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Old 24th July 2007, 07:29 AM   #531
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Yes! A lowish VAS and Qts 0,3 - 0,4 seems to work well in tapped horns.

Click the image to open in full size.

A Eminence Kappa 15LF in a tapped horn.
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Old 24th July 2007, 08:08 AM   #532
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Default Circlomanen....

are you running HS v16.2? I have V16.2 and I was trying to play with the values that you showed on your screen shot of the Beyma driver but nothing seems to be comming out the same. I am trying to see what happens to the Fr when I play with the size of the throat and the expansion. My input parameters page does not look like yours. I am curious to know what happens to the response in reality after 100 Hz, seems to me that I recall William saying that things were smoother than what HS showed.
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Old 24th July 2007, 10:32 AM   #533
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Yes, that is Hornresp V.16.20 im running.

Please post your results. I have run these specs on three different computers, all with 16.20, all with the same result.

Johannes.
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Old 24th July 2007, 12:55 PM   #534
freddi is offline freddi  United States
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having trouble saving models in version 16 (not 16.2) Your 765 liter horn model looked good with B&C 15trx 100. I already have 15trx40 but need to keep bulk & weight managable for one person to wrestle -have too many junk and vintage speakers taking up space.
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Old 4th August 2007, 02:37 PM   #535
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Default Re: Re: Tapped horns for dummies

Quote:
Originally posted by Sabbelbacke

So far, that´s not discovered in full extend. It seems that drivers with a fairly high fs work better, resulting in a smoother frequency response.

If I'm not mistaken, the FS won't affect the "smoothness" of the response. It *will* affect the F3. The smoothest response would be achieved by juggling qms, qes, BL, the location of the drive, location of the tap, and the flare rate.

Quote:
Originally posted by Sabbelbacke
So far most dedigns use a conical flare function, since it´s most easy to build.
Not only is conical the easiest to build, it also gives the lowest F3. The easiest way to grasp this is to realize that a "real" horn and a bandpass box are just two points on a spectrum. The "real" horn trades F3 for efficiency; reducing it's size lowers the efficiency, but it ALSO lowers the F3. How great is that? This is one of the reasons why "real" horns are a bad idea for subwoofer duty; raising the efficiency raises the F3.

I wrote a paper about this:

http://home.comcast.net/~j.vanommen/...oaded_Horn.pdf

See this too:
http://www.audiogroupforum.com/csfor...ad.php?t=62292

Quote:
Originally posted by Sabbelbacke
Of course, others are possible, too. hornresp and Akabak are capable of doing conical and exponential types. Theoreticaly, Hyperbolic and others should work, too. You can do some tweaking with the frequency response in Akabak and hornresp if you differ flare rate on the first and last segment from flare rate of the main part.

Well, it´s mostly trial and error so far, but hornresp and Akabak are very useful tools to keep it quite simple.

Like al transducer cabinets: Just building some random box and putting some random speaker in it mostly results in garbage, same here.

The more area the hornmouth has, the more seinsitivity you gain.

My guess is that general rules of picking a speaker for a special application apply here, too. Bigger drivers (and ones with heavy cones) have more difficulties moving fast than small ones.
Anyone that says this on a subwoofer board should lose their credibility instantly

Can't we just put a stake in this silly myth and get it over with?

IMHO, Dan Wiggins has written the best debunking of this myth, but it's no longer on his website. I even tried to get it for you from the Wayback Machine, with no luck.

To quote John Janowitz,
"In terms of overall sound, many people feel vented or PR systems sound "slow". There is a very good reason for this. The "speed" of bass is equal only to the frequency. The lower the frequency, the slower the driver moves. Systems described having very "tight" or "fast" bass are the ones that lack in very low output. My favorite Tom Nousaine quote was about a subwoofer that everyone said was so "fast." He said "the bass was so fast it got up and left the room." It sounded fast because higher frequencies are faster."

Quote:
Originally posted by Sabbelbacke

Just like when you compare 2x10" with a 15". on the other side - bigger drivres ususaly are build for subwoofer applications where high excursion rates are common. If you find a small driver with the same xmax-capacity as a big one and use as many small ones to add up Sd to the big driver - you can get it to work (assuming that the overall quality of the compared drivers is the same and the resulting TSP are euiqvalent)

You should´t mix two tunings or allignemts in one box, since phase and pressure difference will start interact with each other and mostly cancel each other out.
The original poster was correct. A combination of two tunings may improve the smoothnes of the response. He was also correct that it WILL be difficult to model. Akabak can do it.

