I've been building stereo speakers for my own personal use for nearly fifty years now.
I'm no expert on speaker theory but I've learnt a good deal about putting drivers together to form some interesting speakers over the years.
Ive tried most of the formats- traditional moving coil box speakers, electrostatics, ribbons, horns, open baffle and I've had good results with all types.
Some memorable memories are Goodmans Axiom 80 and 300 bass driver in bass reflex, Crown electrostatic panels , Edgar and Azura tractix horns, Supravox full range field coils on open baffles, Tannoys, in different configurations and many more, all of which gave me a great deal of enjoyment and satisfaction.
Ive also owned many commercial designs- Quads, Tannoy, JBL, Martin Logan, Magnaplanar, Acoustat, Canton, Acoustic Research, Lipinski, Nakamichi, too many to remember.
Ive always been attracted to horns, and spent a good part of my audio journey listening to them, although I will admit its sometimes been a love/hate thing.
They do some things so well , particularly dynamics and low distortion , and can also be prone to less than accurate responses that can cause a "horn" sound that can be shouty, quacky or other coloured descriptions.
Like every other type of speaker there are good and bad implementations of horns, the smaller horns integrated with a single bass driver are usually less than successful, as the high sensitivity of the horn rarely mates well with a single bass driver.
I went through a lot of horns trying this approach, and while they can sound good , I was never happy long term.
But I love the ease and dynamics of a good horn, and I think they come closest to the sound of real music than any other design.
After many years I have built myself a horn system that has few faults and imo sounds superb, and I would like to describe it here.
Firstly, I would like to point out that this is not attainable for the average home.
This system needs a very large room to function properly , the horns were initially designed for cinema and PA work and will be severely constrained in a normal domestic situation.
Starting at the bottom I have a pair of massive tapped horns, over 7 feet high and very heavy. Tapped horns are very effective at very low frequency, and can give prodigious output at 20hz, which is exactly what we want for a "real" subwoofer.
They have two 15 inch drivers in each cabinet.
I consider sub bass to be in the 10 to 30 hz region, anything over that is woofer territory, and usually handled by a systems woofer drivers.
Music that has any content under 30hz is very rare and a real subwoofer will mostly not be functioning during playback, and should not be heard, or contributing to playback.
The tapped horn is good for very low output, but has some terrible frequency abberations over 80hz.
I have it filtered with a minidsp digital crossover so that it is flat from 20 to 40 hz region with a steep 48dB rolloff from 40hz.
This gives me a "genuine" subwoofer that is mostly invisible but comes alive with sub bass effects, such as thunder, electronic bass music , pink floyd helicopters, etc.
The tapped horn crosses over to a subwoofer/woofer which plays from 40hz to 90hz.
This a pair of JBL dual 15 inch cabinets , so a total of 4 JBL 2226 drivers, which are highly regarded for the bass they produce.
They provide most of the low bass and are responsible for the bass kick and slam.
Once again, minidsp digital crossover , 12dB at 16hz and 48dB at 90hz, which combined with the cabinets acoustic rolloff gives flat response from 40 to 80hz.
Solid state amplification for the subs, they sound fine with tubes, but I use solid state to keep the heat down, and tubes are getting expensive!
Now we get to the heart of the system, the bass/lower mid horn and the mid horns.
The bass horn is a 50 hz Azura front loaded horn , designed by Martin Seddon . It has a 15 inch Yamaha horn specific driver and one 90 degree fold to accommodate the length needed to get 50 hz cut off response.
For years I used various mid horns with single 15 inch bass drivers in bass reflex or Onken like encloures, but I always became jaded with the sound.
These types of bass enclosure simply dont have the sensitivity to keep up with a high sensitivity mid horn, even when used with active amps theres a lack of integration between the drivers, they just dont sound right, the horn always seems to dominate.
The Azura bass horn however has the sensitivity to match the horn and as it is also a front loaded horn like the mid horn , it integrates well, and in combination with the lower mid horn, they combine to "disappear " which is a sure sign of good integration.
Bass is simply effortless and flows with precision and ease, perfectly matched with the rest of the very dynamic system.
Now we come to the mid horns. There are many types of mid horns, my favorite is the radial and bi-radial horn. They need to be decent size to really work well, but they give the most realistic and natural sound, without the phaseiness, and shouting qualities some mid horns have.
I have a lot of respect for the engineering that JBL did in the 70's and 80's, they took horn design beyond what was thought possible. Its a shame that economics decimated the engineering prowess in the 90's, who knows what we could be listening to today, although the top end JBL gear is still very good, albeit expensive.
After trying many horns, the JBL 2360A mid horns completely blew me away . These are almost a metre square and were designed for cinema use. With 90x 40 degrees dispersion they have a huge soundstage , with ultra precise imaging.
They are slot loaded and what comes out of that slot is amazing.
What I like the most about high sensitivity horns is the almost discernable levels of distortion they produce, and when you only have a requirement of 50 milliwatts for 100dB sound level, then you have the amplifier working at vanishingly low levels of distortion, and subsequently you then have a reproduction that is as close to perfect as possible.
The 2360 is easily the best mid horn I've heard, bearing in mind it can only be used in a very large room .
Destination Audio uses an almost identical copy of the 2360 in their $95,000 Vista horn speaker.
A reviewer said this about the speaker after hearing it at a hifi show, which I think sums up the sound of the 2360.
QUOTE :
The utterly compression-free presentation of the Vista horn, in casting sound fields into the listening space, presented a directness of communication that drew even the most uninitiated spectator into its world. If music were a divine reflection of the human spirit, then the DA System would be the sentinel of the art form.
