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Reed Dual MCM 2421 Tapped Horn - ShopSub

post #1 of 70
11/11/10 at 7:18pm
Thread Starter 
My addiction set in again and wanted a pair of subs for my garage aka ShopSub. Lilmike gave me a set of plans and said try this...it should please you. A huge thanks to Lilmike for his incredible/ridiculous design and time most importantly.

Design consists of 2-8" MCM 2421 drivers, in a push-pull slot-loaded tapped horn. 1 1/2 sheet of plywood, and some time, less than $100 bucks into this build.

So far I am powering this single cabinet with a dayton 240 watt plate amp giving approximately 170 watts @ 8ohms. One thing is certain it moves some air and definately exposes noises from your house and garage that you didnt know your house could make. This beauty contains some output!

I took some measurements outside at 2.83v @ 1 meter with a dayton 240 plate amp as shown below.

I will put together a pdf with all the dimensions and layout and such as I did with Lilmike Anarchy Tapped Horn design in case somebody wants to build it and piss off neighbors.







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post #2 of 70
11/11/10 at 7:27pm
Looks great Todd!

Might want to clarify that the drive level is definitely more than a watt there, the numbers are at something like 6 dB above what the model suggests.

Edit - new measurements posted.

Response is nice and flat, that's for sure. Not at all bad for a beta test....

Quit playin on the forum, go crank some tunes and knock more stuff off the walls.
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post #3 of 70
11/11/10 at 7:46pm
That's some clever folding in there!!! Make sure to post the Hornresp charts also please. What is the overall volume on that bad boy?? Nice job guys.
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post #4 of 70
11/11/10 at 8:17pm
Thread Starter 
too late mike, three pictures already took dive bombs, smoked the veneer on my ikea cabinet, but more sadly, a 80+ year old sail boat my grandpa made went sailing off a shelf as well
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post #5 of 70
11/11/10 at 8:31pm
That is sorta funny until the last bit, which just sucks - hope that you can fix the important stuff.
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post #6 of 70
11/11/10 at 8:37pm
Quote:
Originally Posted by tsloms View Post

That's some clever folding in there!!! Make sure to post the Hornresp charts also please. What is the overall volume on that bad boy?? Nice job guys.

Thanks. Rest assured, we will post/share it all. This one measures significantly better than it models. This was the beta build. Todd discovered a few construction issues I'd like to address in the final version of this fold, but to be honest, I don't wanna change too much, I'm afraid I'll screw it up!

By the way - the drivers are on sale in the current flyer....
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post #7 of 70
11/12/10 at 6:53am
That FR graph is a thing of beauty - nice to see this design already in the wild
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post #8 of 70
11/12/10 at 6:54am
Nice folding and execution guys. Response looks good and flat from 35-150hz. Any chance to take a 1w/1m response?
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post #9 of 70
11/12/10 at 7:26am
I was wondering what happened to this old project.

It's nice to see the concept done right. The rear chambers are more even, and are no where near as deep, as it appears half of the driver is free.

Nice work on bifurcating the first two folds together. That can be fun to do.
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post #10 of 70
11/12/10 at 11:12am
Lil-Mike,

After looking at this - I'm wondering if there might not be some mic / or pre-amp clipping or some such. That aside - I'm going to have to build some of these little beasties! I think EVERYONE needs some of these little beasties in their shop/garrage! Gorgeous fold BTW...

And I I have to tell you I can't wait to see how our little project turns out!

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post #11 of 70
11/12/10 at 12:45pm
Thread Starter 
im up for any help. how would i know if i clipped my mic or amp. my plate amp was opened up to 180hz and gain at about 1/4 way open, no pre-amp involved. i will take measurements all day. i will get 1 watt measurements either tonight or tomorrow.
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post #12 of 70
11/12/10 at 1:25pm
Forget measurements throw up the PDF.

Do the measurements afterward.
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post #13 of 70
11/12/10 at 2:21pm
Thread Starter 
i will work on the pdf tonight, i like to put up all the info in a pdf so anyone can print them out and build with ease instead of trying to figure out some chicken scratch stuff and piece meal it together. i may hold off a bit though in respect to lilmike to see if he wants to change the beta to address some of the very minor construction details.

this is the first sub to make my neighbor open her mouth. Out of my THT in living room, 4-TH anarchies in my bedroom and 2 TH Tangbands in my office, this one has got her attention
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post #14 of 70
11/14/10 at 5:48pm
That is a great looking subwoofer. I'm looking to build two somewhat similar for dance music use, but figured I ask a couple of simple questions first.

What are the outside dimensions of your completed sub?

If you had to guess about how much does it weigh? (Or rather, can you lift it yourself?)

The current sub in my home-theater is a pair of sealed 12.5 cubic foot enclosures built into the stage below my screen. Each has a 18" driver capable of displacing 6.5L of air with xmax of 27mm (one way) Needless to say, with 13L of displacement they move a LOT of air and can easily play down into the 10 - 15 Hz range at pretty high levels. You can see them here:
http://www.hometheaterforum.com/foru...0#post_2737960

I don't expect the MCM 2421 woofers in the tapped horn to do the same, but would like them to get down to 35 - 40 Hz. (They will be for dance music, not for home-theater, so they do not need to go as low)

Oh yes, VERY NICE folding of the horn.

