'LGT' Construction Diary

[wigginjs]

I knew it would be expensive but nearly £1600 for four 12's is waay over budget.

Wait, maybe I'm missing something, budget?! From the other projects I've seen you complete I was under the impression you didn't have a budget !

[ShinOBIWAN]

Originally posted by m0tion


Wait, maybe I'm missing something, budget?! From the other projects I've seen you complete I was under the impression you didn't have a budget !

Yeah but 1600 quid! I could buy a tidy car for that money.

[ShinOBIWAN]

Heading towards something like this now:



EDIT: I was playing around with idea's and that's the one I like the most so far. It shows a dome tweeter in there which can be ignored, although I have the option to play around with swapping that middle section if the Ribbon doesn't do it for me.

EDIT2: The black bits around the drivers would be recessed and lined with felt for helping with diffraction ala. Wilson etc.

[ShinOBIWAN]

Its also now transformed into a 3.5way. The dual 12's will be side firing. This gives me a good bit of breathing room and will likely mean an end to the idea of using subs.

Driver line up:

RAAL 140-15d
2x 5" C-Quenze 15cm
2x 8" Flex Unit
2x 12" still not sure which yet though, smallish volume will be a big decider.

[ShinOBIWAN]

And an updated image with a rough sketch of the side:

[ShinOBIWAN]

OK this is the absolute final design, no really! I'm now locked into nearly all the driver choices since I've made a point of ordering them to stop me from swapping



I'm giving the RAAL a go first but if it turns out I'm thoroughly dome inclined then I can swap out the tweeter and XO box as shown here:



And final driver choices are:

Treble(1.5Khz+): RAAL 140-15d
Mids(200hz-1.5Khz): 2x 5" Q-Cuenze
Bass(50hz-200hz): 2x 8" Flex Units
Sub(15-40hz): 2x Peerless XLS10

The bass drivers will roll off natural and the subs will be blended to pick up the slack.

[tinitus]

Nice .... and now your in for some serious work

edit.... well, small point ..... I think your design will benefit from a slightly slanted front on mid/woofer section ... just to make it even harder

[wigginjs]

I think your design will benefit from a slightly slanted front on mid/woofer section ...

Brings up an interesting point. From what I remember you are doing passive xo's for this one, so, what is your plan for phase alignment? From the design it isn't going to be by staggering the driver's distances from the listener, so do you plan on implementing an all-pass filter in the xo network or having asymmetrical xo slopes? Are there any more options I'm not aware of?

[ShinOBIWAN]

Originally posted by tinitus
Nice .... and now your in for some serious work

edit.... well, small point ..... I think your design will benefit from a slightly slanted front on mid/woofer section ... just to make it even harder

It sounds like a small change but that would turn the project from something that was just about manageable by my skills into something that I'd have serious doubts about being able to do. Its nice to push yourself but there's already so much to account for that I just feel I'd be kidding myself if I made that change. The pretty 2d drawings are a nice indicator of overall look but they hide most of the wood working complexity. The inner wall and bracing structure for the bass-mid-sub cabinet is a little overwhelming and I'm having trouble getting my head around it, I know how I want it and the volumes needed but its a different matter arranging the panels to suit.

[tinitus]

Sure.. its not easy to move around inside a box

In my latest box with bracing/matrix I used 12mm inside .... I used a router to make 12mm tracks...and could simply slip the matrix/bracing into place with some polyurethane foamglue ... it should not be a tight fit