Obviously the overall response has some problems, so I thought a "highlight" of the directivity Face was getting from that waveguide would be more interesting. That's all.
Can someone explain why a speaker with waveguide in the tweeter doesn't have, what I experience subjectively as transient response or energy, like other horn types have?
Is this mostly related to the lens or something else?
This goes for all waveguide speakers I've heard and I have several at home. The largest I've heard is a 12" waveguide, never listened to a 15" or 18" size one.
Is this mostly related to the lens or something else?
This goes for all waveguide speakers I've heard and I have several at home. The largest I've heard is a 12" waveguide, never listened to a 15" or 18" size one.
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I'm not sure. I haven't been always been aware of what type of horn I've listened to.
Let me however share a few pictures of some that I've listened to. Last one is muliticell which is more appropriate for large venues and I believe the orange one (Living Voice) uses exponential with TAD driver. All of these horns have a better transient response or have more energy in my ears then a waveguide. Several of them also have resonances with the typical "horn" sound, but not all and I doubt that's the explanation.
All the horns that you show will be resonant and/or beamy, while a well designed waveguide will not. Maybe you hear this as transient response. It would not be uncommon.
I guarantee that if you looked at the actual transient response (impulse response) the resonant horns will have more ripple than the waveguide.
Yes, as we discussed earlier in this thread, and also in the "adapters" thread, there are a LOT of products sold as waveguides that are highly resonant. Without measurements to confirm the response, it's hard to know what devices suffer from perioidic ripple and other response anomalies. Some look like they would be smooth, but in truth show large peaks and dips in response.
That's really what this thread is all about. Back in the 1970s, when constant directivity horns were introduced, they all promised uniform polar response and largely achived that. But what they lost in the trade was smoothness, and tend to sound artificial. Modern waveguides can improve upon this paradigm, but I've seen some that were no better than a Mantaray. Upon casual inspection, they look like they would be smoother, but measurements prove that they are not.
That's really what this thread is all about. Back in the 1970s, when constant directivity horns were introduced, they all promised uniform polar response and largely achived that. But what they lost in the trade was smoothness, and tend to sound artificial. Modern waveguides can improve upon this paradigm, but I've seen some that were no better than a Mantaray. Upon casual inspection, they look like they would be smoother, but measurements prove that they are not.
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Wayne,
Some of those early constant directivity horns such as the EV horns and the JBL horns with sharp corner transitions were anything but smooth in a polar plot. The sharp transitions between sections were terrible and a good exponential horn just sounded much better both on and off axis. The Altec Mantaray had it all over both the EV and JBL versions in that regard.
Some of those early constant directivity horns such as the EV horns and the JBL horns with sharp corner transitions were anything but smooth in a polar plot. The sharp transitions between sections were terrible and a good exponential horn just sounded much better both on and off axis. The Altec Mantaray had it all over both the EV and JBL versions in that regard.
Exactly, that's my point. I agree with you, 100%.
Exponential horns have great acoustic loaading and sound nice, but they create a pattern with collapsing directivity. Old-school constant directivity horns generate a pattern that's uniform, but their response has a ton of ripple, and they create diffraction and therefore have astigmatism.
So to me, the grail is a waveguide/horn with the smoothness of an exponential horn and the pattern of a constant directivity horn. It isn't possible, of course, the acoustic load isn't going to be as good as an exponential because the flare profile has more in common with conical shapes. But some are better than others in this regard.
Exponential horns have great acoustic loaading and sound nice, but they create a pattern with collapsing directivity. Old-school constant directivity horns generate a pattern that's uniform, but their response has a ton of ripple, and they create diffraction and therefore have astigmatism.
So to me, the grail is a waveguide/horn with the smoothness of an exponential horn and the pattern of a constant directivity horn. It isn't possible, of course, the acoustic load isn't going to be as good as an exponential because the flare profile has more in common with conical shapes. But some are better than others in this regard.
I doubt the the horn in the bottom photo, which appears to be an 1505 or 1803, will be either resonant or beamy.
