Dr250's build Question

[slapaddict]

Hello all it has been a while since my last post
I have plans for T39,T48,T60 and dr250's. I've been reading the forums religiously and now ready to start my first build. First i'm constructing T60 slims and dr250's. As i look over the updated plans (march 2012) i notice that the 30 ohm resistor is not mentioned but only the 4 ohm on pg.35. The Old plans(pg33) do mention the 30 ohm resistor. Is this a change or a typo? I'm so excited to start making sawdust and see how they sound. going to start with one t60 and two dr250's....that sound about correct? Thanks for your time in advance.

[Grant Bunter]

The 30 ohm resistor is certainly in my March 12 plans and is included in my build:
http://billfitzmaurice.info/forum/viewt ... 30&t=18214
In my plans it's on page 34 under the heading "piezo high pass filter".

In my plans, page 35 begins with the construction details for the compression horn array.

Indoors (because you can wall or corner load), the usual ratio is 1:1 top to sub, outdoors, 1:2 top to sub (because outdoors you can't wall/corner load).

Hope this gets sorted out for you, enjoy your builds

[slapaddict]

Grant Thanx for the quick reply. My docs dont show the 30 ohm so i'll copy and paste from the old plans, that should do it. Is the only change in the dr250 new update(march 2012) the seperate tweeter array chamber? Oh and wonderful build I've went through it previously..... oh about 3 times just to get my feet wet. I'll look in my original email, maybe its my error with my ADHD fingers Gottcha on the 1:1 Indoors and 1:2 outdoors. Tops to subs. Guess i'll be building two of each to begin with then add two more t60's.

[slapaddict]

Oh, Now I see its the same diagram showing, i was just looking for the words "The 4 and 30 ohm resistors are ten or twelve watt non-inductive, intended for crossover usage" Quoted from the old plans. The updated plans just relocating the 4ohm resistor to account for the increased sensitivity. Thanx Grant

[DJPhatman]

slapaddict, since your plans are over a year old, ask for an updated set from Bill.

See this thread for more details.

[Grant Bunter]

Is the only change in the dr250 new update(march 2012) the seperate tweeter array chamber?

Pretty much.
The horn throat component has a slightly different structure.
The ports in the new plans are up the top rather than down the bottom.
Also, the tweeter array doesn't need to be sealed as it is in it's own housing/module now.

Oh and wonderful build I've went through it previously..... oh about 3 times just to get my feet wet.

Cheers

[slapaddict]

slapaddict, since your plans are over a year old, ask for an updated set from Bill.

See this thread for more details.

DjPhatman i just recently updated the dr250 plans thanx for the heads up.
Bill your the the best, How much better can it get! Love this forum.