Beginning of some DIY speakers

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klankymen said:
awesome! How did you end up doing the woofer holes?

Our project has been put on hold for a while as well, but we are also due to continue next weekend (routing the holes).

I used an adjustable circle cutter for the main hole (just a tad smaller than 4"), then ran a slight chamfer on the front (so that the stepped part of the woofer can sit right) and a 1cm chamfer on the back. Turns out I didn't route deep enough on the front, leaves about a millimeter of space once it's screwed tight. Also, you might want to return your woofers (I can't, as I caulked them in this morning before reading Zaph's post). Apparently, MCM has released their die cast aluminum framed woofers: http://mcmelectronics.com/product/55-3853 that doesn't have the stepped portion:

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Coming to the Zaph Audio test baffle...

New MCM cast frame woofers 55-3870 (5") and 55-3853 (4"). These are based on the aluminum cone designs they've had for a while, such as the 55-1853 that I use in the ZBM4 design. A flimsy frame is indeed a low point of that driver, so I'll take a look at these and see if they are worth the additional cost. A redesign of the ZBM4 with the current Dayton ND20FB is in order, so I might as well take a look at that woofer right away too. The 5" version appears to have an excellent well ventilated frame, a large step up from the cheap stamped frame in the 55-1870. What we can't see is any other changes that there may be in the surround, spider and motor that may improve performance or make it worse. We'll see. Also, I'll be testing the current ferrofluid version of the Dayton front mount neo ND20FA tweeter. I'm expecting differences from the old T version.

Brendan
 
I just realized I didn't finish my log...stupid me. The following pictures are a couple months old....sorta like a look back in time LOL. Finished assembling the dampening that will go in the speakers. Zaph's plans called for some Sonic Barrier...but ever the cheap-***, I decided to use a mixture of carpet padding with two different densities, similar to the 3-layer approach. For the back and the top I layered two pieces of chopped foam padding with some denser open-celled padding to create a 1 1/4" pad. The sides and bottom were covered in a pad consisting of two sheets of chopped-foam. My homemade approach worked relatively well...absorbed the unnecessary bass frequencies and tamed down the muddiness...which left me with a pair of pretty balanced and neutral bookshelf speakers.

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General shot of dampening.

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2-layer stuff.

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1-layer.

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Best spray adhesive for open-celled foam...impossible to tear apart bond...foam rips first.

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Back and top done.

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Closeup.

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Current source (rockboxed Sansa with attenuator and JBL Power 20)

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Angle shot (temporarily home)

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Another angle shot (temporarily home)

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Beauty shot (temporarily home)

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Living on my desk for the time being.

I know I should get some stands...believe me, it's in the works...plans are to get a couple of cinder blocks and glue them end to end so that they make a column. Seal, then paint them, install some spikes at the bottom, and voila...homemade 'dead' stands. I hoped you enjoyed this thread...pretty rewarding and satisfying.

Brendan
 
Nice work, looks really good cyber.

Any word on that bargain mini rework with the 5inch cast frame and the PE neo tweet? Such a tease, to set you up with a XO for the tweet - I hope the feedback you gave him was good enough that he decides to publish. I understand the Madisound tweeter is fragile, hence my preference for the PE...
 
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