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Discussion Starter · #1 ·
Updated 4/23/14 with final pictures


I have decided to deviate from the regular Tempest design and turn these bad boys into towers. These will be used as LCR behind a 130" Seymour XD AT screen. I chose to build towers because I wanted to give up as little real estate behind my AT screen as possible.


The original design calls for a box that is 14.5 x 26 x 14.25, mine will be 14.5 x 41 x 9.5 which equates to roughly the same internal volume. 9.5" is about as shallow as I could go while following the rule of thumb to leave the diameter of the port between the rear wall and the end of the port. The port lengths are 6" with roughly a 2.75" diameter that tapers down to (I need to measure again). This depth should also leave me several inches behind the drivers.


Any thoughts on my design?


Amputating Erich's nicely cut CNC front baffle. The top portion left is 20.5". There was just enough room between the woofer cutout and ports to do this.



A new 20.5" bottom board will be glued on with three new port holes cut with my trusty Jasper jig. Prior to cutting Erich's front baffle I traced the new port holes on the new lower baffle. Stacked the three boards together and drilled a pilot hole in the center of each circle. Stacking the boards together and drilling will make sure each new baffle will have the ports in the same location and saves me from doing this 9 times.




I cut a test hole that was 3.75" in diameter, using my setup the port mouth slid in a little too easily. I went down to 3 11/16 and this seemed to fit more snugly with a little cleanup with my drum sander which is why I traced the port holes on each new baffle.



I glued the new baffles together last night. I will try to blend in and route new 1/2" round overs after these are finished drying. I did some test pieces prior to gluing to make sure my router settings are matched up accurately.



With the exception of the braces I have all the boards cut with 3/4" rabbets. Since I had the router out I decided to use my 3/4" rabbeting bit instead of setting up the table saw to do it. About half way through I was wishing I had taken the time to set the table saw up. Using the router took much longer to do.



One big bit.



I am only doubling up the front baffle behind the drivers and a couple inches lower than where my seam in front baffle will be.



Cut all my braces. I am placing 3 "window pane" braces in each box. 1 between the drivers, 1 below the woofer, and another half way down the box.



Rough fit boxes.



I cut a 3" hole in the back for a home made binding cup. I will use posts I bought from Erich.




To get the crossover further away from the magnets I mounted it under a brace. While it will be more difficult to get out if I ever need to, it won't be impossible. I can still get my hand in there through the woofer hole to unscrew it. I drilled bigger mounting holes in the board and hot glued the plastic washers on prior to mounting for convenience. I really don't know what the recommendation is for the minimum distance away from the driver.


I went ahead and put my damping material in and mounted the crossovers. With the length of the cabinets I figured it would be easier to do this prior to fully enclosing them. I chose to use egg crate mattress topper as my damping on the sides and PE damping sheets behind the drivers solely because I had all of this laying around. Used 3M sticky spray to attach. Black spray paint behind the ports.



New front baffle turned out nice. Other than the color of the mdf you can't tell there is a seam or where the new 1/2" round over is.




Finished box prior to painting. I wish I would have taped the driver openings from underneath prior to gluing on the front baffle.



Finished boxes after Duratex.





In relation to size these are sitting in front of a 130" screen.



Now that I have the speakers done I guess I need to start working on the room/wall so I can put these behind the AT screen.


My full collection of HT DIY. Frame for 130" Seymour XD screen, dual 10" NHT, Madisound Swifty bookshelves with stands, and the 3 Tempest. Next build will be 2 - Dayton 18" Ultimax's that have been on backorder.
 

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Discussion Starter · #2 ·
Reserved
 

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Discussion Starter · #5 ·
Realtight, what size are you going with?
 

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Discussion Starter · #11 ·
Sorry I have been slacking with the thread. First post has been updated with current progress.


realtight - way cool dude
Quote:
Originally Posted by tuxedocivic  /t/1524687/tempest-towers-build-thread#post_24554335


Great idea! I'm surprised we don't see more towers.


You may have changed the tuning a bit putting the ports down at the bottom of a slender cab like that. Shouldn't be an issue though.

Thanks for chiming in Tux. I enjoy following your posts. I like the look of the ports at the bottom, but what would it have done performance wise if I would have left the ports directly under the woofer cutout?


I haven't used REW before and don't currently have a mic, but I plan on ordering one from PE and doing some testing when I am all finished up.
 

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Quote:
Originally Posted by tuxedocivic  /t/1524687/tempest-towers-build-thread#post_24554335


Great idea! I'm surprised we don't see more towers.


You may have changed the tuning a bit putting the ports down at the bottom of a slender cab like that. Shouldn't be an issue though.
Would it be better to build the same cabinets as Bud, but leaving the ports in their original location on the baffle?


Has anyone looked at taking one of these designs and adapting into a TL? Would there be any advantage?
 

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Doing a TL with any of these designs is a great idea. I don't have much knoledge of TLs. DIYspeakerguy and EternalVelocity (might not have those names quite right) used to hang around here and throw out TL ideas. To my knowledge, the only draw back of TL is dictated form factor and some added construction complexity. When these designs were first kicked off, we didn't give any box details other than the baffle width. We left it up to the end user to choose their XO parts, design the box, etc. But as more and more people are drawn into the DIY realm, they need some of those details. Then every once in a while, someone changes them, and that can be ok and even encouraged. So I'm happy to see someone is saying "hey I want a Tempest tower" and then building it.


As far as performance is concerned. It probably hasn't changed things much. I'd suggest putting a very thick wad of stuffing in the lower 1/3rd of the enclosure, but that would kill off the ports. So you can't do that, so there will be some line reflection there. What it does depends on the height of the enclosure and a couple other variables. Because the enclosure doesn't have a second chamber in it, like most TLs, there's likely a short wavelength reflection that will change the ~120hz range and possibly the tuning a little is my guess. What that change is I don't know. Leaving the ports in the middle would mean the bottom of the enclosure could have been stuffed like mad and kill that reflection.


Don't lose sleep over it, it's very benign. Might even be an improvement, honest. I was just throwing it out there for people to be aware. I agree it looks good that way. You could try PM'ing Jeff the designer and asking for his opinion if you wanted. But I'm gonna guess once in the room, you'd never know it.
 

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Discussion Starter · #14 ·
Would it be beneficial to go ahead and loosely fill the cabinet with polyfill?
 

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Discussion Starter · #17 ·

Quote:
Originally Posted by WereWolf84  /t/1524687/tempest-towers-build-thread#post_24561819


@Bud Heavy,


do you assemble the crossover on your own? any changes on the crossover configuration since you are building the tower version instead of bookshelf?

I ordered the assembled crossover, hence it is the crossover designed by Jeff Bagby.
 

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Discussion Starter · #20 ·
Updated with some finished pics. I need to start working on the room next so I can put these behind my AT screen.
 
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