I to did want to know this. But I shouls try to see how quiet I can get it on the out side, but super loud inside? So I should aim for that... So pretty much, the more quieter I make it on the out side, by the sounds of it, it will be louder in side?

And if you think of it this way, a sealed box inside your trunk, cab, or hatch, with the windows down, is like having your hole car the sub box, and the windows are the ports when they are down... I think that is a not to bad way of explaining it?

-db

 

I tryed it out on an old, straight country road and found it depended very much on the frequency. My friend measured the distance with his odometer and we used walkie talkies to communicate.
The 50 Hz tone that made it hard to breath in my car lasted just over 100 meters. The
A 40 Hz tone made it a little over 200.
A 30 Hz tone wasn't very loud in my car, but made it 600 yards
A 25 Hz tone that coule barely be heard in my car due to my 43 hz tuning made it just over 1000m .

 

Read my above post why sealed boxes are louder outside than inside...

And yes I have experimented myself with the same sub in various configurations and the sealed could be heard from farther away.

 

yea, it kinda sucks that people get pissed when u try to tweek your system... whether its your neighbors, or the people in a parking lot or whatever, they need to realize that really its no different then a soccer team practicing in a feild.... cept for the 140+db..... but thats minor....

but i agree with the whole time and place for everything, when it comes to hittin the volume button.... nice summer day, out cruisin around.... sure.... just kinda be kindful of lyrical content (easy E might be a bad choice for this....) out cruisin the local hotspots on a friday night.... sure... but be mindful of where u park your car after advertising the system to all the ladies.... (and the nice guys who would kindly take all that dead weight outta your car and even sell it on your unknowing behalf).....

ressie areas past say 9pm probly not a great idea.... and not within about 2 blocks of your house.... again nice neighbors willing to do weight reductions on your car for the price of a new window.....

 

When the distance from a source of sound is changed by a factor of two, you either loose or gain 6db.

It seems to me that if we are dealing with a driver in an open environment, the sub's resonant frequency (fs) is going to be produced the loudest at any distance. In a sealed box, fb will be produced the loudest. in a ported box fb will also be produced the loudest as long as fb is the same or higher then the drivers fs. If the ported box is in a car then fc is going to be produced the loudest provided fc is higher then fb. If fc is less then that, then fb will still be the produced the loudest.

More then likely in your experiment, 43Hz should have been the loudest at any distance....

 

Forgot to add one piece of insight that's kind of relavent to the topic.

As I recall, it's not really possible to break 150db in an open environment by any conventional means...

So, say you have an SPL car that's making 149db's at 1 meter from the window... roughly speaking, at 1km it would be whisper loud....

 

Just a last word on this... the highest score ever recorded in a drive-by SPL competition was 129.4dB using a Treo sub if I remember right, 6 feet from the open windows of the car.

 

actually, the loudest cars in open air are a pair of chargers that appeared in CAE about 6 months ago, and they were metered @ 169 or so dB out in the open.

 

???? dosen't seem very likely to me..... maybe they were doing outlaw and just had the doors open or something (but the mic was still in the car)????

Any link to this info ???