Wolfhorn SDX Design Finished - Page 5

What is this "time" thing you speak of? I also write for Allpar.com now and then.

Which reminds me... progress on this horn may be anything but fast. I have too much on my plate right now to hurry things along. I'll git 'er dun as fast as I can, and update as often as I'm able.

It's close enough to build time to just drop these in here, I reckon.



Sketchup zip file attached. It's 2D, but all internal panels are 300mm deep. Not hard to remember. I was too lazy to make this one 3D.

Edit - added full size image to the zip. Photobucket made it too small.

 

SDX 3K.zip 249.27734375k . file

3K has some errors in the corners, it turns out. No horn gain on the two 180 degree bends. Spent the morning working on it, and I now have a version 3L. Box length gets slightly shorter, horn gets slightly taller.

Not bothering with the Hornresp sim on this one. It's almost identical to 3K with a slightly higher corner. In comparisons with the Tang Band horn, however, the slightly higher corner and corresponding 3" shorter horn length is probably an issue with my quick and dirty Sketchup measuring. I won't lengthen this one any more out of concerns I'll run out of wood.

As is, 3L still fits on 3 sheets of stock. Still need the extension piece on that one internal panel. But there's horn gain in the corners again. Probably not the most mathematically accurate, but this is literally all I am willing to do on this. Y'all can pick 3K or 3L as you wish. I'm building 3L. Hoping to start cutting wood later this week as I find time.

 

SDX 3L.zip 220.49609375k . file

Updated the zip file in my last post to make the panel measurements easier to lay out. This post gets a screenshot of my cutlist diagram and the Hornresp sim for version 3L.



Weatherwise, it looks like Saturday is a good day for wood cutting. That may change, but we'll see.

 

whsdxr3l.txt 0.408203125k . file

This one will hit 120dB in quarter space at 16Hz. Just wanted to throw a little more temptation at you

And that's just past Xmax. 300W. Let it get closer to Xmech? Slightly more SPL

Should mention though that anything above 500W in is not recommended. Can't get enough SPL with one of these and 500 watts? Build another one. Over 600W into this box is driver destruction territory.

Well, I would have gotten the woodcutting done today, but somebody's circular saw needs that somebody to go out and buy it a new plywood blade. How did I find this out? The hard way, of course.

I got one cut done, and only one - the new saw guide. Used the old two part guide with a perpendicular board for strengthening to make it.

Gee, do you think the blade's warped at all?



Thankfully, this is only the saw guide. I intentionally left scrap in there for when I do the real cut on one of the side panels from this sheet. So, all is not lost on the wood supply side of it yet.

Here's my cutting platform, built from scrap pieces of pressure treated 2x4:



The drill is so powerful it buried the screws halfway to China in there, so I'm not worried about the saw blade hitting them. Will still avoid cutting near where the screws are.



The bad blade. Lasted me through five sheets of this stuff, and five only. Not sure if that's normal, but around here the pickings are slim for saw blades. Will grab a new one tomorrow if I can and get back at this on the weekend. If the weather holds.

lol - it was really happening.

I just hope the store is still doing the exchange-a-blade stuff. Would be nice to at least recycle the old blade. I could not believe the amount of wobble the thing had by the end of that cut.

The platform is awesome so far. Much easier to work with the saw on that thing off the edge of the patio than scampering across bare concrete on my knees. Longest section of 2x4 is 12 feet - gives it a lot of weight and stability.

Not loose, just dull. Makes me push it too hard, and then it heats up and warps. I ran the saw off the wood after that cut and watched the blade... warped so bad it looked like a record left out in the sun. Then it cooled off and looked almost normal again. Still has some warp to it even cool.

I may have to go to one of my ripping blades to finish this. Too many people owe me money and nobody's paying.

New blade in the house. Also grabbed a few last minute things. Another box of screws just in case 200 isn't enough, the straight brackets that will hold the kludge block to the one panel I can't cut to size (they will be removed before the last panel goes on), and a couple plastic scrapers.

Also grabbed a 1" wood boring bit for the Speakon.



Now, I just need the rain to go away... again...

Gasp... Wolfie's getting stuff done. Uh-oh!

Not a cloud in the sky today, so I was out there making sawdust. Unfortunately, I only managed to get two of the three sheets chopped up today. I don't know about you guys, but when I've been out in the sun and I stop sweating, I also stop working in the sun.

Cutting the two biggest panels for this project is hard enough. Doing it when I haven't been able to exercise properly since last June due to knee issues only makes things harder. I need to work on my cardio.

That said, I am pleased to report that 4 of 12 panels are done and they are accurate to +/- 1mm. You know the saying "measure twice, cut once?" I'm a little more OCD than that. I measured 4-5 times for each cut. Took 3 hours that way, but at least I now have panels way more accurate than the last tapped horn had.

