Hello guys,
This enclosure is an simple rear loaded horn, that uses transmission line theory to achieve it's lowest possible f0 point, then the f3 point.The "ports" you guys think you see at the back are just handles, built around the angles of the loading wall.They are not even, but provide a good grip area as this little enclosure is heavyyyy.
The angle at front you're seeing is more like 37degrees.The box has 4 folds on the inside, and each has their own expansion rates which eventually add up to the final horn.The only thing different here, is that we have a compression chamber that loads the horn, and provides good rolloff without sounding like a rock falling to the ground lol.The length of the line was calculated to provide 1/4 wave (degree) phase shift, allowing the front and rear wave of the speaker to be in harmony, and not cancel out each other upon exit, making the single woofer sound like two woofers.The horn then works as an expanded wave guide to bring the efficiency up to 50% as measured and predicted by "hornresp". This is a combined efficiency rating.
I once built one of these for a vehicle using one pair of TC T1000 8".On around 1800wrms, at a burp they did 148.9db at 42hz, which is kind of low as compared to what you guys do up here.Please note this was done on IASCA legal windscreen, fully sealed up in a trunk.
Here's the buyer's reveiw of the sub, and before he had an alpine type r 10" woofer.
Here's a link to my build forum, it's the first and only one of it's kind locally here in Trinidad-
http://www.mktrinievents.com/forum/phpBB3/viewforum.php?f=116
Please feel free to join and post your comments there, I will be posting my builds here also for your entertainment !!!!!!!!
Thanks for your complements !!!!!