Yes, that’s what I’m trying to do. I was pretty sure that it would work in a rectangular box, since I have done a similar MLTL build using a straight tube constant size CSA.
Is the MLTLX model available on your web site? That would help a lot!
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Not yet,
You can post in the link below asking for this model, it's the right place to talk about the model using FreeCAD so we do not disturb this thread that is mode related to Boxplan.
https://www.diyaudio.com/community/...loudspeakers-plan-hornresp-integrated.391237/
Where? other than the corner on the bottom left there is very little wasted space.
Mark
nothing matters then.. why even use a ’shape‘ for a subwoofer/bass freq design. Everything should just be rectangles/cylinders with parallel end points, if nothing matters. like a telescope . Same reasoning too ?
bounce it back and forth and gain from super position of what isn’t quite big enough to make it past the next turn or ’ LP filter’ ? Don’t use more than one turn or two for OdTL …. Everything else is wasted output/design snake/maze,, a taper is just a long drag/infinite LP filter on the system too. kinda silly as well if you consider the bottleneck Like bass reflex ?
bounce it back and forth and gain from super position of what isn’t quite big enough to make it past the next turn or ’ LP filter’ ? Don’t use more than one turn or two for OdTL …. Everything else is wasted output/design snake/maze,, a taper is just a long drag/infinite LP filter on the system too. kinda silly as well if you consider the bottleneck Like bass reflex ?
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Ok. I give you that. But I'll counter with the reality of this particular design. If I took out that central filler I lost to much gain. This enclosure is not small. It is 92 inches tall, 32 inches wide and 16 7/8 inches tall. As for your assertion that a corner reflector makes no difference, I can remember studies done by Bruce Edgar in the 80's in Speaker Builder magazine that said otherwise. I cannot say that I know the answer to this. I haven't done a horn without them. A tapped horn is much more of a resonant system than a true front loaded horn. Very similar to a bandpass in that the resonances are used to fill the upper and lower peaks in the response (I know you understand this. Just for the sake of clarity of thought.)
Mark
The correct answer for "reflector" is of course, it depends. I think it was Danley that pointed out that if the reflector's size was less than 1/4 wavelength (or was it 1/2 wavelength? I can't remember) of the highest frequency the horn was designed to produce, then it would make no difference to the in-band response of the horn, apart from reducing output because of the reduction in volume. Elsewhere I've seen it said that the purpose of a reflector was to reduce the difference between the longest and shortest distances around a bend, which in turn pushed cancellations higher. Probably the same source that suggested that 180 degree bends in horns should be avoided, and the closer to the mouth you got, the more they should be avoided.
So, theoretically, if the aim was to produce a horn that's good to 200 Hz, any reflectors that are less than 42 cm in length are probably going to make little difference to the horn's response in its usable passband, and you also want to make sure that bends don't result in a difference of over 80 cm between the longest and shortest paths around the bend.
All bass horns are resonant systems, btw
Designing the horn without the "gap" in the center would be a challenge though as the design is one with varying expansion. It might require an entirely different fold ...
So, theoretically, if the aim was to produce a horn that's good to 200 Hz, any reflectors that are less than 42 cm in length are probably going to make little difference to the horn's response in its usable passband, and you also want to make sure that bends don't result in a difference of over 80 cm between the longest and shortest paths around the bend.
All bass horns are resonant systems, btw
Designing the horn without the "gap" in the center would be a challenge though as the design is one with varying expansion. It might require an entirely different fold ...
Um, I'd argue no. I'll add my definition of what a resonant system is. A bandpass or a tapped horn literally uses self generated harmonics to fill in the upper and lower peak in the output. A front loaded horn better not be doing that if it is designed correctly. I have designed all of them. Some for PA, some for car audio and some for the heck of it. I think that you are right when you are not concerned with anything above 200 hertz. Now when I have time I should make an enclosure that I can do both versions and measure it all properly.All bass horns are resonant systems, btw
Mark
So are you calling a driver resonance an additional harmonic? Definitely it's true that a driver has a resonance. It's a spring suspension. What I am referring to as a resonance, is a spurious addition to the initial signal input. A bandpass enclosure as well as a tapped horn do exactly this. Harmonics generated at a differential frequency between the tuning of the upper and lower peaks are what is generated. And old old trick in musical acoustics. Pipe organs, woodwinds, brass instruments and to a degree even strings. But those are all primary producers of music. A reproducer of music should not add anything to the signal to be reproduced if it is to be called high fidelity or true to the source.
No reference made to what you personally like. That's a whole other topic. Many people really like those added harmonics. All the more power to them. Music is there to be enjoyed. I hear those harmonics and don't really like them. I hear the additions. So I chase the clarity of a horn system, or a maximally damped sealed system. One with really good transient response.
But. Many recording engineers are banking on your speakers being able to hum along with your tunes. So when you have a speaker that doesn't hum along. Well it doesn't sound right. It's not what you are used to. I have played pop music on horn loaded systems and watched the entire bass line fall apart because the speakers could handle what the engineers actually recorded. And watched the jaws drop from the people that thought there was really low bass on their recording.
Designing is all about learning what the person wants. It's always in front of mind when I work on something.
Mark
If that was indeed what was happening, a THD plot of the output of a bandpass alignment would show high THD.
That's been entirely the opposite of my experience when measuring my BP builds, where THD remained low, sometimes VERY low, down to the frequency where the low-pass filtering feature of the design was no longer effective, e.g. a bandpass design with an upper cutoff point of 100 Hz was very good at filtering distortion at 50 Hz and higher, but not so good at filtering HD below that level.
Example - the picture below is from my "Enigma" build, driven at a voltage level high enough to cause the driver to exceed Xmax. Notice the flat THD profile from 50 Hz up? We're talking ~1% THD - at 70W, the point where Hornresp predicted that the driver would start to exceed Xmax. This particular BP design has an upper acoustic cutoff point just above 100 Hz. And that blip around 150 Hz? Caused by the circuit board rattling in the box, subsequently fixed
FWIW, I use the THD response to determine the best HP filtering for the build. For this one, filtering out everything below 30~40 Hz proved to be effective.
Oh, and all bass horns are effectively bandpass designs
I think that you are running into limitations of this type of distortion measurement. I build a number of boxes using the same drivers. Each had the same Fs as well. All were matched to the same spl level. And played the same music through all of them. Vented, Front loaded horn, true tapped horn with 7db of gain, and a flared port kind of enclsoure that I thought I invented for a short time before doing more patent research.
The cleanest version of the track was via the front loaded horn and second was the vented enclosure. The tapped horn hummed along with the tunes, as did the other self resonant system that I designed.
https://www.diyaudio.com/community/threads/winter-diy-ottawa-meet.176350/post-2445138
Mark
The cleanest version of the track was via the front loaded horn and second was the vented enclosure. The tapped horn hummed along with the tunes, as did the other self resonant system that I designed.
https://www.diyaudio.com/community/threads/winter-diy-ottawa-meet.176350/post-2445138
Mark