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Horn loaded sub with horn loaded speakers


mustang guy

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I have experimented quite a bit with matching subs to my LaScalas, and have personally found that the horn loaded subs sound best by a wide margin. I was never sure exactly why, but I was just reading through a very long thread where Lynn Olson mentioned something that gave me an epiphany. Here is the snippit:

Lynn Olson - diyaudio thread top of page 3 pgph 7

I've been thinking quite a lot about dispersion characteristics - most horn-fans don't know it, but unless they've got an all-horn system, the dispersion is not in fact constant with frequency. The direct-radiation bass unit radiates over 360 degrees (omnidirectional), then gradually narrows down to 180 to 90 degrees (depending on crossover point), then hands off to a horn with the specified radiation pattern (typically 120 to 90 degrees), which then narrows further as the frequency increases (unless it's a constant-directivity horn, which have their own problems). The narrow sidelobes that appear in the polar-pattern curves also appear as ripples in the time-domain, frequency-domain, and impedance curves - this is a consequence of antenna theory, where errors in one domain must appear in the other domains as well.

Lynn is one of those people who can explain things well. I am not going to try to expand on this, but I will say that it makes PERFECT sense. To my ears, a radiator sub is a mismatch. My brain is recognizing the errors in the time-domain and frequency domain, and even though I don't really get why, it just doesn't sound right.

Thank you Lynn. I guess there is a lot our brains and ears do that we are really not cognitive of.

Edited by mustang guy
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I have experimented quite a bit with matching subs to my LaScalas, and have personally found that the horn loaded subs sound best by a wide margin. I was never sure exactly why, but I was just reading through a very long thread where Lynn Olson mentioned something that gave me an epiphany. Here is the snippit:

Lynn Olson - diyaudio thread top of page 3 pgph 7

I've been thinking quite a lot about dispersion characteristics - most horn-fans don't know it, but unless they've got an all-horn system, the dispersion is not in fact constant with frequency. The direct-radiation bass unit radiates over 360 degrees (omnidirectional), then gradually narrows down to 180 to 90 degrees (depending on crossover point), then hands off to a horn with the specified radiation pattern (typically 120 to 90 degrees), which then narrows further as the frequency increases (unless it's a constant-directivity horn, which have their own problems). The narrow sidelobes that appear in the polar-pattern curves also appear as ripples in the time-domain, frequency-domain, and impedance curves - this is a consequence of antenna theory, where errors in one domain must appear in the other domains as well.

Lynn is one of those people who can explain things well. I am not going to try to expand on this, but I will say that it makes PERFECT sense. To my ears, a radiator sub is a mismatch. My brain is recognizing the errors in the time-domain and frequency domain, and even though I don't really get why, it just doesn't sound right.

Thank you Lynn. I guess there is a lot our brains and ears do that we are really not cognitive of.

Finally another one gets it.

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Wasn't the Heresy called that because it was the first Klipsch speaker that did not horn load it's woofer? Clearly PWK got it long ago.

As far as the "narrow side lobes causing ripples in the time domain" stuff, aren't such things managed by reducing early reflections via speaker placement and room treatments? The only frequencies which would cause ripples would be above the room's Schrader frequency, which is not even in the sub's bandpass, so I'm not sure how his words directly relate to horn loaded subs. Maybe I'm off base, but it seems horn loading subs is more about dynamics and avoiding cone movement induced distortions, giving full respect to the dynamics of the music with minimal speaker colorations.

Edited by Ski Bum
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Wasn't the Heresy called that because it was the first Klipsch speaker that did not horn load it's woofer? Clearly PWK got it long ago.

As far as the "narrow side lobes causing ripples in the time domain" stuff, aren't such things managed by reducing early reflections via speaker placement and room treatments? The only frequencies which would cause ripples would be above the room's Schrader frequency, which is not even in the sub's bandpass, so I'm not sure how his words directly relate to horn loaded subs. Maybe I'm off base, but it seems horn loading subs is more about dynamics and avoiding cone movement induced distortions, giving full respect to the dynamics of the music with minimal speaker colorations.

