Re: The correct sound
Konnichiwa,
If you are talking midrange/treble, completely agreed.
Where LF is concerend, that is another story.
I once compared the RT60 measurements of pressure mode transducers (various) with Dipole Woofer transducers, in similar rooms. All presure mode systems (including domestic horns, even large examples of this) showed an increase of the RT60 with lowering frequency and severe room modes putting bumps into the RT60. EXCEPT the dipole, which showed a nearly flat RT60 below around 1KHz (RT60 reduced above that) and was flat enough in room in terms of requency response.
The very substantial increase in reverb time at low frequencies is what gives most speakers their unnatural low frequency sound. Of course, many have learned to regard this effect in reproduced music as being "the correct sound", that cannot be helped.
As I grew up with large Valve Radios, which are in effect dipoles I never learned to regard the common Bass Bloat as "good sound" so for me the cookie crumbles the other way.
BTW, if a horn is LARGE ENOUGH it will also show excellent pattern control and will be very desirable, except of course for it's size.
Sayonara
Konnichiwa,
Coolin said:
If you are talking midrange/treble, completely agreed.
Where LF is concerend, that is another story.
I once compared the RT60 measurements of pressure mode transducers (various) with Dipole Woofer transducers, in similar rooms. All presure mode systems (including domestic horns, even large examples of this) showed an increase of the RT60 with lowering frequency and severe room modes putting bumps into the RT60. EXCEPT the dipole, which showed a nearly flat RT60 below around 1KHz (RT60 reduced above that) and was flat enough in room in terms of requency response.
The very substantial increase in reverb time at low frequencies is what gives most speakers their unnatural low frequency sound. Of course, many have learned to regard this effect in reproduced music as being "the correct sound", that cannot be helped.
As I grew up with large Valve Radios, which are in effect dipoles I never learned to regard the common Bass Bloat as "good sound" so for me the cookie crumbles the other way.
BTW, if a horn is LARGE ENOUGH it will also show excellent pattern control and will be very desirable, except of course for it's size.
Sayonara
Magnetar and Coolin,
Have either of you put your well executed dipoles side by side with a good horn to listen to which has a more realistic sound especially in the vocals? My system doubles as home theater, so I want vocals and dialogue to sound like a real person is there. I've done the comparison with boxes and dipoles and it's really no comparison, so I'm boxless. Are you saying that horns can take me a step further?
Have either of you put your well executed dipoles side by side with a good horn to listen to which has a more realistic sound especially in the vocals? My system doubles as home theater, so I want vocals and dialogue to sound like a real person is there. I've done the comparison with boxes and dipoles and it's really no comparison, so I'm boxless. Are you saying that horns can take me a step further?
johninCR said:
Not really side by side - not enough room .
It takes much more work to get a horn to really "beat all" then
most people want to put in to it. Articulation and inner detail
is beyond good electrostats and dynamics, tone and "they
are here" realism can be scary - !
So my answer is YES , with many, many buts. You need to really
get out and hear a good horn system and look at the different
options and the complexity of building it before you let the sawdust fly.
A bad horn speaker can sound awful. And really good one's are
rare birds on the brink of extinction -- I'm in NE Ohio if you want to hear mine.
nothing more than a logic proof.
Most recordings have enviormental sound (reflected/reverberent sound), EVEN if its artificial (and many of the artificial enviorments are quite sophisticated).
So if a recording has this information and the playback system is unable to put you at the location of the performance then something is wrong with the playback (and most probably with the speaker/room interface). (of course because the recording acts like a mirror the perspective will still be skewed, though this is a function of the source whereas the other is a function of the playback mechanism.)
Fairly easy, No?
This of course doesn't mean that your system provides other traits that more realistically recreate the signal where other, (and probably most other), systems fall short.
Most recordings have enviormental sound (reflected/reverberent sound), EVEN if its artificial (and many of the artificial enviorments are quite sophisticated).
So if a recording has this information and the playback system is unable to put you at the location of the performance then something is wrong with the playback (and most probably with the speaker/room interface). (of course because the recording acts like a mirror the perspective will still be skewed, though this is a function of the source whereas the other is a function of the playback mechanism.)
Fairly easy, No?
This of course doesn't mean that your system provides other traits that more realistically recreate the signal where other, (and probably most other), systems fall short.
comparing
I did not compare directly no but i have no doubt at all.
