TanKen 1808 - Tang Band 1808 Build

jparkhur · « **on:** 24 Apr 2012, 06:41 pm »

I will start to post some build pictures and thoughts one the next week. Time is coming more freely lately and I can get some projects done. I have been provided the following design from David over at Planet10, with much appreciation on my part, thank you. Here is the basic design and will of course be using the Tang Band 1808. I have tried this driver before and really liked it in OB, not in Half Chang, bad on my part. I am looking forward to putting this one together and comparing across the board. The 1808 driver, PE binding posts, wire?, 3/4 bamboo-two 4x8 sheets, (i'll use the extra for a mini pair of fonkens maybe-Dave???, the inside brace will be 3/4 MDF to save on cost. My primary goals are to make a speaker (bamboo is not cheap) that takes my listening level up a few notches especially in the lower frequencies. I have really enjoyed the full range diy stuff here and am looking to mix them with a GR 8 inch sub once Danny has access to the mini amps.

Driver : http://www.parts-express.com/pe/showdetl.cfm?Partnumber=264-894&AID=1457538&PID=5567334&SID=skim23608X823435X96fef81dd116e3d7ad3b4a8c89ff4a04

chrisby · « **Reply #1 on:** 24 Apr 2012, 06:42 pm »

brave man Jon

jparkhur · « **Reply #2 on:** 24 Apr 2012, 06:45 pm »

For some reason Chris, that statement does not sound very good for me? It will be fun... If I screw up the bamboo at 220 a sheet, I will bend myself over......... JP

ejfud · « **Reply #3 on:** 24 Apr 2012, 09:04 pm »

This will be a fun build to watch. They look very cool.

planet10 · « **Reply #4 on:** 24 Apr 2012, 09:15 pm »

Quote from: jparkhur on 24 Apr 2012, 06:41 pm

the inside brace will be 3/4 MDF to save on cost.

Due to its lack of stiffness MDF is a bad choice for the critical holey brace. Use plywood. Or even solid. Using bamboo would be a waste. Using MDF for the brace would be a waste of the bamboo -- if you had to use any MDF, besides the vent spacers, the place to use it would ve the inner sides -- because it is not really seen. Plywood here is the good choice thou (this is how we have done alll our bamboo builds)

dave

planet10 · « **Reply #5 on:** 24 Apr 2012, 09:19 pm »

Quote from: jparkhur on 24 Apr 2012, 06:45 pm

If I screw up the bamboo at 220 a sheet, I will bend myself over...

Jon,

That is why Chris said brave... we made that mistake with PAWO, which led to a near year long search for a driver that would work in the design so as not to have to burn the bamboo.

You are the initial beta builder of this design -- we have a good track record but not perfect with these designs, and always make sure our 1st builds work before making them pretty.

dave

planet10 · « **Reply #6 on:** 24 Apr 2012, 11:47 pm »

When Jon posted the basic drawing to the AC gallery, the forum software mangled it by converting it to a jpg... here is the original.

dave

jparkhur · « **Reply #7 on:** 25 Apr 2012, 12:18 am »

Thanks David. I was just getting to it. Your email sent it as a png full scale and the AC wacked it to the far above. Will change inside brace to left over Baltic Birch. Thanks. Im cutting it.. Live and Die by the Dream....its costly i know.. ever see my half change... ha. ah ah ha

doorman · « **Reply #8 on:** 25 Apr 2012, 01:41 am »

Having built a similar sized pair of floorstanders, using a pair of Dave's FE167E's, I'll be really interested in your experience with the TB's.
Best
Don

planet10 · « **Reply #9 on:** 25 Apr 2012, 04:37 am »

Quote from: doorman on 25 Apr 2012, 01:41 am

Having built a similar sized pair of floorstanders

As tall, but not near as big. After giving it a heft today i'm thinking about 15mm ply.

dave

chrisby · « **Reply #10 on:** 25 Apr 2012, 04:45 pm »

Quote from: jparkhur on 24 Apr 2012, 06:45 pm

For some reason Chris, that statement does not sound very good for me? It will be fun... If I screw up the bamboo at 220 a sheet, I will bend myself over......... JP

that's pretty much where I was going - the largest bamboo enclosures I've made were a much simpler rectangular shape

just take your time with the layout - I tended to go a bit overboard with grain alignment and dadoing on my several bamboo "Ken" builds, and that can cause some grief, and particularly with the highly figured Neapolitan stranded lower yield than you might wish for, but the results speak for themselves.

also, I'd invest in a brand new 80T saw blade for the project, or at the very least one that's freshly resharpened

skeeter99 · « **Reply #11 on:** 3 May 2012, 03:18 am »

Consider me following!! Very cool looking design I cant wait to hear your thoughts with how it turns out!

Scott

mboxler · « **Reply #12 on:** 3 May 2012, 06:43 pm »

Quote from: skeeter99 on 3 May 2012, 03:18 am

Consider me following!! Very cool looking design I cant wait to hear your thoughts with how it turns out!

