What does one purchase after owning horns?

Duke of Audiokinesis introduced a new speaker at RMAF called the Strato-Prism. This speaker was easy to drive (16 ohms) and has good efficiency and plays deep bass rather well! (in addition to being very musical, cohesive and revealing) Its not as efficient as the Uno, but 30 watts is plenty of power on it. Plus the price is great- $4800 for the pair if I recall right.

Just to dispel a couple of common myths, Sound Labs are capable of impressive dynamics, and horns are able to be as uncolored as the best ESLs and magnetic planars in existence.

Much is owed to setup- the gear and care upstream.

Weseixas, I think that Classic Audio Loudspeakers will be showing at Axpona. Its a new show, at a new location, so unlike THE Show or RMAF, everyone will be at square 1 trying to figure out how to make the rooms work properly. So you will want to keep that in mind regardless of the room you check out.

If he has the T-1 there, the midrange horn runs from 250 Hz to about 10KHz. It has a beryllium diaphragm and so lacks breakups in the audio passband. Plus the magnet is a field coil. Field coils behave much the same way that ESLs do- those are the only technologies wherein the field does not sag when the amplifier makes power to move the diaphragm. So it is very fast and transparent!

I have dropped this link many times:
[ur]http://www.atma-sphere.com/papers/paradigm_paper2.html[/url]

It has to do with two different design, test and measurement techniques, both of which are alive and well in high end audio.

Weseixas subscribes to the Voltage paradigm which I subscribe to the Power paradigm. This gives us plenty of lively debate. I use the word 'paradigm' on account of the fact that quite often an individual who subscribes to a certain paradigm will have the opinion that anything outside that platform of thought is inherently 'wrong'. That's pretty much the definition of paradigm...

Anyway, several points. First, I did not make this stuff up. The Power paradigm existed before I was born (1956 for those keeping track) and, much like the tubes that are often at the heart of its tenets, failed to be displaced by the newer wave of transistors and constant-voltage theory that followed.

IOW it is quite possible to have bass that is not at all muddy, even with an amp that has a sizable output impedance. All you have to do is design a speaker that anticipates that, and Duke has mentioned one technique already. Now its a simple fact that all horns from the old days use these same design rules. When you try to use an amp that has constant-voltage characteristics on such a speaker, the crossover will not work correctly!! So the result is that the horn may well be subjected to frequencies it was not designed to reproduce. A lot of horns 'honk' when this happens.

IOW, horns got a bad rap on account of the fact that most of the old ones were not designed to work with transistors (in a nutshell).

Now the converse occurs when you use an amplifier with a high output impedance on a speaker that uses the Voltage rules in its design. For example, the woofer may well be seeing frequencies that the designer was trying to prevent it from seeing- perhaps an octave or two higher than it was supposed to go. This can cause the woofer to sound 'muddy'.

The bottom line here is that someone disparaging horns, amps with high impedance outputs, or planars and amps with very low outputs, **without taking these differences in design rules into account** is selling themselves short.

Now I am not an expert on the Avantgardes, but I can tell you that at least in the case of the Trio, it is one of the few horn speakers in high end that is designed to work with transistors or constant-voltage amplifiers. Consequently the task of finding a tube amp that sounds right on them is a big challenge. I suspect this is part of the reason why there are often blend problems when you try to use tubes on this speaker. So I have this advice: If you like tubes and you want a horn speaker, stay away from Avantgardes. It you already have an Avantgarde are you are trying to use tubes with it, now you know why its been so hard to find something that makes the drivers/woofers blend properly.

Larry, I too like a nice flat frequency response. I'm not happy with it if I hear deviations or rolloffs at the extremes. So my system is a hybrid- horns on top and bass reflex woofers on the bottom.

One thing about perceived frequency response though, that ought to be considered:

The human ear perceives distortion as frequency response variation. This is why two amps can measure flat on the bench but tonally sound very different.

Mrdecibel, I suppose this all could be boiled down to damping characteristics. How you would have to view it is like this:

1) some speakers like lots of damping and others don't.
2) Some amps have lots of damping and others don't.
3) Don't mix the two or the combination will not sound right.

Its my opinion that our ears are the most valuable things that we have as audiophiles, and that our ears are the most important thing in audio (I guarantee we would not be playing with audio gear if we had no ears). To that extent it is also my opinion that the more we design our equipment to obey the rules that our ears are using the more our equipment will sound like real music.

It is this latter point where things get dicey. In a nutshell, if you were to guess, what are some of the more important human hearing rules? Duke has pointed at some of them, and I'm on record saying that how we perceive the volume or sound pressure of a sound is the most important hearing rule. If the equipment violates this rule the resulting sound will not be perceived as real no matter how good the system handles everything else.

Dr. Herbert Melcher, and Nobel Prize laureate neuro-chemical scientist, has documented that if the system violates certain fundamental hearing rules, there is a tipping point where the processing in the brain moves from the limbic system to the cerebral cortex- the difference between emotional and intellectual response. He has some pretty hard numbers on this- essentially documenting the subjective experience. I am hoping he continues this research!

T_bone, In the case of Avantgardes, all you have to do is look at what sort of amplifier the designer is using (that is the case with most speakers). He uses a low power transistor amplifier, which explains the 'crossover' of the Trio (its all caps- no chokes, so the impedance of the speaker drops as frequency increases since the lower frequency drivers are not rolled out of the circuit).

