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My C-Notes came in 5th in the recent Iron Driver contest in NYC. After experimenting with some budget woofers I decided that the cost restraints were going to limit me to a two way if I wanted a quality crossover. That led to a fairly straight forward MTM using the Iron Driver and a Vifa XT25SC90-04 tweeter. http://www.parts-express.com/pe/show...umber=264-1014 The 1.2 cu. ft. box was constructed with 1/2" Baltic birch and braced with 1/2" dowels through the side panels. They were designed to place the tweeter at ear level while placed on the required 24" stand. I'll try to post the box dimensions after I get them back. (too many box plans in the pile)
Stacking the side panels to drill through drill holes for dowel bracing.
Imageshack has dropped my account. PM me with an e-mail address if you'd like a zip file of the images.
Gluing strips to the edges of the side panels to allow for round overs later.
Gluing up the boxes.
Driver hole cutouts.
Filling the holes left by the 1/2" dowels. I left the dowels short so they wouldn't telegraph through the veneer.
The boxes with the 1" roundovers done on the router table.
Black Formica applied to the back and top.
Furring strips were installed around the inside of the cabinet bottom to fasten the removable bottom panels.
Titebond II glue applied to the box.
Titebond II glue applied to the NBL quartered walnut veneer.
Ironing on the veneer.
Ready to trim.
Trimmed.
Finished with dark walnut Watco Danish Oil with a top coat of satin poly.
Tweeter rebate template in place.
Tweeter rebate cut with top bearing router bit.
Ready for drivers?
Boxes lined with acoustic foam.
Really ready for drivers.
Boxes with the drivers and port installed.
The crossover.
1/2 pound of Acoustistuff kept in place with tape wrapped around the dowels in the top section of the box.
Ready to wire.
The crossover. 12db/Oct electrical low pass for 24db/Oct acoustic low pass. 24db/Oct high pass with series notch filter network across the tweeter.
Uploaded with ImageShack.us
C-Note Iron Speaker Parts List
Quantity & Part Discription
2 - Peerless XT25SC90-04 Tweeter
4 - Peerless 830656 5 1/4" Woofer
2 - 3.9 Ohm 5 Watt Resistor R1
2 - 4 Ohm 10 Watt Resistor R13
2 - 47 uF Non-Polar Cap C2
4 - 12 uF Polypropylene Cap C8 & C11
2 - 18 uF Polypropylene Cap C5
2 - .70 mH 20 AGW Inductor L3
2 - .10 mH 18 AGW Inductor L6
2 - 1.5 mH 18 AGW I-Core Inductor L9 (Modified by removing 18 turns to make 1.2 mH)
PE Numbers
264-1014
264-1078
015-3.9
016-4
027-352
027-430
027-434
255-042
255-202
266-552
Total parts cost for drivers and crossover parts for 2 speakers - $188.96.
The PE port used. http://www.parts-express.com/pe/show...number=260-478
R-Carpenter's wonderful measurements can be found here.
http://techtalk.parts-express.com/sh...82#post1858682
From the measurements it was pointed out that the port was tuned a little low. It was tuned lower than the Sim I did while designing and I plan to fix that when I get them back. The design called for a slightly small box tuned lower than normal to push the excursion limit below 40Hz and keep F10 up. That seems to work but will work better when I move the port tuning up a little.
I couldn't be happier with how these turned out and thank everyone for their input and comments.
Next stop - DIY Iowa 2012 in Grinnell.
Ron
Stacking the side panels to drill through drill holes for dowel bracing.
Imageshack has dropped my account. PM me with an e-mail address if you'd like a zip file of the images.
Gluing strips to the edges of the side panels to allow for round overs later.
Gluing up the boxes.
Driver hole cutouts.
Filling the holes left by the 1/2" dowels. I left the dowels short so they wouldn't telegraph through the veneer.
The boxes with the 1" roundovers done on the router table.
Black Formica applied to the back and top.
Furring strips were installed around the inside of the cabinet bottom to fasten the removable bottom panels.
Titebond II glue applied to the box.
Titebond II glue applied to the NBL quartered walnut veneer.
Ironing on the veneer.
Ready to trim.
Trimmed.
Finished with dark walnut Watco Danish Oil with a top coat of satin poly.
Tweeter rebate template in place.
Tweeter rebate cut with top bearing router bit.
Ready for drivers?
Boxes lined with acoustic foam.
Really ready for drivers.
Boxes with the drivers and port installed.
The crossover.
1/2 pound of Acoustistuff kept in place with tape wrapped around the dowels in the top section of the box.
Ready to wire.
The crossover. 12db/Oct electrical low pass for 24db/Oct acoustic low pass. 24db/Oct high pass with series notch filter network across the tweeter.
Uploaded with ImageShack.us
C-Note Iron Speaker Parts List
Quantity & Part Discription
2 - Peerless XT25SC90-04 Tweeter
4 - Peerless 830656 5 1/4" Woofer
2 - 3.9 Ohm 5 Watt Resistor R1
2 - 4 Ohm 10 Watt Resistor R13
2 - 47 uF Non-Polar Cap C2
4 - 12 uF Polypropylene Cap C8 & C11
2 - 18 uF Polypropylene Cap C5
2 - .70 mH 20 AGW Inductor L3
2 - .10 mH 18 AGW Inductor L6
2 - 1.5 mH 18 AGW I-Core Inductor L9 (Modified by removing 18 turns to make 1.2 mH)
PE Numbers
264-1014
264-1078
015-3.9
016-4
027-352
027-430
027-434
255-042
255-202
266-552
Total parts cost for drivers and crossover parts for 2 speakers - $188.96.
The PE port used. http://www.parts-express.com/pe/show...number=260-478
R-Carpenter's wonderful measurements can be found here.
http://techtalk.parts-express.com/sh...82#post1858682
From the measurements it was pointed out that the port was tuned a little low. It was tuned lower than the Sim I did while designing and I plan to fix that when I get them back. The design called for a slightly small box tuned lower than normal to push the excursion limit below 40Hz and keep F10 up. That seems to work but will work better when I move the port tuning up a little.
I couldn't be happier with how these turned out and thank everyone for their input and comments.
Next stop - DIY Iowa 2012 in Grinnell.
Ron
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