Scott

+1

I'm breaking in a pair of Zigmahornets with EnABLed Merrill DCA4's. Although the sound is "small", I love the way the speakers disappear while playing soft music. I'd like to try to make a pair of "larger sounding" single driver speakers, so I'll be following your build as well.

Courious...can one build a "square" enclosure first, then rip the front bevels of the already glued pieces, or is it better to bevel first, glue last? I'd use cheaper materials than you...'cause I'm cheap.

Good luck!

Mike

Æ · « **Reply #13 on:** 3 May 2012, 06:58 pm »

Quote from: mboxler on 3 May 2012, 06:43 pm

Courious...can one build a "square" enclosure first, then rip the front bevels of the already glued pieces, or is it better to bevel first, glue last?

Not sure which way is better, but I'd rather build square corners first, then push the assembled enclosure through the table saw with the blade tilted at the correct angle to acheive the bevel.

strider · « **Reply #14 on:** 3 May 2012, 06:58 pm »

Quote from: mboxler on 3 May 2012, 06:43 pm

Courious...can one build a "square" enclosure first, then rip the front bevels of the already glued pieces, or is it better to bevel first, glue last?

Build the enclosure as a rectangular box, then rip the bevels on the cabinet. Just be careful, it gets interesting the longer the rip!

planet10 · « **Reply #15 on:** 3 May 2012, 07:05 pm »

Quote from: mboxler on 3 May 2012, 06:43 pm

Courious...can one build a "square" enclosure first, then rip the front bevels of the already glued pieces, or is it better to bevel first, glue last? I'd use cheaper materials than you...'cause I'm cheap.

With smaller variations you usually build square and then run the box thru a table saw. This gets more problematic as the box gets bigger. For the similar size EmKen (Beta 12 LTA) Chris pre-beveled the sides.

The box design is premised on using reasonable quality materials, ultility grade Baltic Birch (or similar at a minimum) -- MDF is not suitable

dave

Æ · « **Reply #16 on:** 3 May 2012, 07:09 pm »

Quote from: planet10 on 3 May 2012, 07:05 pm

The box design is premised on using reasonable quality materials, ultility grade Baltic Birch (or similar at a minimum) -- MDF is not suitable.

MDF is suitable!

Q: What properties does MDF exhibit?

A: MDF has many qualities that make it an ideal replacement for plywood or particle board. It is dense, flat, stiff, has no knots and is easily machined. Its fine particles provide dimensional stability without a predominant "grain" (as is the case with lumber). Unlike most plywoods, MDF contains no voids, and will deliver sharp edges with no tearout. MDF is very well damped acoustically thus making it an ideal material for speaker enclosures.

planet10 · « **Reply #17 on:** 3 May 2012, 07:54 pm »

Quote from: Æ on 3 May 2012, 07:09 pm

MDF is suitable!

Q: What properties does MDF exhibit?

A: MDF has many qualities that make it an ideal replacement for plywood or particle board. It is dense, flat, stiff, has no knots and is easily machined. Its fine particles provide dimensional stability without a predominant "grain" (as is the case with lumber). Unlike most plywoods, MDF contains no voids, and will deliver sharp edges with no tearout. MDF is very well damped acoustically thus making it an ideal material for speaker enclosures.

This cabinet is designed using the same push the box resonances out of band so that they are never excited methodology.

Material siffness and resonate qualities are paramount. To get as stiff as 18mm BB you'd need 1 1/4" MDF. But that is a lot heavier so to counter the mass lowering resonance you'd have to use even thicker material, say 1 1/2". Now you have even more issues with energy storage, and, due to it's homogenous nature, low Q resonances, which is counter to the need to keep potential resonances of high Q. So you need to add more braces to push resonances and Q higher.

It is easy to see that all the details will need changing. And even in 18mm ply these boxes will not be light (big strong guy, but more practically 2). To get anything even similar in MDF it would weigh on the order of 3x as much. And it still wouldn't have the finesse or sonics. And likely cost more. Especially if you factor in the health care if the extra weight causes a back injury or lands on your toe.

MDF is not suitable.

dave

Æ · « **Reply #18 on:** 3 May 2012, 08:39 pm »

Quote from: planet10 on 3 May 2012, 07:54 pm

MDF is not suitable.

So says you. . . .

Hmmm, I wonder why so many other loudspeaker builders, loudspeaker designers, loudspeaker companies, including those with 'real' engineers use and/or recommend MDF?

MDF is suitable.

jparkhur · « **Reply #19 on:** 3 May 2012, 09:32 pm »

My thread, my build, play nice. I appreciate all the help I have received across the board from many members. The wood shop I stain at has even told me that a solid Baltic is more dense and a better mate to most speakers. Physics is all around us. If I could only be like KEF and own carbon fiber??? I am still working on these and have some changes to materials that everyone will be happy to see.

Play nice please.