Joe L.
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post #15 of 70
11/14/10 at 6:34pm
Very nice guys!
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post #16 of 70
11/14/10 at 7:54pm
that is not an easy build. props!

seems in the same spirit as a danley labhorn...

the transition from a side-by-side to the front fold seems abrupt. i guess that doesn't matter as your frequency response looks pretty good.
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post #17 of 70
11/15/10 at 6:42pm
Thanks to all.

We're working on a few changes to the design based on the results. I really want this to be something that anyone can put together, and I want to get the response as smooth as I can make it. Looks like I can make a change or two to the manifold and improve things on both accounts.

We're also trying to sort out radman12's measurement gear. Ain't it great when the same gear gives you different numbers when you do the same thing???

Ahhhh, hobbies. Glad I don't do this for a living.
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post #18 of 70
11/30/10 at 10:47pm
Awesome folding! I don't see the pics of the freq response though....

Sweet design!!!
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post #19 of 70
11/30/10 at 10:56pm
Quote:
Originally Posted by rhapsodee View Post

Awesome folding! I don't see the pics of the freq response though....

Sweet design!!!

Look one post up for an explanation.

We're working on it....
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post #20 of 70
12/2/10 at 5:22pm
Hi,
The 55-2421 drivers are on sale for $26.99 in the 2010 Winter Deals catalog(page 48), does anyone have one that has a source code printed on the back, it's the code under the red arrow on the back of the catalog?


I'd like to order some drivers if someone could share the code.

Thanks
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post #21 of 70
12/2/10 at 6:29pm
Very cool; what are the exterior dims?
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post #22 of 70
12/2/10 at 6:39pm
Quote:
Originally Posted by NEO Dan View Post

Hi,
The 55-2421 drivers are on sale for $26.99 in the 2010 Winter Deals catalog(page 48), does anyone have one that has a source code printed on the back, it's the code under the red arrow on the back of the catalog?


I'd like to order some drivers if someone could share the code.

Thanks

WSC21A - they're posted on the website too, you just gotta know where to look.

http://www.mcmelectronics.com/conten...mo/flyer/index
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post #23 of 70
12/2/10 at 6:42pm
Quote:
Originally Posted by dykz34 View Post

Very cool; what are the exterior dims?

Hmmm, Prototype 1 is 16" wide, 21 7/16" deep, and 48 1/4" tall.

That may change a little bit though, I have a few ideas I am working on to improve things a touch.
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post #24 of 70
12/2/10 at 7:00pm
Quote:
Originally Posted by lilmike View Post

WSC21A - they're posted on the website too, you just gotta know where to look.

http://www.mcmelectronics.com/conten...mo/flyer/index

DOH... LOL @ me

Thanks Mike
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post #25 of 70
12/3/10 at 8:38am
Quote:
Originally Posted by lilmike View Post

Hmmm, Prototype 1 is 16" wide, 21 7/16" deep, and 48 1/4" tall.

That may change a little bit though, I have a few ideas I am working on to improve things a touch.

Cool, thanks. The original sims and graphs are not posted anymore, but I'm assuming this was a 25 or 30hz horn?
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post #26 of 70
12/3/10 at 9:28am
So about those measurements, I remember a graph was posted and it looked as flat as the dakotas. Dropped off at 30hz but what music goes below that.
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post #27 of 70
12/3/10 at 10:17am
I never got around to posting the sim, as I'm still working on it. This was a beta-build. The radman is a great beta tester. Tuning is a touch under 30 Hz. Response will probably get lumpy above 100 Hz, the question is "by how much". The rework may change tuning a bit, but will make it lots easier to build.

The initial measurements were wonky. Radman12 measured things twice with the same gear, the same setup, and in the same place but he got different results, so we pulled the plots. His SPL meter is the problem, that much we know. We will get it sorted.

I'm working with radman12 to get him hooked up with some better measurement gear, but with real jobs and the rest of life, that's not coming together as fast as I'd hoped it would. Etching my own circuit boards was not easy, but I got that done last weekend.
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post #28 of 70
12/3/10 at 10:25am
Quote:
Originally Posted by lilmike View Post

I'm working with radman12 to get him hooked up with some better measurement gear, but with real jobs and the rest of life, that's not coming together as fast as I'd hoped it would. Etching my own circuit boards was not easy, but I got that done last weekend.

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post #29 of 70
12/3/10 at 11:00am
Quote:
Originally Posted by soho54 View Post
Oh - I'm plenty confused too.....believe me....

This is the DIY section, so I'm in the right place, right???

You see, I'm a DIY-sort of guy, and I often pay dearly for it.

See - I think I can do anything myself....but I don't figure out that I should not have gone down that path until it is WAY TOO LATE to back up...

After several failed attempts, I finally managed to successfully etch some boards for the Wallin mic preamp II. I have the rest of the parts for these and will put at least one together this weekend if I have the time, but I definitely have to brew myself another batch of beer this weekend - I'm running out way too fast (like I said, I'm a DIY sort of guy...)
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post #30 of 70
12/3/10 at 11:42am
Interesting project.

I never mess with boards myself. I tend to go point to point, and add some electrical tape for short prevention. I have actually used old Avon boxes as project casings to minimize bumping into mains connections.
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