I find it quite amusing to read a post from you talking about transparency, honesty, and ethics. I wouldn’t begin to enjoin you in a discussion about your feelings. However, there is a transparency to your posts - one that I doubt you will ever see. Some customers have such unrealistic expectations, and are so high-maintenance, that they should be avoided like the Plague.
I know, that you know, that I know, that you don’t know that you don’t know.
Your crossover is too low. Try 400Hz. Use one of your TD18 drivers for the bass facing forward. Or, use both TD18’s in MTM, or side-by-side like in the JBL Everest setup. My preference would be for one TD18 below the horn, which suits a monitor application.
I know, that you know, that I know, that you don’t know that you don’t know.
Your crossover is too low. Try 400Hz. Use one of your TD18 drivers for the bass facing forward. Or, use both TD18’s in MTM, or side-by-side like in the JBL Everest setup. My preference would be for one TD18 below the horn, which suits a monitor application.
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Paul... I agreed to a price... and later was told they wanted more money... are you suggesting that I am being unreasonable, having impossible expectations and consequently this is my fault???? I told them 150hz horn for a specific amount of money... they agreed along with the requirement to purchase immediately... looking back, that was a red flag. Yes I have the proof
Your speculation on the loudspeaker is of sound mind...
But I know, that you know, that I know, that you really don't know....
Youve never used or heard or measured an Axi2050 on a horn as large as mine, in your life.
Your speculation on the loudspeaker is of sound mind...
But I know, that you know, that I know, that you really don't know....
Youve never used or heard or measured an Axi2050 on a horn as large as mine, in your life.
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Your Axi2050 is not built to use a 200Hz crossover. Try using some the manufacturer's and professional's advice. The Jubilee uses it to 400Hz. I've heard them online and they sound like a giant set of headphones. 400 Hz is a very reasonable limit. Obviously you can't currently experiment with a 400Hz crossover because your woofer cabs won't allow it.
Build a test cab with some of that cheaper patched up plywood.
A c-c spacing of 34", crossover at 400Hz, with a front firing TD18, might just be the ticket.
Build a test cab with some of that cheaper patched up plywood.
A c-c spacing of 34", crossover at 400Hz, with a front firing TD18, might just be the ticket.
I assume that you are talking about woofers. Woofers tend to have a fixed efficiency/bandwidth product, meaning that increased bandwidth comes at the sake of efficiency. There is no way around this. As long as the driver stays within it's Xmax (assuming this is spec'd correctly) then excursion is not an issue in this regard. I know that you (and others) believe that as displacement goes up so does "distortion" and hence lower sound quality, but there is no evidence that this is correct, and I highly doubt that it is.
Nonsense! My waveguides cannot be seen and its clear that how they look has nothing to do with how well they perform acoustically.
I was thinking the Axi2050... we've talked about a lot of things I just don't offhand recall ever discussing with you your thoughts on bandwidth versus any driver outside of the context of the limitation having to do with excursion
This is the information that I was looking for and I am sure that this train to thought applies to the axi just as much as it does to a dynamic woofer. I am but a humble student and I entertain the thoughts within this thread in particularly yours with high regard
So I also believe that within xmax, a large bandwidth is possible. This is why I tried to monitor THD directly at the source it is the only metric that I have to try and gauge how much excursion is happening. If I go off of my horn simulation where I've tried to re-create a horn with a similar cut off as my own measurements... I am within xmax
This is the information that I was looking for and I am sure that this train to thought applies to the axi just as much as it does to a dynamic woofer. I am but a humble student and I entertain the thoughts within this thread in particularly yours with high regard
So I also believe that within xmax, a large bandwidth is possible. This is why I tried to monitor THD directly at the source it is the only metric that I have to try and gauge how much excursion is happening. If I go off of my horn simulation where I've tried to re-create a horn with a similar cut off as my own measurements... I am within xmax
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This happens all the time and I seriously doubt that it is illegal in your country or any other. People have a right to voice their concerns when they feel maltreated. I have been on the receiving end of these kind of things many times. It made me be more careful with how I dealt with clients even though I felt that I was the one who was maltreated.
Clearly there was bad communication and everyone here knows how difficult Camplo can be, but there is nothing wrong with his complaining about how he was treated. Personally, I would never hold someone to a promise that they made that they now wish they hadn't - they will always return the favor somehow (as Camplo has found out.)
Then I don't understand the question. I would never try and push any transducer beyond about a decade because that seems to be the limit at which problems begin to occur and tradeoffs have to be made. In my experience compression drivers all have the same limitations regardless of size. Bigger go lower, but then not higher. Smaller drivers go higher, it's a tradeoff. Bigger will have a higher power rating - if you need that. In a home it is never a limitation.
