2xDR 280 build

[LelandCrooks]

10-12 hrs is more than adequate. Don't worry about the voltage. I just turn up the amp until the excursion is almost at xmax, Do it slowly. If you hear ticking, it's too much.

[Robin_Larsson]

Thanks Leland! Since no one objected, I guess 30hz is good?
How about the compressiondrivers, dont need burn in?

I´ve finally been able to put up some pictures, on a Picasa webalbum, so they can be left in high resolution, so you can see all my mistakes Lets see if this works: https://picasaweb.google.com/1010506717 ... directlink

So, next "problem", handles, what kind should I use? I´ve been wanting to use the same kind, or even exact same model as I´ve just recently put in to my Titan 48s, you can see 2 pics of them in the album above. The handles are Penn Elcom HT1070 http://www.penn-elcom.com/product/hardw ... 1070/1272/
Perfect size for the Titans, only one ended up taking up any real space in the horn, going through a panel One is of course in the driver chamber, but I didnt put any reducerplates in them, so shouldnt matter;)

I would like that type of handle, but these feel to large for sitting the sides of the DR´s, dont they? feels like they would take up almost 30-40% of the cross-section of that half of the hornpath. If I put them in the middle, and say the lower part of the horn that is. That must affect the output of the cab noticably?

I could of course choose a similar handle that is smaller, but still, they will take up a lot of space, the hornpath is only around 94mm wide in that area, and even the smaller handles are around 50-60mm deep..

How much of the hornpath can be blocked before it actually disturbs the soundquality and output? I know that Bill put in that kind of cabinet handles in the latest drawings, but those are rather small..

What kind of handles do everyone else use in their DR´s? I know many seem to use the same kind if recessed handles that usually are used on equipment cases, and I do see the advantage of those, they dont take any space in the horn at all, but yeah, I really dont like that look...

I was thinking that it might be possible to put H1070 (Marshall handles) in the top and bottom of the cab, so they would end up in the driverchamber instead of the hornpath, should affect performance less? But it wouldnt be so practical for lifting them up on stands, and in the future, line array riggings.

So, what do I do about handles?

Thanks guys!

[bitSmasher]

Wow, table router + templates... very nice work. should be easy enough to build another 8

[Robin_Larsson]

Wow, table router + templates... very nice work. should be easy enough to build another 8

Yeah, I´ll build more as soon as I can afford it and have the time:P They still do take a lot of time to build, little over 3 weeks now, and we are as good as ready, gonna skip some of the cosmetics for now, to get them done for a gig on friday... Drivers going in today, atleast thats the plan:P
The woofers are breaking in as we speak, but I´m not sure about what to do with the compression drivers, do they need to be broken in?

I´ll try to get some more pics up soon:)

One thing, the dampening in the inside of the cab, got hold om some eggcrate foam, looks good, but they vary a bit in thickness, would it be catastrophic if the foam is only say 20mm in some places and 25 in others? I´ll try to use only the pieces that are 25mm if I have enough. I guess I need to put foam on the inside of the compressionhorn module also? what about the sides of the compressionhorn it self?

//Robin

[Robin_Larsson]

So, now the woodworking is done, atleast for now, started to put in dampening material and drivers today. The plans say I should put foam dampening in the driverchamber, and polyfill around the throathorn, I´ve done that, but after that the plans are a bit unclear, it says to put foam on the backpanel of the piezo-modules, on the woofer side, but it doesnt mention anything about what to do when you have the compressiondriver module, which doesnt have a closed back, because of the CD´s themselves. So the outside of the compressionhorn and the inside of the whole module is a part of the driver chamber.
I´m really unsure if I should put foam everywhere in the module or not..
I would really appriciate an answer on this, preferably fast, they are gonna play on friday I know I shouldnt rush them, but it should be alright, and I dont really have any choice..

In the picture I attached you can see how I´ve put dampening foam in them now, is this enough, or should I cover the small exposed parts of the baffle also? And yeah, how about the HF module?:)

Handles and a proper grill, and proper paintjob om the HF horn and well, the whole cab, is gonna have to wait till after this rental on friday, l´ll paint them black tomorrow and put on a simple foam front for now..

Dampening glued in place

More dampening

The inside of the compressionhorn module, with the Beyma drivers installed

Compressionhorn.jpg (42.61 KiB) Viewed 1286 times

[Bill Fitzmaurice]

Either foam or poly is OK in the module. 100% coverage isn't necessary.

[Robin_Larsson]

Thanks för a very fast reply Bill! I´ll try a bit tomorrow, see which is easiest.
Other than that it looks ok? I´m guessing there´s no need to cover the baffle also?

[osse]

Cant wait to hear them on friday;-)