Project Quick, Easy & Cheap – IXL18.4 LLT - Page 2

soo

I really would like to downfire this sub and have the 3, 4" diam x 34" length port outlets on the opposing wall similar to SonoSub's. (sub on the bottom, port outlets on the top)

That would leave 5.75" between the subs magnet and the end of the ports.

Is that enough room?

Will there be interference having the ports 5.75" directly behind the subwoofer driver?

My IXL18.4 arrived.



And for anyone else questioning the actual depth of the IXL18.4, here's a pic that shows the height next to a tape measure:



Still pondering around my open question (above) regarding the spacing between the the back of the sub and the end of the port, wondering if 5.75" will be enough clearance for the 3, 4" ports?

You've got a great memory. As you and many others have preached you can achieve far superior performance at a fraction of the cost going the DIY route.

With the growing competition it's great to see the prices of these drivers coming down. I would have never thought I would see the day of an 18" sub with an SD of 1029 sq cm, XMAX of 22mm for $235 shipped.

I am extreamely impressed by the Mach5Audio offering.

Oh yeah..

What are people using to mount these beasts? Hurricain nuts? Do they have matching screws? Got any recommendations on size (diam/length) for these?

Excellent. Thanks Scott.

PS. I am very envious of your dual RLP-18s. I can only imagine how complete your theater now is with those two twin coffins.

So I have a funny story to tell.

On the weekend I was at Lowes spec'ing out more materials for the project. I eyeballed a 10' long 4" black ABS pipe which would be perfect if I cut it to make 3 ports. After talking to one of Lowes associates they mentioned that they don't cut the pipe but if I came back during the week he'd get a hacksaw and cut it for me. As I only have a car I had to have the pipe cut.

Anyways. I go back tonight, find another associate and tell him the story that I was there on the weekend and that I wanted to have the pipe cut. He says 1 sec, goes around to the purchasing counter and hands me a hacksaw. Perfect. So I head back and find myself some pipe and begin cutting in the middle of the isle while other shoppers roam around me.

With the noise it's making a few other associates eyeball me and the guy who I spoke to on the weekend comes over and stares at me for a few seconds as I continue to saw away. He then proceeds to say "Excuse sir, what are you doing?" I then explained to him that I was cutting the pipe. He then asked "Where I got the saw from".. At this point I was half tempted to tell him I just went over to the hardware dept and got one but instead decided to let him know another employee authorized my usage of the saw and gave me it to use. The associate is pissed at this point and grabs the saw from my hand and says "He'll cut it".

So he then gets down on the ground with me as I hold the pipe steady in the middle of the plumping section. Hacking away at the pipe.

Maybe not as funny as I type it but I felt it was pretty hilarious while it was happening.


I found it was kinda difficult to cut the pipe accurately all the way around, having the ends meet while keeping the cut at 90 degrees. What are people using to cut ABS pipe perfectly?

Okay. So I've been thinking about the bracing and handling of the long 34" ports.

Before I did any more cutting/glueing I wanted to ensure the design was perfect.

Below are some Sketchup drawings of what I am thinking. Note that the orientation of the subwoofer will be vertical similar to a SonoSub. In my drawings it does not include the dowels and base plate at the end where the sub is located. I welcome peoples comments/advice on this design:

A couple questions.

1) Around the perimeter of the bracing I am leaving 1.5". Could I go thinner? or is 1.5" okay? Does this current bracing I am proposing restrict the airflow to much?

2) Does having the internal ends of the port being flush mounted to the bracing add any adverse effects?

3) Is 5.75" between the end of the port and the back of the driver enough room?

4) How much room should be left between the face of where the subwoofer is and the base plate? Basically how long should the dowels be?

5) I'm leaving 2 5/8" inches in between the ports and the side walls. Is this suffice or should I move the ports closer together, more towards the center leaving more room? What is the effect if the ports are very close together?








Better shot of the bracing itself:

Thanks for the insight.

In regards to #5. If I didn't do a 3/4" roundover on the port endings internal to the enclosure, what am I looking at as far as distance between the ports?

Thanks again for all your help.

Okay, 2 designs,

Design 1: 1.75" between ports, 3.5" from port to side wall
Design 2: 1.5" between ports, 3.75 from port to wall.

Neither one of these is optimal, leaving 4" between the side wall and the port.Assuming I don't round over either ends, which would be better?


Design 1: 1.75" between ports, 3.5" from port to wall.


Design 2: 1.5" between ports, 3.75" from port to wall.

I noticed that BassBox pro reflects that having two flush ends as the vent end type apparently lowers the tuning freq. I am guessing that it has something todo with the end correction calculation?

Below are two screenshots. One with a single flush end reflecting a 14.25hz where as the two flush ends reflect 13.7hz. Not a major difference but still.

Anyone got a technical explanation for this?

I managed to cut out the interior braces this past weekend. I discovered that that my router jig isn't cabable of making small holes (4.5"). So I ended up making the cuts with the jig saw, making them a little larger than the diameter of the 4.5" ABS pipe. This way it will give me some room to move when I'm fitting them through the tight port ends. I'll end up securing them with some small pieces of stock wood and liquid nails.

* Edited substituting with Photobucket image:



Also, I started thinking about the end result and figured I'd cover the 3 ports with some grills.

I was looking at these at Parts Express: 5 1/4" black snap on grills.

.

Anyone had experience with these? Will they be to intrusive causing port whistle/noise?


I wish Parts Express was a little more explicit on their details, outlining the actual diameter (inside/outside)

Anyone know what's going on with AVS?

They are blocking all of my images.. Replacing some of the path with *******

http://www.derekreynolds.com********...d/IMG_2536.jpg

Also wanted to report that I ended up returning my Craftsman router to Sears opting to get a more powerful 2 1/4 Skil 1825 with the multiple base sets (fixed/plunge). I had a $10 off coupon and the router was only $89 which brought the price to $79. I figured for an extra $20 it was worth getting a more powerful router with variable speed and multiple bases.