2 x DR250 (melded) + 2 x DR250 (CD horn) March 2012 plans. Completed

[biggerrigger]

That's good to hear. I have a 10" 60 tooth that I was going to use to cut 60 tweeters with in the next two days. Thanks for the heads up.

[Grant Bunter]

That's good to hear. I have a 10" 60 tooth that I was going to use to cut 60 tweeters with in the next two days. Thanks for the heads up.

I reckon the I can place the time when the tooth got chipped!
I dived in a bit hard on one cut and on that particular piezo it took more of the barrel and consequently bit into the screw more as well...
Blew that one to pieces

So, slow and steady and all you may see is the odd spark.

I finished off the barrels with my angle grinder with slim steel cutting blade. Quick and neat with a few well placed swipes...

[SirNickity]

Dumb question -- why not remove the piezo from the horn first? Three screws, lift, and separate!

[Bill Fitzmaurice]

Dumb question -- why not remove the piezo from the horn first? Three screws, lift, and separate!

Ever made one? If you had it would be instantly obvious.

[Grant Bunter]

Dumb question -- why not remove the piezo from the horn first? Three screws, lift, and separate!

Fair call!
It becomes more obvious when you build a melded array.
Part of cutting up the piezo's is taking a slice off the outer part of the barrel, and sometimes, not always, part of the screw head (due to manufacturing variances). This is so the piezo's will butt up to the one beside it (on either side) when assembling/glueing the array. Not doing this adequately leads to gaps in the array, and the array not being the correct length in total. If you take off the piezo and remove the screws, then all you may trim is the half of the barrel. You would then have to readdress the screws and the remainder of the barrel after reassembly, meaning more steps to achieve the same result...
Does that make sense?

[Bruce Weldy]

I didn't have a choice.....mine were from that batch that were glued down tight.

[SirNickity]

No, I've never made a melded array -- hence the question. I'm making the 6-piezo line array for the SLAP's -- and the piezo came right off so I didn't get crap in them while gluing and sanding and painting them.

Looks like these have an entirely different set of challenges. Makes sense now. Thanks Grant.

[rogerc]

I rotated every other tweeter so the screws don't clash

[Grant Bunter]

I rotated every other tweeter so the screws don't clash

I guess that would work as well. After my error, I'm just following the plans (not that I wasn't trying to do so before)

[AntonZ]

I rotated every other tweeter so the screws don't clash

That's exactly what I did. Take the elements out when cutting & gluiing, then install the elements a bit different:


And wire like so.

[biggerrigger]

And this works with the tweeters cut at 2.0"?

[Grant Bunter]

This may seem like an odd question...

Arrays are done, but it occurred to me as I was checking over the plans:
Why does the melded (and flat) array in these latest plans need to be airtight?
The array is in a self contained module, with it's back plate sealing the driver chamber...

[Bill Fitzmaurice]

Why does the melded (and flat) array in these latest plans need to be airtight?
The array is in a self contained module, with it's back plate sealing the driver chamber...

It doesn't, that's one of the advantages to the new DR revision. I don't recall if I changed the array section of the plans to reflect that, I'll take a look today.

[Grant Bunter]

Why does the melded (and flat) array in these latest plans need to be airtight?
The array is in a self contained module, with it's back plate sealing the driver chamber...

It doesn't, that's one of the advantages to the new DR revision. I don't recall if I changed the array section of the plans to reflect that, I'll take a look today.

No worries Bill,
Thank you.
I was only wondering, regarding not having to worry about sealing the array, and a couple of coats saved = less time...

[SeisTres]

Very nice. Didn't know the new plan didn't need airtight tweets. Mhh, this and the no access covers just might win me over instead of ot12's if i get into building again. But then again, ot12's are just a breeze and do everything i need. we'll see