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Old 7th July 2010, 08:37 AM   #1
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Default Trying to delve into the world of Akabak TH

Forgive me if this is ignorant I'm really trying. Using the export feature in Hornresp I'm trying to further my understanding of tapped horns. I decided against increasing/adding inductance [Le] to the design since it is only adding a simple 1st order Lowpass filter in reality. In looking at the Hornresp models Driver Displacement window I decided to add filters in Akabak, a Lowpass @90 and a Highpass @39, which definetly keeps the excursion under control and levels out the curve. I'm still learning as far as phase is concerned, I did invert the driver polarity for fun.

Am I getting any closer?

Akabak Script in txt file

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Old 7th July 2010, 05:08 PM   #2
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I'd suggest giving this a read. Good stuff.
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Old 7th July 2010, 06:32 PM   #3
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I read that last night, I even turned it into a nice pdf doc. The only reason I was able to get this far in Akabak was reading that. I have several other modeling programs and I just modeled this same driver in 6 other types of enclosure (sealed,ported,ported w/active HP,4th order BP, single and dual reflex 6th order BP). It would seem phase will do as it pleases. Even in a simple sealed box phase will shift over the response curve, I've just never bothered to pay so much attention to it until now. So my guess is that until I actually build one see how it sounds and possibly use my X-Frame88 and test gear to apply active bandpass filters to try and correct the phase it'll be fine. But then I could be completely wrong...
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Old 9th July 2010, 05:58 AM   #4
soho54 is offline soho54  United States
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Don't stress over phase too much. The only reason it was brought up in the other threads was to try and get people to build something "horn" like, in keeping with the treads intentions. If you tried to follow what was there, you had a pretty good chance of actually ending up with at least a semi-horn, and not just a generic quarter wave resonator.

In reality you can do a tapped pipe, or whatever else that will work for your needs.

In the AkAbak script the drivers phase isn't inverted, the node names(9,11) have just been re-named. This can cause problems later when trying to add to your script.

To flip the polarity easily you would change:
Driver Def='Driver''Driver'
Node=1=0=9=11

to
Driver Def='Driver''Driver'
Node=0=1=9=11

Last edited by soho54; 9th July 2010 at 06:02 AM.
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Old 9th July 2010, 10:38 AM   #5
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soho54,

Thanks for the advice changing 1 & 0 is definitely a little easy to keep track of then changing every 9 to 11 and vice-versa. I also what to thank you for your work on the Akabak for Dummies thread! That was a HUGE help. Akabak is pretty intimidating at first and I'm sure it will take a while to really get into it but I've got a basic understanding now . I can hardly wait until I'm able to build one of these things and see how it sound . I had a bad kidney removed on the 18th (NOT FUN) so I've been doing allot of reading on these and other things
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Old 10th July 2010, 10:06 PM   #6
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Some wasted space but oh well 37x28.5x17.75 (ish)

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Old 15th November 2010, 05:23 AM   #7
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soho54

Thanks for the intro to AkAbak - I had no trouble at all using it given your crystal clear instructions!

I am happily modelling away with this (and Hornresp and MJK worksheets) and I reckon I understand it OK.

HOWEVER.......

What is the go with enclosure and duct/waveguide damping in AkAbak?
Most of the things I am playing with require some damping/stuffing to control Q.
What is the correct way to simulate this? I have read as much as I can find but I still can't quite grasp this bit.

TIA for any help on offer!

Keith Arnold
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