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Old 8th November 2008, 08:42 PM   #1
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Default can any body help to analise

inputed parameter, calculated, as posted pics are result.
pl give any advise.
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Old 8th November 2008, 08:44 PM   #2
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2nd
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Old 9th November 2008, 12:54 AM   #3
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Hmm, there's no context provided. I'm just a newbie but here's what I think the gurus would say. To build a BLH you ultimately need:

1. the driver and specs
2. your target for low-end response (e.g., 50Hz?)
3. whether the horn is front-firing or rear-firing
4. size of the chamber
5. size of the throat
6. size of the mouth
7. length of the path
8. the flare rate (exponential?)

Here's a simplistic attempt at an explanation. (In reality, the gurus wouldn't do it quite this way but it's just an example.)

Imagine you have a little bass reflex box. And attached to the BR's vent is a gigantic horn. How long? How big? What shape? Let's find out.

First figure out the tuning of the BR. Let's say the box is tuned to 200Hz. So simplistically, we're going to "feed" the horn with 200Hz and below. Down to what frequency? You have to choose that. Let's say 50hz. That means the vent will feed the horn with 200Hz and below.

Now you are committing to the mouth's size and length (dictated by the size of the 50Hz wavelength). There's so much more as well, e.g., the quarter-wave action (additional low frequency resonance below the horn's proper tuning).

So really, you have to design it on paper, then use MJK for testing purposes. MJK will tell you whether it's any good. I would ignore those graphs until you have really fleshed out your design with many, many iterations on paper and in MJK.
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Old 9th November 2008, 01:02 AM   #4
MJK is offline MJK  United States
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Since he did not get the worksheets from me, MJK will not be telling him anything.
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Old 9th November 2008, 01:27 AM   #5
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Hi Martin, oh, I did not know that. I am very sorry to hear that. The worksheets are the bargain of a lifetime at any price.

Bigcatdairy, how did you obtain the software?
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Old 9th November 2008, 10:27 AM   #6
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He was busily posting on the main loudspeakers section a little while ago asking if anyone could provide him with the old sheets, claiming he could not afford $25 to buy them off Martin due to the poor exchange rate. And while I sympathise about duff exchange rates generally, that's not a justification for not paying. If you can't afford it, you can't afford it. Tough. There are lots of things that I would like that I can't afford, so, oddly enough, I live without them.

As Mr Bigcatdiary doesn't seem the least bit willing to do any background reading on horn design either, not even of free material on the 'net (God forbid he should consider buying a book), I for one, have decided to ignore him, on the basis that I have little inclination to help people who don't make an attempt at helping themselves. The fact that he's now somehow aquired Martin's worksheets without coughing up the required sum only increases my less-than-charitable sentiments.
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Old 9th November 2008, 01:43 PM   #7
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Quote:
Originally posted by MJK
Since he did not get the worksheets from me, MJK will not be telling him anything.

ok, i'll try to transfer $ to u~
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Old 9th November 2008, 01:58 PM   #8
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Quote:
Originally posted by Scottmoose
He was busily posting on the main loudspeakers section a little while ago asking if anyone could provide him with the old sheets, claiming he could not afford $25 to buy them off Martin due to the poor exchange rate. And while I sympathise about duff exchange rates generally, that's not a justification for not paying. If you can't afford it, you can't afford it. Tough. There are lots of things that I would like that I can't afford, so, oddly enough, I live without them.

As Mr Bigcatdiary doesn't seem the least bit willing to do any background reading on horn design either, not even of free material on the 'net (God forbid he should consider buying a book), I for one, have decided to ignore him, on the basis that I have little inclination to help people who don't make an attempt at helping themselves. The fact that he's now somehow aquired Martin's worksheets without coughing up the required sum only increases my less-than-charitable sentiments.

when i said i can't afford it? just meant very inconvenient to transfer. dunno y u said so,as i just liked to get it anyway to save some bucks. ****!
and the original old sheet was free, i just got the old sheet from sb else, i did't break any rule. on the other hand, he didn't say to transfer old sheet is prohibited. if he emphersise so, i promise to delete it. big deal~

so, if everybody thought i was wrong, ok,now i promse to pay him anyway .
stop distorting my mean!! thx!
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Old 9th November 2008, 02:07 PM   #9
MJK is offline MJK  United States
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If you are using the old worksheets that is OK.

Please do not send any money, last week I stopped selling licenses to the new worksheets. For a number of reasons it just did not make any sense to continue.
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Old 9th November 2008, 02:24 PM   #10
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Quote:
Originally posted by MJK
If you are using the old worksheets that is OK.

Please do not send any money, last week I stopped selling licenses to the new worksheets. For a number of reasons it just did not make any sense to continue.
yes, just got the old sheet from another person from this forum, that y on my post just ask for old sheet. thx for understanding.

what a pity that u stopped. like to ask y if u dont mind~

next month i'll go back to china, i hope that i can get a new sheet from u, money can transfer freely there. bcoz i found ur work sheet is more understandable for me.
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