledge, equipment, and training.

First, I found that I could never seal the hatch area well enough. So, too much air leaked around the baffle, and that canceled-out a significant portion of the output. You can correct this with more power and more drivers, which helps to some degree.

Second, there was no tuned enclosure to help control the speaker's resonant frequency. So, the sub system tended to sound boomy and non-linear.

Third, there was no tuning to help the driver extend below its natural low-end roll-off frequency, so the subs tended to lose their impact and sound muddy on the low end frequencies.

When you add power to compensate for #1 and #3 above, the non-linearity of #2 really comes to haunt the system. It just sounded like a big, loud mess.

I did achieve the goal of creating more room in the trunk. But it came with significant audio sacrifice.

[Brian-bmw]

Originally Posted by DocMike

I think a lot has changed over the past 15 years with woofer design. I think for SQ systems, which most of us want it may be a no brainer. Additionally I am not so sure a BSW stealth box would look any cleaner than a 8 inch with a grill in the lateral trunk wall. Infact, after hearing a friends M3 with kicker compVT in the deck, 2 6.5 subs will probably out perform it.

Give it a try and let us know what you think.

[DocMike]

Originally Posted by Brian-bmw

The two main issues were: 1) the trunk of a hatchback is really is not sealed well enough, and 2) the drivers really do need the benefit of a tuned enclosure. Give it a try and let us know what you think.

1) the trunk of a hatchback is really is not sealed well enough

I think in the X5 we are talking about the lateral wall being sealed from the trunk area and the interior of the car. Those "cubby" holes are pretty air tight from the rest of the cabin, you can take one off and close it to appreciate the seal. And from what I have seen, the sedan rear deck installs, are less sealed than these compartments.


2) the drivers really do need the benefit of a tuned enclosure

Woofer travel is a major problem with infinite baffle design. I am sure however, technology has improved as i stated over the past 15 years. I could break down the necessary specs, and give data of the changes that have taken place, but as I posted there are some companies that have designed IB specific woofers with the necessary specs.

If I can find a spare set of lateral wall covers, I may attempt this. I do still have a fiberglass itch that needs to be scratched every so often. Nothing like catching a fiberglass box you made 10 years ago show up on ebay.

[chefwong]

Just a shout out for Jeff on the linked google image. Jeff is quite the ~sq installer~ down south.

[m5james]

Originally Posted by DocMike

am I missing something here, seems like a very logical install. Why are we trying to stuff small boxes and find tiny thin drivers when we can do IB set ups??

Here are some examples of IB installs

Sounds Good - Projects

This is definately something I'd have to hear in person over what people have done and used here in the stock location before I could take the plunge and go outside the box...literally.