I must say this is related to my earlier comments about disliking the sound out of phase from the rear. And this was already with a baffle of about 2.5wide and 4 feet high. the tweeter was not placed optimally so it was a "breadboarded" design. There was no EQ but also not a real lack of bass when positioning them together to create a larger baffle. So stereo was partly lost but still no slam.
I think the sole reason for this improved "slamming" with horns is that the air is being held firmer in place while being slammed by the drivers. I think its that simple. Thus not only microdynamics but also the macrodynamics are conveyed to the air.
I have not heard better than what i have now, but i have never heard other horns for home use.
Mine sound pretty darn realistic. They indeed sound like You are there and not They are here.....
Magnetar,
If you listen to a good recording in a real acoustic setting do you feel like the performers are in the room but the recording hall is kind of left out (faded out of notice) ofcourse you can hear it but is it seperated from the performers in such a way that your inclined to say that you are not present where they are making the recording?
Indeed, you must think out the enclosure to get near that boxless sound.
Coolin
I did not compare directly no but i have no doubt at all.
I must say this is related to my earlier comments about disliking the sound out of phase from the rear. And this was already with a baffle of about 2.5wide and 4 feet high. the tweeter was not placed optimally so it was a "breadboarded" design. There was no EQ but also not a real lack of bass when positioning them together to create a larger baffle. So stereo was partly lost but still no slam.
I think the sole reason for this improved "slamming" with horns is that the air is being held firmer in place while being slammed by the drivers. I think its that simple. Thus not only microdynamics but also the macrodynamics are conveyed to the air.
I have not heard better than what i have now, but i have never heard other horns for home use.
Mine sound pretty darn realistic. They indeed sound like You are there and not They are here.....
Magnetar,
If you listen to a good recording in a real acoustic setting do you feel like the performers are in the room but the recording hall is kind of left out (faded out of notice) ofcourse you can hear it but is it seperated from the performers in such a way that your inclined to say that you are not present where they are making the recording?
Indeed, you must think out the enclosure to get near that boxless sound.
Coolin
Re: comparing
That's the thing, I want that boxless sound not "near" it. Without comparing side by side you can't hear the difference. I thought my boxes sounded pretty good until I put them next to my first simple OB's. That's why Bose is so successful, they avoid side by side comparison. If space is the problem, just set each up right and left.
Coolin said:
That's the thing, I want that boxless sound not "near" it. Without comparing side by side you can't hear the difference. I thought my boxes sounded pretty good until I put them next to my first simple OB's. That's why Bose is so successful, they avoid side by side comparison. If space is the problem, just set each up right and left.
This whole "you are there" vs "they are here" argument is a bit silly. It depends on the recording. Classical music recorded with spaced omnis over the conductor will be "you are there". Close miked rock, jazz or whatever - or nearby ORTF or Jecklin disk - should sound like "they are here". Either way, a well executed horn system can do this most convincingly IME.
Greg B
Greg B
Kuei - perhaps the term "infrawoofer" would be more appropriate, since infrared waves are among the longest in the electromagnetic spectrum (microwaves and radio waves are longer, but their names aren't quite appropriate).
http://www.gen.umn.edu/faculty_staff/jensen/1135/med_term_activites/Prefix_medium_list.htm
This sight says infra- (prefix) means under or below; super- is over or above.
http://www.gen.umn.edu/faculty_staff/jensen/1135/med_term_activites/Prefix_medium_list.htm
This sight says infra- (prefix) means under or below; super- is over or above.
I've just been looking back through this thread, and there are a few things I'd like to bring up again ...
1. room interaction ...
It seems that bass dipoles handle room modes better. This is a clear advantage. However there is the suggestion that this is only in small or medium sized rooms. How exactly is this different in large rooms?
Someone seemed to suggest that horns are designed to work with room modes. Can anyone elaborate on this and whether or not it may be helpful in the fidelity department?
2. Distortion
It's not clear how much horns really reduce distortion.
It's also not established whether or not this difference can be perceived.
What is important with distortion, it not the quantity as indicated by %THD but the nature of the distortion itself. There is current research which indicates this carried out by Dr Earl Geddes, which is shown on his website
3. Transient response and dynamics
It seems that dipoles have a good transient response due to the fact that they don't pressurise the air inside a box. Is this true?
What is it about horns that make them more dynamic? Is it that they have such a huge amount of output to draw on to hit transients? Could the same thing be achieved with a sufficiently large dipole?
4. Detail
Some have mentioned that horns have more detail ... how is this so? Can anyone elaborate a little more?
