I use .2836 lbs per ^3" for density of CS. Appears to be close.
ron
(close only counts in horse shoes and nuclear devices)
ron
(close only counts in horse shoes and nuclear devices)
I propose we change the name of this speaker from Curvy Chang to Crack Cocaine!
I spent almost the whole day in front of these things throwing CD after CD in the player. Couldn't move till my wife finally came home and gave me hell!
marce - I raised the front of the CC up 3/4" and I think it was an improvement at my listening position. The speaker is low compared to where I sit and raising the front just a bit improved the sound I think.
I used 3/4" plywood to build my cabinet. Next version needs to be beefed up significantly.
Scott and Ron how would the dimensions be affected if I used a 2" baffle and increased the thickness of each end of the compression chamber to 2" as well?
Keeping all internal dimensions the same, if I used a 2" baffle would I just extend the front edge of each side by 2"? If I used 2" material for the ends (top and bottom) of the compression chamber would I shorten the little piece on the back (the port) by 2"?
I'll add some extra bracing to the sides as well. Yes, it will make it heavier, but it will be more than worth it my friends!!!
Thanks -
Bruce
I spent almost the whole day in front of these things throwing CD after CD in the player. Couldn't move till my wife finally came home and gave me hell!
marce - I raised the front of the CC up 3/4" and I think it was an improvement at my listening position. The speaker is low compared to where I sit and raising the front just a bit improved the sound I think.
I used 3/4" plywood to build my cabinet. Next version needs to be beefed up significantly.
Scott and Ron how would the dimensions be affected if I used a 2" baffle and increased the thickness of each end of the compression chamber to 2" as well?
Keeping all internal dimensions the same, if I used a 2" baffle would I just extend the front edge of each side by 2"? If I used 2" material for the ends (top and bottom) of the compression chamber would I shorten the little piece on the back (the port) by 2"?
I'll add some extra bracing to the sides as well. Yes, it will make it heavier, but it will be more than worth it my friends!!!
Thanks -
Bruce
As long as the internal dimensions and the baffle inset is met then it can only improve. DO NOT change the inset, its required,
ron
(CC =curve chang i have no idea about crack as i have never done it, i have enough health problems)
raised the front of the CC up 3/4" and I think it was an improvement at my listening position. The speaker is low compared to where I sit and raising the front just a bit improved the sound I think.
Its a focused energy, its sent where the focus point is.
ron
(CC =curve chang i have no idea about crack as i have never done it, i have enough health problems)
raised the front of the CC up 3/4" and I think it was an improvement at my listening position. The speaker is low compared to where I sit and raising the front just a bit improved the sound I think.
Its a focused energy, its sent where the focus point is.
ronc said:
Thanks for the quick reply Ron!
Just to be sure I understand correctly it's ok to use a 2" baffle and extend the sides 2" as long as I preserve the baffle inset and maintain the internal dimensions.
Adding 1.25" to the top and bottom of the compression chamber is fine? Do I need to extend the overall length of the cabinet by 2.5" (1.25" per end) or will it be alright?
Thanks -
Bruce
abpea said:
I can't help but think that adequate bracing would be more effective than brute force.
dave
Odd question I know, I notice in some pipe designs that you can replace a curved exit guide with a 45 degree flat deflector.
A curve is a wave guide, correct ? A flat reflector is a blunt version of the same ?
Can the flat refelector in the Changs be replaced with a curved reflector or does it serve a different purpose ?
I'm guessing no as the exit mouth forms a conical pipe ? If I added a curve at the bottom I'd have to change the upper/lower outer shape of the woofer chamber to compensate ?
I had an idea for some really swoopy speakers 🙂 Oh no, I'm now three pairs of speakers ahead of myself.
Chilis half done, some kind of swoopy Kimchi to think about and now a mote in my minds eye of another pair, sigh.
Sadly, I wish my woodworking was as good and easy to produce as the pitures in my head. I always end up compromising the finish and consturction, perhaps I need less thumbs or something ( with my skills that is a real possibility )
Love your renders stevodude ! You do nice work.
I do already have a pair of DIY subs... But, if I had an oppourtunity to re-engineer (hide) them within a beautiful speaker the Mrs would probably explode with sheer joy 🙂
Thanks again for the inspiration everyone, I think I've finally picked up a real hobby 🙂 I'll post some chili pics when I've finished them.
Cheers,
Sedge.
A curve is a wave guide, correct ? A flat reflector is a blunt version of the same ?
Can the flat refelector in the Changs be replaced with a curved reflector or does it serve a different purpose ?
I'm guessing no as the exit mouth forms a conical pipe ? If I added a curve at the bottom I'd have to change the upper/lower outer shape of the woofer chamber to compensate ?
I had an idea for some really swoopy speakers 🙂 Oh no, I'm now three pairs of speakers ahead of myself.
Chilis half done, some kind of swoopy Kimchi to think about and now a mote in my minds eye of another pair, sigh.
Sadly, I wish my woodworking was as good and easy to produce as the pitures in my head. I always end up compromising the finish and consturction, perhaps I need less thumbs or something ( with my skills that is a real possibility )
Love your renders stevodude ! You do nice work.
I do already have a pair of DIY subs... But, if I had an oppourtunity to re-engineer (hide) them within a beautiful speaker the Mrs would probably explode with sheer joy 🙂
Thanks again for the inspiration everyone, I think I've finally picked up a real hobby 🙂 I'll post some chili pics when I've finished them.
