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Old 24th March 2011, 02:55 AM   #3651
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Look at Horst Moller's double horn designs:

Hornlautsprecher

They are mostly back loaded horns, but they do use the principle of two differently tuned enclosures working together.

Using a common mouth for two tapped horns doesn't save you any space, you still need just as much box volume. And if they are tuned to different ranges and their mouths are close together or common, you will get slightly worse performance because the output of one horn will be partly out of phase with the other horn at some frequencies, causing cancellation.

The only real advantage of having two overlapping passband tapped horns is that if you set the resonant frequencies properly, the electrical impedance peaks can be made to "interleave". This flattens the overall impedance curve seen by the amplifier, which can be useful when using small tube amplifiers etc.
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Old 24th March 2011, 03:36 AM   #3652
soho54 is offline soho54  United States
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Quote:
Originally Posted by sdad View Post
BTW, what did you use to mark up the pdf?
I took a screen capture of the pdf, and then drew over it in MSPaint. Fast, dirty, but it works.

Quote:
Originally Posted by sdad View Post
: the areas of multiple outputs can be summed into a single input. That is HUGE.
You can also vary the areas too. Say two 100cm^2 waveguides/ducts merging into a 400cm^2 waveguide/duct. The pressure change can do interesting things sometimes under the right circumstances.


Quote:
Originally Posted by sdad View Post
The technique of doing the 180 (or whatever angle) is to create a series of waveguides apparently. Is there a rule of thumb for how fine to divide?
You just use the 90deg lines, and then radians to the point halfway between them and the corner. With lesser degree bends it gets a little looser.

It is used for simulating from a real world build, or a finished horn from plans. That is why I used it there, habit. It isn't for the initial design work.

It is normally used to check your build plans after you have converted your original model into 3D/2D build plans, to make sure you did it right. A lot of people have problems bending a horn, and don't catch that something is off until after it is built, and tested. Most then still blame the software to varying degrees.

Good luck.w
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Old 24th March 2011, 09:40 AM   #3653
sdad is offline sdad  United States
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Quote:
Using a common mouth for two tapped horns doesn't save you any space, you still need just as much box volume. And if they are tuned to different ranges and their mouths are close together or common, you will get slightly worse performance because the output of one horn will be partly out of phase with the other horn at some frequencies, causing cancellation.
In the very limited amount of time I played with this idea, I was able to create a complete mess to what I thought to be an improvement in character. Try the script I originally put up. The ducting removal and conversion to the proper way actually didn't alter anything regarding fr curves.
I understand that size of cabinet is not affected with removal of the center baffle. Hoping for sound to become more single point over broader range, instead of multiple sound sources.
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Old 24th March 2011, 10:18 AM   #3654
hm is offline hm  Europe
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Thanks DON,

best dokumented with KORNETT + simulations,
and RDH20 measurements
kornettmess
rdhmess
my TH experience the SUBFANFARE
subfanfare
__________________
http://www.hm-moreart.de

Last edited by hm; 24th March 2011 at 10:23 AM.
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Old 24th March 2011, 08:24 PM   #3655
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Quote:
Originally Posted by sdad View Post
... Hoping for sound to become more single point over broader range, instead of multiple sound sources.
For bass, you may find that multiple sources are preferable to single source.
The wavelengths of bass frequencies are so long that you can place the speakers well apart from each other and still not be able to localise the source. There are several threads here on diyAudio which are devoted to the art and science of using multiple subwoofers spread around the room.

Having two or more subwoofers, each designed to cover a slightly different range, can be better than two identical subs. For example, your room might have resonances at 50 Hz (length) and 90 Hz (width). If you put a sub in a corner, you get a 50 HZ resonance and some 90 Hz resonance. If you put the sub on a long wall, you lose the 50 Hz resonance but the 90 Hz resonance is worse. If you have two subs covering 30-60 Hz and 60-120 Hz, you put the 60-120 Hz sub in the corner and the 30-60 Hz sub on the long wall.
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Old 25th March 2011, 12:39 AM   #3656
sdad is offline sdad  United States
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Isn't there a saying about not being able to see the trees for the forest? Here I am trying to fill in valleys and flatted peaks by arranging phase within the enclosure. Need I go on? I do recall seeing a web site or 2 that has a java script calculator showing nodes and antinodes within a room for a given speaker/listening position. Given that and my trusty rta, I should be able to get data on each speakers' location.
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Old 26th March 2011, 02:00 PM   #3657
sdad is offline sdad  United States
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Arta and Steps each have the ability to provide distortion information, based on input data from a microphone input. This is end of process stuff, though

Mathematically, there is a Volterra Series which can be used to predict distortion components based on a non-linear transfer function. This can be handy during the design phase. Difficult to use properly, however.

Is there easily obtainable a piece of software that would run a theoretical distortion analysis assuming that I can supply a "reasonable" (non-linear!)function as input? Is there a Spice module that might pull this off?
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Old 27th March 2011, 12:03 AM   #3658
sdad is offline sdad  United States
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Default Questions using HornResp and EasyHorn

I used EasyHorn to calculate some data to enter into HornResp.

Things didn't go so smoothly, so some questions came up which I haven't been able to find answers to in the help file. Always the way, right?

I have screen shots, but attachment upload size restrictions are killing me. It's a pdf of about 800k. I can break file apart into multiple files, but somehow that seems to go against the spirit of the original intent of file size limits. Someone willing to snag this file as an email?

In a nutshell, I am getting beat up when entering data in the sequence outlined by EasyHorn. HornResp is complaining when I do a 3 section input, wants something other than 0 for S5( not used of course in 3 section), it complains in a different manner when I do a 4 section input, S4 is > than 1 (but its the mouth for crying out loud!), Loudpeaker Wizard doesn't have "Set S2 to variable" option.

Little things I'm sure, but being the newb, not sure what to do next.
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Old 27th March 2011, 12:56 AM   #3659
rafaro is offline rafaro  Guatemala
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Default Any problems phasing Tapped horn subs with upper freq system?

Since THs have so many internal phase interactions are there any problems mixing with upper freq systems? Is it a matter of time delay? Imagine the upper system with a midbass driver whose voice coil is time aligned with the TH driver. Where do we go from there?
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Old 31st March 2011, 04:43 PM   #3660
sdad is offline sdad  United States
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Default Help setting up HornResp for TH

I included an attachment .doc showing the error message I get on Hornresp. I am following instructions on EasyHorn. I show both windows. I go into wizard, change size of s2 and s4 with same results. ??? What fundamental error am I making?
Attached Files
File Type: doc Untitled 1.doc (103.0 KB, 24 views)
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