No, I haven't, and not entirely sure whether I want to! What I have done (so far) is run the horn through a small mixer, listening to the source on headphones and EQ-ing the horn to match. Today, I am going to dial in a Boss GE-7 guitar EQ pedal to see if I can further open the sound. Lots of choices here.
tapestryofsound
Not folklore, it's true for any driver since in the higher octaves it's just a point source in a waveguide [WG] same as a compression driver and why you want a rising on axis response driver to blend with the lower horn loaded octaves to get that life-like 'big' sound whereas with the compression driver it requires mass quantities of EQ to be ~ flat out to ~ 20 kHz.
In the end, both wind up with similar useful efficiencies, though sound nothing alike.
Note though that while most drivers are limited to < 3 octaves there are some really wide BW drivers with 'monster' motors [< ~ 0.18 Qes] that can do up to ~ 3.5 octaves.
GM
So, to answer your question, I believe the horn to be not so much 'acoustically dead' but alive and well
.Thank you GM, for correcting me about this. There are times when it can be quite difficult to sort the wheat from the chaff, and I really do appreciate when I'm pointed in the right direction. Perhaps this is why I have obtained an overall better result by using a guitar speaker driver
tapestryofsound
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You're welcome! FWIW, when I came to the audio BB's in late '96 the amount of [intentional] misunderstanding/misinformation re speaker [system] design in general and horn systems in particular was beyond defining and unfortunately most [all?] of it is still 'out there' to confuse and confound those who aren't 'practiced in the art', so when in doubt, search proven sources. The 'truth is out there'.
GM
GM
While one can successfully horn load such a high Qt, it's not practical except for OB or its horn derivative, i.e. open back, so technically a BLH and tune its 'Qness' for best overall performance via 'gapping' it to the horn throat as Bruce Edgar did on one of his early mid bass? horns.
GM
Strangely enough, I've been thinking along the lines of an open baffle for my next build. Something like a tractrix at the front with an exponential at the back - all in one piece with the driver in between. And this time around, doing plenty of quick prototypes to get me into the zone ......
tapestryofsound
It is very kind of you to say so.
I understand Colombia is famous for its lilies and orchids, and while working on my build in the depths of what was the hardest winter of a lifetime, I would often find myself comparing the horn, with its LeCleac'h curved mouth, to a summer lily. Something tells me that pollinating insects use the 3D internal echoes of their wing beats resonating from deep inside flowers to determine the quality and quantity of pollen to gather.
I think Colombia would be a very good place to build hornspeakers
tapestryofsound
Yes, that is what I meant to say, only you said it better than I did. Part of me naturally wants to blur the boundaries, and if I can see it within these minds eye, then there is no stopping me. Anyways, it's hard to know or quite understand when and where an open baffle, as a concept, begins and ends ......
tapestryofsound
I am now seriously thinking of fitting an Alpair 10 M/P to my horn speaker build. With some hand built shims and gaskets, I reckon it would be possible to use the existing cabinet and compression chamber.
But first, I need to know a few things before I finally jump in, and hope to get some help here.
The X-max of 7.5mm - does the cone move forward of the bezel? - I don't want it hitting the far wall of the compression chamber.
My speaker lives in my workshop in a barn hayloft. The temperature range is between -15C in winter and +40C in summer. The humidity during the winter runs anywhere between 0 and 100%. My question is that I imagine the Alpair 10 is made to very fine tolerances, and would heat (with expansion) or coldness (and contraction) affect the mechanical operation of the unit? Would either the metal or paper cone(s) handle such extremes equally well?
To be honest, I am not entirely sure a metal cone would be sonically suitable for a front loaded horn, but I am open to suggestion.
The rubber gasket - is it in front or behind the speaker frame? If it is behind, I could hold the Alpair in the compression chamber well with a succinct amount of uniform pressure without the use of bolts or screws.
Yes, lots of questions, but it is very isolated here
Kindness tapestryofsound
But first, I need to know a few things before I finally jump in, and hope to get some help here.
