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fiogf49gjkf0d  de charlus wrote: | I propose to array the drivers, and horns, as laid out beneath, from top to bottom;
Ale Acoustics 160Super (15hZ-1000hZ, 110db/w)15hZ - 150hZ Lower bass
Vitavox AK 151 (50HZ-8kHZ, 100db/w) 150hZ - 350hZ Upper bass
Vitavox S2 (200hZ-16kHZ, 110db/w) 350hZ - 1500hZ Lower mid
Ale Acoustics 45Super (500hZ-20kHZ, 115db/w) 1500hZ - 6kHZ Upper mid
Acapella TW1S (5kHZ-50kHZ, 110db/w) 6kHZ - 50kHZ+ Tweeter
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Charlus,
maybe you realize it, or maybe not, but you are in the beginning of a very very
long journey. The journey could easily be walking in a simple circle (or
multiple circles) or a straight road – it all depends on how well you know your
inner world. This is more about discovering yourself and much less about
applying different audio methods.
First you
should learn/discover the simple rules of the game – the rest is how you play
with them. With an audio project of this scale, you certainly need to know a
lot about human perception – on cultural level and on purely anatomic/psychoacoustic
level. This knowledge comes with
listening practice and experimenting with practically everything you could.
Reading the
first post of this thread, I see the very typical mistake most of the audio
people repeat and repeat – you are determining the crossover frequencies
between the channels, thus trying to construct a theoretically correct acoustic
system, but you are not trying to create sound. If you try to accomplish some
kind of very exact sound, it is impossible to know where your crossover points
will be, and also it is impossible to know if a certain driver will meet your
requirements. There is no such thing as default sound of a driver – it can
sound as anything, depending on how you use it.
Your
strategy is to let your uppermid channel to play in the range 1,5-6kHz, your HF
channel from the 6kHz up, and to achieve very good integration of the channels.
This is the first difficulty you will meet when starting to experiment. Not
because the ALE driver will have different sound signature compared to the
Acapella tweeter, but because these two channels have very similar audio
gravity forces and each of them will “pull” the sound at its axis, so it will
be extremely difficult to focus the sound at the axis of any of them. First of
all, I should define what I call “Audio gravity”, because it is very important “parameter”.
This is purely psychoacoustic measure of the ability of a certain source of
sound to “pull” the sound of the surrounding complementary sound sources. Actually
it is not the driver that “pulls” the sound – it is how your brain reacts on
the incoming to the ears sound and interprets it as a sound images. I will
mention some of the easily understandable rules: the audio gravity is stronger
when: 1) the sound of the driver is focused within itself, 2) has extended
frequency response towards the UHFs, 3) has relatively mid or big size for
better intelligibility, 4) has a correct ratio between sound energy vs. sound
amplitude level (!), 5) has extended frequency response towards lower part of
the sound spectrum and so on and so on.
Now let see
what you have with your predetermined crossover frequency of 6kHz between your
upper mid and HF channel. First of all, your ion tweeter has very little energy
at 6kHz (not to mention lower than that) compared to its 16+kHz range. You will
immediately notice there is some kind of thinness and dynamic efforts in the
sound, and you will experience lack of physical density in the sound, which
directly relates to the ability of your system to express the musical messages
with the required “full breathe” magnitude. You can measure all day long, but
you will not recognize the problem by performing measurements – the frequency response
will be exactly as you expect it to be, but you will still experience the deficiency
of energy in the sound. Second of all, the audio gravity of your upper mid
channel is relatively weak. What do I mean by saying that? If you lowpass it at
6kHz, let say it has 10 Cockooricones of audio gravity force. Allowing it to
play up to 10-11kHz will raise its gravitational “pull” not with 200%, but with
400% and then it will have 40 Cockooricones of psychoacoustic pulling force and
now there is much higher chance to successfully pull the sound of the HF
channel at its axis. But keep in mind
this is a very simplistic type of integration success – to adjust the adjacent
channels to appear like a focused source of sound. Usually this is where most
of the audio people stop (if they ever achieve it). The much higher level of
integration is the super structural integration - it affects the inner structure of the sound – I have never heard commercial
loudspeakers which have it. This type of integration is only possible when
using a main channel having very high audio gravity, which is positioned on a
virtual center of audio gravity, formed by several drivers with very low
gravity force. Each of these channels should have clear (the reverse of foggy
or blurred) but very diffused/unfocused within itself type of sound and it must not
have a focused center, because otherwise it will immediately multiply the
amount of the Cockooricones.
Another important requirement for these
surrounding channels is none of them to sound physically shallow (for example most
of the direct radiating cones sound very shallow, just like a drivers in the
air – they sound like sound efforts and not like flowing music) and it must
have depth. I mean depth as a dimensional property, not as a frequency response
depth. When you succeed to accomplish/build that type of sound, then the effect
of integration will gratify you with some audio properties you haven’t met at
the audio shows. One of those properties is the very convincing illusion of physical
density and solidity of the sound images. The sound images will became so
solid, that if you throw a stone at the sound image, when the “stone” “hits”
the “target”, it will not penetrate through the image, but will bounce back. This
is exactly the opposite effect of the ghosty sound images that most of the so
called high end systems produce. I know it is slightly stupid example, but it
is a correct example of what happens when you hit this level of integration.
So if you
want to build a serious sound in your home, one of the many many things you
should reconsider is how to use your Acapella ion driver and to spend some
5-10-30 years until you find a way how to eliminate your HF channel and to
build an upper mid channel that does not need a tweeter support to sound as there
isn’t something missing in it. Hell, I
have to stop writing – I haven’t said a word about the musical aspects, and
this is a veery deep ocean. I hope you already read the threads in the “Playback
listening” section…
"If you can't explain it simply, you don't understand it well enough." -A.E.
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