Pano,
I am not going to say that the old Altec multicell horns can't sound great, but if you look at an accurate polar plot of those at higher frequencies they are anything but very smooth. Adding all of those individual square shapes together is just what they had to work with back then with materials available. Any square horn section will have problems with the square corners that is just how it is with any square horn shape of any size. But I have heard these horns many times with old Altec and even JBL drivers sound sweet if I can just forget about the fact of what they are doing to the waveform!
ps. The bottom W bass bins look like the old RCA cabinets I moved as a youngster back in the day along with the A2's we used for PA. Brings back memories for sure.
I am not going to say that the old Altec multicell horns can't sound great, but if you look at an accurate polar plot of those at higher frequencies they are anything but very smooth. Adding all of those individual square shapes together is just what they had to work with back then with materials available. Any square horn section will have problems with the square corners that is just how it is with any square horn shape of any size. But I have heard these horns many times with old Altec and even JBL drivers sound sweet if I can just forget about the fact of what they are doing to the waveform!
ps. The bottom W bass bins look like the old RCA cabinets I moved as a youngster back in the day along with the A2's we used for PA. Brings back memories for sure.
Could be, I don't know if that's the main reason for what I'm experiencing. I think it's same as many call dynamics and I don't experience a waveguide being as great in that matter. The waveguides I've heard do sound natural and clean though.
The round horns in the pictures sounded very resonant and so do the Avantgarde Trio and Duo. The Living Voice speaker with exponential horn was much better and cleaner but lacked coherency , not suprising considering it's a four way passive speaker. If I can be honest; those super tweeters are so stupid.
The Altec speaker (from 1937-8?) with multicell horn sounded most natural of all and I couldn't detect any typical "horn" sound from the little time I listened.
Anyone that has listen to my system would certainly consider it beamy. I have round wood 350hz tractrix horns for my mids. If I move my head 6" either side of dead center, the image falls apart...... When in that head notch, the imaging is better than any other horn I've heard. That being said, anyone who has listen to my system knows that there is only one (1) chair in the listening position. I am not running a disco.
djn,
Six inches, that would drive me nuts and tell me something was really wrong about the implementation. One of the reasons that I find some of the multiple round horns randomly positioned and at large center to center distances, just doesn't make any sense at all.
Six inches, that would drive me nuts and tell me something was really wrong about the implementation. One of the reasons that I find some of the multiple round horns randomly positioned and at large center to center distances, just doesn't make any sense at all.
I would expect them to be resonant because there is a sharp mouth termination which will cause a reflection and internal standing wave. Now if each cell were a different length this might help, but that is not the case.
And of course the fact that you use these kind of horns does not bias your opinion in any way.
Until your perceptions are put into objective terms it will be impossible to define a "reason".
Earl,
If you only look at a waveform that completely forms within the length of one of these multicells or any square horns before it reaches the mouth will you still have a reversion wave or only for a partial waveform that reaches the termination of the mouth?
ps. for clarity let us say something like a 10khz wavelength or above?
If you only look at a waveform that completely forms within the length of one of these multicells or any square horns before it reaches the mouth will you still have a reversion wave or only for a partial waveform that reaches the termination of the mouth?
ps. for clarity let us say something like a 10khz wavelength or above?
All horns will have a collapsing polar. And the way you deal with it is broadband treatment to avoid colored reflected energy and live with a smaller sweetspot.
If one desires a speaker that doesn't collapse, CBT is the answer. It's the only speaker that can give a spacious "Toole" response with little coloration.
The waveform propagates no matter how short it is and it will eventually arrive at the mouth and reflect. How long the waveform is has nothing to do with the problem (unless the waveform is much much longer than the horn, in which case different things can happen.)
There are degrees of collapsing polars. And a CBT does have a collapsing horizontal polar.
I think the biggest problem with the old multicell horns is the fact they work like an array, in both horizontal and vertical planes. This is a problem at high frequencies where the cells are acoustically distant from one another. So they suffer from comb filtering.
Radials didn't have that problem and I think some of them sound really good. Smooth response and nice horizontals.
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