Circlotron, horn loaded bass ports, still interested?

[Cal Weldon]

I made some flare horns out of heavy fiberglass that have the complete flare showing on the port exit and a significant amount horn inside the cabinet to do the "capturing of the air" ie: a compression chamber.

I have tried again and again to import pictures to this site but am unable even after receiving instructions.

So if you are interested, go to:

http://f16.parsimony.net/forum27133/messages/2863.htm
[Cal's Pic's]

I tried to make it a hyperlink.

They ports are the four different coloured things in the center of the upper dual 10's cabinet. If you are wondering, I have set them up as Red Green (Canadian T.V. show), and black & blue (the colour of your eardrums when you are finished listening) The bottoms are Altec A4's if you haven't seen those before.

If you are still interested, I can tell you how the horns were made etc.

Happy Crankin'

Cal

[kelticwizard]

Here is the first pic.

[kelticwizard]

Here is the second pic.

Gotta go for now. Will post instructions on how I did this later.

[Bull]

Really nice soundsystem,looks like the bass horns can shake the foundations.

[Cal Weldon]

Ya Bull,

They probably would if I could get them inside. You see the A4's just don't go in any door I have in my house.
The poor girls have to stay in my garage.
It takes two trucks just to take them somewhere.
My neighbours don't like them.
Time for a new home.

That's OK, I have a smaller outdoor set up using A7 cabinets that suit me better

Cal

[Circlotron]

Originally posted by Cal Weldon
If you are still interested, I can tell you how the horns were made etc.

Of course! In particular, I'd like to know what the performance is like compared to a conventional port. I'm all ears...

[Cal Weldon]

Ok, things to understand:

1) I couldn't find info on how to design these. I thought this my new design, but something told me it could't be, I not that smart.

2) This set up was really just intended to satisfy an itch I needed to scratch. It's been a lot of years since I put something together.

3) It is for outdoor or hall or barn use only, accuracy was little considered, volume was more the issue.

Now, since I was winging it with these port horns, this is how they transpired:
I simply took a 14"circle, cut it in half, put the two curved sides together, spaced them around 1/2" and viola!, this was the start of it. I simply estimated [guessed] at what the spacing should be. The size of the circle was arrived at by using the largest circle possible in the cabinet to make the flare as long as possible, keeping in mind that the full flare of the horn was not to extend into the cabinet, only a portion of it.
I had already built the shell of the cabinets before I decided to go strange on the ports.

A two piece mould was made from wood and arborite, and the horns are made of multi layered fiberglass, some 1oz, then 2oz, then roving and some more 2oz. In all I would guess you would call this about 20oz fibeglass, it's 1/4" thick. After releasing from the mould, placing them against the cabinet, and deciding how much of the back of the horn to cut off to allow for clearance at the back of the cabinet, it looked right at about the 90 maybe 100 degree part of the horn. This left about 3" at the back of the cabinet.

Now the testing was very scientific. I held the first one of these up to some different woofers. woofer on one side, my ear on the other, both near and far. Found that to be useless, then I decided to try having someone speak through it from the backside. That was useless again but kind of funny to see the guy's duck lips when he was finished.

Ok, put them in a cabinet. This is good. The bass response from the port is quite low, which for me is good, cause I'm not to into muddled bass. Have someone place a towel in the port to block it to check for the difference. Good again. Noticeable drop in the very low end.

Testing complete. Finish horns. Use ends of spray paint cans for horns. End up with enough paint in each can to do one horn. Have the only multi coloured speakers on your block. Make mid/tweeter boxes. Buy A4 cabinets on ebay, paint, fill with woofers, hook up and listen.

Smile