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Old 7th October 2008, 08:54 PM   #11
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Location: Fort Collins Colorado
Actually I remember Tom Danley saying something about that driver.

HORN RESP QUESTION.

I'm a little confused on S1. and the Speakers opening.
Is S1 the back of the horn, and the center of the speaker goes as shown on s2? How do you manipulate the hole the speaker fires through or does it assume a full circle. I.E. 13" round hole for a 15?

Or put another way. Were do da speaker goeth?
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Old 7th October 2008, 09:04 PM   #12
jbell is offline jbell  United States
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Does this help?
Center of dustcap is 22cm from end of horn
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File Type: jpg thpaths.jpg (46.3 KB, 775 views)
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Old 7th October 2008, 09:12 PM   #13
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Very much so ...
Gee that was quick..Mr Bell.

Am I correct that the hole the speaker fires through is full size?


I have somthing I want to try.

S1 680
S2 819.72
S3 1600
S4 2391
S5 3415 23x23 inches
L1 8.26
L23 114cm
L34 105.10 cm
L45 21.0 cm
Angry looking little box. Has a ripple above 140 but since it's going on an active system cut at about 110 24db/oct I figure I won't have to worry about. Sacrificed a clean curve for more ummph. Will figure out the fold once I determine how to load the driver into the horn. I.E. square hole/ full hole/v hole.
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Old 7th October 2008, 09:20 PM   #14
jbell is offline jbell  United States
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In this case, yes. I'm not sure (although I've seen posts about) how to model a TH with a smaller than driver sized hole -- Basically creating a compression chamber the size of the cone, etc...

There are many 'tricks' to creating an optimum TH, that I wish I knew how to model in hornresp. like a compression chamber, polyfill stuffing, multiple horn path length's, etc..

My design was the most basic TH that is possible.. but still seems to work well.

good luck

TRY
making L12 and L45 both 16.9cm (edge of driver is touching edge of horn)
go to the driver section in the TH wizard and make LE 4.9 instead of .9 (which is what littlemike suggested -- a 4mh inductor)

and amazing enough, it's almost exactly my TH design, only a little shorter/louder/not quite as low (50cm shorter)
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Old 7th October 2008, 09:28 PM   #15
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Quote:
Originally posted by jbell

My design was the most basic TH that is possible.. but still seems to work well.

I'll second that.
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Old 7th October 2008, 11:51 PM   #16
GM is offline GM  United States
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Quote:
Originally posted by jbell

1. It's a PA sub, 40-120hz is the powerband.
2. +- 3db at MOST within that band. (Ideally, MUCH flatter -- no one note wonders please)
3. PA cabs can be big, but not enormous, probably about 600liters, not much more.

7. These will be used in groups, probably 4 at minimum, up to 8.
1) 40 Hz is F3, F6, what? I mean it's my understanding that what passes for LF in most concerts these days is that 40 Hz is > -24 dB referenced to 60 Hz and if true, then for only an octave of flat BW it's probably best done with a simple BP similar to this: http://www.speakerplans.com/index.php?id=x1

2) +/- 1.5 dB is potentially doable, though size may make it an impractical tolerance.

3, 6) As noted, this driver wants to 'feel' a large Vb. Attached sim looks good at 55 V/10 mm excursion, but is a calc'd ~966 L net.

4) Hmm, due to its size, not much for stacking, though you could slice it up into 2, 4, whatever number of cabs as required for easy hauling/handling, though will be unusable individually.

GM
Attached Images
File Type: gif eminence kappalite 3015lf 27.25-204.88 hz expo th.gif (18.7 KB, 605 views)
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Old 8th October 2008, 02:13 AM   #17
jbell is offline jbell  United States
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GM:

yes what 'passes' for bass in many places is 60hz, partly due to the 80's and all of those W-bin's that I would like to really forget, that conditioned us for that sound...

I've built tubas and titans that are -13db 40hz-100hz, and I don't like that sound. Not sure about what screamers is looking for, but for me, I need my 40hz... And yes, I know, first harmonic is 10db hotter from a bass than the fundamental, so even a 5 string only needs 62hz for the harmonic... still, It just doesn't sound 'deep' without that fundamental.

I can live without 40hz being flat, but about -6db at most is what I like to listen to, even out doors.

So, since I'm a novice compared to others, in terms of designing TH, etc.. What can you suggest to screamers for his 3015lf's? that's in the 600 liter range or smaller? I can't seem to come up with much better than this with -6db@40hz. (56volt, 2pi, 5mh)
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File Type: jpg 3015lf-4.jpg (44.6 KB, 605 views)
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Old 8th October 2008, 02:33 AM   #18
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Jim -

Looks similar to what I came up with last night. Nothing esoteric, just conical flares. Seems that simple works OK for this driver.
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Old 8th October 2008, 03:44 AM   #19
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If one works through large sound companies, one becomes used to the sound of 8-20 double 18's screaming away. It is a highly distorted sound but it has an underlying power to it, 40-50HZ.
You normally can't get that sound in a 4-6 sub system except at very low volumes. The thing I liked INSTANTLY about the th-115style box, it has "That" sound. If I find myself pushing 40-50 up on my eq with 4 double EV 18's and then a massive crash cut with a digital crossover at 33, something is wrong.
I've tried a lot of subs, the ones I like I can't afford nor justify the expense.
I'm looking to build horn loaded subs with one driver in each, so I can run 2 to 3 off half an amp. Most shows need 4 bass bins. and 6 tops. I can run all that from one amp rack with horns. Now I have to use two amp racks because of the doubles.

I've gotten LOTS of offers to buy EAW, MEYER, Yorkille and JBL Pro subs, All double 18's. and all over 800 bucks per box. More weight, more power, and more costly repairs. Doesn't fit my budget business model.
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Old 8th October 2008, 04:09 AM   #20
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Quote:
Originally posted by jbell
Does this help?
Center of dustcap is 22cm from end of horn

you have no idea how much your picture cleared up Hornresp for me...i still had no idea of what those numbers meant until the picture pointed out what sections where what for me.

thumbs up.
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