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

[Grant Bunter]

Does me having done this the way I have affect the benefit in offsetting the throat horn divider and it's consequent improvement in mid range response?

Yes, though I can't say by how much. It's one of those theory things where I never tested it the 'wrong' way to see what would happen.

Thanks Bill.
Given that I placed the throat horn divider above my midline, and the middle braces top edge is on the midline, if I remove the throat horn divider and line it up with the middle braces, everything will be correct again...
Hmmm how to achieve that Apart from very carefully.

[Bill Fitzmaurice]

Given that I placed the throat horn divider above my midline, and the middle braces top edge is on the midline, if I remove the throat horn divider and line it up with the middle braces, everything will be correct again...
Hmmm how to achieve that Apart from very carefully.

If the throat horn divider is offset from center you don't want to move it. Which is AFU? The throat divider or back braces?

[Grant Bunter]

Given that I placed the throat horn divider above my midline, and the middle braces top edge is on the midline, if I remove the throat horn divider and line it up with the middle braces, everything will be correct again...
Hmmm how to achieve that Apart from very carefully.

If the throat horn divider is offset from center you don't want to move it. Which is AFU? The throat divider or back braces?

The braces were where I messed up.

The top edge of the braces is on the midline, with the remainder below that.
So if I cut out the throat horn divider and line it up with the braces, the throat horn divider will still be offset from midline, but below the midline instead of above it...

[Bill Fitzmaurice]

What matters most is that the back braces, and then the horn braces attached to them, are offset from the cab center. I wouldn't try to move the throat divider.

[Grant Bunter]

What matters most is that the back braces, and then the horn braces attached to them, are offset from the cab center. I wouldn't try to move the throat divider.

Sorry Bill, I missed your post before I gave it a go....

In order to fix up my... errr... mistake

I cut out the horn throat divider, and lined it up with the middle back braces, which come towards the bottom of the cab, with their top edge on midline, meaning they are offset.
After the repair the horn throat divider also remains offset as it is now on the opposite side of midline.
If being one side of midline is required for better mid range response, it is still that, and now it is also lined up with the braces...
I hope this is clear.

Cutting out the throat horn...

PL'ed back in place inline with the middle braces and now offset below the midline rather than above it as it was before (you can see where it was) :

I will need to reapply hot melt glue to the reflectors in a few spots when the PL has set...


That handy little hacksaw blade holder has been in my toolbox for 20 years.
Just as I was nearly done cutting it broke. Plastic, therefore not repairable, well not where it broke anyway.
I wonder if I can find a new one...

[Tom Smit]

Good recovery, Grant!

[Grant Bunter]

Tom,
Thank you.
If I had been more on the ball the recovery would not have been required.
Simple mistakes
Ces la vie.

And I found a new hacksaw blade holder thingy too.

A post repair pair pic to follow once the PL is dry. <--- Say that quickly 5 times lol...

[SirNickity]

It's not about the failure, it's about the recovery. Very well done. I know I would have been tempted to say "eff it" and glue chunks of scrap in to cover the difference. This is a classy fix.

[Grant Bunter]

^ cheers Nick.

[Grant Bunter]

As promised:
Post repair pair pics.

I have turned the left cab upside down to show viewers what the cabs should look like when done correctly...

@ Scott Brochu: it was doable!

[Grant Bunter]

Day 9.

4 hours including cleanup. Lots of mess today...

Doing the melded array has been worrying me!

Since I hadn't started on the module, and the array needed to be done sometime...

I built 3 jigs to cut the piezo's with my compound miter saw.

I needed to do this because the miter saw cuts down rather than the up a bench saw does.
My reasoning was, the first thing the saw blade meets should not be a screw, so the jigs I made let me cut down, including the barrel and sometimes a screw edge. I wonder what it did to my saw blade, we'll find out soon enough.

1 to take off the first side
Another to take off the second side.
The final one to make the 45 degree cut.

I also made the Array assembly jig.

Three jigs on the left and the second array cut and ready for assembly on the assembly jig:

And the first array assembled and dry:

I shouldn't have been worried.

I did lose a few piezo's though. It's often said, order more than you need. Do that

[BassMe]

Looking good. Bet the excitement is building

[Grant Bunter]

Looking good. Bet the excitement is building

It's getting to the "I want it done" stage lol.

Making the mistake I did knocked the wind out of my sails a bit. Shouldn't have, as from the outset I thought it likely there would be some hitch.
I'll just have to suck it up, there's a way to go yet...

[biggerrigger]

Grant, How did your blade end up after cutting the edges of the screws?

[Grant Bunter]

Grant, How did your blade end up after cutting the edges of the screws?

It's a 60 tooth TCT blade and there is one slightly chipped tooth.
Shouldn't affect nice clean cutting...