I'm in the very beginning process of building another pair of Ricks speakers and I started thinking that it might be of help to those of you who are thinking about or planning to build a Selah kit if I post a design/build journal or blog, if you would call it that. I'll try to keep it succinct but please be patient with my casual stream-of-consciousness style of writing.
I posted in Ricks circle a while back asking for input on a 3-way design. I trust Ricks judgement 100% but handing Rick a sum of money for a ready made kit was too easy. I wanted to get a little input from other folks here and throw Rick a curveball. Driver selection turned into a bit of a learning experience for me, and hopefully for any of those who followed the thread. Bryan, one of Ricks dealers, was very helpful in driver selection, infact Bryan just about called the driver lineup that will be used in this design. We have spoken quite a bit over the past couple years so Bryan had a pretty good idea of what I was looking for, his input was valuable.
There were many factors which went into the driver selection, including my
massive room size 45' L x 22' W x 14' H, my favorite music style which is mostly acoustic with a mix of alt/modern rock & Latin, a budget of $2k for parts and most importantly Ricks willingness to take on the commission with the somewhat random heap of drivers I specified. I should note that one reason I
keep going back to Selah is because of Ricks willingness to adapt a design or invent a design based on
my individual needs. I liken the service of Selah to what I think of as an exceptional dining experience where the chef is willing to do a tasting menu based on my personal preferences.
The drivers:Bass: Seas L26 2ea.
Mids: Seas w15 Nextel 2ea
Tweet: Scan Speak 6600 AirCirc
The test drivers are slowly trickling into Ricks shop so it will be a short while until Rick gets into his "mad scientist" mode. So, for now I'm left to decide on cabinet design. I should preface by telling you that I own and operate a small/medium sized woodshop and I will be building the cabinets in-house. I will, for the most part, use equipment that is not beyond the scope of most hobby woodworkers. I must warn everyone that have a taste for modern design, more specifically
BAUHAUS STYLE and these cabinets will reflect it. These will not be your typical "box".
This thread could go on for quite some time as this is going to be a rather casual project for both Rick and I. To help keep the length of this thread from getting out of hand I kindly ask that general questions not be posted here. I will gladly answer questions regarding the build process through PM and Rick, I'm sure, will happily answer any design specific questions in a new thread or PM. Rather than add more posts to this thread I will continue to modify this post with new informationThanks
-c.
More to come....
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2/27/07
Enclosure design is underway. Because I chose to have Rick design this speaker with
front firing L26 Bass drivers vs. sidefiring, I am pretty much forced to build two enclosures, an upper and lower, per channel. There are solutions for single cabinet designs, such as Rick and Bryan did with the RC5 but this approach is a bit monolithic for this project.
Rick has given me rough baffle width specifications of 8" for the top enclosure (mtm) and 12" for the lower bass enclsure (ww). Volume, which will have a little bearing on the height of the enclosure and much to do with the depth, is yet to be established. for the time being I am working on the "facade" of the enclosure. My inspiration for the facade is based loosly on a
CHAIR called the Wassily chair by Marcel Breuer. The enclosures themselves will lack sharp corners and will visually have a curved, flowing appearance. My aim is to get away from the sort of monolithic or stacked shoe box look that is conducive to this type of 3-way design.
To soften to look and emphasize line, I will use large radius horizontal lines. I would like to use 2" radius edges on the upper cabinet and 3" radius on the lower cabinet, again these are the
horizontal edges I'm talking about. To accomplish this I can build a square edged box and use a router table or shaper and round the horizontal edges but frankly I don't have bits large enough to do the job. So I will use preformed corners which are readily available.
If the upper enclosure was tipped on it's side it would resemble this...sort of
:
This is about as far as I can go without knowing the internal volume and ultimately height & depth of the two enclosures.
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Found two sources for bent plywood aka quarter cylinders to make the horizontal edges
AIT and
Tape Ease This should be a heck of a lot easier that making my own bent laminations.
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Update 3/6/07
Still patiently waiting on the new Aircirc ss6600 tweeters to roll in at Madisound.
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Updated 4/3/07
Experimenting in my shop with high pressure laminates trying to get the laminate to bend around a 3" radius with causing any stress cracks or craze. I've found a great laminate called MicroDot by Formica but not sure how to bend it yet. I first saw this stuff used as the top surface on a very expensive custom table on one of my jobsites...to think is just Formica
If I can get it to bend easily I will use MicroDot with solid fronts and backs.
Kicking around some ideas....
Black Microdot with Maple or American Black Cherry baffles
White Microdot with Walnut baffles
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Update 4/11
Box volume for the dual L26 drivers is going to be just short of 4ft^3. This is going to be a petty big box but not too bad to deal with, the big rounded corners might help out a bit from a visual standpoint.
I ordered a 4x8 sheet of MicroDot in both "White" and "Steel" colors. I also ordered a new color called "Oxygen" but it is back ordered for quite a while. This stuff is priced abou tthe same as a moderately priced wood veneer. I'm not too far from building boxes as Rick is pulling the design together quite nicely.
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Update 4/20
Laminate sheets came in today. While this stuff looks nothing like a traditional countertop laminate and infact is a bit more expensive than the normal laminates but for this applocation I believe the price is justified. Rick and I were in contact regarding final box volumes and baffle dimensions today. Once he OK's my specs, and feels comfortable with the test boxes I'm good to begin building
. I will begin posting photos in the very near future to show the build process.
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Update 4/23
Still trying to get the MicroDot Formica wrapped around a 2" radius corner. This stuff is very think and meant for horizontal applications, to my knowledge it's not sold in a V32 grade for forming. I'm having a hell of a time but it's too cool to give up.....
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Update 4/24
Rick gave me the go ahead on the cabinet dimensions. Spent the day in my shop cutting boxes. I was able to bend MDF on a 2" radius without trouble so I didn't need to use the preformed radius corners that I mentioned earlier. Figured out the key to get the MicroDot to bend is heat evenly to 315* I shot a heap of pics in the shop today but I cannot locate the cord to my camera
. I will post all the pics ASAP. In the meantime there is a good little bit on bending MDF with pics
here.
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Update 4/26
Still no camera cord...I'll grab a card reader tonight. The pics from yesteday are not pretty......
I've seen lots of references to bend MDF with kerf cuts. Did you fill in the voids left in the kerfs with anything after the bend?
Yes, I fill the voids with epoxy/mdf dust (as a thickner) before bending and then wipe off any excess that gets pushed out of the kerfs. I tried to bend the entire speaker cabinet when it was prelaminated with the MicroDot and it gave out....broke in a few placeson the bent corners and I went ahead and broke it in a few more out of frustration
.
I think you must first bend the mdf into shape, allow it to dry and
then apply your outer layer, whatever that moght be...formica, veneer, paint, etc. I actually thought this from the beginning but I wanted too badly for this to be a "piece of cake", one-step operation, which it isn't. The shear strength of the contact cement (if using Formica) or rigid glueline (veneer) is too great and doesn't allow "slip" to happen on the outside of the bend. Back to the drawing board....another cabinet in the garbage.
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Ran out of room, can't continue to add to this post so I continued this on page 4....added pics
