#triodes

Edward Victor Appleton – Scientist of the Day

Edward Victor Appleton, an English physicist, was born Sep 6, 1892, in Bradford, West Riding, Yorkshire.

Ok this is just about horn speakers in general. It is a good example of compromising some things to get something else.

As I said earlier horn type speakers can be very efficient. They can also get really weird.

These are Avant garde Trios. Rather single minded I think. Low wife acceptance factor. Oh and if you have to ask how much.....

Slightly more conventional are the big Klipsch beasts.

This is a Klipsch Jubilee (image from their website). This is their statement halo product. Man Cave required.

You should also recall the Altec Horns I mentioned a while ago. Horn speakers excel at efficiently converting electrical energy into sound waves. But they do compromise some things to get that. If you go down the Single Ended Triode rabbit hole you will need horns to get reasonable sound pressure levels. So what are the compromises?

Horns change the sound. It is from several effects. Some are resonances in the throat of the horn. Others are reflections that occur as the signal exits the horn. In most general terms it makes the sound kinda honky. That is great for brass instruments as that is their natural sound. Some horn speakers are better and others are worse for this.

You can easily see that those funky Trio things would be great for trumpets. Hell they are trumpets.

If you have such you can get used to the sound and adapt in your mind that this is natural and right for say the human voice. You may even prefer it over something another person would think is better.

There is another thing. That big Klipsch for example is a problem. Several products over the years have been built to maintain phase alignment between different drivers. The signal going into a speaker is all aligned. The Dahlquist DQ10 was conceived around several drivers each optimized for a particular frequency and they were mounted so a music signal was properly aligned as it emerged. They did that by moving the driver mounts to the front or back to compensate for phase in the really complex cross over network.

You may note that diffraction around sharp edges was not part of the design brief.

It worked well and reviewers really liked it. It was also stupidly inefficient so you needed big amps to make it happy. Oh and it had a nice modesty screen so it was not as ugly as this naked example. The whole point of it was it was based on the idea of signal coherence with broad frequency response. Let the other chips fall where they may.

Full range electrostatics are naturally aligned too. The Quad Electrostatics even use phase alignment to simulate a point source. Rather tricky that. Oh I should mention that there are single driver full range speakers out there.

This characteristic of alignment is heard as a coherence of the signal and helps maintain a sharp image. To the degree some people are sensitive to phase and time alignment that is their issue with big horns.

Big horns are not naturally aligned. The front faces may line up, but the driver offset distances at the small end is what matters. Those Altec VOTTs are rather bad in this respect. The different distances the signals must travel from the driver to the face of the horn can be off by several feet. Some people suggest driving each speaker driver through it's own amplifier and a DSP processor to realign the phases would work a charm. That is getting complicated, and not really in keeping with Triode simplicity and naturalness.

As is so many things a product has some basic idea behind it. If that idea drives everything then compromises will be made somewhere. This is true with all Audio stuff. Tubes are better or worse than solid state. FETs are better than Bipolar transistors sometimes. Film caps are better than electrolytic. Class A or Class AB or Class D or Class H which one to pick? You can buy examples of each of those. They all vie for the State of the Art.

Very often it is a choice of business sense. What can we make and sell? Klipsch has those big horns, but the bread and butter of the business is rather more conventional types. Halo products can be loss leaders or just so expensive very few are sold. You gotta sell to survive.

The only type of speaker I have never built is a horn loaded one. Too complex and until recently my carpentry skills could not do it justice. But I like what I have now. Simple two way Bass Reflex and Phase aligned. Not efficient at 87ish dB per Watt at 1meter. (Klipschorn is 105 dB at one Watt) But I have a big amplifier.

One of the audiophile tribes believes in Horn loudspeakers and very small amplifiers.

There are tribes. Or cults if you prefer. Utter faith in one idea over another. Brand loyalties are just part of it.

There was an "art exhibit" in NYC where a very clever person installed an exotic sound system in a gallery. It was very interesting. He goes by the brand handle of OJASNYC. His name is Devon Turnbull. He started out in fashion design, but had studied audio engineering in school. Hey you dig up the stuff yourself, I want to talk background.

Central to his approach are BIG Horn loaded speakers. Last century a company called ALTEC manufactured big speakers for movie theaters. If you have seen one or two movies in theaters in your life you have heard them. Back at the beginning audio amplifiers were not that big. Double digit Watts were rare. One aspect of Horn speakers is efficiency. Very high efficiency. The price of that efficiency is cost. OR put less awkwardly the price is high as these are big units.

Oh and ugly. And OLD. The drivers he prefers are ALTECs made by an old man in the midwest who took all the designs and tools when the ALTEC company shut down the professional division to concentrate on Bluetooth shit.

This is not a bad audio approach as horns match the impedance of the air in the room and deliver BIG sound. Few ideas do that better. Actually nothing does that better.

One down side is well do you want anything else in the room? Altecs were always intended to be on the other side of a movie screen. I for one cannot have such a set up as I am not rich and have a small house, and a wife.

Also if you know about "room sound" you will notice a host of issues with the display in the picture. Too many for me to list here and now.

But there is more.

Triodes. An original 100 year old vacuum tube concept is called a triode. It has three parts, an Anode, a Cathode and a grid. The grid varies the flow of electrons between the Anode and the Cathode. From this you can build all sorts of things including amplifiers.

You can build a thing called a single ended triode amplifier. That is a class A circuit that is very simple and very low power. Simple does not mean cheap. Funny that.

It is a literal article of faith that simple triode circuits are best. Like organic tofu. But also low power so it is a match made in audio heaven to put puny single ended triode amps with BIG horn speakers.

I have said this is a hobby of emotional response. I have heard big horn speakers in theaters and some homes. Klipsch is the brand leader for high efficiency consumer horns. But as for everything they have a voice. If you like it, it is good.

If I had to characterize the sound of big horns versus my invisible speakers it is scale. An orchestra appears on the other side of the wall of my room. But it is miniature. OR I am sitting well back in the audience. My wall is 18 feet not 100 feet long so an orchestra would never fit full size. A Klipschorn for example would blow that up and put a huge image in your face. But it would be looking through a zoom lens. That and I would have to take lots of furniture out of my little room to fit that set up in.

For that there is not more detail or any subtlety. I have that now. Your system has to fit your needs both audio and physical.

I have simple Bass Reflex boxes. Not very efficient, but I have a rather big amplifier. That is a better fit for me.

Triodes - Chicken Strut from Chunked