One more question about horns ... is the noise level of the amp a problem? Suppose you had the volume turned up say in a movie, in quiet moments is noise a problem, since the efficiency is so much higher?
1. room interaction ...
It seems that bass dipoles handle room modes better. This is a clear advantage. However there is the suggestion that this is only in small or medium sized rooms. How exactly is this different in large rooms?
Someone seemed to suggest that horns are designed to work with room modes. Can anyone elaborate on this and whether or not it may be helpful in the fidelity department?
2. Distortion
It's not clear how much horns really reduce distortion.
It's also not established whether or not this difference can be perceived.
What is important with distortion, it not the quantity as indicated by %THD but the nature of the distortion itself. There is current research which indicates this carried out by Dr Earl Geddes, which is shown on his website
3. Transient response and dynamics
It seems that dipoles have a good transient response due to the fact that they don't pressurise the air inside a box. Is this true?
What is it about horns that make them more dynamic? Is it that they have such a huge amount of output to draw on to hit transients? Could the same thing be achieved with a sufficiently large dipole?
4. Detail
Some have mentioned that horns have more detail ... how is this so? Can anyone elaborate a little more?
One more question about horns ... is the noise level of the amp a problem? Suppose you had the volume turned up say in a movie, in quiet moments is noise a problem, since the efficiency is so much higher?
Good question, I've always heard that sealed bass box is the best for transient response, when cone move forward it makes a depression in the box wich call back the cone so in a sealed box, cone is helped by the box to come back to the 0 point.
In free air, (I may be wrong) we can think that transient response only depends of driver and power amp and surely be better than any system based on resonance (ported, bandpass etc.) but still not as good as sealed enclosure...
I'm want to build my new 3-way loudspeaker and considering every options, I've heard the Orion from linkwitz and it sound greats, the "no box sound" is a real pleasure, linkwitz told me to forget Orion (and dipole) due to the fact that I can't place it far from the wall, dipole works well when far from wall, it means some time in the center of the room wich is not a good option for my wife
Reading this thread, I'm now thinking that it's true that adding a rear source in midrange have drawbacks like adding a source that does not exists in the record so dipole and open baffled are not "high fidelity" ?
Maybe true in midrange but for bass between 40 and 150 Hz, we may consider that room interraction is already so important that dipole can be the better option.
For midrange, there's room to improve box, a well build box don't have any "box sound", I used to build sealed midrange box with success, and I'm considering the sealed option for a good bass response, today DSP are cheap like power amp, drivers can manage lots of watt, so for a domestic use, using multi amplification sealed box may comme back
OK, I'll make an attempt.
1. Room interaction.
Dipole output means, that front and back radiation of the driver will interact. Below a certain frequency, related to baffle size, this interaction will mean increasing cancellation of the output at 90 degrees off axis. This cancellation will manifest itself as an increasing loss in bass at 6 dB/octave. To maintain on axis output flat, there needs to be some kind of electronic EQ (Siegfried Linkwit's approach), or some well adjusted use of baffle size, room interaction, and driver resonance (say, KYW's approach). The end result will be, flat on-axis response, and well behaved constant directivity index off axis in a figure of eight pattern: full output on axis, -6 dB down at 45 degrees.
For the power spectrum this means, after equalisation, that the total bass power output is on average 4.8 dB less than the output from a direct radiator (the direct radiator will be omnidirectional in the bass region).
Above the frequency where cancellation starts in the bass, on-axis output will actually alternately cancel or double the on axis output (midrange frequency). In theory this would mean, comb filtering. In practice, due to irregular baffle size and other effects, this will just lead to a smooth stabilization at +6dB output. In other words your driver just became *more* efficient in the mids. The same off axis power as in the bass is retained.
The single biggest advantage of bass and mid dipoles is the constant power vs. frequency output. Most other systems are flat only on axis and do not have constant directivity. Therefore the off axis power which interacts with the room, is usually boncentrated in the bass. Even *without* any strong room modes, that means the total power radiated in the room by a dipole will be much more flat vs. frequency, than that of direct radiators.
The second advantage of a dipole, in the bass, is that off axis power output is 4.8 dB less than that of a direct radiator. This is the main reasonb for the decreased effect of room modes. About the velocity vs pressure thing, I am not sure how and where that comes into effect. To my understanding the main effect comes from the decreased off axis output.
2. Horns and distortion
Horns are impedance transformers and make driver to air coupling more efficient. They also increase directivity, which gains again some afficiency. Therefore both excursion related distortion and amp related distortion are decreases. This usually means decreased harmonic (nonlinear) distortion.