Why are you the only person in conversation about this that actually gets it... I get it.. you get it... it must be the PhD
Do you know that they told me that I talked them into a price that they could not deliver on!!!! I told them I have this much to spend that if they couldn't produce the product at that price that I was walking away!!! Almost a month later they said "I let you talk me into a non relistic pricing" 😫 all I could think was please don't steal my money.
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Together I interpret these two comments to say that looking at your chosen tweeter that you stay within Xmax and that is all. With your chosen tweeter you can make it about a decade before you are pushing the driver outside of Xmax...
At this point in time my own personal experience supports these sentiments. What is very interesting to me is that you are the one professional that speaks on thd/imd and excursion in such a way and when you do so no one dares contest.
If I repeat your thoughts in my own words outside of your presence I received much flack 😏
I too am under the impression that I am staying within xmax with my axi2050 crossed at 200hz. This is likely the reason why I do not perceive any degradation in sound quality nor is there any shown that I can discern in the measurements.
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Professional - " Moreover, the driver is rated for 150W down to 300Hz, and the diaphragm is large, so for domestic use, using it down to 100Hz or even lower would not be a problem. " Isn't Kolbrek that guy who is highly respected in the community who wrote this highly respected book?Your Axi2050 is not built to use a 200Hz crossover. Try using some the manufacturer's and professional's advice. The Jubilee uses it to 400Hz. I've heard them online and they sound like a giant set of headphones. 400 Hz is a very reasonable limit. Obviously you can't currently experiment with a 400Hz crossover because your woofer cabs won't allow it.
Build a test cab with some of that cheaper patched up plywood.
A c-c spacing of 34", crossover at 400Hz, with a front firing TD18, might just be the ticket.
Why do you guys keep ignoring the 15" driver I have, yes, I did try a 400hz crossover., and a 600hz, etc... At that time I concluded that 200hz sounded the best. I also compared the 15" to the dual 18"s and concluded the only difference was that the 18"s had more LF extension. I tried tone burst in the area that the slot should be acoustically loaded, and there was no notable difference between the 15" and slot loaded woofers that I recall.
I would like to try a MTM with a Constant Directivity Waveguide. I will likely, try it, one day.
With current setup there are advantages. Having the Woofer at the floor, (I flipped the PPSL cabinet as seen in the above) provides the best FR, in an untreated room, that is, outside of soffit mounting which puts the woofer, so much at the floor it is in the floor.... Covering down to 200hz on a single axis, provides incredible imaging, the vocals only break single Axis Character, on the most extreme Material, ie Barry White
OK!? Barry broke the Facade, otherwise, the majority of vocals sound as if coming from a single axis, when the Horn is crossed over at 200hz at 36" inches.... At a distance farther than 54" this was not possible with a 300hz or higher XO. I started at 600hz, and kept going lower and was like yeah I still prefer 200hz xo. with just 2 acoustical axi's to recombine, and at such a low frequency, a seamless crossover, is very easy to achieve.Constant directivity I have not. I do have a very smooth off axis transition. Like super smooth. I cannot show you in measurements until I take them. but look at the polar of the FaitalproLTH142 elliptical tractrix, and consider that is easier for my horn to have a smooth off axis transition because the larger dimensions are more forgiving.
I only sit in the window, which is much bigger than would be suggested by some commenters.... According some commenters, I am being more strict than I have to. I Spent time figuring out the size window I would have at 1m at about 17khz. and it was about the size of a basketball. I find that acceptable... In practice it sounds like the sweet spot is much larger. Some think that I was being too strict anyway
So I am left with a room power response of a rising DI. As long as I have tuned the SPL at MLP, I don't really think there is a reason for me to worry about my ability to listen critically, in line of being a reference monitor used for studio sound engineering. The Large Width of the front baffles, High DI of the horn, and close proximity make for a very high amount of Direct Sound vs Room. That is exactly what I designed this system to do.
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I can certainly point to the results of several psychoacoustic studies of the perception of nonlinearity. In a good loudspeaker the nonlinearity is very low order, which we know has very low audibility. This holds until we begin to approach Xmax, at which point the nonlinearity curve begins to go to higher order and sometimes - such as with clipping - very high orders very fast. This then becomes quite audible. Hence, it is only very near X-max that typical nonlinearities in loudspeakers become audible. Stay away from the extreme excursions and the nonlinearity is not audible.
what about intermodulation distorsions , joseph crow found them pretty high with the Axi crossed too low ? i crossed my B&C DCM50 at 400hz with my 220 240 260 ? cut off round horn as the 14inch Tad 1601a is not too bad in this zone . i have found a solution to with the beaming of the big Horn i use a faital HF108 facing the ceiling and time aligned with the rest over 10Khz it brings more sparks and air to the sound . it was the only way for me to keep the point source effect ..
as the 14inch Tad 1601a is not too bad in this zone . i have found a solution to with the beaming of the big Horn i use a faital HF108 facing the ceiling and time aligned with the rest over 10Khz it brings more sparks and air to the sound . it was the only way for me to keep the point source effect ..
