[PWK Papers Unpublished]

Be careful. Soon "the experts" will show up to crap on pwks musings....

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

"Distortion is inversely proportional to efficiency."

It's the increased sensitivity that's responsible for the reduction in modulation distortion. The two are linked together, and one cannot be examined or discussed without the other.

There is no free lunch with any of this stuff. In this.case, the reduction in modulation distortion results in a nasty frequency response and limited bandwidth.

Okay John. Some of the K-55-V and K-55-M drivers give solid performance for almost four decades, and the FR is, well, umm - acceptable. I personally think they sound great - at least in my average sized rooms.

Geesh!!! Horns don't have a low pass filter unless they are folded. And if you have a ragged freq response....DON'T BLAME THE HORN. So much for the experts on this forum.....

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

Modulation distortion is produced when the acoustic driver's cone or diaphragm moves - and the more it moves, the greater the modulation distortion.

Isn't that wonderful...

so what happens if I build a bass horn using a 15" cone driver and, in fact, realize a reduced cone excursion but the problem is that the reduction occurs over a range of frequencies that's narrower than the frequency range I'm trying to operate my bass horn over?

This is what happens, you end up with a horn that has a high sensitivity over that region where you've realized this reduced cone excursion. In other words you end up with a Klipschorn folded bass unit...

What??? You never heard of path length differences???

[Deang LaScala/Crossover Thread]

I see a lot of posts from people who are reinforcing their bass bins. I remember reading a Dope from Hope or something to that effect where PWK explained why that was a bad idea. Does anyone remember the document?

Hey Dean.........not sure what document you might be thinking of but I can tell you that I had a conversation with Jim Hunter shortly after buying some new LaScalas in 1984 about the sidewall resonance and he and Klipsch was well aware of it and suggested a brace from the dog house to sidewall as one solution. He also explained that due to how the majority of the LaScalas were used(ie: sound reinforcement) and production issues of the dog house not being perfectly centered thus making each brace would have to be custom fit so they hadn't put it into production.

I will say that if one does the bracing there might be some benefit to tweeking the crossover as my understanding was done in part for the LaScala ll due to it's stiffer sidewalls.

miketn

Yeah, I hear it, even at moderate levels. It's irritating to be sure. It's like the resonance is being used to augment the low frequency performance. I'd forgotten how the character of these speakers (Heritage) change as the volume goes up. As long as I keep it below 90dB, it sounds very nice, and I can't really find much to complain about -- most of the complaints would be centered about the fact that my poorly recorded material has been rendered unlistenable -- something I think we're all used to by now.

I'm double handicapped. I'm not a wood worker, and I'm not an engineer with a lot of cool test equipment -- so I can't properly design new filter arrangements. I know my limitations and I'm not embarrassed by them. With good numbers and reliable plots, I've have managed to stumble into some simple things that work pretty good. Having Bob, Dennis and John willing to accommodate me, provide input, and do testing for me, has been nothing short of awesome.

Last night I added a 128uF electrolytic in parallel with the K-33. I was curious to see what the effect on the resonance might be. Sure enough, it was greatly reduced, but then something else didn't sound right and I need to get my laptop down there to see what's going on. The real problem right now is that I'm eight builds back and can't do any serious testing until I get these networks done.

Did you try a 124.57 uF cap?

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

This Frequently-Asked Questions (FAQ) thread discusses some reasons why horn-loaded loudspeakers sound more realistic than direct-radiating loudspeakers, such as cone-type and planar type drivers.

Several manufacturers currently make or have made horn-loaded loudspeaker designs: Klipsch, ElectroVoice, JBL, Altec, and several smaller manufacturers.

"Why do horn-loaded loudspeakers sound better than direct radiating loudspeakers?"

Chiefly, the reason is due to low modulation distortion (i.e., not harmonic distortion). Horn-loaded electro-acoustic drivers typically have 25 dB lower frequency modulation (FM) distortion levels and 15 dB greater efficiency than when using those same drivers without horns to produce the same sound pressure level (SPL).

"What is Modulation Distortion, and Why is It Important?"

Frequency modulation (FM) distortion, sometimes called Doppler distortion since it is largely caused by the movement of the driver's cone/diaphragm at lower frequencies, is caused simultaneous modulation of higher frequencies that are also being reproduced by the same driver at the same time.

Amplitude Modulation (AM) distortion is primarily due to driver nonlinear response when the cone/diaphragm is operating near its extent of maximum movement under high-load conditions. Figure 1 gives a visual representation of the two components of modulation distortion vs. time:

Figure 1 AM and FM distortion visualization

Both of types of modulation distortion are very objectionable for listeners due to their non-harmonic frequencies that are produced.

