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

[Grant Bunter]

Two more hours today
Sanded sheaths on cab 2. Drilled holes for ports. Cut ports from PVC joiner. Installed ports with hot melt glue.
Added middle braces (which I had cut, shaped and fitted some time back):

I have a question regarding the 4" ports for low power situations.
How critical is that length?

The reason I ask is because I came up with an idea to prevent the ports slipping into the chamber and have something to grab for easier removal. I trimmed down the joiner on one side to the joiner mid flange. The other side I left with about 1/4".

You can see it:

[Grant Bunter]

Couple more hours...

Just to show that pre bending the back halves (even when you over bend) doesn't mean they will sit where they end up:

It does make them much easier to bend though.

Using ratchet straps does make this part very easy:

And after the PL has cured

This took maybe 45 mins all up, starting one half then adding in the other and working around both ways.

The rest of the time was more paint on Cab 1 and install adjustable top hat and speakon plate.
No pics of that as yet, will wait until the cab is done...

[Grant Bunter]

Did about an hour and a half including cleanup time.

I put the sides on cab 2, after trimming up the back halves.

Trying to get cab 2 up to cab 1...
Need to move on to the next project, I need to remind myself to take as much care with the second cab as I have on cab 1.

I had a Crown amp turn up today as well. Those drivecore amps, man they're light.

Any thoughts on the ports????

[LelandCrooks]

None from me, I have yet to do the adjustable ports. Nice job on the cab though.

[Drey Chennells]

Any thoughts on the ports????

If I read the mods correctly, I can't comment definitively although I suspect 1/8" more length to be negligible. I've used PVC pressure plugs to seal the ports for 3 way tune. In sealed use the ports are pushed all the way in to maintain the correct chamber volume.
http://www.lowes.com/pd_23508-138-33401 ... Id=3572630

[Grant Bunter]

Thanks Leland, high praise from you

Drey, thanks for your input as well. I discovered your build (pictured above) the other day and love that stealth grill!
If the extra 1/8" port length IS critical, I could adjust by trimming the other end. I just need to know...

Since I don't know enough about helmholtz resonators etc:
What concerned me more/most was distance of projection into the chamber and whether or not that was more of a consideration than the port length overall.

All this came about when I cut 2 the two ports for cab one and put them in place. I turned the cab over to keep working and the ports both fell into the chamber.
Obviously this would not be a good thing to happen mid gig. If movement in the cab could cause it, then so could vibration when the cab is running.
So I thought this method would stop the ports ever falling in and ease removal.

Bill, would you please advise?

[Bill Fitzmaurice]

The original was measured with the ducts fully inserted. An eighth of an inch won't bother anything. If anything the PVC should be very tight in the coupling, almost needing a lubricant to get them out again.

[Grant Bunter]

The original was measured with the ducts fully inserted. An eighth of an inch won't bother anything. If anything the PVC should be very tight in the coupling, almost needing a lubricant to get them out again.

Excellent news!
Thanks so much Bill!

If they should be that tight, all the more reason to have something to remove them me thinks.

I will check the fit of the tubes more closely. If they are loose a coat of something might tighten them up...

[Grant Bunter]

I feel like I got further today than in ages.

4 hours, including cleanup.

Put in topper and filters in cab 1.

Screwed melded array to module, fed wire through and hot melt glued, put topper on back (cut a small hole in the topper to give the driver vent some space).
It's just sitting there at the moment as another coat of paint to go on.

That would be rattle tin "Plum Purple", however it doesn't appear as bright in normal light as it does with the flash.

And cab 2 is catching up.
Sides trimmed, back cut, cutout for Speakon plate done
Trimmed up kept pieces for cosmetic options
Back and cosmetic options on and after PL setting:

It's all good

[SirNickity]

Those things are so cool. Some day I'll build 200s...

[Grant Bunter]

An hour or so completed trimming up the back of cab 2 and filling some holes with PL and some sanding.

No point in putting a pic up, it looks the same as cab1 as cab 1 did at the same stage...

[Titanium Hand]

Wow Grant Those Drs are a massive amount of work! You've displayed the ability of quite the craftsman. I bet they're going to sound magic. Bloody big effort mate

[Grant Bunter]

thanks TH

I'm looking forward to the day I can fire them up...

[Grant Bunter]

This build took a back seat for a while, while I built a couple more T39's.

Yesterday, (all) for Cab 2, I built the Woofer LP and Piezo filters and installed into the cab.
Bogged a couple of holes.
Put in the mattress topper.
Installed the driver.
Pre drilled the screw holes for the Speakon plate and adjustable top hat.
Painted the piezo's to match the other array and (after waiting for the paint to dry) reassembled.

The day before I did the other module housing the same as the first.

Total for both days was 3 hours...

[BuiltByBoyScout]

Any updates or timing totals so far?

Great build.

I see you use fluting as spacers lol