18" Easy Button End Tables 24" x 21" x 36" hwd

This will be my construction and documentation thread

This will work with anything from a Dayton Classic 18" with a 240 watt plate amp up to the Exodus Audio Maelstrom-X on 3KW. The RSS390HF-4 and the BASH 300 look good. I'm personally thinking the eD 19Ov.2 on a EP2500 will be used in my build.

Every version should include some form of subsonic filter at ~10Hz, the PE and BASH plate amps are easiest, I can calculate the resistor values and post them. Once I get the EP2500 I plan on figuring out how to mod the filters, I will share that info

Proposed build:
24" x 21" x 36" hwd
Internal volume just over 6'³ @ ~10Hz, port area > 6" id.
The experiment is to get the low tune and useable response into the single digits while cheating the port resonance



This set of cut sheets is for a two cabinet build. You will need 4 sheets of 3/4" MDF

You need to make two #1, one #2, and one #3.

UPDATE:
I have come up with a slightly larger design that features larger ports with an aggregate area >8"Id. The volume is also up around 6.375'³ the tuning should come in around 12Hz.
You will need a 1.25" round-over for the port bends and opening, it's available at MLCS.
Don't forget the 4-$2.50 pillows from Wal-Mart
The Shiva-X on a filter modded(easy to do) PE BASH 500 would be provide amazing deep bass response in this box.







Here is a 6'³ sealed vs old vs new comparison:

Raw response, no SSF or room gain added.
As you can see there is ~2dB more output on the low end vs the old design.
The response with the Maelstrom-X will still tend to be a bit lean in most rooms, but it has all the usable extension and articulation you could ever hope for. The system group delay factor (Sum of (GDxHz) is below 250 down to 15Hz.

Construction Section:

Just got back from HomeDepot




You will need a roundover bit 1.5" or 1.25" will work
MLCS has them @ $46 for the 1.5" #8658 or 39$ for the 1.25" #8659

Here are the Cut sheets for the single cab build:

tundrSQ,
I do have a smaller version for 15" divers that is 3 sheets for 2 boxes.

But for this you could use 2 handi panels instead of the 4th sheet, to save some money. I just noticed Friday when I bought MDF the pricing for 4 handi panels is almost exactly the same as a regular 49" x 97" sheet.

Good point, I think there is more than enough scrap to get these cut.

Right,
like you would ever NEED another sub

Just busting your chops

You've not even got your BEAST running yet.

Your just hooked on MDF dust ........ Like me

Those TC colseout 12" are a sweet deal, 3= 4ohm load though.

Me, I like the 19Ov.2, as long as the params are not BS.

I ordered an 19Ov.2 this afternoon. So we shall see shortly.

I requested in the notes of my order that they include detailed TS params (including inductance) for both versions of the 19Ov.2 to be published in this thread along with the parameters I measure here. We shall see if there service/support is on the ball

Kil4Thril,
Good idea. I'll invite them over while I'm at it


*****

Here is a preliminary of the in-room response I am shooting for. This would take into account a custom modded EP2500 filter section and room gain of 6dB per octave @30Hz. Most rooms have better gain than that. The rising response will be mostly eliminated by bass management, but this gives you the option to raise the X-over point for when you want to get lots of impact.
I have a couple parametric EQ's already that will allow me to prototype this filter before I mod the EP2500. I am waiting to order the EP2500 until after I've got the sub completed, should take about a week.

I have now inhaled enough mdf fiber to officially have "Woodboogers"



Hopefully I'll get the four holes router'd out in the braces and then it's on to glue up

Kubbie,
I had a headache till just a couple hours ago. I used to get nosebleeds when I cut lots of MDF.

Update,
eD shipped yesterday, yea.
It's about this far away:


I'm feeling a bit screwed though. I can't locate my Jasper Jig to cut the two holes in the braces:


I've got no real extra cash ATM so I'm gonna give a good look around before I bite the bullet and go buy another router that I have a Circle Jig for.

tundrSQ,
i have some Baltic Birch but I I'm more partial to MDF, that is the saw is more partial to it.

I found the Jasper Jig I had used it as a shim when I reassembled s squirrel cage fan from a HVAC unit. that was why I knew I had just seen it. I had been walking by it several times daily.

There was decent progress today: click on picture for slideshow


And my driver has left columbus and should be local within the next hour or so.

kemist1117,
the origional version is narrower at 18.5" . I would tennetavely recomend the 21" wide version I am building now, but hold on untill I confirm tuning. I Will have to redraw the origional if you want it.

Here is a link to the origional

The current has more bracing and a double baffle to allow you to flush mount the driver

I used 1.5" raidus in the drawings, there's still plenty of meat there.
The bar clamps are from Rockler. Not cheap but I catch them on sale.

Plenty of meat in the corners, see:

My woofer got punted by FedEx, causing a bent frame and loose motor assembly:

But I guess that is to be expected when the motor is 2-25mm slices of magnet and a 19mm top plate


Alex at eD was quick to start the process to get the driver picked up and a new one on it's way. I should have a replacement tomorrow.

I finally got one finished
Here is the impedance data for tuning:
;===================================================
Vented box test completed: Sat Apr 26 21:51:39 2008
Vented box drive current 3181.82 uA
Shunts: No Shunts Used
;------------------------------------------------------------------
Revc = 5.1217 (box test)
flo = 7.6685, Zlo = 26.5810
fhi = 34.8161, Zhi = 70.4773
fm = 10.4869, Zmid = 5.8855
Fsb = 25.4592
Ha = 0.4119
Alpha = 0.7912
Qloss = -1.#IND
;-------------------------------------------------------------------

It lives