following on from this I am now just about to start to put this horn together. I am going for 85mm deep!!!!- cheers XKR971. The scaled plans are now 22 inches square and I have a question about the driver mount and horn mouth openings. At this scale the circle cut out for the driver is only 3 inches and it looks like its going to be pretty tight to get a 4 inch driver in there, without removing some of the initial curved horn material.
What have other builders done to get round this? I will be able to get the 4 inch driver to fit, but might need to reduce the horn length by about 4 inches.
lol. I may even find I can get everything to fit when I try the build, but wanted to see if anyone had encountered the same problem.
cheers
Brad
Brad
If you are set on a 22in Cornu and this driver, you may need to trim some of the channel away to make room. I would recommend enlarging to a 27in Cornu if you have the ability.
I must've been tired the other day. After thinking about it some more, mirrored or not shouldn't make any difference, since we've got horns firing pairwise left/right and up/down. Now I'm just messing around with stuffing, trying to get it just right.
I've been scouring this thread trying to find sims for Tang Band W4-1320 in a 24"x24"x4". I was quite sure I'd seen sims for that one but now I'm unable to find it. Maybe I just remember other sims. Do you have one for that xrk971?
As it stands now, the sound's really nice, except when it isn't. I believe midrange peaks are the culprit. As long as nothing excites them, such as soft singing with some bass, the frequency balance is great. At other times, it's like someone speaking in a small box made of foamcore (I wonder why ). Is the big midrange peak seen on the sims caused by the speaker chamber or the horns? Maybe lining the chamber with something like foam rubber could help?
I've been scouring this thread trying to find sims for Tang Band W4-1320 in a 24"x24"x4". I was quite sure I'd seen sims for that one but now I'm unable to find it. Maybe I just remember other sims. Do you have one for that xrk971?
As it stands now, the sound's really nice, except when it isn't. I believe midrange peaks are the culprit. As long as nothing excites them, such as soft singing with some bass, the frequency balance is great. At other times, it's like someone speaking in a small box made of foamcore (I wonder why ). Is the big midrange peak seen on the sims caused by the speaker chamber or the horns? Maybe lining the chamber with something like foam rubber could help?
cheers Carl and XRK971,
glad I asked the question.
only thing is that I bought 10x 5mm foam boards at 24 inch x 33 inch to make up this test Cornu. Originally I was going to go for a 40 x 40 inch beast LOL.
am I ok to work with 85mm depth if I scale up to 27 inches?
Brad
glad I asked the question.
only thing is that I bought 10x 5mm foam boards at 24 inch x 33 inch to make up this test Cornu. Originally I was going to go for a 40 x 40 inch beast LOL.
am I ok to work with 85mm depth if I scale up to 27 inches?
Brad
lol. same question about 40 inches. will I be ok at 85mm depth.
reason Im asking is that I have cut most of my foam strips.
I may just go for the big one I originally was thinking about as its going to be a pain to go beyond 24 inches with the foam boards. I may just source plywood for the main panels.
wonder how the FR10 models at 27, 36 and 40 inches. suppose the excursion would be better than the Fostex FE103en.
Brad
reason Im asking is that I have cut most of my foam strips.
I may just go for the big one I originally was thinking about as its going to be a pain to go beyond 24 inches with the foam boards. I may just source plywood for the main panels.
wonder how the FR10 models at 27, 36 and 40 inches. suppose the excursion would be better than the Fostex FE103en.
Brad
lol. same question about 40 inches. will I be ok at 85mm depth.
reason Im asking is that I have cut most of my foam strips.
I may just go for the big one I originally was thinking about as its going to be a pain to go beyond 24 inches with the foam boards. I may just source plywood for the main panels.
wonder how the FR10 models at 27, 36 and 40 inches. suppose the excursion would be better than the Fostex FE103en.
Brad
85 mm is fine even at the larger size of 27in. At 40in, you need larger depth about 6in deep. The thin underlayment ply that Cal refers to is great - very smooth, stiff, not too heavy and cheap.
I must've been tired the other day. After thinking about it some more, mirrored or not shouldn't make any difference, since we've got horns firing pairwise left/right and up/down. Now I'm just messing around with stuffing, trying to get it just right.
I've been scouring this thread trying to find sims for Tang Band W4-1320 in a 24"x24"x4". I was quite sure I'd seen sims for that one but now I'm unable to find it. Maybe I just remember other sims. Do you have one for that xrk971?
As it stands now, the sound's really nice, except when it isn't. I believe midrange peaks are the culprit. As long as nothing excites them, such as soft singing with some bass, the frequency balance is great. At other times, it's like someone speaking in a small box made of foamcore (I wonder why ). Is the big midrange peak seen on the sims caused by the speaker chamber or the horns? Maybe lining the chamber with something like foam rubber could help?
I am pretty sure I did those for Prezden at some point. He had to trim the channels for the driver to fit - so I would advise a larger 27in size.
Well, mine are already built, so there's no way they'll become 27". I also had no problems getting the driver to fit, so you might be thinking of another driver. This one's cage is really small.
In that case, you are good - I think it was the magnet that was the problem - this was a huge ferrite magnet. Do you have a Nd magnet version?