It is for this reason that despite the efficiency of the speaker, quite often larger tubes amps are preferred, so they won't sound rolled off. Our Croatian dealer sold a number of MA-1s to Avantgarde Trio owners for this reason- you don't need 140 watts with that speaker! IME the smaller Avantgardes are less problematic in this regard.

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With regards to distortion in horns, to be kept low the design of the horn is quite critical. FWIW, the guy that did the JBL horns also designed the horns and drivers for TAD. The TAD horn has a problem with spiky response right near the cutoff frequency on their driver. Classic Audio Loudspeakers ran into this problem and had a new horn designed by Bruce Edgar that does not have any issue with this at all.

IMO the fact that horn-loaded drivers don't have to move much to make a lot of sound helps keep their distortion down. If set up right they can be as low or lower distortion than anything out there. If set up wrong the distortion can skyrocket. As in all fields, the application of generalizations is fraught with difficulties!

Chadeffect, it does appear the newer Trio has a higher impedance. Their website does not have a lot of technical data, but it seems pretty sure that 3 of the 4 passive crossover components must be caps. If a choke is added to the bass horn, the overall impedance would not be such a hard load for tube amps as the earlier Trios. Overall it would appear that the speaker is nominally an 8 ohm load.

Mapman, I've been involved with some field-coil driver design exercises in the last few years. It is true that you get greater efficiency with field coils, but if so it will only be by 1 or 2 db. The main thing that governs efficiency is precision gaps with focused magnetic fields.

What field coil offers is a magnetic field that won't sag, something that no permanent magnet can claim. Its like the electro-static principle in that regard. IOW I would not look to this approach so much for greater efficiency as I would as a way to make the driver faster and more transparent.

Larry, If I get what you are saying, you have even more reason to check out horns. Regular dome tweeters don't handle very much power (2 watts is common). Most horn tweeters handle about the same power, but are *also* lot more efficient, effectively making them able to handle a lot more material than any dome tweeter ever could.

Weseixas, here is my comment:

Regular dome tweeters don't handle very much power (2 watts is common).

I am not saying that 'a dome tweeter cant[sic] handle more'. To misquote me here and then knock down the resulting argument is a logical fallacy called a Strawman. see http://www.nizkor.org/features/fallacies/straw-man.html

The idea of a logical fallacy is that it appears logical but is in fact false. There are of course many tweeters than handle more than 2 watts, but 2 watts is indeed quite common. There are horn tweeters than can handle 25 watts; given that they are about 10db more efficient than many dome tweeters, said dome tweeter would have to handle 250 watts do produce the same output. Do you know of any that do that? I don't; but if they are out there they are pretty unusual.

Unsound, with respect to

Even without things like vented baskets, and ferrofluid cooling, dynamic tweeters are typically capable of providing more than enough volume for typical rooms.

IMO the issue is one of how relaxed the sound is. Its been my experience that the system should lack the quality of 'being loud' and instead should seem to not sound very loud, even when (by most audiophile standards) it is. It is a fact that electronic reproducers tend to add artificial loudness cues to the sound, making it hard to sit in the room when peaks are hitting 100db. But an orchestra can hit 120 db peaks so it seems to me that if a system is able to do that without stress or strain (IOW it is **relaxed**) at such volumes, then we would be far more likely to play the system at higher volumes.

One of the first things I noticed upon installing a horn system (Classic Audio Loudspeakers) was the simple fact that without any particular intention, we tended to play the system at much higher sound pressures than we had done with the previous dynamic speaker, **even though we had the power to play the dynamic speaker at higher volumes**. This simple fact of the matter was the horns didn't **sound** loud, even though they were in fact playing louder.

This is why I make such a big deal about loudness cues. Making sure they are not distorted by the playback system IMO/IME separates the wheat from the chaff.

Before Y'all go calling Unsound and Weseixas trolls, consider the fact that their advocacy is what keeps certain parts of this community on their respective toes. I for one value their input, even though I often disagree. If they can present an argument that has merit, I feel that it should be considered.

I used to have a very similar viewpoint about horns as Unsound as often expressed:

horns can play louder than most any other loudspeakers, but they're a one trick pony, IMHO, sounding completely obnoxious in every other regard.

Now that I no longer agree with this comment is only based on my experience have having to re-visit what horns are about. This is experiential, and we don't all have the same experience. IMO/IME, it is probably more important to sort out why that is the case- I think we can learn more if we look at it that way.

BTW- I was the one that mentioned the 120 db. If an orchestra can do it, we should be able to in the home too. That we are not there yet ( 'turn that !@#$%^ down!' ) says a lot about the weaknesses in our technology.

Weseixas, when I use the term 'efficient' or 'efficiency' with regards to speakers its usually with the 1 watt/1 meter spec in mind. If you say 'sensitive' or 'sensitivity' to me in the same context I assume you are talking 2.83V/1 meter.

Not into caffeine, but I think you will find that a good majority of dome tweeters are indeed rated at 2 watts, with some of greater power handling, although the latter is less common than the former. I'm not used to seeing horn tweeters that handle less than 2 watts, and I have seen them handling as much as 15 watts; with immensely higher efficiencies (10X) that horns have over domes, this can be a significant advantage.

Weseixas, I think T-Bone has a good point- where is the science that says that horns are 'discombobulated'? Do you have a link that is peer-reviewed?