"Why Horn-Loaded Sounds Better Than Direct Radiating" FAQ

[Deang]

Resonance peaks.

[Chris A]

Perhaps you two should start a thread on the efficiency of horns? This FAQ (not really a typical thread) is concerned with why horns subjectively sound better, a subject clearly difficult enough to tackle without also trying to discuss the engineering-related subject of acoustic efficiency at the same moment.

The comment by our buddy Chris A puzzles me a bit. I'm on John's side. You can't talk about subjective "why" without talking about engineering "why."

Regarding "subjective" I heard my first K-Horn on Thanksgiving Friday on 1974 at a dealer in Ithaca, NY. Everything about music reproduction changed for me, right then. I daresay it is the same for others.

In this hobby (which concerns love of reproduced music), we're all trying to find a better way of doing things with the hope that better hardware or software makes things subjectively better. But what is the link between them?

PWK spent a lot of intellectual effort on linking music, horn hardware, analysis of distortion, efficiency, and what is essentially subjective enjoyment of music, in a scientific way. A lot of others at the time, and to this day, engaged in hucksterism.

WMcD

See https://community.klipsch.com/index.php?/topic/151138-why-horn-loaded-loudspeakers-are-subject-to-design-tradeoffs/

[Chris A]

A relevant article just uploaded by jtkinney in another thread - talking about modulation distortion:

https://community.klipsch.com/index.php?app=core&module=attach&section=attach&attach_id=94224

[Deang]

Sorry, but I'm pretty sure we're allowed to post whatever we want wherever we want. The problem here is that you don't seem to understand how these things are related. You're making comments that invite comment. That's what forums are for. If you don't like that -- write a book or something.

Again, you're not a moderator.

I have a better idea, I think I'll just refuse to post and add you to my ignore list. That way you can ponificate away and I won't be annoyed.

Edited July 11, 2014 by DeanG

[ClaudeJ1]

Sorry, but I'm pretty sure we're allowed to post whatever we want wherever we want. The problem here is that you don't seem to understand how these things are related. You're making comments that invite comment. That's what forums are for. If you don't like that -- write a book or something.

Again, you're not a moderator.

I have a better idea, I think I'll just refuse to post and add you to my ignore list. That way you can ponificate away and I won't be annoyed.

Dean, while I agree with the spirit of your response, you need to include, at the very least, a partial quote with these kinds of responses. It's the only way to know to whom you refer as opposed to guessing and reading backwards up the post totem pole.

Edited July 11, 2014 by ClaudeJ1

[ClaudeJ1]

Sorry, but I'm pretty sure we're allowed to post whatever we want wherever we want. The problem here is that you don't seem to understand how these things are related. You're making comments that invite comment. That's what forums are for. If you don't like that -- write a book or something.

Again, you're not a moderator.

I have a better idea, I think I'll just refuse to post and add you to my ignore list. That way you can ponificate away and I won't be annoyed.

Dean, while I agree with the spirit of your response, you need to include, at the very least, a partial quote with these kinds of responses. It's the only way to know to whom you refer as opposed to guessing and reading backwards up the post totem pole.

Nevermind, Dean. I figured it out.

[Deang]

Good, I have no issue with you whatsoever.

[Ski Bum]

"So again, what does 'controlled directivity' have to do with why horn-loaded loudspeakers sound better?"

Basically, in small listening rooms such as home listening rooms there is a great advantage to keeping excess midrange and tweeter energy off the walls, ceiling, floors and other furniture, directing that acoustic energy instead toward the listeners without first reflecting off of another surface. The advantage shows up as dramatically improved soundstage imaging and the perception of realistic playback.

Wanted to quote this for emphasis. I would posit that the improvements to soundstage/imaging are that by using controlled directivity speakers correctly one can end up with an image that is independent of listener movement, and that is the key. This results in a quite relaxed, natural listening experience, and one dipoles and direct radiators can't really pull off.

I've posted this link before...it's by Bill Waslo, heavy hitter of the DIY community, and a nice complement to Chris' Corner Horn Imaging FAQ thread.

[Chris A]

Wanted to quote this for emphasis. I would posit that the improvements to soundstage/imaging are that by using controlled directivity speakers correctly one can end up with an image that is independent of listener movement, and that is the key. This results in a quite relaxed, natural listening experience, and one dipoles and direct radiators can't really pull off.