On the other hand, real horns store energy (linear distortion). This means resonances and this influences transient response. Proper construction and/or EQ can control this problem, but I suspect that area is the main challenge with good horn construction.
3. Dynamics
I am somehwat at a loss here. Real dynamics can/could be measured. But usually dynamics are discussed as *perceived* dynamics, and here any effects could interefere: for instance actual dynamics could be the same, but perceived dynamics could be lower for some system due to smeared transients. Or perceived dynamics could be higher, due to overshoot on transients. Both effects would be unnatural, yeat not really related to dynamics per se.
For horns, the advantage is in high efficiency, so there is a good chance a horn will be physically capable to actually deliver a peak while a dipole may have a problem. Proper design and output capability calculations show that dipoles can compete in this area - but it is an area where the horn has it a lot easier to reach the target.
4. Detail
Here, things get even murkier. Perveived detail may actually be graininess, or may come from frequency anomalies (drivers with a hump in the 2-4 kHz range often sound more "detailed", that seems to be the case with Lowthers apparently, but if you EQ the hump out, they become ordinary...).
1. Room interaction.
Dipole output means, that front and back radiation of the driver will interact. Below a certain frequency, related to baffle size, this interaction will mean increasing cancellation of the output at 90 degrees off axis. This cancellation will manifest itself as an increasing loss in bass at 6 dB/octave. To maintain on axis output flat, there needs to be some kind of electronic EQ (Siegfried Linkwit's approach), or some well adjusted use of baffle size, room interaction, and driver resonance (say, KYW's approach). The end result will be, flat on-axis response, and well behaved constant directivity index off axis in a figure of eight pattern: full output on axis, -6 dB down at 45 degrees.
For the power spectrum this means, after equalisation, that the total bass power output is on average 4.8 dB less than the output from a direct radiator (the direct radiator will be omnidirectional in the bass region).
Above the frequency where cancellation starts in the bass, on-axis output will actually alternately cancel or double the on axis output (midrange frequency). In theory this would mean, comb filtering. In practice, due to irregular baffle size and other effects, this will just lead to a smooth stabilization at +6dB output. In other words your driver just became *more* efficient in the mids. The same off axis power as in the bass is retained.
The single biggest advantage of bass and mid dipoles is the constant power vs. frequency output. Most other systems are flat only on axis and do not have constant directivity. Therefore the off axis power which interacts with the room, is usually boncentrated in the bass. Even *without* any strong room modes, that means the total power radiated in the room by a dipole will be much more flat vs. frequency, than that of direct radiators.
The second advantage of a dipole, in the bass, is that off axis power output is 4.8 dB less than that of a direct radiator. This is the main reasonb for the decreased effect of room modes. About the velocity vs pressure thing, I am not sure how and where that comes into effect. To my understanding the main effect comes from the decreased off axis output.
2. Horns and distortion
Horns are impedance transformers and make driver to air coupling more efficient. They also increase directivity, which gains again some afficiency. Therefore both excursion related distortion and amp related distortion are decreases. This usually means decreased harmonic (nonlinear) distortion.
On the other hand, real horns store energy (linear distortion). This means resonances and this influences transient response. Proper construction and/or EQ can control this problem, but I suspect that area is the main challenge with good horn construction.
3. Dynamics
I am somehwat at a loss here. Real dynamics can/could be measured. But usually dynamics are discussed as *perceived* dynamics, and here any effects could interefere: for instance actual dynamics could be the same, but perceived dynamics could be lower for some system due to smeared transients. Or perceived dynamics could be higher, due to overshoot on transients. Both effects would be unnatural, yeat not really related to dynamics per se.
For horns, the advantage is in high efficiency, so there is a good chance a horn will be physically capable to actually deliver a peak while a dipole may have a problem. Proper design and output capability calculations show that dipoles can compete in this area - but it is an area where the horn has it a lot easier to reach the target.
4. Detail
Here, things get even murkier. Perveived detail may actually be graininess, or may come from frequency anomalies (drivers with a hump in the 2-4 kHz range often sound more "detailed", that seems to be the case with Lowthers apparently, but if you EQ the hump out, they become ordinary...).
Konnichiwa,
The larger the room the lower the room mode frequencies. If the room is large enough most modes will fall below the musical usefull range and in areas where getting substantiative output from either dipole or horn becomes difficult.
