I have been converting the measurements to actual sizes of cuts,
Looks like it is going to eat plywood.... to the tune of $150 per speaker, with lots of left overs
I looked at another way of cutting them (to the same dimensions), but it is difficult and would probably need some big saws, this would produce 2 full sides and 2 half sides (which can be joined down the centre, which should get both drivers out of the $150 worth of plywood (3 sheets 2440x1220mm), with enough scraps for a subwoofer or some mini monitors left over.
Looks like it is going to eat plywood.... to the tune of $150 per speaker, with lots of left overs
I looked at another way of cutting them (to the same dimensions), but it is difficult and would probably need some big saws, this would produce 2 full sides and 2 half sides (which can be joined down the centre, which should get both drivers out of the $150 worth of plywood (3 sheets 2440x1220mm), with enough scraps for a subwoofer or some mini monitors left over.
We may want to break this out into a separate thread to not pollute this one, but I have plans to make a pair as well and would love to see your cut plans.
How were you planning to perform the cuts? I'm thinking a circular saw and a guide would work as I have the equivalent of a Fisher Price table saw. Also, the semicircular cutouts on the bottom to form the feet would be a challenge for me. Any advice on that?
Kofi
Yep I would make the arch space as big as possible in order for it not to act like a second port restricting the first.
My boards come in 1220x1440mm, which is a bit of a mismatch
It has to first be cut down to 1220 x 1646mm, the top an bottom (short sides then need to be shaved at angle just shy of 2,1:18.
I will use mittred angles, wich makes one side of the cut panel wider than the other, the lower side of the shaved top and bottom is always on the wide side.
I would start the first panel as the line running from top to bottom through the centre of a panel, so the first cut would be half of a side, this cut is done at 45degrees front to back and will be the side of the next headless pyramid witch fits in inverted next to this cut, so from the same board the panels cut next to each other will be face, rear, face, rear., this takes care of the tops and bottoms being angled correctly also...
Our first panel was only half a side, the second one you mark out can be a whole side, as can the third, the forth one will only leave enough space for half a panel again, So you can get up to three sides out of one board
My sketch has some rectangular blocks used as spacers to get the measurements right, I am starting to like the look of this band down the centre, it also shows the cut off piece on the top of the main board
My boards come in 1220x1440mm, which is a bit of a mismatch
It has to first be cut down to 1220 x 1646mm, the top an bottom (short sides then need to be shaved at angle just shy of 2,1:18.
I will use mittred angles, wich makes one side of the cut panel wider than the other, the lower side of the shaved top and bottom is always on the wide side.
I would start the first panel as the line running from top to bottom through the centre of a panel, so the first cut would be half of a side, this cut is done at 45degrees front to back and will be the side of the next headless pyramid witch fits in inverted next to this cut, so from the same board the panels cut next to each other will be face, rear, face, rear., this takes care of the tops and bottoms being angled correctly also...
Our first panel was only half a side, the second one you mark out can be a whole side, as can the third, the forth one will only leave enough space for half a panel again, So you can get up to three sides out of one board
My sketch has some rectangular blocks used as spacers to get the measurements right, I am starting to like the look of this band down the centre, it also shows the cut off piece on the top of the main board
Attachments
Hi All,
I had wanted to jump right into the next phase: plans and building ...but I'm spending a little more time reading about baffle size and diffraction issues than I expected. Interesting stuff.
However I didn't want to leave it hanging unsaid that I'm grateful to everyone who has helped me get this far.
Over the course of this thread you have allowed me to remain authentic to my fledgling sense of direction. It may have cost you all extra time and patience but I think that says a lot about this DIYaudio forum community and its culture of ethics, high standards, and understanding.
So I think this thread has done more than chronicle the pursuit of one solution. It's also provided a good demonstration of the kind of effort you are willing to make to allow others to evolve their knowledge and hold on to their vision. And that's a good combination for everyone here both new and old.
Jerry
I had wanted to jump right into the next phase: plans and building ...but I'm spending a little more time reading about baffle size and diffraction issues than I expected. Interesting stuff.
However I didn't want to leave it hanging unsaid that I'm grateful to everyone who has helped me get this far.
Over the course of this thread you have allowed me to remain authentic to my fledgling sense of direction. It may have cost you all extra time and patience but I think that says a lot about this DIYaudio forum community and its culture of ethics, high standards, and understanding.