I've posted this link before...it's by Bill Waslo, heavy hitter of the DIY community, and a nice complement to Chris' Corner Horn Imaging FAQ thread.

I like that article a lot - thanks. The discussion on having good off-axis polars probably needs to be beefed up here. However, that article does it for me.

[IB Slammin]

Perhaps you two should start a thread on the efficiency of horns? This FAQ (not really a typical thread) is concerned with why horns subjectively sound better, a subject clearly difficult enough to tackle without also trying to discuss the engineering-related subject of acoustic efficiency at the same moment.

[/qu

"So again, what does 'controlled directivity' have to do with why horn-loaded loudspeakers sound better?"

Basically, in small listening rooms such as home listening rooms there is a great advantage to keeping excess midrange and tweeter energy off the walls, ceiling, floors and other furniture, directing that acoustic energy instead toward the listeners without first reflecting off of another surface. The advantage shows up as dramatically improved soundstage imaging and the perception of realistic playback.

"If that's true, then why do dipole loudspeakers have a large perceived depth of field?"

Planar dipole loudspeakers radiate approximately equal amounts of acoustic energy forward and rearward, but not much from the sides, top, and bottom of the loudspeaker. That acoustic energy radiating to the rear of the loudspeaker bounces off the front wall and returns to the listening position as delayed reflections, as described above. That delayed reflected energy doesn't exist on the recording so the effect of this "front wall echo" is perceived as increased depth of field.

The problem with that of course is that this added acoustic reflection information isn't in the original recording. You can achieve the same effect by using a reverberation unit, where you can also control its intensity and delay time. The only way to control the front wall reflections using planar dipoles is to move the speaker either into the room more or back toward the front wall. Most successful setups using these type of loudspeakers usually have larger dimensions in room length, width, and height to accommodate adjustment of the front-wall reflection. This usually requires at least 6 feet (2 metres) of spacing, which intrudes significantly into the usable space of the room. Additionally, just like all other types of loudspeakers, it is very desirable to keep any near-field acoustically reflective objects out of the near-field of the loudspeaker in order to preserve their soundstage imaging performance.

Cone-type dipole loudspeakers typically have the added disadvantage (or advantage, depending on your point of view) of having increased off-axis energy that the reflects off of side walls and other close-by furniture. These early reflections can create havoc with your soundstage imaging as described in the Corner-Horn Imaging FAQ.

So if the standard by which we measure "sounding better" includes accuracy in recreating the original sound space of the recording itself, dipole loudspeakers actually intentionally create a different sound space image than the original in order give the listeners a feeling of depth that wasn't actually there to begin with.

"So what's wrong with that?"

Nothing, as long as the listener really doesn't care about accurate sound reproduction.

I got all of that. But Chris and Mike, you and me listened to the KPT 415 LF unit below a K402 horn. A 107db combo. Didn't see/feel excessive diaphragm excursions. What I did hear/feel was IMPACT from the reflex.

Just saying.....

Warm regards,

tc

[Chris A]

I got all of that. But Chris and Mike, you and me listened to the KPT 415 LF unit below a K402 horn. A 107db combo. Didn't see/feel excessive diaphragm excursions. What I did hear/feel was IMPACT from the reflex.

Just saying.....

Warm regards,

tc

Yes - both Miketn and I heard them. To be honest - I was impressed only with the power, not the sound of the bass bin. In fact, that demo turned me off to big bass reflex cabinets, and redoubled the deal with the Jub bass bin for me.

YMMV.

Chris

Edited July 12, 2014 by Chris A

[mikebse2a3]

I got all of that. But Chris and Mike, you and me listened to the KPT 415 LF unit below a K402 horn. A 107db combo. Didn't see/feel excessive diaphragm excursions. What I did hear/feel was IMPACT from the reflex.

Just saying.....

Warm regards,

tc

Yes - both Miketn and I heard them. To be honest - I was impressed only with the power, not the sound of the bass bin. In fact, that demo turned me off to big bass reflex cabinets, and redoubled the deal with the Jub bass bin for me.

YMMV.

Chris

Not sure how I got brought into this but anyway....

tc I agree with you the KP-415 is impressive and what that experience did for me was to allow me to actually experience (under a reasonably controlled condition) what PWK reported in his research and that is how important it is for any given reproduced SPL Level to minimize the amplitude of motion of the loudspeaker.

