Stasys X Data |
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jethrocker
Old Croc Joined: 07 June 2006 Location: Chiapas, Mexico Status: Offline Points: 1942 |
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Well, Rog said there are 5 chambers so we can assume there is some mad bandpass hybrid going on.. (come to think of it I don't think that was really a secret)..
I was picturing a kind of pyramid effect with the two drivers in their rear chambers, ported into a largish front chamber, then a shared chamber which the two front chambers are ported into, then the horn.. I then remembered Rog said that each driver has its own horn. So a shared rear chamber with two chambers cascaded in front of each driver? Rear chamber ports could vent into front chamber or directly to the outside, or the rear chamber port is the horn with an nth order bandpass on the front of the driver? Basically a combination of high order bandpass/horn hybrid, just tweaked to perfection.. |
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tb_mike
Old Croc Joined: 01 October 2004 Location: New Zealand Status: Offline Points: 2744 |
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port tuning of 27hz!
impedence plot tells alot :d Its even more intriguing now! Is it a 60hz horn with a bandpass element tuned to 27hz.... |
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Jake_Fielder
Old Croc Joined: 08 October 2007 Status: Offline Points: 4231 |
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2 drivers with front chambers and a 1.6m horn infront of each of them, then picture the drivers with a rear chamber (22l) then both rear chambers port into the 5th chamber which acts like a really long port, because for the tuning Rog wanted (28) at the port diameter he wanted the ports would be too long (4.5m). then the 5th chamber ports to the outside.
simple
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Jake_Fielder
Old Croc Joined: 08 October 2007 Status: Offline Points: 4231 |
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Its just a dual ported horn, the complicated bit is the shared chamber that has been put in the place of two long ports.
The thing that really puzzles me is how you can have a rear chambers port matching the output of the horns, i dont know how thats done!
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jethrocker
Old Croc Joined: 07 June 2006 Location: Chiapas, Mexico Status: Offline Points: 1942 |
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Hang on a minute, just looking at the box again..where do the drivers load?
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Jake_Fielder
Old Croc Joined: 08 October 2007 Status: Offline Points: 4231 |
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Theres 2 heat sinks on the rear, so the magnets are touching the back wall heat sinks.... theres already been a thread discussing this....
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Jake_Fielder
Old Croc Joined: 08 October 2007 Status: Offline Points: 4231 |
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I think from the side...
Theres 2 heat sinks on the rear, so the magnets are touching the back wall heat sinks.... theres already been a thread discussing this....
Edited by Jake_Fielder - 15 April 2008 at 11:14pm |
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jethrocker
Old Croc Joined: 07 June 2006 Location: Chiapas, Mexico Status: Offline Points: 1942 |
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Other thought... would the excellent group delay have anything to do with ports that are the same length as the horn itself?
And the way Rog talked about the chambers I'm not sure all of them have a direct input from the driver, either from front, rear or through another chamber.. Remember some of the ported horn designs posted up with additional ported resonant chambers at tapped points on the horn path? Thats why I asked about the driver loading, as I'm wondering what is behind the two flares at the sides if the driver/chamber arrangment is, as it appears to be, in the center of the cab. |
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Rog
New Member Rogers Archive Posts Joined: 23 March 2010 Status: Offline Points: 2166 |
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Ha ha, good to see its got you thinking.
Really its just a double 18" reflex cab with front loaded drivers. There is a clever cloaking device that makes it look like there are ports and horns.
tb mike is close with the port tuning at horn cutoff. Its about 28Hz for the port and about 57Hz for the horn. The pivital point of the whole design is 50Hz. You can see somthing going on at 50Hz in all the plots. Its the point where the ports output meets or takes over from the horns cutoff point. There is a small dip in the THD plot, a peak in impedance and a dip in GD.
Jake F said that the port output is as loud as the horns output. I would not argee. The frequency plot really gives away what is happening here. Above 60Hz the response averages 105dB with 106.5dB peaks. The plot shows a typical horns response of peaks and undulations. Below 60Hz the reponse smooths out. This is typical of the output from a port. Its also at an average of 103.5dB, so it not as loud as the horns output. Any port has losses, the longer the port the greater the losses due to there being a greater wall surface area. If you take a 4.5 meter port with its considerable losses and now make it only 45 cm long, you will have less losses and more output. Of course the new shorter port can never have the same tuning frequency as one thats 10 times longer, or can it, ha ha.
Yes peaks in the impdance plot are undamped areas, so the port/horn tuning lies at the lowest point between peaks. The highest small peak is due to a harmonic of one of the chambers resonances. Looking at the Z plot its quite an easy cab to drive, this is born out in reality as well.
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Rog
New Member Rogers Archive Posts Joined: 23 March 2010 Status: Offline Points: 2166 |
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Also one of the Jakes said it was the ultimate bass bin.
Well no. The ultimate bass bin is the size of a small briefcase, weighs 3Kg has no moving parts and can do 140dB at 10Hz. Stasys X is quite a long way off from that, but I do think that Stasys X is at the edge of what can ever be achieved from its volume. There's no getting away from Hoffmans Iron Law and with the materials and technology we have at this time I think Stasys X is making as best use of the space it occupies as anything ever will. Its got to the point where thats it, you will never get anymore out in terms of SPL or frequency response from its size enclosure. It doesn't matter who tries or what they try with it can only ever be matched. Give me a bigger enclosure or materials from 200 years in the future and it can have more output and play even lower. But for now its reached 100%effeiciency of what you can ever get from what we have.
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adambomb
Old Croc Joined: 10 April 2006 Location: United Kingdom Status: Offline Points: 3220 |
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Until some bright spark comes up with something new ay Rog!
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Jake_Fielder
Old Croc Joined: 08 October 2007 Status: Offline Points: 4231 |
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Thats what i meant, as you said, i cant see it getting any better for the size, unless better driver or cabinet technology is available.
Thats really interesting Rog, thank you, you've really got me thinking with these tit-bits of information.
Do you take your plots in a 26 meter long warehouse BTW?
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