So I think this thread has done more than chronicle the pursuit of one solution. It's also provided a good demonstration of the kind of effort you are willing to make to allow others to evolve their knowledge and hold on to their vision. And that's a good combination for everyone here both new and old.
Jerry
How are you progressing?, please keep us posted and motivated with construction pics....
I started thinking the large 'nome just looked too gothic. Ended up adding a rounded rear wing (gonna be hard but I once made a rococo chair), I'll probably fill this with sand to avoid resonance and to provide braceing to the inner panel. And a nice clip on grill.
I started thinking the large 'nome just looked too gothic. Ended up adding a rounded rear wing (gonna be hard but I once made a rococo chair), I'll probably fill this with sand to avoid resonance and to provide braceing to the inner panel. And a nice clip on grill.
Attachments
Nordic said:
Hi Nordic,
I've been thinking about what is making it look gothic - or at least what we loosely call gothic. To me it's two things which are mutually reinforcing though happening at a subtle level.
First, adding elements of a strong curve approaching a 180 "U" to tapering straight lines in the design. Combining such curves with converging straight lines is a Victorian aesthetic. Sticking with just straight lines has helped the converging lines of the Metronome seem more contemporary perhaps unconsciously borrowing on the crystalline motif.
Combining 180 curves with parallel straight lines avoids this. But the Metronome is defined by it's vertical convergence in both form and function.
Second, the prominent parallel top and bottom in an otherwise converging vertical theme. Tall and thin dominates most other Metronomes allowing the more distant parallel tops and bottoms not to compete for our attention as much. When the top and bottom are compressed as in the 12 inch variation it not only brings these two surfaces closer together, it also lessens the clear aesthetic dominance of the vertical taper. And it is a shape we associate with "gothic" being a common Victorian motif used in architectural roof shapes as well as stone tombs and monuments.
During my analysis it occurred to me that the conventional converging straight line Metronomes could look even more contemporary in a clean and energetic crystalline sense by adding a faux top. Still parallel internally to the bottom in keeping with it's function. But externally with a cosmetic slant upwards from front to back or tilted from one side to another or something organic in between. We find crystals pleasing and this is how many naturally terminate.
However, I do like the large and more gentle visual curve you've added using contrasting color and value. I think the benefit it conveys is to somewhat harmonize or bridge the two effects I've described. But to me it just needs a little help to overcome them. This visual curve would be completely effective if either the top surface were rounded (preferably in an arc vs a large radius edge) or if the rear curve were less prominent. (Perhaps less than 90 degrees.) I'd imagine such a modified rear curve would still help with box regidity, internal reflections and rearward wrapping external diffraction if these were it's functions.
Jerry
Thanks, yes I did try to round the tops, but hit a brain fart, figured out how to do it properly afterwards(was a long time since I did technical drawings at school), I did figure out lots of hidden thingies in sketchup now. Will add the curve later, but it iis going to be even harder to make... the current curve can be made by cutting grooves from top to bottom.
At the moment I listen to music with the covers off, but it is nice to put them on if you have guests over...
At the moment I listen to music with the covers off, but it is nice to put them on if you have guests over...
I am worried about the angle of the driver.... It seems to be an afterthought in the whole design, in the 12" cast AN metronome, they are slanted backwards/upwards at just under 7 degrees. At my listening position about 4m away, that means they are pointed up by almost half a meter from the centre of the driver.
No, it's not an afterthought. Like the Cain & Cain Abby, where the driver is also mounted on a sloping baffle, Metronomes are not intended for a listening distance much over ~ 8 - 10ft. They're meant to be used in the nearfield, or for relatively close listening, in modestly sized rooms, where the tilt (in the case of the larger designs) places the listener slightly off-axis, & thus compensates for the naturally climbing FR that many FR drivers, including the AN 12in CF have over ~1KHz. If you want to sit further away from them, & you feel that having the driver angled in this way would bother you in your situation, then I suggest you build something else, or modify it to your own taste.
Lol, they are so pretty I could place them anywhere, but wireing may become dangerous...
If you have have any specific project in mind (even one of your own), I would appreciate it if you drop me a mail.