Many people are familiar with harmonic distortion. This type of distortion is due to integer multiples of input frequencies greater than one than the input or recorded frequency(ies) being reproduced on the output of the loudspeaker under higher load conditions. Figure 2 gives a view of frequency harmonic amount vs. relative input frequency:

Figure 2 Harmonic distortion visualization

Harmonic distortion is not as audible as modulation distortion due to the internal signal processing of the human hearing system, particularly the lower harmonics like second, third harmonics. Higher-order harmonic distortions (fourth, fifth, sixth order harmonics, etc.) are more easily detected by human hearing. Some sources call this human hearing effect "harmonic masking".

Contrasting the above harmonic distortion, modulation distortion (AM, FM, intermodulation, etc.) produces non-harmonic frequencies not found in the input signal driving the loudspeaker. Because these modulated frequencies are not related in integer multiples of either the lower or higher frequencies being reproduced, these distortion-produced frequencies are much, much more audible and objectionable than typical harmonic distortion. Figure 3 shows a visualization of both major types of distortion (harmonic and modulation distortion) versus frequency.

Figure 3: Visualization of harmonic and modulation distortion

Note that modulation distortion shows up on the higher frequencies reproduced, which is typically more audible than lower frequencies due to the frequency response/acuity of the human hearing system.

Additionally, the modulation distortion frequencies shown in figure 3 are not integer multiples of either the lower fundamental frequency or the higher one. These non-harmonic frequencies are much more objectionable to listeners compared with harmonic distortion at the same relative amplitudes.

It can be seen that harmonic distortion will also modulate the upper frequencies making the effects of harmonic plus modulation distortion much more objectionable to listeners. The effect of these types of mixed distortions can be described as the speakers sounding "loud" and "opaque" while responding to high input signals.

"Why is Modulation Distortion So Much Lower in Horns?"

Modulation distortion is produced when the acoustic driver's cone or diaphragm moves - and the more it moves, the greater the modulation distortion. Horn-loaded drivers reduce the amplitude by a factor of ~10-30 (relative to using that driver as a direct radiator) that the driver has to move to produce a certain SPL output level. Less cone/diaphragm motion equals less modulation distortion.

Any acoustic driver that is horn loaded will experience a dramatic decrease in required motion in order to produce output SPLs.

You forgot one word in your last statement.....properly.

[What is more accurate horns or cones]

"I assume that's a rhetorical question. Perhaps you should start your own thread on the specifics of what you clearly object to in your quoted statement."

Are you serious? You're talking authoritatively on this topic, and you seem to have no problem fielding questions from others. So, if one agrees, they can stay in the thread, but it they disagree, they should start their own thread![/quotes

Silly Chris. Deang is the authority...

[What is more accurate horns or cones]

In my case, I've found that the weakest is the recordings themselves 99%+ of the time.

Considering that your percentage is so high, would it be fair to ask if the playback system used when drawing those conclusions somehow might be the culprit and not the music itself?

For years it has been said on this forum that a good speaker reveals the flaws in bad music While there are many merits to that idea, I have found several cases where the speaker has been the culprit (or something else about the system). Take for instance, the Khorn. All of the arguments being made here about horns are true for the Khorn, and there is no shortage of people making the same "garbage in / garbage out" justification about hearing bad sound. It's been a lingering question of mine whether or not the speaker or the music should be considered "at fault" - especially knowing there was no way the artists would ever release something they thought sounded bad when they heard it in the studio...When the Jubilee came around, I realized a lot of that "bad music" all of a sudden started sounding very good on the Jubilee. It is not hard to make an objective argument for the superiority of the Jubilee - and I bring that up because here we have an example of the previous speaker being the culprit. The Jubilee (like anything in the audio world) is not without its compromises - thus why I have a signature reminding myself of that.

Anyways, if we are going to claim that 99% of the music sounds like crap through our systems, then I would suggest one of two things must be true:

• Wrong expectations of the playback system.
• 99% of the world has different listening tastes.

I would be embarrassed to say that 99% of the music sounds bad on my system - and you're making it a point of pride and justification for your decisions. I certainly don't mean for this to be confrontational - although I know that's how I come off most times and I'm working on improving my writing skills. I just don't get how we can share in our understanding of theory or our experiences if you're going to turn around and say the music I enjoy and have great emotional connection with is somehow crap. I'm over here having a blast with a much lessor system - and isn't that the point of it all? All the techno babble is just a means to a very subjective / emotional end.

I just like good music and do whatever it takes with my system to maximize that enjoyment.

I like to hear good music and have to make it sound good on my system but most of it, dare I say 99%, is definitely not reference and recorded like crap.

[Dobly Atmos]

Emotiva's take on Atmoshttps://m.youtube.com/watch?v=4GLDCzlmLr8

Hmm I have to say I'm not impressed. Looks no different then going 13.1 if you ask me.

Wrong.

[Dobly Atmos]

I totally agree about the gimmicky thing, Gary....spot on.

What's gonna be a shame is all the Atmos HTIB systems that go even cheaper to support having more speakers.....

You ever heard a Dolby atmos cinema?