3 way vs. 2 way

[michael hurd]

Basically, you can say that if it goes low, it surely does not go high. There is no free lunch. No single driver/ flat panel/ ribbon/ horn or direct radiator that exhibits low distortion, good polar response, with smooth frequency response.

Back to your thoughts about the sound of explosions, etc in free space. With an explosion, you have a very large amount of air that is rarefied ie: displaced. This hot gas is expanding in all directions, initially producing high frequencies, and as the " piston " expands, midrange and low frequencies. Since this is a rapid event, we perceive it all at once.

[RFK]

I know that a one way driver would not work with today's technology. I was speaking just in theory relating to things I've read in scientific magazines about future speakers being for lack of better expression single "sound orbs"-Star Trek type stuff. But in the 1960's when the original Star trek was made alot of things that were impossible then are now reality. Even the transporter. Believe it or not one of my brainy doctor friends told me of a company that has actually teleported one molecule from one pod to another-the transporter from Star Trek! Maybe 20 years from now instead of a molecule it might be a human-beam me up Scotty will then be reality!

[michael hurd]

Doudou: Headphones remove the room from the equation, as we are always on axis of the driver, and there are no sounds reflecting off boundaries in a finite space. And yes, neighbors can be a pain!

[doudou]

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On 9/24/2004 3:51:18 AM michael hurd wrote:

A one way driver as you suggest would not work. To produce low frequencies, with low distortion, you need a large piston diameter. The trouble is that as the frequencies increase, the wavelengths become comparable to the dimentions of the driver, then the sound becomes concentrated, and begins to beam. In other words, the polar response changes. Add to that fact that mass begins to work agains you, then you start to see why we have multiple drivers in a single enclosure.

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your totaly right.it s very difficult to make a such speaker.but theoricaly it should be the better way to reproduce a sound.

any way, some wide band speakers already exists.they cannot reproduce all sounds from 20 to 20khz in a good way for the moment,and as you said they have lots of trouble.(if i remember well, the main problem is the impedance wich is not linear at all and the phase which suddenly changes at some frequencies as you sais).

i was not talkink about the headphone speakers.

[doudou]

yes, headphones are the only speakers that sounds as the constructor wanted it to sound because there is no room.

so why not placing one Khorn on each side of our heads directly next to our ears

[dodger]

Greetings:

My take comes from a different perspective. Bass.

As one that will be age 52 shortly, there is a large difference in the watts able to be used and the actual number of watts that are used in HT, Live Sound from groups, etc.. The SPL from the bass, whether it be the bass guitar, kick drum (we used to call it the bass drum) and the low end in movies from explosions, fires, auto wrecks and such has increased dramatically. I have been to concerts where it was very difficult to hear either the Vocalist or lead instrument - guitar, organ, piano, etc. due to excessive bass.

SPL in theaters has for the most part increased. More and more of us "older folk" are bothered by the volume. This is in part due to bringing the mids and highs up to match the increased bass. The watts consumed in just a low frequency that is felt more than really heard in the mix is amazing.

I can remember the first time one sound company brought 1000 watts into play for the entire P.A.. Now, we have bass amplifiers at 1500 watts and higher.

So my point is that as people have become used to a higher SPL, a three way system just does not match the multiple drivers in THX, automobiles, HT, etc..

Thus we have the sub-woofer. An extra money maker for speaker companies. As the subs increased in popularity, more two way speakers came out. Then those two ways were not matching the lows of the three ways, let alone the subs. So in effect some of the subs are doing the standard lowest end that three ways (good design of course) have PLUS a lower end.

We have some that say use one sub. I don't know about anyone else, but even though bass is omni-radial, when listening to a good recording and the two way speakers are not cutting it, I can still tell where the main source of the bass is.

So in short, a demand for more and lower frequency bass, the increase in HT and multi speaker systems and the downsizing of speakers has been the major contributers to two ways so more subs and amplifiers can be sold.

I am in no way arguing physics - other than the downsizing of speakers - I am noting the desire for sales and profits.

dodger

[TBrennan]

RFK---I'm sorry but these new hot-zooey woofers fail to impress me. IMO the best woofer ever made for midrange reproduction is still the Altec 515. Light, stiff paper cone, BIG motor, 3" edgewound coil. The 416 comes in a solid second.

I think Klipsch eliminated the dedicated mid driver and horn when they went from the KLFs to the RFs simply to save money. It's simply not the proper way to build a 2-way horn speaker, in fact it's barely a horn speaker at all. If you're looking at Klipsch to see advancements in SOTA horn technology you're looking in the wrong place. Look JBL and TAD.

[Deang]

Tom, don't you agree that it's about high sensitivity, low distortion, and good sound. I don't think it matters much how you get there.

[PhilMays]

I really do not have the technical knowledge to back up my statement as obviously so many others have. However my KLF-20's sounded more detailed in the mids and highs. My RF-7's sound more open and full.

At first I liked the KLF-20's over the RF-7's. Now I'm not sure. Perhaps I've just gotten used to the RF-7's.

Does this make sense?

[Q-Man]

Isn't this where Fini comes in and says something like he prefers a 3-way as long as it's with two girls? Or do I have that wrong?