Cheers,
Sedge.
Yes, you could curve it, but the whole design of the waveguides would need to be re-worked.
Bracing the air cavity / reflex box should be sufficinet. If you want to double something, I'd suggest doubling the thickness of the side-panels, or making them out of 14ga CRS. That would make more of a difference. The wallet might wince though.
Bracing the air cavity / reflex box should be sufficinet. If you want to double something, I'd suggest doubling the thickness of the side-panels, or making them out of 14ga CRS. That would make more of a difference. The wallet might wince though.
The experts keep mentioning bracing will be very important with these.
I suggest upsizing the side panels to 25mm, then go nuts with the bracing.
First, to brace the heck out of the top, back and front of the compression chamber.
Effectively you make a curvy chang, split it down the centre and glue the two halves either side of a sheet of 12mm ply with a bunch of random holes through the compression chamber part.
Of course you'd actually make it 12mm wider with lots of bits of 12mm ply for the vertical bracing. These vertical braces go in the horn mouths as well.
To brace the sides of the cabinet take the offcuts from the curved front, Glue them perpendicular to the sides, so if you were looking down from above they would be sticking straight out like ears. The profile looking directly at the front would be an oval shape. I suppose you could call it a Prince Charles Curvy Chang.
What is the optimum listening distance for these again? 8 feet?
Edit: If the cabinet was made with angled or curved back you'd cut one end off that offcut so it blended neatly with the back of the cabinet while provifing some outrigger feet for additional stability.
I suggest upsizing the side panels to 25mm, then go nuts with the bracing.
First, to brace the heck out of the top, back and front of the compression chamber.
Effectively you make a curvy chang, split it down the centre and glue the two halves either side of a sheet of 12mm ply with a bunch of random holes through the compression chamber part.
Of course you'd actually make it 12mm wider with lots of bits of 12mm ply for the vertical bracing. These vertical braces go in the horn mouths as well.
To brace the sides of the cabinet take the offcuts from the curved front, Glue them perpendicular to the sides, so if you were looking down from above they would be sticking straight out like ears. The profile looking directly at the front would be an oval shape. I suppose you could call it a Prince Charles Curvy Chang.
What is the optimum listening distance for these again? 8 feet?
Edit: If the cabinet was made with angled or curved back you'd cut one end off that offcut so it blended neatly with the back of the cabinet while provifing some outrigger feet for additional stability.
11 foot or more is preferable.
Assuming 3/4in BB ply, the back-chamber (BLHs don't have compression chambers: the room is their CC) wouldn't benefit greatly from increasing the material thickness. Bracing it as Dave has shown in a recent 167 render would be fine. It's not that large a box. I'd avoid bracing in the mouths if possible or the waveguides would need redesigning & the aesthetics aren't great.
Assuming 3/4in BB ply, the back-chamber (BLHs don't have compression chambers: the room is their CC) wouldn't benefit greatly from increasing the material thickness. Bracing it as Dave has shown in a recent 167 render would be fine. It's not that large a box. I'd avoid bracing in the mouths if possible or the waveguides would need redesigning & the aesthetics aren't great.
i found the bracing shown earlier in the thread to be sufficient, my sides are 36mm in places with the decorative side panels bracing wich helps. Like the curved back version, bur would need a bigish room to fit them in.
Has anyone tried concrete tile-backer board? I've used it in bass reflex enclosures will good results. Rather heavy, but no cabinet resonance.
carpenter said:
There is a new type of paperless gypsum wall board that showed up at my local Lowes a few months ago. I've been thinking about sandwiching a piece of that between two pieces of plywood to create a constrained layer panel as cabinet material to experiment with.
Would be heavy but should significantly reduce resonance as well.
Bruce
I've never heard of paperless-gypsum. Tell me about it's features.🙂 It would certainly be cost effective.
carpenter said:
Here you go, everything you ever wanted to know about paperless gypsum board:
Paperless Gypsum Board
Enjoy -
Bruce
[Edit: My local Lowes is selling a 4x8 sheet of 1/2" paperless gypsum board for $12.95]
OzMikeH said:
The exact centre is not a good place to put a brace. Even offset 1/2 the width of the material is sufficient to make a positive difference.
dave
Indeed! I had occasion to use it recently and wish it had been available back when I had to re-do most of my home's walls, ceiling.
GM
GM
I just remodeled my bathroom and had to use a sheet of that. I did not like it. The screws were getting pulled through it. Actually for a while I thought I screwed into a water pipe because it sounded like leaking water when the crews were being pulled through from its own weight. And before someone ask, yes I used a drywall crew gun that sets the crews perfectly flush with the drywall. So for using it as a sandwich for speakers, it could be interesting on the results, but for remodeling I would use caution using it. I think the paper stuff is a lot better.
YMMV
John
YMMV
John
Well at least the speakers wont be prone to mold?
Sounds like a good material for test speakers but i have seen the techs in the fabrication area come up with some excellent shapes using shaped styro and the fiberglass chopper gun i bought them.
ron
11 foot or more is preferable.
Well it could be closer, but the effect would be like wearing a giant set of earphones and you would lose a great deal of energy. However if the focus was changed it could work.
Sounds like a good material for test speakers but i have seen the techs in the fabrication area come up with some excellent shapes using shaped styro and the fiberglass chopper gun i bought them.
ron
11 foot or more is preferable.
Well it could be closer, but the effect would be like wearing a giant set of earphones and you would lose a great deal of energy. However if the focus was changed it could work.
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