I have a pair of Celestion Ditton 2's which have VERY tired-looking cabinets, so I plan to make a new pair, paying close attention to the internal dimensions. ("Mother Ditton's Littul Kittons" ? 😀)
(I will also replace the caps in the XO while I'm at it.)
The Ditton 2 design has a rear-firing port, and so they can't be placed too close to a wall.
I'd like to change the port location. I understand that I must preserve the port length and the X-sectional area.
My options are bottom-ported - for mounting on a wall bracket - or front-porting.
With regard to the front-ported option, and as I'm building new cabs, could I use a slot port (right across the bottom edge of the front baffle)? Is it as simple as X-section and length, or is there another factor to consider?
Thanks
Doug
(I will also replace the caps in the XO while I'm at it.)
The Ditton 2 design has a rear-firing port, and so they can't be placed too close to a wall.
I'd like to change the port location. I understand that I must preserve the port length and the X-sectional area.
My options are bottom-ported - for mounting on a wall bracket - or front-porting.
With regard to the front-ported option, and as I'm building new cabs, could I use a slot port (right across the bottom edge of the front baffle)? Is it as simple as X-section and length, or is there another factor to consider?
Thanks
Doug
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Doesn't winisd give slot ports as an option ?
Just tried it.
Has option of round or square ports, so by extension... you should be able to use that to calculate your slot dimensions.
Just tried it.
Has option of round or square ports, so by extension... you should be able to use that to calculate your slot dimensions.
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I did the same thing with a pair of Ditton 33.
http://www.diyaudio.com/forums/multi-way/279226-new-life-old-ditton-33-a.html
18mm ply - fully braced chamfered edges - sound a lot better. Need to refinish them - as I was a bit impatient.
re ports - I'm a bit fan of front ports - go for it.
http://www.diyaudio.com/forums/multi-way/279226-new-life-old-ditton-33-a.html
18mm ply - fully braced chamfered edges - sound a lot better. Need to refinish them - as I was a bit impatient.
re ports - I'm a bit fan of front ports - go for it.
Nice work.
Here is a pic of my refurbed Corals, in Silky Oak veneered ply. ��
Attachments
Slot ports have larger end corrections that shorten the vent; considerably if three cab walls form it: http://www.diyaudio.com/forums/atta...-dayton-port-length-effective-port-length.jpg
GM
GM
Greets!
With rare exception, nowadays I prefer to keep audio related topics on one of the appropriate forums.
GM
With rare exception, nowadays I prefer to keep audio related topics on one of the appropriate forums.
GM
Oh sure, there's a thread I made. You chose to disable DM's. 😛
http://www.diyaudio.com/forums/multi-way/307437-urgent-slot-ported-version-tango.html
My apologies to the OCD mods. c:
http://www.diyaudio.com/forums/multi-way/307437-urgent-slot-ported-version-tango.html
My apologies to the OCD mods. c:
Hmm, me and math don't get along too well, so this is the best I can do on short notice, time available.........
I see much has already been addressed and not clear on what specific info you're wanting, so just rambling on a bit:
2" dia.[i.d.] ^2*pi/4 = ~3.142"^2 area/7" wide slot = 0.449" high and if this slot isn't close to any of the cab's walls, then it stays near enough the same depth. [i.d. = inside dimension]
The slot's high aspect ratio will lower tuning a slight amount due to the extra friction losses, but the higher math skills required to solve wave equations is literally 'Greek' to me.
If the slot is a [near] full width one, then the 4th side [top] vent panel will be much shorter than 7" and without my Excel SS you'll have to get someone else to do the math from bjorno's document where the end correction is k = 2.227: http://www.diyaudio.com/forums/atta...-dayton-port-length-effective-port-length.jpg
This style vent is physically smaller than the pipe, so net volume [Vb] will be slightly more, though not audibly obvious, but again, don't know how to accurately calculate it.
If you just make it a square tube to put it in the same location, then it will be ~3.1412^0.5 = ~1.772" i.d. on a side, though you can make it a little rectangular up to a ~1:1.273 ratio if you prefer without affecting its length; i.e. if one side is ~1.772*1.273 = ~2.256", then ~3.1412/~2.256" = 1.393" or any rounded off combination in between.
All that said, why not find a cardboard, plastic, etc. tube that's around 2" dia. and adjust the length as required: http://www.diyaudio.com/forums/full-range/53708-fe126e-enclosure-question.html#post600466
GM
I see much has already been addressed and not clear on what specific info you're wanting, so just rambling on a bit:
2" dia.[i.d.] ^2*pi/4 = ~3.142"^2 area/7" wide slot = 0.449" high and if this slot isn't close to any of the cab's walls, then it stays near enough the same depth. [i.d. = inside dimension]
The slot's high aspect ratio will lower tuning a slight amount due to the extra friction losses, but the higher math skills required to solve wave equations is literally 'Greek' to me.
If the slot is a [near] full width one, then the 4th side [top] vent panel will be much shorter than 7" and without my Excel SS you'll have to get someone else to do the math from bjorno's document where the end correction is k = 2.227: http://www.diyaudio.com/forums/atta...-dayton-port-length-effective-port-length.jpg
This style vent is physically smaller than the pipe, so net volume [Vb] will be slightly more, though not audibly obvious, but again, don't know how to accurately calculate it.
If you just make it a square tube to put it in the same location, then it will be ~3.1412^0.5 = ~1.772" i.d. on a side, though you can make it a little rectangular up to a ~1:1.273 ratio if you prefer without affecting its length; i.e. if one side is ~1.772*1.273 = ~2.256", then ~3.1412/~2.256" = 1.393" or any rounded off combination in between.
All that said, why not find a cardboard, plastic, etc. tube that's around 2" dia. and adjust the length as required: http://www.diyaudio.com/forums/full-range/53708-fe126e-enclosure-question.html#post600466
GM
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