QUOTE :
The sense of the extraordinary and the best sound of the exhibition, however, was primarily due to the total coherence of the sound, angelic analogy (for a completely incomprehensible digital output), as well as natural expression, supported by the literal presence of artists in the room…In each instance immersion of an audiophile battle depth and at the same time, one of a kind, because no other loudspeakers I know of, including other horn speakers, immerses the listener so deeply in the sound. Usually there is some distance - music there, listener here - but with Destination total unity and full identification prevail.
Vista with JBL2360 copy, got a spare $95,000?
The Azura bass horn and jbl 2360 horn have simple passive crossovers, just an inductor on the Azura and a capacitor /inductor on the 2360.
Digital crossovers are great for bass, but once we get into the vocal ranges I only use passive crossovers.
Simple 6dB passive crossovers have the best phase response which relates to bigger soundstages and realistic imaging.
There is something about 6db crossovers that is just "right" , they are full of life and texture.
The proviso is that the drivers being used have to be very good, with no nasty frequency extremes.
The JBL 2360 is not as well known as the JBL 'bum cheeks" 2344 horn. This was used in the 2440 and 2445 studio monitors , which were famous for their sound and are still highly regarded and expensive, if you can find them.
With a 100 x 100 degree dispersion , the 2344 has the widest soundstage Ive ever heard.
Although very satisfied with the 2360 I decided to incorporate the 2344 into the system as an upper mid range horn to compliment the 2360.
I was after a slightly stronger central image , and the ability to fine tune the sound , slightly warmer , or even drier , depending on the music and mood. It worked out very well, and despite the complexity, it is beautifully integrated and wholesome sounding.
JBL 2344 horns
The horn tweeter is a JBL 2404 "baby cheeks" tweeter. Recognise a theme here? Again, simple 6db crossover.
So we have a 6 way system of sub, sub/woofer, bass horn, mid horn, upper mid horn and tweeter horn.
The custom built preamp has outputs for sub, sub/woofer, bass horn, all of which have adjustable level controls on the preamp. There is also a fixed output for the mids and treble.
The outputs for sub and sub/woofer go to seperate minidsp digital crossovers and then to high power solid state amps.
The outputs for bass horn goes to passive crossover and then to EL34 push pull tube amps.
The outputs for the mid horns goes to passive crossovers and then on to 6C33C-B single ended amps for the 2360 and 300B SE amp for the 2344 horn.
The tweeters have 300B single ended amps, again through passive crossover.
To set them up I use REW and with a microphone at listening position I adjust each driver to a set level, 75dB pink noise.
I can do this very accurately with the level controls on preamp and amps.
After this its just a matter of fine adjustment to find what sounds best to my ears, I dont rush this, it can take days for the magical settings to arise , and further weeks to really bring it alive.
Most of the time the system is set up with studio monitor type sound- very acurate for a discerning critical sound that enables the recording to be replayed as it was recorded, nothing more and nothing less. Good recordings sound fantastic and bad recordings sound less than fantastic. Essentially I enjoy a recording that was produced and engineered for the highest possible dynamics, which this system is easily capable of reproducing.
However, sometimes i want to listen to a more relaxed "beautiful " sound, and I can easily obtain this with adjustment of the individual amps level controls. A little more midrange, a bit less top end, maybe a touch of upper bass. Im essentially using the amps level controls as a sort of mixer , with many possible combinations of sound.
This is the finest system Ive built. Because of its size and complexity you would expect it to have a very big sound, which it does, but its not so much a wall of sound, but an astonishing recreation of the recording. It has unlimited finesse, and subtlety that can convey any type of recording from quiet single instrument recordings to massed orchestras, with an accuracy and transperancy that is so believable.
Wheras all conventional speakers present a convergence of all the instruments in a recording into a stereo mix, this system presents every single instrument and voice, into a single , easily identified and precisely located place in the soundstage. Its so easy to differentiate and locate every single piece of the recording exactly at the amplitude and position it should be at, there's no perception of restriction or compression you get with modern conventional speakers.
I think that the hi fi industry really debased itself with a relentless profit based and unwise decision to move away from high efficiency speaker systems .
The advent of high power transistor amps enabled low efficiency compact moving coil speakers that approached similiar sound levels in a limited domestic space , but with highly compressed soundstages that are flat and involving.
The difference between a horn system that is capable of 130dB from 1 watt and a system that is capable of 80 dB from 1 watt is so dramatic as to be almost indescribable, go back to the reviewer's description of the DA horn system to get a glimpse of what I am trying to describe.
And my 6 way system is even more revolutionary and evolved than the DA.
The extraordinarily dynamics comes with an unrivalled sense of power, it can so easily recreate a concert hall , it really does come as close to the real thing as is probably possible.
All this with low power single ended amps on the mid horns.
Yes its ugly, takes up a lot of space, its a complicated system and very expensive in terms of a custom preamplifier , 6 + amplifers , and a tremendous amount of man hours to design and build a system that requires so much synergy to actually work with such a tremendous result.
I just wish every audiophile could hear this speaker, it would change how we think about modern speaker design and hopefully induce a renaissance towards high efficiency, accurate and realistic audio.
I did find the physical presence of this system a little overwhelming , its a huge speaker over 7 feet high and nearly 14 feet wide.
Its visually dominating so I covered the whole system with speaker cloth.
Now I can just completely involve myself in the music , without being distracted by the visual appearance of the system.
This turned out to be a very worthwhile move, enabling very deep contemplation and enjoyment of the music
