That is a pretty good analogy and at this point we can put the bed the fact that a large horn will not operate properly in a small vehicle.  I've thought about it a bit and finally understand why Steve's idea would work (under certain conditions) and why my idea that the vehicle would act as an extension of the horn was false.

As Steve mentioned, there are alternatives that will work.  The imperial needs immediate boundary loading, optimally a corner, and then a large area to radiate into, this is where my false assumptions came into play.  I forgot that both requirements must be met.  A downward firing imperial through the floor could be the perfect answer to those kids that want to annoy people, as the pavement and van bottom (excluding mouth area) would approximate corner loading and the sound radiates outside and around the vehicle.  The vehicle would probably have to be very low and be sitting on concrete to ensure adequate boundary loading and even then probably would not work as well as a corner.  Aren't some SPL comps measured outside the car anyway?

The only way I could possibly imagine to get the output INSIDE the vehicle would entail lying the imperial flat on its back in a tight, leakproof van, kicking out the windshield and parking face first in a large concrete parking garage.  That would fulfill the requirements for corner loading and large area room.

I can't believe you guys are still talking about this.  An Imperial won't work in a van, unless you put it facing the rear or side door and open the door.  Then it will work outside.  The reason is because the horn itself won't function properly.  It needs much more air volume for the horn to couple to.  Sure you might hear/feel some bass, but in a room you'd hear/feel more, so in a van it would just be a waste.  For outdoor parties it would be great.  With the seats out, put it up against the back seat facing to the rear and open only the back doors.  That would enlarge the mouth and give you even more bass than if you took it out of the van.  Any other use in a van is a bad idea.

I understand everything everyone has said, but hold me to it, I WILL put an Imperial in a van, one day.

Anytime someone's told me I can't do something, I've done it and then some.

I've designed an adjustable slope screen, the first of it's kind. I've designed and built my own personal hovercraft. I've built a propane turbo-jet out of an old crapped out turbo charger. I've written script within a program to make it do something the developers said wasn't possible. I've designed perpetual motion and free energy. I WILL put an Imperial in a van.

Jet, if I had the appropriate measurement equipment I'd throw the old Imp into a van right now, just to settle this one way or the other, once and for all.

Are there ways to implement horns that have never been dreamed of yet?  Sure.

Are there possibly even better ways to gain horn efficiency without the horn, that haven't yet been invented?  Of course.

But with technology and our understanding of it the way it is now I am comfortable with the assurance of the pros that large horns will not work in small spaces.

A couple of posts ago, I stated that the fault in my thinking was that I forgot to meet ALL the conditions that a horn requires to operate properly.  Namely boundary loading (optimally corner loading) and a large area to radiate into.  I thought the intimate boundary loading presented by the van would be enough but there is no large area to radiate into unless you start smashing out windows and use the outside world as your room.  Once you do that, you lose the boundary loading of a solid corner and the tuning would raise dramatically unless you park the van in a corner of some kind.

At the same time, I flat out refuse to believe that a big horn in a vehicle will make no noise, it's certainly going to sound like something, I'm just not smart enough to know exactly what, without trying.

It is astounding what innovation and an inquisitive mind can accomplish but I can't see the big horn/small vehicle paradox being worth spending a whole lot of time on.

If you are onto free energy and perpetual motion, I would focus on those things, and a couple of years down the road, when you are the wealthiest man on the planet, you could have these smaller questions worked out for you, without lifting a finger.

Believe me, I understand your enthusiasm and I understand that a person with your type of inquistive nature WILL succeed in the end, even if the reward you receive at the end is not the implementation of the original goal.

But look at it from this point of view - even if you succeed beyond your wildest dreams in this particular area - it's not going to get you anywhere.  Size and weight are major considerations for vehicular electonics.  There are thousands of people at work designing ways to make things smaller, not bigger.  This includes the vehicle itself.  Note the size of the average van 20 years ago compared to today.

By the time you get this worked out, there will be louder and much smaller options - for example the Sunfire sub is already available (for home audio).  THAT is the direction automotive electronics is headed, like it or not.  How long is your customer going to be happy with his 2 seater van, getting 10 mpg, with no more storage area than a sports car?  Even if it puts out 180 db, it's going to be one of those things people look at for a minute and then go sit in the car with the blonde and an a.m. radio.

kinda off topic but is it not a calculation on how low you can go in a car??
I remember learning that in a car audio coarse at one time.
has to do with wve length and so on??
I was an spl guy so 70 hz was what we went for.
shayne

It's ok Jet, I ahve the same porblem.