Horns x direct radiators x listening distance

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My Audio listening Room is Large 5mts x deep 6mts. The listening distance is ~ 4m. All rooms in the last 6 years, my playback was installed, were moreless this size. After many years listening and experimenting with different kind of horn systems and configurations, i have moved towards a simple 2 way solution, basically direct radiators : Beyma TPL, and 12p80nd. They sound superior by all means compared to my previous big 5 way horn rig. This is making me questioning. Why is that so ? Some systems, which were the most impressive ones, i ever heard, where AV Trio based horn systems. BUT: They were ALL installed in BIG rooms. That means, above 50sqm. That is making me think: what is the correlation between direct radiator x horns, room size ? I remember, when i was a kid, my dad was a speaker builder, he said: These kind of speakers do have the property of launching the sound wave far apart, and the energy/efficiency far away is not being lost. My point is: Could it not be, that hornspeakers shine only, and give THAT impressive sound, when the sound waves emitted through horns do have the hability to evolve enough in the room they are in ? Maibe some experts could give their opinion on this.

Angelo
 
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Of Horns and such

Hi Angelo,

In most cases, the more simple=the better. I have tried a 5 way two different times in my audio-life, neither performed well.
It seems as if you have stumbled upon a synergistic combination that works for you. You are probably hearing a coherence in wavelaunch that you had not been able to arrive at in your previous "horn system" attempts.
There is also something to be said for "similar characteristics in wavelaunch".
That is, horns go with horns. Multi-horn systems do require a large room to
"meld" the outputs. Medium sized rooms using direct radiator 2 way, or 3 way
systems often fit the room better. One challenging aspect of many systems is what has been done to tame the dreaded baffle step response that often plagues the system's ability to sound natural down through the lower midrange. Without this being adressed, a system will sound artificially detailed at the expense of listening fatique within a short time. Approaching system design with "getting the midrange right" was old-school and spot-on. It could be you have found 2 drivers and a corresponding x-over that just happens to
be a synergistic and magical combination.
I have also reached a very nice and unexpected synergy in an all horn system. In my system, the "Bell-Labs" midrange is handled by one section.
It's a Tang-Band 1772 driver mounted in a vintage round horn. It's effectively a point source, and in a horn system like this, baffle step is non-existant.
The mid-bass is a hybrid horn of sorts, fed by a ppsl motor housing 2 @ Eminence 4012HO drivers. This affords me the "punch" I have always sought after, yet, at the same time is very smooth and graceful in the lower mid-range; male vocals are superb. The very deep bass range is handled by an infinite baffle system extending down to 17Hz. Highs and super highs are easily and effortlessly expressed through the Stage Accompany Ribbons.
This is by far the best I have done after 41 years of "tinkering". You have also seemed to have reached something you are exicted about enough with to want to share with the entire audio community- and that is good. Point being, there are many paths to audio nirvana depeding upon one's own personal tastes and, as you say, a system "fitting the room". My listening room is somewhat larger than what you had descibed for your past systems, but not to a huge degree. Life-like dynamics and a realistic presentation are the 2 lumps in my "cup-of-tea", but many others will disagree and place some other aspect of "sound" in their priority list. To that I say: to each their own and......HAPPY LISTENING !!
 

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Hi Scott

i follow the evolution of your system already a few years. Very interesting outcome. What are the crossover points, and what it the room size ?
It seems your approach is to make the Tang Band to play in a wide range, and only reinforce the two frequencye extremes , and so getting high coherence ?

Your eminence 4012HO has a very linear frequency plot from 100hz up to 800hz without hornloading.

http://www.eminence.com/pdf/Definimax_4012HO.pdf

The Tang Band 1772 has a slight efficiency increase of about 10db above 1khz, below its very linear as well.

http://www.tb-speaker.com/detail/1230_04/w8-1772.htm

Have you measured your channels individually ? Theoretically, you should have a decreasing frequency plot in both horns.

Someone posted this at parts-express forum, similar solution :

TB full range W8-1808

How do they sound. Awful, if you want to listen to over-compressed music like The Police or Steele Dan, but absolutely fantastic is you like more dynamic sound like well recorded classical music, J L Hooker, Rory Gallagher “On the Boards”, JT etc. If it's live - it sounds fast and dynamic and a little shouty just like a real live performance.

I am using a DEQX (another great Australian invention) crossover, but not applying any correction filter. I have tried both models in the horns and find it hard to pic the difference.
 
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Hi Scott

i follow the evolution of your system already a few years. Very interesting outcome. What are the crossover points, and what it the room size ?
It seems your approach is to make the Tang Band to play in a wide range, and only reinforce the two frequencye extremes , and so getting high coherence ?