Hi all,
i did not find the time to read all the 600+ posts of this monster thread.
But i tend to agree with @paul7052.
For all my own findings @camplo, your setup cannot work well.
Even with the biggest elliptical LMH woodhorn and the Celestion AXI2050 driver, your slot loaded woofer mounting work only for a subwoofer crossed with less than 85 Hz. In the kick bass frequency range you get really bad resonances, that's physics.
Here a Clio Pocket WCD (Wavelet Cycle Decay) measurement with a big 21 inch bass i use where i tried the slot loaded setup.
Massive resonances for frequencies above 200 Hz.
You will need a third way for the two kickbass octaves between 85 Hz and 340 Hz.
Celestion FTR15-3070c CB in a non rectangular cabinet for reduced cabinet resonances will work, very low distortion levels in the kick bass range.
Well, this is only my humble personal opinion, nevermind - Stefano
P.S.:
With two 15 inch or 18 inch and a large horn 2 and a half way could work - like this here:
another thing, the giant set of headphones effect mentioned here, i had the same thing trying this setup, even with listening distances over 4 to 5 meters, large horns with no diffraction like the elliptical LMH horns beams up to 30 degrees in the high frequency two octaves from 4 to 16 kHz
i did not find the time to read all the 600+ posts of this monster thread.
But i tend to agree with @paul7052.
For all my own findings @camplo, your setup cannot work well.
Even with the biggest elliptical LMH woodhorn and the Celestion AXI2050 driver, your slot loaded woofer mounting work only for a subwoofer crossed with less than 85 Hz. In the kick bass frequency range you get really bad resonances, that's physics.
Here a Clio Pocket WCD (Wavelet Cycle Decay) measurement with a big 21 inch bass i use where i tried the slot loaded setup.
Massive resonances for frequencies above 200 Hz.
You will need a third way for the two kickbass octaves between 85 Hz and 340 Hz.
Celestion FTR15-3070c CB in a non rectangular cabinet for reduced cabinet resonances will work, very low distortion levels in the kick bass range.
Well, this is only my humble personal opinion, nevermind - Stefano
P.S.:
With two 15 inch or 18 inch and a large horn 2 and a half way could work - like this here:
another thing, the giant set of headphones effect mentioned here, i had the same thing trying this setup, even with listening distances over 4 to 5 meters, large horns with no diffraction like the elliptical LMH horns beams up to 30 degrees in the high frequency two octaves from 4 to 16 kHz
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I know its awesome the clarity that is had without a bunch of arrivals at my listening position. I calculated the beamwidth at my intended listening distance well before I purchased that horn, so there were no surprises for the sweet spot being bigger than predictions had suggested. My predicted nor the actual sweet is too small for me...
thanks for joining the conversation and sharing btw, I hope you stick around for a while so we can really pick apart each others perspective
What I can't find but remember discussing is the idea that the difference between a well designed BR and a Sealed subwoofer are negligible once in a room. Someone had said that only in the most quietest of rooms, would you be able to hear the difference. The connection between these issues of decay are related to FR. After FR has been equalized to be neutral in response, it is actually Group Delay that is culprit. Once you flatten GD all issues have been removed... Energy cannot be created nor destroyed. In this, we have Standing waves increase SPL due to an initial delayed signal, and a constructive coincidence of arrivals. I hope I said that right lol!....
Anyway, like I said, not all slots are created equal. This is a 1" measurement of my PPSL in the bad acoustics of the hard floor upstairs, and even then... Wheres the issue>? The room will swamp these measurements....
The GD/Decay issues of the 150hz f6 horn even, because they are already below the Schroeder, are swamped by the room, if high passing the worst of it, wasn't enough.
Anyway, like I said, not all slots are created equal. This is a 1" measurement of my PPSL in the bad acoustics of the hard floor upstairs, and even then... Wheres the issue>? The room will swamp these measurements....
The GD/Decay issues of the 150hz f6 horn even, because they are already below the Schroeder, are swamped by the room, if high passing the worst of it, wasn't enough.