The KP-415 (4 x15" drivers) proves to me that as the direct radiator system approached the radiating area of the horn (which means the amplitude of motion required for a given spl was becoming comparably closer between the systems) the sound performance became (impressively) closer to the Jub LF but IMHO the Jub LF was still cleaner sounding and thus more accurate. The progression from a single 15" to a dual 15" to a quad 15" to a Jub LF systems was to perceive the clarity and dynamics/Impact improving as the radiating surface area increased.

I also think it's very important to remember that not all distortion is unpleasant and when it comes to a matter of taste in sound reproduction some might find the system measuring higher in a certain type of distortion preferable which is a separate issue from the fact of which is closer to accurate in the measurement of said distortion.

By the way tc I own the KPT-904 (dual 15") and enjoy them very much..... it's all good

miketn

Edited July 13, 2014 by mikebse2a3

[Chris A]

...what that experience did for me was to allow me to actually experience (under a reasonably controlled condition) what PWK reported in his research and that is how important it is for any given reproduced SPL Level to minimize the amplitude of motion of the loudspeaker.

The KP-415 (4 x15" drivers) proves to me that as the direct radiator system approached the radiating area of the horn (which means the amplitude of motion required for a given spl was becoming comparably closer between the systems) the sound performance became (impressively) closer to the Jub LF but IMHO the Jub LF was still cleaner sounding and thus more accurate. The progression from a single 15" to a dual 15" to a quad 15" to a Jub LF systems was to perceive the clarity and dynamics/Impact improving as the radiating surface area increased.

To be fair, I heard the same thing but I wouldn't use the word "impressively". It wasn't close...to my ears. In fact I was amazed how different it sounded even though there was approximately the same surface area of KPT-415 drivers as from the mouths of the Jub bass bin.

For those that want a description of what I heard: the heavy bass drum beats on the KPT-415 had a sound a bit like "very muffled splintering wood" for every bass drum beat on the KPT-415, whereas the Jub bass bin was clean and accurate sounding, with no higher frequency distortions to the bass beats, IIRC. This also corresponds to lower AM distortion levels for the horn-loaded bass bin. I also heard a slightly tighter performance from the Jub bin bass - no "overhangs" or "thumps".

Chris

Edited July 13, 2014 by Chris A

[Chris A]

Updated post #12 on transient intermodulation distortion (TIM) to reflect its difference from intermodulation distortion. Gary - thanks for that question.

_

I assume that over time more research will be done in this area. I have to admit that I've not spent as much time researching this subject as other modulation distortion areas. I believe that the moving mass effects of cone-type drivers is still a factor in produced distortion, especially when using direct radiators in wide band applications such as decade-wide driver passbands.

Edited August 10, 2014 by Chris A

[diamonddelts]

Read this entire thread. Very interesting responses. Thank you.

[Schu]

I am sure curiosity is integral, but does it matter to you as an end user why it sounds better... it just does. It's magic.

[MikeFord]

Some like magic, some would rather peek behind the curtain and know how it works. Besides if you don't know how it works you don't have much chance at doing anything to make it work better.

[Andy Andrews]

More than 80% of the sound from a classic symphony orchestra comes from the horn or reed section. This is because this class of instrument also radiates more efficiently into the auditorium and at a frequency range at which the human  ear is most sensitive. Not surprisingly, the exponential horn is analogous to the shape of horn and reed instruments. Trying to make a paper or polymer cone, metal dome or electro-static array propagate sound pressure levels similar to what you hear in the live concerts requires lots of power with its  commensurate increase in distortion. Bell Labs researched the problem in the late 1920s and discovered horn speakers were superior, if intelligibility was the primary goal (as in fidelity).

 

We have come full circle since the beginnings of high-fidelity sound systems, with lots of experimenters with fanciful claims and new configurations, each claiming to outclass the other. But, in the end it is not possible to refute the laws of physics and we have seen horn-loaded systems once again dominate the market. There is a reason - they sound most true to life. And they use least energy for a given gain level - good for the warming planet.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Sancho Panza]

Belated Welcome to the Forums, Andy!

[artto]

And Bob Carver said...........................

 

(Klipsch Dope From Hope, Vol. 14, No. 1, 740401)

 

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