Here is a tiny Nd magnet version:
Tang Band W4-1320SJ 4" Bamboo Cone Driver
Here is a fat ferrite version:
Tang Band W4-1320SIF 4" Bamboo Full Range Speaker
cheers Xrk @ Cal,
I was leaning towards using that thin ply - actually I think its 6mm thick, so not that think, but perfect for the job.
what is the largest size Cornu that I can go to with 85mm depth? Cost wise, based on the local sheet size I can work up to and beyond 40 inches and not increase my cost cause of wastage ect.
Brad
I was leaning towards using that thin ply - actually I think its 6mm thick, so not that think, but perfect for the job.
what is the largest size Cornu that I can go to with 85mm depth? Cost wise, based on the local sheet size I can work up to and beyond 40 inches and not increase my cost cause of wastage ect.
Brad
In that case, you are good - I think it was the magnet that was the problem - this was a huge ferrite magnet. Do you have a Nd magnet version?
Here is a tiny Nd magnet version:
Tang Band W4-1320SJ 4" Bamboo Cone Driver
Here is a fat ferrite version:
Tang Band W4-1320SIF 4" Bamboo Full Range Speaker
Yup, that's the one, but mine's got a circular surround. It's the W4-1320SI. After playing around with some EQ it seems I might not have problems around ~200 but somewhere in the 1k - 2k range. If I understand correctly, the wavelength of that would correspond to the width of the chamber the driver's in. Also, the drivers are fresh out of the box and into these boxes, so they've only been playing for a few days. Maybe they'll settle down after a while.
I'll keep playing around with the stuffing...
So I read the first 24 pages of this thread, but didn't find much on how to actually build these things. I suspect getting the first two (opposite) foam strips in goes okay, as there's plenty of space to work.
But how do you get the other strips glued in, with such a narrow working space?
Will a hot-melt glue gun nozzle get down into there, and then I just lift the strip slightly and put some glue underneath, or what?
These look like a fun project, anyway, and I've got 4x Bose SoundDock (original) drivers plus some Visaton FRS8M drivers that could use a home. I'm thinking a 80-90mm deep 500mm square would do the job nicely for trying the different drivers (former are 2.5", latter 3"). Think I'd use hardboard as the front and back boards, and maybe paint them. There's usually a fairly rough surface, so plenty of glue would be needed to seal the strips well.
TIA
Chris
But how do you get the other strips glued in, with such a narrow working space?
Will a hot-melt glue gun nozzle get down into there, and then I just lift the strip slightly and put some glue underneath, or what?
These look like a fun project, anyway, and I've got 4x Bose SoundDock (original) drivers plus some Visaton FRS8M drivers that could use a home. I'm thinking a 80-90mm deep 500mm square would do the job nicely for trying the different drivers (former are 2.5", latter 3"). Think I'd use hardboard as the front and back boards, and maybe paint them. There's usually a fairly rough surface, so plenty of glue would be needed to seal the strips well.
TIA
Chris
Work from inside spiraling out otherwise you can't get glue gun in the narrow channels. Little self contained BT speakers are really cheap now and would make a great cornu for use as MP3 player that is wireless. Just need occasional charging with 5v USB jack. Just need to take one apart - they have 2in drivers with pretty good bass and at least 3 watts.
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Like this:
You'll notice in the 3rd pic that I started at the end of the horn and filled in the last part after. That's so there wasn't a little piece near the end of the horn. This is the 27"
You'll notice in the 3rd pic that I started at the end of the horn and filled in the last part after. That's so there wasn't a little piece near the end of the horn. This is the 27"
Attachments
looking to get the plywood next week. Cheers for all the help so far - im nearly there!
just need to know what is the ideal max size of the front and back panels when using 85mm depth. - was thinking around 32-36 inches.
I now want to go as large as I can. It wont increase my costs to try a larger size Cornu because I will be cutting from plywood panels that are considerably larger.
Brad
just need to know what is the ideal max size of the front and back panels when using 85mm depth. - was thinking around 32-36 inches.
I now want to go as large as I can. It wont increase my costs to try a larger size Cornu because I will be cutting from plywood panels that are considerably larger.
Brad
Working....
So up to now I've finished first Cornu and working around the second.
Here's some photos.
A couple of questions :
1) what do you use for "stuffing" and how do you distribute it inside? Are there any photos?
2) About fixing the front : I'd like to screwdrive instead of glueing so if I need adjustement it would be easy; what is your experience / warnings ???
Thanks a lot
giuseppe (madrid)
PD
Maybe useful put in the first post that foam name in Spain is "caton pluma" so if any other Spanish wants to try them will be easier.....
thanks again
So up to now I've finished first Cornu and working around the second.
Here's some photos.
A couple of questions :
1) what do you use for "stuffing" and how do you distribute it inside? Are there any photos?
2) About fixing the front : I'd like to screwdrive instead of glueing so if I need adjustement it would be easy; what is your experience / warnings ???
Thanks a lot
giuseppe (madrid)
PD
Maybe useful put in the first post that foam name in Spain is "caton pluma" so if any other Spanish wants to try them will be easier.....
thanks again
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