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Old 9th March 2011, 09:40 PM   #571
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OK Oliver; I am not seeing any glaring mistakes in your convershoin of my drawing.
I used some different reference points though. I used 3.5" for S1, 90 degrees from the speaker plate. I had S4 straight down from S2 on the other side of the speaker plate at 90 degrees off the bottom. Is this why my sim looked better?
I did not use two lines into the corners. I only made one at a 45 degrees into the corner on my hand drawings. Is yours going to be more accurate?
Why is the purple line in the unfolded map of my box bent between S3 and ref line #8? If we bend it at S3 and shorten ref line #10 for the bottom deflector the end of the horn will look a lot better.
Andy
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Old 9th March 2011, 09:47 PM   #572
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Quote:
I've made a small correction suggestion for the SS15 to make it more close to the ideal HornResp layout and maybe it will help in the low end efficiency
Djim; What is the ideal HornResp layout?
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Old 9th March 2011, 10:06 PM   #573
Djim is offline Djim  Netherlands
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Pyros, the ideal line you can see in Oliver's post # 559. In the second PDF file this ideal line is purple. The only problem in his representation is within the dashed line (the actual outlines of the cabinet) as it doesn't have enough reference points in corners so it doesn't show the extended volume very good. In this way each corner is represented by four reference points but non of them represents the actual corner.

Last edited by Djim; 9th March 2011 at 10:10 PM.
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Old 9th March 2011, 10:18 PM   #574
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Quote:
Pyros, the ideal line you can see in Oliver's post # 559. In the second PDF file this ideal line is purple. The only problem in his representation is within the dashed line (the actual outlines of the cabinet) as it doesn't have enough reference points in corners so it doesn't show the extended volume very good. In this way each corner is represented by four reference points but non of them represents the actual corner.
Ok but why is it bent after S3 in my box and at S3 in Jim's box?
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Old 9th March 2011, 10:55 PM   #575
Djim is offline Djim  Netherlands
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Because it runs exactly trough the centre of reference line 8. In corners this is not exactly in the centre but around 0.7. This numbre 0.7 stands for the corner correction and is the average value for air molecule density in the corner. These points set out the path lenght of the horn. (I hope I use the correct words but otherwise somebody will correct me)

Last edited by Djim; 9th March 2011 at 11:04 PM.
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Old 9th March 2011, 11:03 PM   #576
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[QUOTE=jbell;2498041]It's entertaining envisioning your minds warping inside out trying to improve this -- which is exactly why I started this thread in
the first place !! QUOTE]

Jim, you're just mean!!! I've spent hours trying to "better" your SS15 and the best I can do is lower the frequency 2Hz at a cost of 2dB. That's not
better, that's just a trade-off. Anders used a B&C driver to get a few cycles lower bottom end, but it's not as flat and it has a dip at 160. Since it's not
a "Neo" it weighs 20# more. Changing to the Eminence 3015LF removes the dip, but raises his bottom end.

Anders THAM15 expanded to 20"x23"x29" (outside), and using the 3015LF, and only one sheet of ply, is the best I can do!

The question is ... Do I have enough faith to build it !!!
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Last edited by Don Snyder; 9th March 2011 at 11:06 PM.
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Old 9th March 2011, 11:11 PM   #577
jbell is offline jbell  United States
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[QUOTE=Don Snyder;2498222]
Quote:
Originally Posted by jbell View Post
It's entertaining envisioning your minds warping inside out trying to improve this -- which is exactly why I started this thread in
the first place !! QUOTE]

Jim, you're just mean!!! I've spent hours trying to "better" your SS15 and the best I can do is lower the frequency 2Hz at a cost of 2dB. That's not
better, that's just a trade-off. Anders used a B&C driver to get a few cycles lower bottom end, but it's not as flat and it has a dip at 160. Since it's not
a "Neo" it weighs 20# more. Changing to the Eminence 3015LF removes the dip, but raises his bottom end.

Anders THAM15 expanded to 20"x23"x29" (outside), and using the 3015LF, and only one sheet of ply, is the best I can do!

The question is ... Do I have enough faith to build it !!!
I'd never be mean to you don, or any of the others that have been so gracious to me...

I also don't want to embarrass myself and admit how many hours I spent coming up with the ss15 design, or how many hours I've spent since trying to make it better.... That's why I know the torture that a person goes through trying.... Kinda warps your head inside out after awhile.
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Old 9th March 2011, 11:24 PM   #578
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Quote:
Because it runs exactly trough the centre of reference line 8. In corners this is not exactly in the centre but around 0.7. This numbre 0.7 stands for the corner correction and is the average value for air molecule density in the corner. These points set out the path lenght of the horn. (I hope I use the correct words but otherwise somebody will correct me)
OK Djim; I under stand what you are saying but that does not answer my question.
The bend in the purple line for my box ended up between S3 and ref line #8, thats not a corner, its the straight part in the back of the box. It should be bent at S3 like in the drawing of Jim's box. Did the progam bend it thare or did Oliver bend it thare?

If you draw a straight line from the top of S3 to ref line #11 and one from #11 to the end, the hole thing looks better. That bend should be at S3 and another one at ref line #11.
Andy

Last edited by 4pyros; 9th March 2011 at 11:31 PM.
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Old 9th March 2011, 11:24 PM   #579
Djim is offline Djim  Netherlands
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Quote:
Originally Posted by jbell View Post
That's why I know the torture that a person goes through trying.... Kinda warps your head inside out after awhile.
Yeah, driving all the way to Germany to find out about stupid flutes... Calling Italians with strange accents over and over again just to find out some silly details about the relation ship between Xmax, Xlim and BL force... Spending hours at the engineering department of a Dutch gas company for gas masses and behaviour in bends... and that all besides about this 'silly' SS15 concept and other JBell 'funny' findings.

Of course... for the good cause... I suppose... I hope

Cheers Don
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Old 10th March 2011, 02:08 PM   #580
tb46 is offline tb46  United States
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Default Post #571....

Hi Y'all,

You guys are quick.

Djim: I'm not going to touch the subject of corner reflectors, or whatever somebody wants to call it. Screamerusa reported his empirical results in the furybox thread, jbell added his practical experiences, and after studying the general area of discussion (over a long time period, front horns, back-loaded horn fullranges) I know less than I did when I started.

4pyros: I looked at the Hornresp files for the SS15 and your modified version again, and found that the difference was mainly from slight changes in the way the original was done, and from the fact that I had not entered values for Vtc/Atc/Ap1/Lpt in the original. I redid the original using soho54's corner method, and added the same front chamber (right or wrong) in both models. They now are quite similar, with your modified version being slightly better in the 144Hz dip area. You'll have to enter the data into Hornresp to see the lines clearly. You can reduce the dips in that area by setting S1 to .01.

As to the purple line in the flare drawing (Post #559), it's just an attempt at showing the average of the respective tapers, kind of a general sanity check for the location of the Hornresp inputs (in other words: disregard if it gives you a problem). To get this any better you will have to draw exactly what was build (which only the builder can do, as there are too many gaps in the dimensions), and use AkAbak.

jbell: I have the feeling you started with a much bigger version, and pared it down until you got the the point of no return. You certainly kept us busy. Nice work. :-)

Regards,
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