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Discussion Starter #1
About four months ago I built a test box(23.5" cubed-sealed) for my new Tempest-X and EP2500.
Then I broke my wrist and was casted. Just after getting my cast off I was jumped and robbed and broke two ribs.

I am finally in good enough shape to build my ported enclosure.


Want to use .75" MDF. I will reuse any panels I can from my sealed box as well.
I tried, when new, to calibrate my sound card and then take readings, but never figured it out after spending time and money.
I'm afraid I still wouldn't be able to do it successfully without a step by step walk through which is a pain in the for anyone.

So....anyone want to step in front of the bus to help? (have tons of room to work with, but a salways the smaller the better unless it robs performance)
 

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Discussion Starter #3
I thought when I did the numbers it was like 5.6, but yeah way too small for ported.
Any of those five are within usable size.
 

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Discussion Starter #5
Right and since mine is double front with one brace and sealed so no port it was ~5.6 net I think.

That's what my research has shown as well in regards to the 13cuft build, but how much does the room play into things?(this is why I went through the trouble of trying to calibrate so I could test to help others help me)

Thanks Mike.
 

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In 13 cu.ft., tuned to 16 hz with 600 watts input, Xmax is reaches at 13.5hz, a HPF is probably not needed.
Tuning the same size cabinet to 19 hz, with 600 watts input, Xmax is reaches at 16 hz and a HPF would be needed at 15 hz.
That being the case, a 16 hz tune would provide more low end ouput and have a smoother overall frequency response.

Eagles.JPG
 

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Discussion Starter #8
Very cool!
Thanks for the work!!
Anyway to overlap the sealed box's curve?

Big thumbs up to Mike!
(**What numbers do you use for the Tempest-X?....my T/S were incomplete an possibly wrong)
 

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Discussion Starter #10
Thanks for the help and link.
I'm suprised they all model basically the same from 50Hz up....I suppose I'll need some boost somewhere above 45Hz.

Is there 8" pvc? Those flares from wood look difficult, have to decide on dimensions. :)
 

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Eagles,

Why not do Neo-Dan's MAX slot-port end-table (the larger one)? 8cf, slot-port, reasonable dimensions w/o getting too huge. Requires fill, but so? His graphs looked excellent. As a matter of fact, that's the box I'm planning (first box!) to build here in a couple of weeks. EP2500, IXL 18.2.2, and on reluctant wife! :foottap: O'well, I'm way hooked on this stuff!

Good luck!

--D
 

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Discussion Starter #12
Dan actually made my my grounded xlr cable as well.
Only thing is 8cuft seems small for a tempest-x.....this driver needs/wants alot of space.(seemingly more than its' 18" brother)

Luckily I've been too busy, so I still have some time to think about it.
 

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Interestingly they Tempest X models very well in that small (8cf) ported box too. Theoretical yes, but still very impressive when compared to it's 13cf brethren.

Of course I'm still a noob at this and the more I study the less I know! Example is every time I decide on the small Easy Button Max End Table design, I study some more and start to shudder that I won't get the SPL out of it that I want...Then start thinking sealed is the way to go (my wife is NOT pleased about a 18" anything in our HT room!

Never the less, I should have my driver next week. :smile: I'll post my build and results as this adventure begins.

--D
 

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You could also look into passive radiators instead of a port. It is a lot more expensive, but with two 18" PR1816's from Creative Sound you can tune it to 15 Hz and not have to worry about the port fitting, or port chuffing, or losing the port volume. The only problem is that the box size is still too small... You are looking at a f3 of about 25Hz with a 15Hz tune, not impressive... Also with your 16hz tune and 13 cubic feet, and an eight inch port, the port length is 35" which is proabably too long for the box. At 1000 watts your port air speed is off the chart and your waaay over your xmax too.
 

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Discussion Starter #15
Yeah, at the price of PR's I would rather buy a second driver.

Still not sure of what to do here....figured better not to rush into something.
Possibilities include:
1. Build a ~8/9cuft ported box as long as the 8x32 port works well enough
2. Build a ~12/13cuft ported
3. Buy a second driver and build a second sealed enclosure(maybe too much space taken up if collocated and that's what I would want to do most likely)
4. Sell my driver and enclosure and buy a more monstrous driver that can handle tons of juice(1K-2K) in a relatively small enclosure
 

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I'm in the same boat as you EAGLES. I'm torn between a solid sealed 24" box, or NeoDan's end-table (the bigger one). My Mach5 18.2.2 (I got the last one :) ) will be here next week.

My feeling is that building both won't be that big of a deal. WAF is important, but the overall low-end extension is important to me. In the event that I find I'm LOVING the 8^3 stuffed slot port I'll keep it. If I find that the 24" cube is just dandy, the wife will be happy! , BFD's on e-bay right now are in the $40 shipped range. Nothing really to loose there! I'm just itchin' to find out how Dan's design sounds with an 18" driver. I can think of a lot of things worse than spending a weekend building a nice slot-port box and a 24" cube to apease my bass jones!
 

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Discussion Starter #17
I thought I had read that the BFD's had issues in certain set-ups....sure wish I could remember.
That is a sick price, but don't want to throw away money either.
 

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Hey Eagles,

I'd skip the PR approach because I feel the same way that you do about just buying another driver. If you do go ported skip the 8cu footer and go for the 13ft design to really see what the TempestX can do in a ported box.
 

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Discussion Starter #20
ROFL.
I wish one could do that actually....would allow for a smaller box and if you could run them behind a screen or entertainment set-up.... :)
 
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