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Old 1st January 2008, 08:23 AM   #901
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I have a hangover, so can't face power tools at the moment...

Happy new year all!
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Old 1st January 2008, 09:50 AM   #902
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Default DVC in Hornresp

Dear church of fellow bassheads,

How would one go about entering T/S parameters for a DVC woofer in hornresp? Simply use the parameters of one coil and multiply voltage by the appropriate factor (dependent on series/par config) to get effective power? or do the parameters need to be calculated for both coils and entered as two configured coils looking like one effective load?

very happy new year from switzerland... may ye all grow happy and fat bellies.

Mike
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Old 1st January 2008, 11:27 AM   #903
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Default My third TH.

Im building a small TH with a 5,25 inch speaker to my friend.
He saw this video and was hooked. http://www.youtube.com/watch?v=dKQTo0w5sNE

Click the image to open in full size.
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Old 1st January 2008, 11:38 AM   #904
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Click the image to open in full size.

This is what hornresp has to say about it.

The box will be 75 x 32 x 17,4 cm or 29,5 x 12,6 x 6,85 inch.
I dont think hornresp gives the right efficiancy but i do think it will be awsome considering the small size of driver and box. At least i hope so.

Johannes.
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Old 1st January 2008, 12:17 PM   #905
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That's tiny!
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Old 1st January 2008, 12:46 PM   #906
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happy new year first of all.

@Circlomanen
the 830512 seems to have an xmax of 2mm only. Do you think this will be sufficient for a TH? Other that that I like the idea of a very small TH a lot.


Keep us posted please!

Erik
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Old 1st January 2008, 01:13 PM   #907
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Since almost every tapped horn suffers from very strong frequency response ripple with their associated 180 degree narrow phase jumps (not only above 80Hz but across the whole passband) I'm wondering how are you going to cross over the tapped horns with a main system?

The experience that I have in this area is with scoop type rear loaded horns, which behave quite similar to tapped horns, and crossing them over to a midrange with proper on-axis summing is *extremely* difficult. Optimum summing is only achieved with the help of a DSP xover and 4 or more sharp parametric EQs to flatten phase. Otherwise, you may find the system summing at 60Hz, cancelling at 80Hz and summing again at 120Hz, which in practice sounds bad to terrible depending on room acoustics (it sounds particularly bad in big reverberant spaces because if something does not sum on-axis, there are a lot of chances that it will sum off-axis).
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Old 1st January 2008, 01:46 PM   #908
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Quote:
the 830512 seems to have an xmax of 2mm only. Do you think this will be sufficient for a TH
No, not for War of the worlds at ref levels, but i will have to see what happens. I will probably blow a speaker or two, but its part of the fun.
This whole project has a 10 dollar budget. Its just some crap laying around that i play with. It will probably end up as a part of my übercheap PC-speaker system.


Quote:
Since almost every tapped horn suffers from very strong frequency response ripple with their associated 180 degree narrow phase jumps
No! Not in their passband.

See what Tom Danley has to say about it in his White paper. http://www.danleysoundlabs.com/pdf/danley_tapped.pdf

Specially the part directly following "Example of a Tapped Horn" in the white papper.

Johannes.
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Old 1st January 2008, 02:57 PM   #909
Eva is offline Eva  Spain
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According to Hornresp, every tapped horn has a narrow phase jump over 100 degrees in the *middle* of the passband, and two or three more jumps in the crossover region. Scoop type back loaded horns (and transmission lines) exhibit similar behaviour.

Is hornresp wrong? I don't think so because I have been experiencing this same behaviour in real systems. For example, optimum overlapping of scoop bass bins with front loaded subwoofers is really challenging.

BTW: Now I think that all this new tapped horn fashion is actually nothing but the good old 1950s JBL D55 "Scoop" bass bin reinvented. It was the most efficient/compact stuff back then (and still nowadays) but this comes at a price. Fortunately now we have DSP crossovers
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Old 1st January 2008, 03:11 PM   #910
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Quote:
the 830512 seems to have an xmax of 2mm only. Do you think this will be sufficient for a TH? Other that that I like the idea of a very small TH a lot.
When playing around in hornresp I saw that the Peerless HDS PPB 830860 seems to work fine in this TH. It has +- 3,5 mm xmax. Not that much, but better.

Anyone know of a good 5,25 inch driver with Qts≈0,4, Vas≈10 L, and Fs≈55 Hz?? +- 20% should work ok.

Johannes.
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