It's a 4-way. The TB covers 250-3.5kHz
Sub-bass below 60, midbass 60-250, Ribbons above 3.5K
Slopes: sub/24/midbass/48/mid/48/tweeter

Your eminence 4012HO has a very linear frequency plot from 100hz up to 800hz without hornloading.

http://www.eminence.com/pdf/Definimax_4012HO.pdf

Yes, it's an ecellent driver, but I wanted to try a ppsl compression chamber driving a horn. Can you say dynamics ? :)
The Tang Band 1772 has a slight efficiency increase of about 10db above 1khz, below its very linear as well.

http://www.tb-speaker.com/detail/1230_04/w8-1772.htm

Have you measured your channels individually ? Theoretically, you should have a decreasing frequency plot in both horns.

The horn actually "lifts" the response as it decends in frequency.
Someone posted this at parts-express forum, similar solution :

That's the 1808. I have heard both. Both are fine, but have slightly differing best uses. I found the 1772's sweeter in the mid-range.

TB full range W8-1808

I do my best to stay away from the PE forum. There might be 10 indiviuals that actually know how to read, and know what they are talking about.
How do they sound. Awful, if you want to listen to over-compressed music like The Police or Steele Dan, but absolutely fantastic is you like more dynamic sound like well recorded classical music, J L Hooker, Rory Gallagher “On the Boards”, JT etc. If it's live - it sounds fast and dynamic and a little shouty just like a real live performance.

I am using a DEQX (another great Australian invention) crossover, but not applying any correction filter. I have tried both models in the horns and find it hard to pic the difference.

I've noticed posts that list fine results rarely get any attention. Kinda makes sense. Since this is a DIY forum, it's mostly those asking for advice and many others offering their opinions. It's a much better place than the PE.
 
Could it not be, that hornspeakers shine only, and give THAT impressive sound, when the sound waves emitted through horns do have the hability to evolve enough in the room they are in? Maibe some experts could give their opinion on this.
Angelo,

The greater the distance between the radiating elements, the further the distance required for integration of the individual sources. In a small room, the reflected sound of multiple widely spaced radiating elements off-axis response can degrade both image and frequency response.
In addition to basic sound quality issues in the near field, there is the imaging problem of the perception of sound "walking" with frequency up and down a large multi-way system when you are too close.

One can "cheat" typical separate component horns with DSP and time align to a close listening point, but the overall room response then is degraded.
If one tries to use physical time alignment of a large multi-way horn system, the horn length differences often will cause mid and high frequency reflections and diffractions from around the various horn mouths.
If one "lines up" all the horn mouths on a single baffle to avoid those problems, the problem of a changing acoustical source off axis comes in to play.

Multi-way systems like Danley's Synergy horns avoid all the above problems of typical separate component horn systems, and can sound excellent at any typical listening distance, even including your ears within the single "full range" horn mouth.

Art
 
While there never really can be an explanation of someone's "subjective" impression (since it can be anything, and often is), I do not see any science behind what you are suggesting. As long as one is not in the near-field of the speakers at mid to high frequencies - say two meters away - the sound waves are just sound waves with no idea from whence they came.
 
As long as one is not in the near-field of the speakers at mid to high frequencies - say two meters away - the sound waves are just sound waves with no idea from whence they came.

I observe a significant difference, which is due mainly through the dispersion characteristic - having a direct radiator a wider dispersion, which opens up the soundstage, and giving more a illusion of " being there ", compared to horns, which seem to be more indicated to throw the sound wave farther apart, and probably retaining the energy of the soundwaves more than direct radiators. My guess is, that this might be one of the main reasons, why i like my 2 way, direct radiator configuration better, than horns, in my listening room. I wonder if there is some empiric science behind my observation.
 
My point is: Could it not be, that hornspeakers shine only, and give THAT impressive sound, when the sound waves emitted through horns do have the hability to evolve enough in the room they are in ? Maibe some experts could give their opinion on this.

Angelo


Hi Angelo,

(no expertise, just experience and some "common sense" i suppose ...)

i would say that "the usual enjoyful listener" does not want to listen in
a very dry room.

Low reverberation time and listening in the nearfield is preferred by sound
engineers during the recording/mixing process.

As i heard and also was often stated in here, many professionals allow or
explicitly want more listening room reflections than at work when listening
in "enjoyful mode" e.g. at home. I wrote "many" not "all" ...

And i also do not want to open pandora's box regarding which kind of
reflexions may be "enjoyful" and which ones may be "detrimental" due
to "spaceousness" or even imageing:

- early vs. late reflections
- ipsilateral side reflections vs. contralateral side reflections
- side reflections vs. reflections from the ceiling

What i want to say is just this:

Given a certain speaker with a characteristic directivity over frequencies
and a certain listening room, almost every listener will - soon - find his/her
prefered listening distance. Our "observed listener" might also have
individual preferences concerning the volume:

- far below "original" or realistic level
- somewhat below or even
- "closely at" realistic level

My own observation in my current listening room is that many listeners
prefer a listening seat somewhere below the critical distance, but also
"not too far away from that", if they are free to choose.