There's nothing unorthodox about a single cabinet with two speakers that are tuned to differnt frequencies and that use different alignments. In fact that's exactly what's used for the majority of loudspeakers! (the tweeter is generally in a sealed enclosure, the woofer is generally in a ported enclosure.)
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Old 4th August 2007, 02:51 PM   #536
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Quote:
Originally posted by Sabbelbacke
Does anyone know how to model the influence of BL-Product?

I have a 10" 8 Ohm Speaker with a BL of 12 which I plan to use in a tapped horn. AFAIK, BL must be high for a speaker to work properly in a horn. But since people building Bill Fitzmaurice´s T24 use Deltalite for these which only have a BL of about 10, I was wondering how much of a difference it would make.
Any clues on how to predict this?
In a textbook horn, the high BL smooths ripples in the response. One of the easiest ways to see this is to download Martin King's front-loaded-horn sim, and play with the BL value. You'll see the response flatten quite a bit as BL goes up.

As the size of the horn is reduced, F3 goes down, and sensitivity go down. At the same time, the influence of BL on the response curve goes down with it.

That's one of the reasons that "traditional" horn drivers aren't optimum for a tapped horn.
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Old 4th August 2007, 03:46 PM   #537
GM is offline GM  United States
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Default Re: Re: Re: Tapped horns for dummies

Quote:
Originally posted by Patrick Bateman

IMHO, Dan Wiggins has written the best debunking of this myth, but it's no longer on his website. I even tried to get it for you from the Wayback Machine, with no luck.
http://www.adireaudio.com/Files/WooferSpeed.pdf
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Old 5th August 2007, 07:23 PM   #538
JinMTVT is offline JinMTVT  Canada
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hey guys, as some of you know
( since they have posted in my thread )
i am currently desinging my new house, and my new home theater room

I was siggested by many of you to go with a bass horn for the sub bass section

Circlo pointed me out to a hornresp graphic that was very interesting

since then i have read some on horns, wich didn't interest me much for higher freq reproduction in the past...

Where do i need to start ?
i am missing very important information on design and all, and i've went through a few hundred of pages already linked from members here, from member pages to jbl papers and so on ..

What i know, is that phisically i will have an available dedicated space of around 10 cubic meter per horn
( i want stereo bass )

i need it to be accurate and loud, this will be used for home theater in a 20 by 25 room ( wich non paralell walls, surround setup with alot of drivers and big sound)


Should i start by playing with hornResp using different drivers to get the feel of what is required?
have you guys come to a concensus about what kinf of driver is required to get correct response?

btw, i don't mind using a few drivers on each side,
but my restriction on the mouth size is around 5' large by 9' high ...each ...

thanks
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Old 9th August 2007, 09:17 PM   #539
zobsky is offline zobsky  India
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Okay, .. I'm considering building one of these tapped horn thingys to mate with my line arrays below 80 - 100Hz (mainly because they are cheao / easy to build). I'd like to get an honest 20 - 25 hz out of it for mixed home theater / music use. Before I commit to this endeavour, could someone who has build one answer a couple of questions: My room is about 11' x 14'.

1. Does it sound okay for music or is mostly an effects / home theater sub . I'd like something that works well for both applications.
2. Any comparisons to other subs (pref. horn loaded)
3. Important - does it HAVE to fire into a corner (1/8th space) to fill. I'd rather have something that works into 1/4 space ie. firing at a wall/floor junction .

I have a few drivers available:
A. 1 x shiva mk IV 12" DVC sub
Fs=20.7Hz
Qts=0.35
Qes=0.37
Qms =0.65
Z = 4 ohm nominal
BL = 11.3
Vas = 0.15


B. 2 x MCM 55-2421 8" sub# Impedance: 4ohm
Z: 3.4ohm
Fs: 25Hz (closer to 30Hz in reality)
Qts: 0.22
Qes: 0.22
Qms: 13.62
Vas: 32.46 (liters)


C. 1 x A low Qts vintage university C-15W 15" DVC woofer (light cone, macho motor), as used in some vintage bass horns. I may have specs somewhere, but not with me at the current time.

Which would work best for my application?
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Old 12th August 2007, 03:49 AM   #540
JinMTVT is offline JinMTVT  Canada
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of the mouth of a horn exits at floor/wall/ceiling junction
taking all of this space

does it makes a 1/8 space??

example

8' high room
the horn mouth is 8' tall
and 8' large ..but the room is 20' large on this wall
the horn mouth touches ceiling, 1 side wall and floor
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