The X-max of 7.5mm - does the cone move forward of the bezel? - I don't want it hitting the far wall of the compression chamber.
My speaker lives in my workshop in a barn hayloft. The temperature range is between -15C in winter and +40C in summer. The humidity during the winter runs anywhere between 0 and 100%. My question is that I imagine the Alpair 10 is made to very fine tolerances, and would heat (with expansion) or coldness (and contraction) affect the mechanical operation of the unit? Would either the metal or paper cone(s) handle such extremes equally well?
To be honest, I am not entirely sure a metal cone would be sonically suitable for a front loaded horn, but I am open to suggestion.
The rubber gasket - is it in front or behind the speaker frame? If it is behind, I could hold the Alpair in the compression chamber well with a succinct amount of uniform pressure without the use of bolts or screws.
Yes, lots of questions, but it is very isolated here
Kindness tapestryofsound
If you are really pushine things. I can check, but the stationary cone is pretty much flush with the bezel. The extra decorative bezel cover adds about 1.5mm to the bezel.
That is a question for Mark, probably easiest to get a hold of him thru Scott (Woden). AFAIK Mark is currently in te UK. I would expect that the extremes of that range might be problematic, the cold worse than the warm.
We treat all our paper cones, so they are less susceptable to humidity, but the metal would be totally immune.
The meta i would think would provide a better balance at the top as the horn unloads, the paper has a vinatge (rolled off a bit) top.
Self stick gaskets are fitted to the back of the bezel, in a design inspired by the ones that failed in the disastrous shuttle launch, soft rubber with a pair of ridges.
dave
Thank you for all of that, Dave - very useful information.
There is enough redundancy in my design to add another 3-5mm extension of the compression chamber by the use of a solid card gasket.
And maybe a metal cone would be better all round, after all! Winter mould growing on finger prints is a real problem here.
A winter workaround would be keep the batteries warm in the house, and take them down to the barn for playback, and to run the speaker on low power until it warms up and expands .........,, but that wouldn't help if the voice coil was locked solid with the cold before power on, would it?
Mark would know the answer to that one
tapestryofsound
There is enough redundancy in my design to add another 3-5mm extension of the compression chamber by the use of a solid card gasket.
And maybe a metal cone would be better all round, after all! Winter mould growing on finger prints is a real problem here.
A winter workaround would be keep the batteries warm in the house, and take them down to the barn for playback, and to run the speaker on low power until it warms up and expands .........,, but that wouldn't help if the voice coil was locked solid with the cold before power on, would it?
Mark would know the answer to that one
tapestryofsound
I took a long hard look at an Alpair 10M in action on YouTube. The X-Max is so great that I can forsee potential problems ahead inside my horn's compression chamber. The sound would be too congested within such a confined space to sound at all musical. I am not the kind of person to compromise.
So, I have decided that if I do eventually go ahead with using an Alpair 10M, it would have to be in a horn designed from the ground up and around what I see is a very carefully designed and engineered driver - I respect that.
In the meantime, what I have is a front loaded horn built and designed around a Jensen 6.5in guitar speaker. It may not be truly audiophile (whatever!) but it is intensely musical and very rewarding to listen to. My next project is to build a supplementary horn woofer to compliment and round out the lower bass from the horn - all in glorious mono. When sitting in front of what is a magnificent cascade of sound cascading from a 4ft wide horn, I do not even think about stereo.
Bye for now
tapestryofsound
So, I have decided that if I do eventually go ahead with using an Alpair 10M, it would have to be in a horn designed from the ground up and around what I see is a very carefully designed and engineered driver - I respect that.
In the meantime, what I have is a front loaded horn built and designed around a Jensen 6.5in guitar speaker. It may not be truly audiophile (whatever!) but it is intensely musical and very rewarding to listen to. My next project is to build a supplementary horn woofer to compliment and round out the lower bass from the horn - all in glorious mono. When sitting in front of what is a magnificent cascade of sound cascading from a 4ft wide horn, I do not even think about stereo.
