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Old 4th May 2013, 08:47 PM   #1761
bcmbob is offline bcmbob  United States
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Foam with a piece of plywood to assist driver mounting. If there is a problem I'll do the entire front baffle with wood. I have a super thin Japanese veneer saw if I need to swap it out.
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Old 5th May 2013, 05:34 PM   #1762
xrk971 is online now xrk971  United States
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I think the DNA may be better off with its own thread I started here: Decware DNA Horn

I just posted simulations of the DNA BLH in the new thread. Short story is that it is a good design. For the cheap MCM 55-1870 driver, reduce the driver chamber volume to about 10 liters. Instead of a round hole between the driver chamber and main horn, an equivalent 0.70 in wide x 7 in deep slot can work just as well.

Here is the simulation for the MCM driver:
Click the image to open in full size.

With stuffing in driver chamber the peaks dshould go away.
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Old 6th May 2013, 07:58 AM   #1763
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Talking I love this Thread!

Hi everyone.

This is my first time posting anything within the speaker section of the forum. Been reading through the FR section with keen interest and loved the idea of putting together some foam board speakers just for fun...

Bought some 10Watt 8Ohm 3" No-Name drivers of e-bay and a pack of foam board of Amazon. Then spent some time putting together these micro FonKen based enclosures...

Aim was to make some test speakers for an 8 Watt amp that's under construction. After a brief test, they sound good but completely lack any LF. Plus, the cabs could have done with dampening material internally beyond the lambs wool [as is recommended], as they just radiate the sound every which way... Still detailing is good enough...

Had fun and might give a few stranger designs a go in the near future...

Paul
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File Type: jpg mFonken_2.JPG (453.8 KB, 279 views)
File Type: jpg mFonken_3.JPG (441.7 KB, 246 views)
File Type: jpg mFonken_4.JPG (419.4 KB, 229 views)
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Old 6th May 2013, 10:40 AM   #1764
xrk971 is online now xrk971  United States
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Buildmesomething,
Wow! Those cabinets look fantastic! You are one of the first people to use the foam core as if it were wood. I see rabbet joints, dados, etc. The fit and finish, I have to say, is the best I have ever seen anyone do in FC! Sorry you did not get much bass out of this design. It may be a mostly due to the driver/cabinet combo. Did you design the cabinet volume/slot dimensions based on the T/S parameters of the drivers you purchased? Because the uFonken cabinets have pretty good bass for a 3 incher when paired with something like FF85wk, from what I have heard.
Keep up the excellent work. Might I suggest you try a MLTL with a 3 in driver if you want bass? Or be one of the first to try the DNA horn with the budget NS525 driver - that thing WILL have lots of bass, down into 30 Hz. Thanks for sharing.
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X

Your craftsmanship is really inspiring.
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Old 6th May 2013, 11:22 AM   #1765
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Excellent workmanship. Also, what is a DNA horn?????
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Old 6th May 2013, 11:43 AM   #1766
xrk971 is online now xrk971  United States
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Ken,
The DNA horn is a design by Steve Deckert, aka Decware. It is the subject of the named thread. Check it out - you would be interested in this design. So far it looks like it may be the budget design of all time with a $3.60 driver and maybe 3 or 4 sheets of FC and should reach 30 Hz with authority. My simulations show that it is a real good design with bass potential. Being a rear firing horn mouth, the sound should sound bigger than its diminutive size may suggest.

The plan is here. Print it out to scale using tiles in PDF print function.
http://www.diyaudio.com/forums/attac...dimensions.pdf

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Old 6th May 2013, 12:23 PM   #1767
KLBIrd is offline KLBIrd  United States
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Thanks for the information. It looks like a real jigsaw puzzle for MDF or wood but in foam it might be easy. I am dubious of "miracle" enclosures promising bass beyond the physics involved but I will give it a try. I have some of the newly released Audience three inch full range drivers and will try one in the DNA. Will post the results.
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Old 6th May 2013, 12:52 PM   #1768
xrk971 is online now xrk971  United States
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Ken,
The implementation of the DNA in FC is indeed simple: the one long stretch internal wall with lots of folds can actually done in one piece with scoring to provide the bends and folds. It is no miracle beyond physics as I have modeled it in AkAbak (with physics) and it does show that it has deep bass extension. You can't just stick your 3 in Audience in it and expect it to work though - get me the T/S params for your driver and I will see what the simulation predicts - maybe there is some optimization to cabinet size, throat or volume that may help.
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Old 6th May 2013, 06:17 PM   #1769
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Thanks X & K ... Looked at a FC building guild by a Warhammer gamer, who recommended using rabbet joints etc. for stronger joints, so I went with that in full...

Unfortunately, I was unable to find any details about the driver. Only what the seller posted for the sale, details say 120Hz - 16KHz so wasn't expecting to much. Will have to do a frequency sweep to find how low they go... And pick music that suites.

Those DNA Horns look impressive, will have a look at driver availability here in the UK... Thanks again

Edit: just priced up a pair of NS525 drivers shipped to the UK from Madisound, $54.81... $47.61 is shipping Not found any info on a UK source yet.
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Last edited by BuildMeSomething; 6th May 2013 at 06:46 PM.
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Old 6th May 2013, 08:17 PM   #1770
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@xrk971---I sat down and tried to model the DNA from the PDF you attached. Some of the numbers are not adding up. Any chance of getting Lengths of each horn segment?
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