If speakers have high directivity that critical distance moves away from
the speakers, thus listeners move away from the speakers too, just to
get "their preferred portion of listening room reverb".

I think this is the main reason and i observed that effect consistently
with "trained" and even "more naive" listeners:

- highly directive speaker > tendency for larger listening distance preferred
- low directive speaker > tendency for smaller listening distance preferred

(choice meant to be "in the very same room")

With some horn systems, where sound sources (e.g. mid - high) have
considerable distance (e.g. multiple wavelengths at crossover frequency),
also group delay may be an issue. If the listener has no possibility
(or no idea about how ...) to reduce GD by toeing the speakers in or adjust
them in vertical angle, he might just prefer the place where the speaker
is "pointing at" and -hopefully- produces low GD and balanced frequency
response at that "sweet spot".

But the main effect of "high DI" speakers is independent from the fact, how
that directictivity is achieved (say horn/waveguide or large membrane area
effectively radiating when compared to wavelength).

So the effect you mentioned seems real to me, but it is IMO not something
"magical with horns" but something "natural", that comes with horns
like it comes with other "higher DI" concepts.
 
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Hi Oliver

I mostly agree with what you say. But I am not sure what you mean by GD and reducing it by "toe-in". I don't follow that.

And

And i also do not want to open pandora's box regarding which kind of
reflexions may be "enjoyful" and which ones may be "detrimental" due
to "spaceousness" or even imageing:

- early vs. late reflections
- ipsilateral side reflections vs. contralateral side reflections
- side reflections vs. reflections from the ceiling

Maybe it is a Pandora's Box, but it is also IMO the single most important topic in the understanding and design of audio reproduction in a small room. Don't get these aspects right and everything else is just window dressing. So ignore it at your own peril.
 
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The rest of the answer

Hi Scott

i follow the evolution of your system already a few years. Very interesting outcome. What are the crossover points, and what it the room size ?
It seems your approach is to make the Tang Band to play in a wide range, and only reinforce the two frequencye extremes , and so getting high coherence ?

Angelo,
I apologize for not answering fully. My overall room size is 24x29 feet.
Right now, my listening area is off-center. I sit 13 feet away from the speakers which are 8 feet apart. A very, very large percentage of the room's surfaces are covered with acoustic foam and/or 2" thick rigid fiberglass. It's an
acoustically dead listening area. I'm hearing mostly direct sound. That might have something to do with your theory. Hope this helps, be well.
 
Hi Oliver

I mostly agree with what you say. But I am not sure what you mean by GD and reducing it by "toe-in". I don't follow that.


Maybe i should give an example:

http://www.acapella.de/img/Sphaeron.jpg

If you listen close to such a "high end dinosaur", and the speaker is
aiming at the farthest seat or there is no toe in at all, there might be
a delay introduced between the tweeter and the upper midrange horn.

This would be the case also, when assuming GD being rather smooth
for the speaker on axis and at considerable distance ... which i
do not know (have not measured).
 
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It was long ago when i listened to that speaker in that particular
room on the picture, must have been 20 years ago or even more.

Mr. Rudolph from Acapella is able to tune his speakers in a
"non offensive" way, making most acoustic instruments sound
rather natural, not the kind of "sizzle" often heard at shows ...

But i remember the speaker did not sound consistent to me at
different levels and i told that a friend who was listening with
me at Acapella at that time.

The impression was, that highs and "sparkle" which were audible
at low levels turned into a more "dull" presentation when playing
louder. That was clearly an anomaly to me, which seemed level
dependent.

As an explananation i thought maybe that plasma tweeter did
not have enough dynamic headroom and would suffer from
compression or any other nonlinear effects. Even though the
effect of plasma glowing (level dependent ...) was very "magic".

But maybe that sonic impression was not due to the tweeter itself.

Very speculative anyhow after that long time and without
possibility of measuring that speaker.

Nevertheless i remember Mr. Rudolph explaining - without being
asked for - that (in turn) the midrange horns would not disturb
the tweeter's radiaton but just introduce a kind of "acoustic shadow"
when listening from an angle where the tweeter is hidden by the
midrange horn: No problem, when sitting at the right place for
the tweeter to be acoustically "visible".

I would say there might have been a lot of wishful thinking within
that explanation ... hard to believe reflection/diffraction not being
an issue e.g. for the tweeter's radiation.
 
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