[Ray Garrison]

michael hurd et al re single driver full range speakers,

It may be true (explain that to Lowther) that a single driver full range speaker is impracticle, or impossible, using direct radiating cone style drivers, but that doesn't mean that there aren't other approaches that could result in a single driver full range system.

Bending mode drivers, like the Walsh cone or the Morel driver, or segmented time-delay driven devices like the Quad electrostatics, or the Beveridge line source style system can produce a full frequency output with reasonable amplitude linearity from a single driver. They all have other drawbacks, but they have some unique advantages.

The Beveridge systems, inparticular -

wowed a lot of people in ways nothing else ever has.

[D-MAN]

The Khorn will go up to 500Hz with the 6x13" slot vs. the "modern" 3x13" slot, which reduces the upper requency pass limit. Higher and mid-bass frequencies (above 400Hz) don't deal well with horn folds, so there is a reasonable limit, but 500Hz is definately do-able in a Khorn along with the standard 6db slope filter.

That also means that the modern K33E is probably not the best choice to use with the 6x13" slot.

So the crossover, throat opening, and driver all require changing to get up to 500Hz out of the Khorn, but it can be done satisfactorily.

Once that is done, there are many ways to configure it into a 2-way. Unfortunately, a quality wide frequency response from a single mid-high freq horn driver is quite expensive, more so than the traditional 3-way Khorn setup. Hence, the main reason that the 3-way Khorn has lasted all of these years - a correctly chosen and maintained price point.

DM

[sfogg]

"he Khorn will go up to 500Hz with the 6x13" slot vs. the "modern" 3x13" slot, which reduces the upper requency pass limit. Higher and mid-bass frequencies (above 400Hz) don't deal well with horn folds, so there is a reasonable limit"

I think the problem in the K'Horn is more the folding of it then the slot. The same woofer with the same slot can get up higher then that in a LaScala or Belle with their more simplifed horn folding.

In my two way LaScala's I run the bass horn to 600hz then cross to the upper horn.

In Al's modded Belle's (still three ways though) he runs the bass horn to 700hz then crosses over.

We both cross over considerably steeper then 6dB/octave though.

Shawn

[formica]

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On 9/24/2004 10:44:21 AM Q-Man wrote:

Isn't this where Fini comes in and says something like he prefers a 3-way as long as it's with two girls? Or do I have that wrong?

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I think Scooterdog beat him to it... in a very discreet (note the ) way.

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On 9/23/2004 10:06:16 PM SCOOTERDOG wrote:

I always fantasized about a 3 way.

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[PhilMays]

I'm married, therefore I would settle for a two-way at this point

[D-MAN]

Shawn, here's where the Khorn slot stuff gets peculiar...

The smaller slot causes more resistance for the cone to work against, and a wider slot lessens it, of course. That is reflected directly to the voice coil (being 4 Ohms with a K33E) but due to physical resitance, it acts like its 16 Ohms to the amp due to the resistance of horn loading.

Hence, wider slot = less resistance (reactance) = increase the resistance of the voice coil in question (i.e., to 8 Ohms).

The Khorn throat proper is still 78 Sq. inches which works out to exactly 6x13" as in the original Khorn (1946 variety). So PWK changed the driver and the slot for 3-way use somewhere since then, but left the horn (and throat) the same.

Moving up 100Hz past the nominal upper freq cutoff of about 400Hz is certainly OK to do, I have done it, BUT the effect is that the K33E gets "too loose" in the low end, that is, it actually needs a certain amount of reactance at the throat to work against or it seems to get sloppy in the low end. Other 8 Ohm drivers work better with the wider throat opening.

That is why I question the validity of using a K33E as a direct radiator as with the Cornwall, etc.

I would not attempt to go above 500Hz with a 6db slope in a Khorn as it tends to destroy the upper frequencies, like you would expect.

DM

[sfogg]

"That is reflected directly to the voice coil (being 4 Ohms with a K33E) but due to physical resitance, it acts like its 16 Ohms to the amp due to the resistance of horn loading."

If that 16 ohm number is correct that is a big difference compared to that woofer loaded in the LaScala or the Belle. Al has measured them at about 6ohm if I'm recalling it correctly.

Shawn

[dodger]

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On 9/24/2004 12:26:03 PM formica wrote:

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On 9/24/2004 10:44:21 AM Q-Man wrote:

Isn't this where Fini comes in and says something like he prefers a 3-way as long as it's with two girls? Or do I have that wrong?

----------------

I think Scooterdog beat him to it... in a very discreet (note the

) way.

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On 9/23/2004 10:06:16 PM SCOOTERDOG wrote:

I always fantasized about a 3 way.

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Well, there has been some bit of allusion to a 4 some set-up. I'll take the 2 subs.

dodger

[D-MAN]

Shawn,

I got that out of "How to build Speaker Enclosures", Davis and Badmaeiff 1978. They don't explain much about it other than "the Klipschorn uses a nominal 3.2 Ohm voice coil driver that acts as a 16 Ohm due to the excellent horn loading" (as close as I can remember).

I am extrapolating to be sure, but I'm probably pretty close to the truth, based on what I have read and some hands-on experiments with my horns.

DM

[D-MAN]

One more interesting thought, the La Scala and/or Belle would be an even better candidate than a Khorn for 2-way in that they only have 1 fold in a very short horn that would have little degradation of the waveform. The same slot/driver/crossover change being required also...

DM