Paul Klipsch himself told me that he considered the Heresy and the Cornwall to be of too high distortion as a center in a 2PH3 system. Even if the "mono in the middle" was operated a -6 db from the flanks, he felt that the distortion was high enough to muddle the low distortion of the Khorns. So after creating the LaScala, he created the Belles (named after his first wife, who died of lung cancer) as the matching center (aesthetically and distortion-wise). He also told me that after creating the K-500 horn for the Belle, the the K-400 was probably a little longer than it needed to be. So, your initial comment about him "getting it" is incorrect with respect to IM distortion.

He also told me that he left the Heresy box empty because he wanted a pure capacitance on the woofer. What he did finally "get," is that the Heresy saved the company from financial ruins because Khorns were too big and too expensive. Heresy accounted for over 50% of the company gross sales. By 1985, even he was suprised that his company had grown so large to over $20 million in sales, later to be grown to 7.5X that figure by Fred Klipsch and Co.

Edited by ClaudeJ1
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I have experimented quite a bit with matching subs to my LaScalas, and have personally found that the horn loaded subs sound best by a wide margin. I was never sure exactly why, but I was just reading through a very long thread where Lynn Olson mentioned something that gave me an epiphany. Here is the snippit:

Lynn Olson - diyaudio thread top of page 3 pgph 7

I've been thinking quite a lot about dispersion characteristics - most horn-fans don't know it, but unless they've got an all-horn system, the dispersion is not in fact constant with frequency. The direct-radiation bass unit radiates over 360 degrees (omnidirectional), then gradually narrows down to 180 to 90 degrees (depending on crossover point), then hands off to a horn with the specified radiation pattern (typically 120 to 90 degrees), which then narrows further as the frequency increases (unless it's a constant-directivity horn, which have their own problems). The narrow sidelobes that appear in the polar-pattern curves also appear as ripples in the time-domain, frequency-domain, and impedance curves - this is a consequence of antenna theory, where errors in one domain must appear in the other domains as well.

Lynn is one of those people who can explain things well. I am not going to try to expand on this, but I will say that it makes PERFECT sense. To my ears, a radiator sub is a mismatch. My brain is recognizing the errors in the time-domain and frequency domain, and even though I don't really get why, it just doesn't sound right.

Thank you Lynn. I guess there is a lot our brains and ears do that we are really not cognitive of.

Finally another one gets it.

You're preaching to the choir, some have to experience it for themselves for the lightbulb to turn on. :)

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I am too busy right now to go through all of this, but is this also saying the converse is true, meaning that if you have a Cornwall or other speakers with direct radiating woofers you should not use a horn loaded sub?

I was reading about time delay in horn subs on another site last night, making the argument that horn subs should not be used with direct radiators for that reason.

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I am too busy right now to go through all of this, but is this also saying the converse is true, meaning that if you have a Cornwall or other speakers with direct radiating woofers you should not use a horn loaded sub?

I was reading about time delay in horn subs on another site last night, making the argument that horn subs should not be used with direct radiators for that reason.

I ran my THT with my Chorus II's a while back and it sounded great, i had it crossed over pretty low (40-50 Hz).

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I am too busy right now to go through all of this, but is this also saying the converse is true, meaning that if you have a Cornwall or other speakers with direct radiating woofers you should not use a horn loaded sub?

I was reading about time delay in horn subs on another site last night, making the argument that horn subs should not be used with direct radiators for that reason.

I haven't actually tested it, but I was thinking the same thing. Most people recommend a reflex sub to accompany a pair of Heresy's when desired. This is probably the reason.

...

As far as the "narrow side lobes causing ripples in the time domain" stuff, aren't such things managed by reducing early reflections via speaker placement and room treatments? The only frequencies which would cause ripples would be above the room's Schrader frequency, which is not even in the sub's bandpass, so I'm not sure how his words directly relate to horn loaded subs. Maybe I'm off base, but it seems horn loading subs is more about dynamics and avoiding cone movement induced distortions, giving full respect to the dynamics of the music with minimal speaker colorations.

