Spawn Olson/Nagaoka Horns the Next Generation

[sippy]

Just out of curiosity, how much would the change from 19mm down to 18mm in line length in enclosures like these?
If I were to re-draw for this material size change, I'd draw the cabinet on paper (1 half), drawing the centre lines of the folds, then draw 9mm either side of these to get the material width.

[planet10]

If you do it right, line length is within mm of the same. When changing over, the size & length of the passage is what needs preserving.

dave

[Jockaruba]

I've been trying to 'redraw' the Kirishima for 18mm wood trying to keep the sizes of the passages the same.

So far the changes from top to bottom (starting from the centre) seem to be relatively easy. Just keeping the distances the same while adding 18mm instead of 19mm.

But the changes back to front are giving me trouble.
Compensating the outer sides with minus 1 mm on both sides is my starting point. But then compensating for piece B takes another mm wile compensating for G an F takes 2 mm because of their overlap in order to get the passages from rear to G and than from G to F and then from F to the front pannel. So where do I compromise?

Or maybe I my approach is all wrong...

Other that that I assume that the stepped deflector also needs to be changed somehow.

Lastly, it seems to me there is a mistake on the overview drawing at the top where the top measures 17 3/4. Unless I am wrong this should be 18 (plus 3/4 for the rear) as it says on the last page.

Jock

[planet10]

At the same time you follow the instructions below, you can fold in change to unit mm (ie rationalize for metric).



dave

[Jockaruba]

Originally Posted by planet10

At the same time you follow the instructions below, you can fold in change to unit mm (ie rationalize for metric).



dave

Hi Dave,
Thanks for all the effort.
I am going to try to redraw this weekend. So far I am not fully understanding the entire proces partly a language thing (I hope ) so I am sure I'll be be back here with some additional questions.

As a starting point for me: You say in your reply " At the same time..." does that mean I do the changes as I described in my mail and than add yours or do I start with the original drawing and than follow only your instructions?

Jock

[planet10]

Since the original was done for imperial measure, the conversion will end up with lots of dimensions that are to the tenth of a mm. It is OK to round to the nearest mm, ie 2" = 51mm (instead of 50.8mm)

dave

[ORNJ]

Hi, I am very interested in these designs.

I was working on a MHW(mid, horn, woofer) monitor but I am reconsidering that and I am thinking that going with something like this or another frugal horn design would be better.....and cheaper as the design I was working on was going to cost $500 in drivers alone and then i would have to get a crossover done somehow...active or passive.

With these great full range horns that wont be a problem. However, I cannot seem to find any sensitivity ratings anywhere for any of the designs. I would like to know this as I have been re-evaluating my budget for the speakers and amp in my listening room that I am working on. If I save enough money going with one of these designs and they are sensitive enough I will get a bottlehead stereomour to go with the Quickie I have coming. Or maybe build a budget F5 and just gradually upgrade to better parts.

My room is 10.5'wide x 10.5' deep x 8' tall. I also plan on acoustic treatments and it doubles as my office. Oh, and it also has double doors on one side and a single door in the opposite corner.

[planet10]

Originally Posted by ORNJ

However, I cannot seem to find any sensitivity ratings anywhere for any of the designs.

The horn only affects the bass so sensitivity is the same as the speaker used in them.

dave

[chrisb]

Originally Posted by ORNJ

Hi, I am very interested in these designs.

I was working on a MHW(mid, horn, woofer) monitor but I am reconsidering that and I am thinking that going with something like this or another frugal horn design would be better.....and cheaper as the design I was working on was going to cost $500 in drivers alone and then i would have to get a crossover done somehow...active or passive.

With these great full range horns that wont be a problem. However, I cannot seem to find any sensitivity ratings anywhere for any of the designs. I would like to know this as I have been re-evaluating my budget for the speakers and amp in my listening room that I am working on. If I save enough money going with one of these designs and they are sensitive enough I will get a bottlehead stereomour to go with the Quickie I have coming. Or maybe build a budget F5 and just gradually upgrade to better parts.

My room is 10.5'wide x 10.5' deep x 8' tall. I also plan on acoustic treatments and it doubles as my office. Oh, and it also has double doors on one side and a single door in the opposite corner.

The room might be kind small for any of the 60 -72" tall double mouth horn to fully integrate, and the acoustic treatment required to tame bass in a square room could further reduce the net floor space.

I'd honestly be inclined to suggest something along the lines of FH3 or BK12 with FE126E or even a direct radiating MLTL - Fostex FF125WK works very well in a moderate sized box ( approx same size as Pensil 7).

any of the smaller single driver systems could easily be built for less than $500 including drivers, furniture grade multi-ply plywood and finishing

[ORNJ]

ok great. the FH3 was on the list but the Spawn family just seemed to catch my eye because of the interesting design.

I'm going to be looking into it some more. I hope to sell some stuff that I no longer use to have the funds to build a pair of speakers and get a bottlehead amp built.

Worst case scenario I will use the JBL 120Ti that are in the garage but they are only 89db sensitive.

hoping to get $1000 for the junk I have around here total