As a rule, the larger the room the less the problems with room modes and hence the somewhat disingenious argument by some in the HiFi Press that big speakers need big rooms, because the small rooms"cannot sustain bass", what actually happens is that the room modes bump up the Midbass and make it "one note" which makes the lower bass output less audible. Correct for room modes though and all is well in a small room.
Horns are not "Designed" to work with room modes, i pointed out that common "domestic" Horns are NOT directional at low frequencies and if they are then placed in the corner they will maximally couple to all room modes, just as a sealed/reflex box in the corner would. And in the fidelity department the results are (obviously) disasterous.
Yes, the transient (and step) response of a correctly arranged dipole is as close as possible to "ideal". Any other Enclosure system introduces compression of the peak and a less clean decay.
You mean besides their ability to reach a higher SPL at a given frequency using THE SAME DRIVER (and numbers) as a Dipole?
The perception of dynamics in an interesting field. I have found that a sufficiently SPL capable dipole usually competes with horns on the dynamics front. However this usually means both a large structure and many large drivers.
I would say that we are again dealing with perception here and no, horns do not automatically have more detail.
The Amplification chain noise level is always a problem. Obviously, if the sensitivity of the speaker increases by 20db the background noise from the Amplifier will be 20db higher.
It is quite trivial to build Amplifiers (even Valve ones) with >> 90db S/N Ratio at 1 Watt which with most high sensitivity speakers will be quiet at the listening position.
However, high sensitivity is not an inherent and exclusive property of horns.
Sayonara
paulspencer said:
The larger the room the lower the room mode frequencies. If the room is large enough most modes will fall below the musical usefull range and in areas where getting substantiative output from either dipole or horn becomes difficult.
As a rule, the larger the room the less the problems with room modes and hence the somewhat disingenious argument by some in the HiFi Press that big speakers need big rooms, because the small rooms"cannot sustain bass", what actually happens is that the room modes bump up the Midbass and make it "one note" which makes the lower bass output less audible. Correct for room modes though and all is well in a small room.
paulspencer said:
Horns are not "Designed" to work with room modes, i pointed out that common "domestic" Horns are NOT directional at low frequencies and if they are then placed in the corner they will maximally couple to all room modes, just as a sealed/reflex box in the corner would. And in the fidelity department the results are (obviously) disasterous.
paulspencer said:
Yes, the transient (and step) response of a correctly arranged dipole is as close as possible to "ideal". Any other Enclosure system introduces compression of the peak and a less clean decay.
An externally hosted image should be here but it was not working when we last tested it.
paulspencer said:
You mean besides their ability to reach a higher SPL at a given frequency using THE SAME DRIVER (and numbers) as a Dipole?
The perception of dynamics in an interesting field. I have found that a sufficiently SPL capable dipole usually competes with horns on the dynamics front. However this usually means both a large structure and many large drivers.
paulspencer said:
I would say that we are again dealing with perception here and no, horns do not automatically have more detail.
paulspencer said:
The Amplification chain noise level is always a problem. Obviously, if the sensitivity of the speaker increases by 20db the background noise from the Amplifier will be 20db higher.
It is quite trivial to build Amplifiers (even Valve ones) with >> 90db S/N Ratio at 1 Watt which with most high sensitivity speakers will be quiet at the listening position.
However, high sensitivity is not an inherent and exclusive property of horns.
Sayonara
MBK said:
Quite a well described attempt
MBK said:
I have not heard this, but it makes sense.
The voice of reason re-enters the discussion ...
The problem with midbass being exaggerated is for small rooms, correct?
There is a room where the Melbourne Audio Club meets, and I'm not sure I understand why, but it is a terrible room for bass. It is large enough to seat perhaps 200, the rear wall is all glass with a heavy curtain in front, the floor is carpet and the side walls are brick. The ceiling is high, as in 4 or 5 m. The bass is terrible. Tiny speakers sound as if they have a lot of bass, and larger speakers which would normally be fine have boomy bass. Any idea why this might be the case?
So how should a horn be designed in a room for maximum fidelity? Suppose it were integrated into the construction of the room and the room was large.
Now this is what we need to see more of in discussions like this! Some actual real information to look at which goes beyond the subjective and seeks the reason behind what you hear ...
What is challenging is to actually determine which after the dipole is best. At first the large horn appears the next best. But then the large sealed enclosure has a better attack, and I suspect psychoacoustics would indicate that the less accurate decay would be masked to some extent by the sharp transient peak.
I would say based on the transient response that dipoles of the same SPL capability would be more dynamic than horns, as horns still compress the peak slightly.
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