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Discussion Starter #62
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.
 

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Discussion Starter #63
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 :D

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.
 

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Discussion Starter #64
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.
 

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Discussion Starter #66
Might be Saturday now. I want the PL to cure on the bottom before the top goes on so I can check for leaks, so I'll do most of the gluing today, finish it off tomorrow, and then the drivers go in on Saturday. Since I left so little room for drivers, I need to make sure I chisel off any PL beads that might keep them from mounting properly.

It's going to be fun to reach the back screws on that innermost driver even with my long arms. This isn't like the Tang Band build, where I had two oval drivers going in right at the mouth.
 

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Discussion Starter #68
In room, against at least one wall? Should do at least 118dB at 1M at 15Hz with 300W in. I'll be running it corner loaded, eighth space, with 350W, so I should see a good bit more than that.

Heavy seems hardly the word... I'm glad those plastic sawhorses are holding :rofl2:
 

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Discussion Starter #70
Depends on the room.

Truth be told, the SDX drivers are only a little behind those used in the Danley DTS-10 in terms of total displacement. If I did good, this box will compete well in terms of SPL with that one. I won't make any promises though, and there's no question it will sound different. I just don't know how different.
 

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Discussion Starter #72
That's the idea :D

I didn't set out to match that box on purpose, but as time went on and I started seeing measurements of the DTS-10 and its drivers, I realized I was closer than I thought. Even the TB W8Q-1071F horn I built is not that far off in terms of driver displacement. Too bad that one turned out to be so unrealistically gigantic.

Realistically though, I expect this project is still a fair bit bigger than the Danley and I don't have the advantage of knowing everything Tom Danley knows. I'll be ecstatic if this thing ends up being even close to Tom's work. All I wanted was an improvement on the TB horn, really, and I think I've easily done that.

And it never hurts to learn new stuff. Learned a lot from the last horn, learning more from this one. Next time, I'll try multiple flare rates. I could have had a better horn than this with these drivers... need to get the folding of the multiples nailed down. My horn modeling abilities are way ahead of my construction abilities.

Anyway, back to the project with me now. Drilling the final holes this morning... PL goes down this afternoon.
 

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Discussion Starter #73
PL phase 1 is complete - all panels are permanently married to the bottom panel now.

This went a whole lot smoother than the last time. Mostly because I knew this time I had enough time to lay down a nice, slow bead... no need to rush things. The partial tube of PL from the storage room did indeed yield useful adhesive, but I had to squeeze the gun grip like Hercules to get it out of there. However, as a result, it looks like I will get this whole project done without even touching my second new tube of the stuff.

Did I get some on my hands? Yes. But the second I did, I went over and washed my hands with the mineral spirits. As a result, I don't seem to have stained hands this time. Of course, I didn't kick the bucket of mineral spirits over this time either. This was helpful in cleaning my slipjoint pliers too, which were in charge of removing and replacing the nail in the PL.

I also used several pieces of scrap wood this time for resting the PL tube on, so I have a lot less of the stuff smeared all over the horn panels inside.

And now, pictures. I decided not to use polyfill at all in this one, though it will get stuffed inside the dead space in front of the horn throat just in case.



Getting ready to PL the first panel... the throat block.



The old tube, ready to go.



Throat segment in place, including the driver baffle. The driver baffle was tough, because it was still warped to kingdom come.



How I pushed out the warp so I could screw the panel down. The dowel has now been removed. That panel ain't going anywhere now.



PL goes down for the last panel. I did inner panels first so that the two side panels would hold the big bottom panel true while I worked on the inner fold panels, and then did the outer panels last with the inner panels holding things true. Worked out great.



All done. Tomorrow I check for leaks, measure and drill screw holes for the top, and PL the top on. Drivers go in Saturday.
 

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Discussion Starter #74
I'm thinking of a word. Starts with "D" - four letters. Rhymes with "fun."



That's all she wrote for the assembly phase. I will have some PL stains on my hands after this one. After pre-drilling a total of seven locator screws, I heaved the top panel in place, got on top of it, and went to town with the drill.

At the end of all this, I still have an untouched tube of PL. Those interested in trying this project should be warned though... I would have needed it had I not had the old stuff in the storage room. Buy two big tubes. Or four little ones. Too much is better than too little. I also have an untouched box of screws left over... 200 was enough for this one with some left over.

Panel fitment is miles better than the last tapped horn, but the top doesn't quite square up as I'd like. Ah well... close enough for horseshoes and hand grenades.

Some pics of today's progress:



Ready to start. Horn off the sawhorses.



Before anything else, I scraped off some of the excess PL and removed the brackets holding the kludge block in place. I forgot to plug the screw holes with PL, but no big deal - they don't go all the way through anyway.



My oops from the other day.



Changed my brain on the polyfill. Thin layer at the throat. Yes, I did remove that errant staple.



Using the two piece saw guide to mark for the guide lines.



Laying down the guide lines using both saw guides to insure straightness.



Final PL beads laid down.
 

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Discussion Starter #78
Thanks :D

Me too. It should come fairly close to the older one, which is currently +/- 2dB at listening position corner loaded between 25-80Hz with no EQ to speak of. I need a better EQ than the Reckhorn B-2 to make it totally flat. Plans are in the works to buy a MiniDSP for that purpose.

The Reckhorn does have EQ applied, but that's only to flatten out its own response and give me a proper highpass.
 
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