I am limited to a similar budget +-$250/set of drivers... (from no claims on insurance policy for 4 years) I have a few unused tweeters here, if something like that is needed
I'd like some bass down to AT LEAST the 30s, my current "woofer" has an FS of 30Hz and is only 84db/w, and that is more than enough bass for the melow stuff I listen to mostly.
I have yet to move so I don't know if my current speakers are up to the larger room... but here they go low enough.
the new room is 5m x 7m (from memory) and the roof I guess is about 2.3 to 2.4m high
If you have have any specific project in mind (even one of your own), I would appreciate it if you drop me a mail.
I am limited to a similar budget +-$250/set of drivers... (from no claims on insurance policy for 4 years) I have a few unused tweeters here, if something like that is needed
I'd like some bass down to AT LEAST the 30s, my current "woofer" has an FS of 30Hz and is only 84db/w, and that is more than enough bass for the melow stuff I listen to mostly.
I have yet to move so I don't know if my current speakers are up to the larger room... but here they go low enough.
the new room is 5m x 7m (from memory) and the roof I guess is about 2.3 to 2.4m high
Hi Scottmoose,
I noticed you like a good wave launch...
Well, the internals have been established: the drivers, category of enclosure and volumes. Now it's the externals: allowing me to deal with aesthetics and selecting an outer form that best augments what I have on the go here.
After a lot of reading about baffle step and diffraction I've decided to go wide and shallow.
I'm particularly looking forward to the benefits this will give me in the areas of wave launch and to handle enough baffle step loss to meet room gain. I think these benefits will be particularly useful in HT (adding weight, realism and dimensional solidity as well as helping my speakers couple with my smallish room.) I also fancy the look and turns out my wife does too.
I figure 20 inches wide is a minimum. Might swing 22" or better with a curvy WAF shape.
I'd be willing to go semi-elliptical a la PMS (Poor Man's Stradivari.) But in all my reading I haven't come across whether this would be wasted on how a large full range driver is more directional. In which case I'd be just as well off with a truncated pyramidal baffle as Planet10 has described. Either way, I wasn't sure how shallow I can go with a 12 inch FR in terms of internal reflection. Or alternatively need to go in terms of external diffraction.
I think this would be an interesting project to contribute: I don't think anyone has made a single large driver interpretation of a Strad. Well - more of an Eclipsa really. Perhaps I am acting on the fondness I had for the Sonus Concertino's I once owned in my formative years. They were my one organic emotional experience in audio. [sniff]
I'm off on a camping trip for a few days but I thought I shouldn't wait till I got back to ask.
Thank you,
Jerry
I noticed you like a good wave launch...
Well, the internals have been established: the drivers, category of enclosure and volumes. Now it's the externals: allowing me to deal with aesthetics and selecting an outer form that best augments what I have on the go here.
After a lot of reading about baffle step and diffraction I've decided to go wide and shallow.
I'm particularly looking forward to the benefits this will give me in the areas of wave launch and to handle enough baffle step loss to meet room gain. I think these benefits will be particularly useful in HT (adding weight, realism and dimensional solidity as well as helping my speakers couple with my smallish room.) I also fancy the look and turns out my wife does too.
I figure 20 inches wide is a minimum. Might swing 22" or better with a curvy WAF shape.
I'd be willing to go semi-elliptical a la PMS (Poor Man's Stradivari.) But in all my reading I haven't come across whether this would be wasted on how a large full range driver is more directional. In which case I'd be just as well off with a truncated pyramidal baffle as Planet10 has described. Either way, I wasn't sure how shallow I can go with a 12 inch FR in terms of internal reflection. Or alternatively need to go in terms of external diffraction.
I think this would be an interesting project to contribute: I don't think anyone has made a single large driver interpretation of a Strad. Well - more of an Eclipsa really. Perhaps I am acting on the fondness I had for the Sonus Concertino's I once owned in my formative years. They were my one organic emotional experience in audio. [sniff]
I'm off on a camping trip for a few days but I thought I shouldn't wait till I got back to ask.
Thank you,
Jerry
VanJerry said:
Both Demetri & Mileva are in this vien. They would only need fancy cabinet work...
Even with a full-range the wider cabinets don't seem to dissapear as well as their narrow heavily champhered counterparts. EnABL experiments are on-going to see if that can remedy the issue.
dave
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