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Folded Horn/Bandpass 15" Design Pics.
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Points: 89 		Post Options Post Options   Thanks (0) Thanks(0)   Quote ARR_PG Quote  Post ReplyReply Direct Link To This Post Posted: 28 October 2019 at 1:20am
Here is the acoustal power with 1200 watts. If anyone can help me get that displacement down to 6mm would be much appreciated. :)
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Points: 89 		Post Options Post Options   Thanks (0) Thanks(0)   Quote ARR_PG Quote  Post ReplyReply Direct Link To This Post Posted: 28 October 2019 at 1:34am
Originally posted by Mikkel Mikkel wrote:

I assume you mean 200watt as 200 volt would be 5000watt @ 8ohm. 

Also i mean using the excursion graph at xmax not using the max spl function. What youve posted doesnt look right at all. Using the 'clean' data when looking at the port velocity will give you a better idea of whats happening. Hope that makes sense.

It looks good now anyways.

See the Diaphram Displacement graph I posted on the previous page. Its 4x more than the driver's xmax :( Any thoughts?
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Points: 1203 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Keen Quote  Post ReplyReply Direct Link To This Post Posted: 28 October 2019 at 4:47am
show us your input params 
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This is a curious design. I think it has two extra resonators in it, that you may not be simulating; the chamber at the horn throat before it pinches in at the driver, and the chamber in the upper front corner that has only a small exit to the rest of the rear chamber. Or am I wrong?
Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA
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Originally posted by studio45 studio45 wrote:

This is a curious design. I think it has two extra resonators in it, that you may not be simulating; the chamber at the horn throat before it pinches in at the driver, and the chamber in the upper front corner that has only a small exit to the rest of the rear chamber. Or am I wrong?

Here is the schematic, I placed the driver between S1 and S2. Parabolic horn with Con export.  (offset driver horn).
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Points: 89 		Post Options Post Options   Thanks (0) Thanks(0)   Quote ARR_PG Quote  Post ReplyReply Direct Link To This Post Posted: 28 October 2019 at 7:50pm
Originally posted by Keen Keen wrote:

show us your input params 

See the first page. All i changed was the "Eg" with the correct power and increased the Port Size.
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Here is a major problem.




If I tweak the port I can get a helmholtz freq around 40hz and a fundamental freq around 40hz. 

If I do this I have to rip off the side panel and change the port size.



The driver's Xmax is only 6mm (terrible).
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Elliot Thompson View Drop Down
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Points: 5176 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Elliot Thompson Quote  Post ReplyReply Direct Link To This Post Posted: 29 October 2019 at 12:46am

It is a double tuned box. Such designs are very efficient (105 dB 1 watt/1 metre based on your previous graph) within a very limited bandwidth at the cost of the loudspeaker losing all control below a certain frequency. Simply put, the loudspeaker is unloading (does not see a box/reacts as if it is in Free Air) @ 40 Hz hence, the reason the xmax is so high when receiving 200 watts (based on a previous post). 

This why.... tuning the box higher, moves the the leap in xmax higher up the frequency range. As far as the loudspeaker is concerned, it does not see a box but merely two tubes. One attached to the front of the chassis and one attached to the rear of the chassis. Where is the compliance?

Best Regards,


Edited by Elliot Thompson - 29 October 2019 at 12:46am
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This graph is from a 1200w input. Eg - 97.98
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Originally posted by Elliot Thompson Elliot Thompson wrote:


It is a double tuned box. Such designs are very efficient (105 dB 1 watt/1 metre based on your previous graph) within a very limited bandwidth at the cost of the loudspeaker losing all control below a certain frequency. Simply put, the loudspeaker is unloading (does not see a box/reacts as if it is in Free Air) @ 40 Hz hence, the reason the xmax is so high when receiving 200 watts (based on a previous post). 

This why.... tuning the box higher, moves the the leap in xmax higher up the frequency range. As far as the loudspeaker is concerned, it does not see a box but merely two tubes. One attached to the front of the chassis and one attached to the rear of the chassis. Where is the compliance?

Best Regards,

Ok thanks for your comments.  Is this something that can be fixed with a bit of research? Or is it back to the drawing board. :(

Power is 1200w in the current hornresp perams.
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Originally posted by ARR_PG ARR_PG wrote:


Ok thanks for your comments.  Is this something that can be fixed with a bit of research? Or is it back to the drawing board. :(

Power is 1200w in the current hornresp perams.



The first thing you should do is drop the power down to 600 watts. If the excursion is reduced by half, then power is one of the problems. If the improvement is still lacklustre then, you should try simulating another 15 inch driver.

 

Since you already made the box, you really have nothing to lose trying the above methods.

 

I added the TS Parameters of the FANE Sovereign 15-600 in Eminence designer just to see if the driver would indeed attain 40 Hz @ -3 dB in a reflex enclosure using the Design Priority Method. The Design Priority Method offers no limitation on the enclosure size so you can achieve the desired frequency @ -3 dB providing the loudspeaker is capable of achieving it.

 

Unfortunately, FANE Sovereign Pro 15 600 is incapable of achieving it. The lowest you can achieve @ -3 dB would be 50 Hz. The driver is not designed to offer 40 Hz without a great amount of excursion involved based on the calculated TS Parameters figures.  

 

This is another reason why the excursion is so high @ 40 Hz. Bear in mind excursion has no influence in terms of calculation to achieve the TS Parameters. One can have a high excursion driver offering 20 mm xmax. However, if the driver is not designed to play the desired frequency you are aiming for, playing the driver below its designed frequency criteria will just have the driver offering a sound as if you were driving fast in your car with the window partially open.

 

A High Pass Filter @ 55 Hz, will more than likely allow you to achieve to 1200 watt mark without exceeding x-mechanical limit if you want to stick with the FANE Sovereign Pro 15-600

 

Best Regards,

 

 



Edited by Elliot Thompson - 29 October 2019 at 10:54am
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I am happy with this. Using only 390w - as my old UKP 1300 Matrix amp gives 390w at 8ohms per channel. 

It is using a Second Order Filter Type. I do not have a digital crossover to hand. Anyone know how I can apply this filter type for the "condenser mic" test im planning on doing this week?

Thanks to everyone who has posted on this thread and all your help. 
 
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