Hi TheBaronGroog,
This is one of the most overrated design I ever seen.
If you model this double TL with HR or MJK you find the maximum input power to be about 2 x4.5 W Rms without exceeding x-max and f-3dB=~32 Hz(tuned at ~16Hz when including stuffing) and by using a box volume of~2 x 275L making:
The equivalent Qt= ~0.433 (Opt Volume for a design is ~2 x107L at a Qt of ~0.54).
The suggested design states a f-3dB at 10 Hz at 4 x Pi (Sr) but this is in reality -29.4 dB down and ~65.6 dB SPL for one section, thus max 71.6 dB for two.
b
PS: In your previous Post# 17 Your basic triangle calculation is quite correct. Post # 20 would work too.
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Hi TheBaronGroog,
This is one of the most overrated design I ever seen.
If you model this double TL with HR or MJK you find the maximum input power to be about 2 x4.5 W Rms without exceeding x-max and f-3dB=~32 Hz(tuned at ~16Hz when including stuffing) and by using a box volume of~2 x 275L making:
The equivalent Qt= ~0.433 (Opt Volume for a design is ~2 x107L at a Qt of ~0.54).
The suggested design states a f-3dB at 10 Hz at 4 x Pi (Sr) but this is in reality -29.4 dB down and ~65.6 dB SPL for one section, thus max 71.6 dB for two.
b
PS: In your previous Post# 17 Your basic triangle calculation is quite correct. Post # 20 would work too.
Morning Bjorno,
That's music to my ears, "I hope you're not inferring that I'm a little basic"
I'm thinking of rotating the vent through 90deg, so it sticks out to the side of the enclosure, see crappy paint file attached. This would enable me to build some shelving to accommodate the amplifier-would this have a negative effect on the response? My understanding is that it shouldn't as the frequencies concerned are longer than the enclosure anyway.
Also, what effect might there be if I arranged the drivers as attached in the "new position"?
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Hi Bjorno,
Hope you are well
I'm finally at the point where I can start getting this built. A friend is going to create a sketchup of the attached picture/design and confirm all the panels will fit together before I take saw to wood!
Could you confirm the port width is 46.6mm? For the life of me I cannot fathom how I came to this figure and need to make sure it is correct!
Best regards,
Greg
Hope you are well
I'm finally at the point where I can start getting this built. A friend is going to create a sketchup of the attached picture/design and confirm all the panels will fit together before I take saw to wood!
Could you confirm the port width is 46.6mm? For the life of me I cannot fathom how I came to this figure and need to make sure it is correct!
Best regards,
Greg
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Hi Greg,
: I looked through all my simulations and pictures of Kef B139 and I also found that I've already posted the Port dimensions..... b
PS: Can you transfer your dimensions ( as drawn in your Picture) to a HR.txt file and Post it to this thread?.
b
Hi, yup - more haste less speed!
I've no idea how I would transfer them to a HR.txt file - will have a look for a guide online, but any helpful tips appreciated. They are in the paint sketch in my previous post #25
I have hit one snag - it appears that 19mm MDF isn't readily available over here so may have to re-design the whole thing as 18mm is...bugger! lol
I've no idea how I would transfer them to a HR.txt file - will have a look for a guide online, but any helpful tips appreciated. They are in the paint sketch in my previous post #25
I have hit one snag - it appears that 19mm MDF isn't readily available over here so may have to re-design the whole thing as 18mm is...bugger! lol
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That is a nice design Bjorno. Thanks for showing details of equations and your thinking process.
@Barongroog, from the drawing showing how the full triangular TL was folded, I think you can assume that the divider is equidistant from top, front, and back wall and equal to half the depth at half height of unfolded TL. That is standard design for these types of boxes.
@Barongroog, from the drawing showing how the full triangular TL was folded, I think you can assume that the divider is equidistant from top, front, and back wall and equal to half the depth at half height of unfolded TL. That is standard design for these types of boxes.
It's also somewhat wrong, as it doesn't account for the decrease in cross-sectional area along the path length in the fold. If the decrease was properly accounted for, the top of the divider will be a bit closer to the top than it is to the front, and a bit closer to the back than it is to the top.
Right, after the above comments I've gotten the graph paper out and had a re-draw. Transposed this into paint - whoop, I'm such a computer whiz! (did try sketchup but would be quicker to translate Encyclopedia Britannica into Swahili than learn that) and came up with the following. Anyone care to cast their beady-eye over it?
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Hi TheBaronGroog,
There seem to be a few errors in your latest sketch (Post #32) which is something, that's almost unavoidable. I don't like the duct inlet as drawn with that little stub around the corner. You should be able to use Hornresp to change a few things around , e.g.: set S1 to 0.01, and change the other values to make it fit you materials without changing the overall performance.
Anyway, I'm attaching a quick run at a drawing using bjorno's original Hornresp data, S2 is still a tad large (also depends what you are referencing to, I did reference to the duct center). Maybe this will help you to get on the right track converting your final Hornresp simulation to an enclosure.
Regards,
There seem to be a few errors in your latest sketch (Post #32) which is something, that's almost unavoidable. I don't like the duct inlet as drawn with that little stub around the corner. You should be able to use Hornresp to change a few things around , e.g.: set S1 to 0.01, and change the other values to make it fit you materials without changing the overall performance.
Anyway, I'm attaching a quick run at a drawing using bjorno's original Hornresp data, S2 is still a tad large (also depends what you are referencing to, I did reference to the duct center). Maybe this will help you to get on the right track converting your final Hornresp simulation to an enclosure.
Regards,
Hi Oliver,
Yes, I figured there would be! I didn't like the step into the vent either, was planning on smoothing that off somehow.
Thank you very much for the plans, very helpful indeed, I'll have a bit more of a play with HR and see what I can come up with and how this might change the outcome.
Greg
Yes, I figured there would be! I didn't like the step into the vent either, was planning on smoothing that off somehow.
Thank you very much for the plans, very helpful indeed, I'll have a bit more of a play with HR and see what I can come up with and how this might change the outcome.
Greg
Right, I've had a chance to have a play.
Widen port width to 50mm.
Increase L12 to 1439mm in order to reduce S1 to 0.1 and maintain horn ratio.
Allows me to remove the 20mm S1 section of wood and use one single piece for the internal wall.
I think I've accomplished changing HR to suit, have attached modified layout and txt, see what you think?
Widen port width to 50mm.
Increase L12 to 1439mm in order to reduce S1 to 0.1 and maintain horn ratio.
Allows me to remove the 20mm S1 section of wood and use one single piece for the internal wall.
I think I've accomplished changing HR to suit, have attached modified layout and txt, see what you think?
Attachments
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Hi,
Looks good to me.
Took opportunity to add some Damping Material and expand your HR Input Screen a bit with a Picture:
b
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I've had a bit more of a play, widened the port to 55mm, realise I will have to increase overall enclosure length to accommodate this.
Active BP crossover 20Hz-60Hz
I've also thrown together a sim for some Focal 6w2 midrange for some floor standers - will be using Dali Ikon Ribbon/Tweets with them and active crossovers.
Thoughts welcome!
Oh, and how do I model stuffing in HR? I can't find it anywhere - do I need a later version?
Active BP crossover 20Hz-60Hz
I've also thrown together a sim for some Focal 6w2 midrange for some floor standers - will be using Dali Ikon Ribbon/Tweets with them and active crossovers.
Thoughts welcome!
Oh, and how do I model stuffing in HR? I can't find it anywhere - do I need a later version?
Attachments
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