40yr old DIY Coral 3way kit, bring back to new life with new enclosure.

Hi! got hold of a pai of coral 3way speakers. want to design a new enclosure to maximize the potentioal of the drivers, any suggestions?

10l-24 35-200HZ woofer
5M-12 0.8-12KHz 40w 8ohm
2H-25 tweeter 5-20KHz 20w 8ohm
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First off, we would need to get some accurate T/S parameters of your woofer. Would you know of someone close by that would have the appropriate gear to measure out this? Second, the cabinet material is "wanting"...we see here the common & inexpensive pressboard, upgrading to a seven, nine ply void-free birch plywood would be much better. Third, a differing enclosure ratio would be more aligned with "modern" styles. Forth, driver alignment along with baffle-step brainstorming should make for better imaging.

-----------------------------------------------------------------------------------------------------------------------------------------------------Rick...
 
frugal-phile™
Joined 2001
Paid Member
I have seen a number of 2H-20 tweeters, very nice, is this what yoyrs look like from the front?. I have also seen those woofer baskets, but OEM units with no Coral name.

Coral-2H-20T.jpg


As Rick suggests you will need T/S to optimize the box, we can assume the Fs is 35 Hz.

Midrange looks like this?

coral-5M-12-5mrS.jpg



Caps will have to go, likely a new XO developed, that will take some effort. Ican likely draw the XO map just from the picture, a couple Cs to create the HP for mid & tweeter and a couple Rs to adjust levels — are both on the tweeter circy=uit or is one in the midrange circuit?

dave
 
OK thanks!
I have a lyngdorf TDAI 1120 that came with a mic with XLR connection, i can see if there is any way to hook it up to my pc to make measurements, if not is there any other way to find parameters to design the box?
i might have to order a USB MIC to test.

i have the space to build the speakers quite large if i want, i was thinking i could try to make a adjustable cabinet of some sort to test difrent volume and dampening solutions?

I have access to a woodworkshop and only my imagination is a limit :)

Planet10: A see the photos of resistors and caps (looks like the 10ince driver was running as a fulltone)
On photo 2: wires from right to left is
  1. INPUT AND BASS
  2. MIDRANGE DRIVER
  3. TWEETER
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Photos of my 2H-25 Driver

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frugal-phile™
Joined 2001
Paid Member
to find parameters to design the box?

Does not require a mic. Either a piece of software or the old manual method. Brian Steele has/had a good description of that on his website.

The numbers you get will noit be collapsed from the curves at the same place as the typical factorey kit, so the numbers ar enot as usuful, usuually a good idea to do a box that can either be eaily retuned or dominates Ilike a horn of TL).

dave