Bye for now
tapestryofsound
I started my build just over a year ago, and after 8 months it was finished. I had only a vague idea of what was actually accomplished as an act of blind faith, and so I began to listen to this massive creation in a state of awe. After 4 months of listening trials, this is what there is to say.
It is very driver dependent. I first tried a 6.5in Visaton BG17 which has a whizzer cone. It was far too bright, and beamed horribly as if the whizzer cone structure was being reproduced as an aural hologram suspended inside the horn tunnel. It hurt the ears so much, I deduced that this type of driver is not entirely suited to housing inside a compression chamber.
My next driver was an entry level Jensen 15 watt ceramic guitar speaker. At first it seemed excellent .......... for about 2 months ......... before I realised that on complex musical passages there was a pocket of harshness that would appear in the upper mid range. Try as I might, I could not level it out either by a 7 point band EQ, or a 2 point parametric EQ. It was good, but not quite good enough to disregard. So it had to go, too.
At 6.5in, there is not much out there in terms of driver choice. I did consider the Alpair 10p, but it meant designing and building a new horn entirely. Eventually, I discovered that Jensen make a range of alnico guitar speakers, and the smallest one would fit. So I got one!
I figured that the alnico magnet would soak up the harshness, and I was right. From the moment I fired it up it sounded good. This is not an audiophile horn speaker as such. Most of my listening is at 8 feet from the cone in a seat just 5 feet away from the mouth. At 4 ft across, it's a big kisser. Shut my eyes and the music is all there, both inside and outside my head. The bass, mids, and treble form together a series of concentric rings of sound that transit smoothly from one to the other - the beaming all but gone. When it all gets too complex, the alnico acts like a doughnut shaped spring that feeds any distortion into the tunnel walls without any undue fatigue on the ear. It is still breaking in, with a long way to go, but I am confident this is the one.
As a first build, I am very pleased with the result. Not perfect, but very more-ish, and if I'm not careful, hours just seem to slip by.
◦
It is very driver dependent. I first tried a 6.5in Visaton BG17 which has a whizzer cone. It was far too bright, and beamed horribly as if the whizzer cone structure was being reproduced as an aural hologram suspended inside the horn tunnel. It hurt the ears so much, I deduced that this type of driver is not entirely suited to housing inside a compression chamber.
My next driver was an entry level Jensen 15 watt ceramic guitar speaker. At first it seemed excellent .......... for about 2 months ......... before I realised that on complex musical passages there was a pocket of harshness that would appear in the upper mid range. Try as I might, I could not level it out either by a 7 point band EQ, or a 2 point parametric EQ. It was good, but not quite good enough to disregard. So it had to go, too.
At 6.5in, there is not much out there in terms of driver choice. I did consider the Alpair 10p, but it meant designing and building a new horn entirely. Eventually, I discovered that Jensen make a range of alnico guitar speakers, and the smallest one would fit. So I got one!
I figured that the alnico magnet would soak up the harshness, and I was right. From the moment I fired it up it sounded good. This is not an audiophile horn speaker as such. Most of my listening is at 8 feet from the cone in a seat just 5 feet away from the mouth. At 4 ft across, it's a big kisser. Shut my eyes and the music is all there, both inside and outside my head. The bass, mids, and treble form together a series of concentric rings of sound that transit smoothly from one to the other - the beaming all but gone. When it all gets too complex, the alnico acts like a doughnut shaped spring that feeds any distortion into the tunnel walls without any undue fatigue on the ear. It is still breaking in, with a long way to go, but I am confident this is the one.
As a first build, I am very pleased with the result. Not perfect, but very more-ish, and if I'm not careful, hours just seem to slip by.
◦
FWIW, my understanding is that it's an OB until it's folded up enough to acoustically load it within its pass-band [Fhm = 2*Fs/Qts'], so must be pretty big to load a high Qts' driver even once the room's boundaries are accounted for.
Qts' = Qts + any added series resistance: mh-audio.nl - Home
GM
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