Sub for convertible - top open/closed

[rjon17469]

A friend asked me to build a subwoofer for his convertible. I think a sealed enclosure would be best, based off the type of music he likes, his bass preferences, and the space available. Now, I realize that the cabin of a car amplifies low bass frequencies, and the smaller the cabin, the higher of a frequency at which this starts. So this is even more dominate in a small convertible.

Now, my main question is, if I design the sub to sound good with the top closed, will I lose all my cabin gain bass when the top is opened? Is there any way I can remedy this?

Thanks in advance!

Reece

[simon5]

You will lose all cabin gain. You cannot remedy this.

It's a good idea to go sealed, so when you'll lose all cabin gain, it won't sound awful.

[Stocker]

If you wanted a super-slick implementation, you could have your cake and eat it, too.

Top-down, make an eq curve that sounds good. LOTS of power and bass-boosting action.

Top-up, make the eq cut out and let cabin gain work for you.

Use a micro-switch or an existing switch for the car's sensor, whatever you can hide.

Of course, if it is a ragtop, you will have next to no cabin gain anyway due to the lossy nature of the top IIRC, so vented is the way, all the way.

[rjon17469]

Originally posted by Stocker
Of course, if it is a ragtop, you will have next to no cabin gain anyway due to the lossy nature of the top IIRC, so vented is the way, all the way.

Interesting. Sounds like something I should test. Does anyone have experience with cabin gain in ragtops?

Reece

[RHosch]

Cabin gain in a ragtop will be almost nonexistant.

[Stocker]

Cabin gain (or room gain) comes because the air in a volume is compressed. If you have flexible walls in your house or a cloth roof to a car, they will be (at least) very lossy, contributing "not much" to the low-bass output of a subwoofer.