Something else I learned - the new "saw guide" is actually less accurate than the two piece metal straightedge. It's bowed 4mm out in the middle. I had to mount a scrap board to it and clamp it down for tension to make it accurate. As a result, I'm going to have to use the two piece on the final sheet. Those cuts have to be as accurate as I can make them, and I don't see any other way to do it. The two piece has one section that's bowed inward by 1mm. That's acceptable, I think. I'll clamp a stiffening board to it, like in the below picture of my new saw guide - should keep it from bowing inward.

One last thing before pictures. The 40 tooth carbide tipped saw blade is the best thing I ever did. Thanks go to lilmike for the suggestion. Way faster than the plywood blade was, and just as clean cutting.



First cut of the day. Much, much better.



One of the big side panels done.



Working on the mouth side. That masking tape was a suggestion by someone to keep the birch layer from chipping. It didn't work. The saw ripped the tape right off the wood. Ah well... I'm not building a work of art, here. I picked this wood because it was cheap, but good quality.



Four pieces done, in their place of final assembly in front of the projector screen. Tomorrow, I hope to be recovered enough to finish off that last panel.

No such thing around here. Have to go into the city for that... three hour round trip, minimum

Can't use Amazon - credit cards are hard to come by when you have my income. Had a prepaid one last year and regretted that decision every second I had it. I might grab a blade off eBay though, or just wait until I'm in the city for other stuff. I may be done with the big tapped horns for a while, but next year I want to try and build new high efficiency mains. That will be the project I'll really want to keep the birch layer from chipping on.

Meantime, I have to finish this project with the blade I got. No money for anything else. It's doing a good job.

A picture is worth a thousand words:



But I'll toss some words in anyway. All panels are now done and ready for the assembly phase. I had to wait almost all day for the clouds to quit spitting on me, so I wasn't sure how much time I had to get this done. As a result, I only have the one picture.

The two piece saw guide worked perfectly today with the stiffening board clamped in place. Not one cut was off by more than 2mm, and several were dead on. And I mean perfect - 300mm exactly. I had perhaps 10mm of scrap left over on this last sheet after cutting four 8' strips 300mm wide.

The assembly is going to go way better on this project than the last one. Speaking of, that part may start Wednesday. I need a day to rest. I hope to have this beast up and rumbling by Friday.

Wasn't aware they had that option. Will have to check into that again. The new Song of Ice and Fire novel is finally coming out. I'll be wanting me a copy of that.

Just a quick note on the project... I have decided not to brace any internal panels on this monster. I just don't think it's necessary with this wood and the 300mm internal width. Happy to save some time during assembly.

Thanks - I can't wait to hear it for the first time

Day one of assembly phase is over. I got as much done as I could. Some roadblocks included a badly warped driver baffle that is still not straight after 3 hours in the sun, and a compact florescent bulb that failed in a way that looked, smelled, and sounded just like an electrical fire starting.

Seriously, that bulb had me racing all over the basement flipping breakers like crazy until I found the problem. I hate those things.

Anyway, I'm almost at the point I can start with the PL. Thanks to the sawhorses, this part of things went much easier. Once again, the jigsaw chose to annoy me while cutting the driver holes, but I think I got them to the point the surrounds won't rub on the cuts now.

I don't know why I bought a new countersink bit. Five minutes into this, and I suddenly remembered why I stopped using the old one on the last build.

And now, pictures.



Check out my innovative clamping method for the top and bottom panels. These were warped, so I piled weight in there to keep them straight while I drilled and screwed up from underneath.





Working on the driver mounting holes and screws. Wanted to be dead sure of no surround rubbing on the sides of the cutout, so I had one of the SDX's help me with that.



Getting closer. To compensate for the panel warp, I used the weight again to hold it straight so I can drill the mounting holes tomorrow. Maybe the panel will be straight on its own by then... the weight stays there overnight.



Last two panels going in.



Another angle.



Does... does it look like a tapped horn yet? Please say yes. My body is aching something fierce

Looks positively skinny compared to the Tang Band horn, but make no mistake... this one is still plenty huge.

Hope to make more progress tomorrow. Will get things done as I can.

Thanks guys

Just found out I put the driver baffle in right, but messed up on which side I predrilled for the driver mounting screws. Good thing I didn't PL that panel yet, and only have a couple screw holes drilled underneath. Will have to flip it the other way tomorrow.

The warp isn't as bad anymore as it was, but even so I may have to cut a piece of dowel to push the warp out just so I can get the thing together. Will tie a string to it so I can yank it out through the driver holes after the top panel goes on.

Edit - also messed up on the placement for the baffle with the extension, which I did get all the holes drilled on. Nuts! I'll fix it and plug the old holes with screws. That side will be facing the wall, thankfully.

Important note - due to reality differing slightly from the last Hornresp model, I have updated the model to reflect measurements I took of the project a few minutes ago. See attached file for what I should be getting from the final product.

That said, I expect the low corner to drop some, even more than this model shows. My Tang Band horn ended up at 15.5Hz, down from 16Hz. The length of this horn is similar.

 

sdxr3lr2.txt 0.408203125k . file