Re: Active 3-way DIY Setup.
I've been going rather slow with this build. I've been doing this while my 3 year old plays in the driveway on her new bike, so I'll work a bit and then jump on mine to ride with her. Trying to balance this project with being a good Dad. Needless to say, I haven't gotten to where I'd like to be, but I have managed to make some decent progress. I got all the pieces cut for the tower and managed to glue them up, sans the front baffle.
So, here's the point at which I beat myself up... you ready? Let's go...
This was my first time cutting dados and I'd say I got about 75% of them right. The other 25% are about 1/8" too large or have crazy spots in them because the router wandered. :mad:
Reading up on dados before purchasing a bit for the router, I found out that typically 3/4" mdf is actually typically undersized and the dado bit for this kind of project is typically a hair smaller: 23/32". I ordered one up from Amazon. When I got the MDF pieces I realized they're actually oversized... say 0.80". Really?! Man! So, I wound up having to make multiple passes anyway, which effectively doubled the time I thought it would take. Lesson? Don't buy a bit until you get the wood... that, or just plan on doing multiple passes since not all wood is created equal.
I also made a TOTAL nooB mistake when cutting the dados for the top braces (3rd & 4th from the bottom in the picture below). I had taken some pre-measurements to make sure those two would give me the airspace needed for the woofer, and I also liked the idea of having a gap between the woofer and mid volumes. Thinking I could treat it with something later (made a post about it here). Anyway, at some point in the process, I cut the top brace about 2" too high; putting it's location just under where the midrange would mount. Didn't realize it until after I glued up the first cab. Speaking of realizing your mistake once you've already glued, I also realized I didn't cut the air holes for the woofer enclosure brace (2nd brace from the bottom) so I had to do the best I could with a hole saw and jigsaw. I got enough material cut out but it looks ugly. Luckily I caught that before I glued the 2nd tower up so I could cut that brace as needed before it was glued in to place. I'd like to say lesson learned, but I doubt it.
I really seem to have no ability to cut a perfect square but somehow they turned out OK. There are some gaps that are going to get some bondo-glass treatment for sure to cover them up and sturdy up the structure. Somehow or another when cutting the top/bottom pieces, my straight edge wasn't so straight so at one point the piece matches up perfect with the cab, but at the other end, it's off by nearly 1/4". Ugh. :rolleyes: But, as sad as it is, I'm actually REALLY looking forward to the bondo/Rage Gold sanding phase on these. That means I'm closer to the end and those spots should clean up. Anything is better than cutting more MDF. I had that stuff all in my beard. Glad I have a respirator because MDF boogers suck!
Maybe you guys can learn some lessons from my mistakes. But, judging by the caliber of builds here, I'm probably the only one making these mistakes and I also seem to be the only guy here who can't cut a square to save his life! :mad:
All said and done, however, I'm pretty happy with how things turned out. The small gaps I have can be remedied and I can take pride in knowing I did this all myself, as much as an aggravation and time consumer it was. I'm about 80% done with the construction. I'm going to double layer the baffle so I need to glue those pieces together. Before they are glued in, I'll line the enclosures with varying density material and route the wires where needed. Not a whole lot to see, but here's some pictures.
http://img.tapatalk.com/d/14/03/13/apy6ynet.jpg
http://img.tapatalk.com/d/14/03/13/8a8u5yde.jpg
Re: Active 3-way DIY Setup.
I've decided to add some tie-rod in to the equation to provide additional bracing. The reason why is because the rod will hold in both compression and tension, and will do so much better than a jacked up, wanna-be squared brace. :rolleyes: $50 in all thread and hardware and I'm starting to brace the fire out of this enclosure.
These are only the vertical supports. I'm actually also considering adding two more main supports in the woofer cabinet and running a board between those two to act as a seat for the woofer and take any torsional load off the front baffle. Though, that may be completely unnecessary.
Anyway, here are a couple pictures. That middle brace got butchered. The other tower will look better. Thank goodness there'll be a baffle to cover up the screw ups. ;)
Attachment 45501
Attachment 45502
Re: Active 3-way DIY Setup.
The above was carried over from the PE forum, so here's the latest update.
I went and bought more tie-rod.
http://i18.photobucket.com/albums/b1...k/IMG_8896.jpg
Some CLD on the midrange enclosure section
http://i18.photobucket.com/albums/b1...k/IMG_8900.jpg
Insulation/foam/stuffing, with some side threaded rods added to the woofer section.
http://i18.photobucket.com/albums/b1...k/IMG_8904.jpg
Close ups, showing some LLP for added mass loading to the midrange enclosure.
http://i18.photobucket.com/albums/b1...k/IMG_8905.jpg
http://i18.photobucket.com/albums/b1...k/IMG_8906.jpg
Re: Active 3-way DIY Setup.
Ain't nothing wrong with MDF in the house. Looking good man!
Re: Active 3-way DIY Setup.
Thanks!
I hesitate to post build pictures because my wood working skills are nill. But, I'm pretty excited about what it's going to be. I put in about 2 months' of research, simulating and testing stuff before I even started. I even built a test speaker just to play around with various woofer locations for a dual 8" woofer setup, which I wound up scrapping in lieu of the single 10". That scan is a thing of beauty.
I'm still trying to decide if I want to fill that air gap between the woofer and mid enclosures with something. Great stuff was suggested, but that stuff is a mess. I think an air gap with some light fill (as pictured) is best. The great stuff is a great mess and I think the air gap as a good air density variation to the cabinet. Sony actually does something similar it seems with their flagship AR-1 speakers. I was reading their "white paper" on the Sony SS AR1 speaker and they mention leaving an air gap between the woofer enclosure and mid enclosure in the cabinet. Start on page 6. Here's the excerpt:
Quote:
What appears from the outside to be a single enclosure is actually divided inside by two thick birch partitions with an air cavity in between. Just as a double-pane window with air in between helps provide thermal insulation in winter, the partitions and air cavity create two well-insulated enclosures: one for the woofer and one for the midrange/tweeter. The mid/tweeter sub-enclosure is also vented with a bass reflex port that’s been carefully tuned and positioned.
Re: Active 3-way DIY Setup.
I would not put foam in there.
Re: Active 3-way DIY Setup.
I'm really not planning on it. I had it in my hand at the hardware store and then remembered all the times I've cursed it. Not only that, but IF I have to get in that section somehow, for some reason, it's going to be a nightmare. I've already coupled the two braces that make up that gap, but I did so with tie rod to stiffen up the panel. I just have the gut feeling a simple air gap is better all around. But, I have nothing to back that up with... other than it's just plain messy.
Re: Active 3-way DIY Setup.
It's pretty rigid when dry, we all know this, if anything it will defeat the purpose by coupling the 2 chambers further.
Re: Active 3-way DIY Setup.
some is. there's a different version that is intended to remain flexibile. I believe that's the window & door version.
oh, I got one word for you: speakOn. :D