I will quote an earlier excerpt of Lynn Olson regarding perception and timing:

...the brain/mind/hearing system assigns sound into different processing "slots": 0-1 mSec is used for localization, 1-25 mSec is used for assigning ambient qualities (how big is the space), and anything delayed more than 25mSec starts to sound like an echo. So measures to reduce diffraction and stored energy in any kind of speaker are worthwhile, since most of the stored energy is going to fall into the 0 to 1 mSec interval, where it damages the sense of localization. Room reflections, including the first one off the floor, are benign - in fact, the floor reflection, although troublesome to measure, actually assists localization.

I don't know enough about what you just said to answer your question directly, but if what you are implying is that what he is saying excludes horn loaded subs, then I'm all ears.

smiley-face-big-ears.jpg

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All the localization cue frequencies occur well above a sub's band pass, that's all. It doesn't "exclude" anything, it's simply not relevant in terms of the frequencies subs put out. It seems to me that he's talking about room acoustics above the room's modal response.

I'm no expert, just a hobbyist who hasn't dusted off my copy of Toole's book in quite some time.

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You're preaching to the choir, some have to experience it for themselves for the lightbulb to turn on.

Until yesterday I had only read about horn subs. I was lucky enough to stop by a forum members house . He had a Lab12, aTHT ,and 2 Danley DTS10's.

All I can say is wow !

As a bonus he had some 402's I got to listen too as well. If you ever get a chance to listen to 402's Don't ! I'm pretty sure you will want some!

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All the localization cue frequencies occur well above a sub's band pass, that's all. It doesn't "exclude" anything, it's simply not relevant in terms of the frequencies subs put out. It seems to me that he's talking about room acoustics above the room's modal response.

I'm no expert, just a hobbyist who hasn't dusted off my copy of Toole's book in quite some time.

The thread is an interesting one, and discusses his idea of a build or modifying some Tannoy speakers using bipole and perhaps no crossovers, but using the driver's own natural rolloff as a crossover. When I read his statement about timing it piqued my interest. Then I ran across his statement about horn loaded speakers and what people with them didn't know, and I stopped reading and created this thread.

I took those statements as a clue as to why we perceive a difference when we mix horns and passives. It clicked in my mind that it was why I like my THT's with my LaScalas far more than either powered subs like my Paradigms or pro/theater speakers like my KPT-684's.

I do know that localization reduces with frequency. I wasn't really thinking in terms of identifying the source of sound. I was thinking in terms of my brain being able to discern a mismatch between a fully horn loaded speaker and a sub which is not.

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This thread has me wanting to tackle a diy tapped horn sub. Table tubas and such are reasonably sized for normal homes, right?

Lots to choose from on the DIY and AVS forums. Most look like a larger version of the one I built for a Lab 12. If you have LaScalas or Belles, you may want to think about an F-20 since it goes higher. For Khorns or any Direct radiator that get down to 40-60 Hz., a tapped horn will get you lower for a given box size. I'm a fan of the $85 JBL 1214 driver for Tapped Horn duty. It's got a higher Fs than the LAB12 (better for Tapped Horn) and costs 1/2 as much. There's a Kraken 212 design on the DIY forum that you can build for about $300 that will rival my Danley DTS-10's if you want some real "nads."

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Hey, Mustang Guy. After reading Jason't comment about me preaching to the choir, I see you have twin THT's. Sahweet. How are you doing time delay?

Time delays can be done using the THT or Table tuba or any of the Tuba's for that matter but is not necessary, anything below 80Hz delays of less than 20ms are inaudible.

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Hey, Mustang Guy. After reading Jason't comment about me preaching to the choir, I see you have twin THT's. Sahweet. How are you doing time delay?

I have Audyssey XT32 in my Integra preamp. Oddly, it just adds distance to achieve the delay. It's somewhere around an extra 12-15' if I remember right. Works like a charm.

BTW, I think on a THT it's around +11-12ms.

Edited by mustang guy
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A direct radiator sub placed in a corner will have a 90 x 90 polar pattern. Same would go for a woofer with proper placement.... and a fifteen would hold that to ~1kHz or so..... at which point it's easy to find a matching tweeter.

I'm not sure polar response / timing is the source of the difference you're experiencing...

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