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Old 5th January 2011, 01:11 AM   #1541
jbell is offline jbell  United States
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Quote:
Originally Posted by Brian Steele View Post
At what input voltage level to the THs are you doing your tests?
28v@10m
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Old 5th January 2011, 01:30 AM   #1542
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Originally Posted by jbell View Post
28v@10m
I think that's the issue right there. The driver parameters typically entered into HornResp for modelling are small-signal (e.g. 1W) parameters. The predicted response will therefore likely be more accurate at that level, and become less accurate as the power is increased.

At 28V in, you're basically feeding 100 times as much power into the driver, pushing it way beyond what can be considered its "small-signal" response. Interestingly enough though:- your 28V measurement results might actually be closer to what what the performance might actually be under real-world (PA) conditions. There aren't that many DJs that run their subs @1W .

I suggest looking into using impedance response testing at low voltage levels (a WT3 can do this for you in seconds) to test the accuracy of build vs the predicted response, then using the 28V measurements to determine what performance would really be like running in a PA environment.
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Old 5th January 2011, 02:16 AM   #1543
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Originally Posted by soho54 View Post
Here are the files you need for HR 2800-101017 non-auto slider version.

I believe this is the last version before the slider updates. Just add a new folder to the HR main folder, and extract these files to it. You should copy your main .dat file, and paste it into the new folder here to move your saved models over. The other bits will be generated once you run the new/old version.
Thanks very much, sir.
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Old 5th January 2011, 11:51 AM   #1544
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Quote:
28v@10m
Explains quite a bit.

Are you going with a ground plane measurement when you are going this?

As in the microphone on the ground.

Are you tipping the cabinet towards the ground when you are doing this?

And adjusting for the reflected image gain due to the ground boundary reinforcement?

By the way I applaud your testing at proper power levels.

And DJ's should all be set up with limiters and high pass filters locked down.

I tend to create things that I am going to call chimp proof from now on.

That includes removing potentiometer connections and placing a properly sized resister in lieu of.

The chimps get to play with a knob and the system stays alive a little longer.
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Old 5th January 2011, 02:57 PM   #1545
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Hi there. being a Macintosh converted for the past 25 years, I can't use HornResp to build my tapped horn with JBL 2235h with 20Hz Fs.

JBL 2235h specs
Components - 2235H

Could somebody compute the results for me? I am not lazy, not just on the dark side of computers... ;-)

Tapper is constant.
I only need 20Hz to 60Hz as the sub will be used to complement my JBL 4530 in a home environement.
Let me know what I can do to improve ;-) I am a noob in tapped horn.



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Old 6th January 2011, 09:07 AM   #1546
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You should be able to run hornresp in one of the virtual win einvironments on a mac (vmware fusion, parralels, etc.. take a look at Comparison of platform virtual machines - Wikipedia, the free encyclopedia). I didnīt try reactos - itīs free, aims on windows-API compatibility and comes as a vmware-machine, which can be run on a vmware player, also free... For Mac, VirtualBox is also free as a virtualizer, all you need is a windows-cd

Of course, via bootcamp you can install win itself on the mac, too.

Without the need of a full win-install, WINE might be able to run hornresp under MAC OSX (http://wiki.winehq.org/MacOSX/FAQs)

Ah, just checked on one option... reactos is no full working option for now: hornresp starts up, but canīt calculate... too bad, but this could become interesting in the future since it will enable one to use hornresp without a windows-licence
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Last edited by Sabbelbacke; 6th January 2011 at 09:28 AM.
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Old 6th January 2011, 10:41 AM   #1547
AndrewT is offline AndrewT  Scotland
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Lee,
you can get much more economical usage from 4' x 8' boards if the 24.5inch depth is changed to 23.9inch and the internal 17inch width is changed to 15.9inch for ~ 9% reduction in external volume.
I have no idea how these proposed changes will impact on performance.

You can get a pair from 3 boards making this a 1.5board design, with a bit to spare.
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Last edited by AndrewT; 6th January 2011 at 10:44 AM.
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Old 6th January 2011, 11:20 AM   #1548
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How about 23.875". Most saw blades give you a 0.125" kerf.

The difference can be made up elsewhere.
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Old 6th January 2011, 11:55 AM   #1549
AndrewT is offline AndrewT  Scotland
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Quote:
Originally Posted by mwmkravchenko View Post
How about 23.875". Most saw blades give you a 0.125" kerf.

The difference can be made up elsewhere.
one only needs one cut to split the 48" into two equal pieces. One might just about get 23.95" but that leaves nothing spare for trueing up an edge.
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Old 6th January 2011, 12:00 PM   #1550
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One thing I have to post is a comment on the response curves posted by JBell.

He has posted I think the only true properly done tapped horn on this forum. THe resulting 12 db/ octave slope is a function of a properly balanced volume of air on the front and back of the driver. It is close to a perfect acoustical impedance match for the driver.

I do this routinely with Front Loaded horns. Below Fc the box rolls off as if it where a sealed enclosure. The 12 db/ octave slope.

To bad I was not awake enough to recognize it at first glance before.

Sorry James. Look first, think second, type third.

If only I could remember the order !
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