Airvoid - Whats the science of it? Just wondering...Meaning...why do this, instead of trying to do something else...
Place a 2nd order xo at cutoff and then find a point that the woofers crosses well using a 6th order low pass on the midwoofer....sounds like GD at first glance...I'll have to check this out in VituixCAD and thank you for the info!
Puppet - I've got the VituixCAd sims...
Hmmmm...
Place a 2nd order xo at cutoff and then find a point that the woofers crosses well using a 6th order low pass on the midwoofer....sounds like GD at first glance...I'll have to check this out in VituixCAD and thank you for the info!
Puppet - I've got the VituixCAd sims...
Hmmmm...
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The nulls you spoke of exist where exactly on the above graph? If I understand you, I don't won't any crossband higher than 600hz.. But if I look at the polar at all widths...it doesn't look like I think it should, for a good xo, that high anyway...revisiting it after looking at the right polars.......600hz is way more directional from the dual woofers than it is the horn.
Ok I think its starting to click why they used the 6th order xo on the woofers and a 2nd order xo layered on top of cutoff.....well played!
Ok I think its starting to click why they used the 6th order xo on the woofers and a 2nd order xo layered on top of cutoff.....well played!
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I have experience with side-by-side 8” woofers; I am using the DIYSG 88-Special as my center channel. At one point, having also made a pair of 88-Specials for a friend, I briefly had all three setup as a LCR arrangement. While I absolutely loved how it sounded, I prefer to not speak out of turn as to whether it was the twin woofers or increased size of the 15” waveguide that improved the quality of sound. Nor am I really sure my experience is even applicable when you’re talking about woofers twice the diameter and crossing over an octave lower.
Having been a fan since experiencing these at a very impressionable age have done it with 4" - 15" and it's just a matter of scaling on a BW curve same as single drivers, using up to four whenever I could for horizontal directivity purposes.
edit: Obviously there's comb filtering issues, so XO point slopes will ideally be lower and/or steeper than for a single driver of a given system design, i.e. as one famous designer opined, "not many 'free lunches' in audio system design".
edit: Obviously there's comb filtering issues, so XO point slopes will ideally be lower and/or steeper than for a single driver of a given system design, i.e. as one famous designer opined, "not many 'free lunches' in audio system design".
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I was thinking brutal honesty
I won't hold my breath, but that would be helpful.
This does not seem like reality
No the most directivity you can have is to cross the horn to the woofer around where the patterns match (if there is a frequency where they do).
The gain in directivity from the woofer at that point up offsets the loss of directivity from the horn going down and allows the higher directivity of the horn to be maintained to a lower frequency when the two are combined. This is what Earl does with the Summa and what most large two way designs aim to do.
This image from the Rey Audio WARP page has a good visual on the difference between the mounting options of side by side drivers.
Angled inwards seems perfect for someone who wants to bathe in a field of direct sound
Get 4 on the go with a big Bi-Radial and you can have yourself Avtar D at home.
Angled inwards seems perfect for someone who wants to bathe in a field of direct sound
Get 4 on the go with a big Bi-Radial and you can have yourself Avtar D at home.
Sim by Vituixcad, 32x17 baffle with 15" woofer in the middle
Sim by Horn Resp
Witch is exactly at the same point that I suggested I'd get the most directivity, how convenient, and uncoincidental
The only issue is those numbers, I think I had single woofer in the sim instead of a double. At 555 there is not a good match, dual woofer to the horn...Actually most of the territory I'm hunting for is suspect. The dual woofers seem to have higher directivity all the way down to 300hz even....
Trying to help you is as much fun as slowing down a chainsaw blade with your hand.
Bull crap, I listen to everything you say.Moving forward...I don't think I have a polar match using side by side woofers vs the polar I'm getting with Hornresp....I can't see letting that go so I unless I can convince myself to move the tweeter axius from being almost directly at my sitting ear level and about 6inches higher to accommodate 3 large woofers on the front baffle....I'll be sticking with the design as is
Good to know, at some point listening might turn into hearing, and hearing into understanding
Having smooth polar transitions, is a priority to this design, so thus I don't feel the same tingly feelings towards it I had before =( hows that for hearing and understanding.
The other config TMMW (vertically stacked that is)...is the other option, putting the tweeter another 6 some odd inches above ear level...I don't like the sound of it, but I keep trying to warm myself up to it.
The other config TMMW (vertically stacked that is)...is the other option, putting the tweeter another 6 some odd inches above ear level...I don't like the sound of it, but I keep trying to warm myself up to it.
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I don't know why tweeter should be at ear height? For purely technical point of view there is no reason I believe, since one can EQ the sound (highest treble) to your vertical angle, especially if there is any kind of reasonable dispersion at the top octave. Or tilt the thing few degrees to get on-axis back to ears. I suspect there is some perception related reason to keep the treble at ear height, difference how the high frequencies, or imaging or something, are perceived depending on both vertical and horizontal angle but not sure if few inches would mean much in this context either.
Quick check on right angle triangle calculator says 6" at 1 meter away is roughly 8 degrees vertical angle and adds ~1.1cm to distance. 3 meters away it would be only ~2 degrees and ~0.3cm. Nothing to sweat about unless the tweeter beams and you would have to boost the top a lot it might, in which case one would just have to tilt the horn.
Mixing up wave guides and mixture of direct radiators the distances from drivers to ear would have to be measured and accounted for in crossover anyway so there really is no problem with technical point of view I think. Perhaps check out scientific studies / experiment how perception changes with elevated tweeter and look if there is valid reason to think about tweeter height.
Though: In your case it is not just tweeter that would get raised but the whole important spectrum of sound, the mids as well due to huge horn. Height (and tilt) of the wave horn (as well as listening distance) changes angles towards specular first reflection points on the ceiling and floor. Rising the horn up would decrease angle towards ceiling a bit and increase to floor a bit, if it means anything. Just something to think on.
Quick check on right angle triangle calculator says 6" at 1 meter away is roughly 8 degrees vertical angle and adds ~1.1cm to distance. 3 meters away it would be only ~2 degrees and ~0.3cm. Nothing to sweat about unless the tweeter beams and you would have to boost the top a lot it might, in which case one would just have to tilt the horn.
Mixing up wave guides and mixture of direct radiators the distances from drivers to ear would have to be measured and accounted for in crossover anyway so there really is no problem with technical point of view I think. Perhaps check out scientific studies / experiment how perception changes with elevated tweeter and look if there is valid reason to think about tweeter height.
Though: In your case it is not just tweeter that would get raised but the whole important spectrum of sound, the mids as well due to huge horn. Height (and tilt) of the wave horn (as well as listening distance) changes angles towards specular first reflection points on the ceiling and floor. Rising the horn up would decrease angle towards ceiling a bit and increase to floor a bit, if it means anything. Just something to think on.
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Did you notice Camplo is playing with horns with a needle point directivity to begin with?
His choice by the way. He wants to have near field listening with this 'head in vice" approach using large equipment.
Does it make the case much harder than it needs to be? Probably.
^Yeah Main takeaway is to question stuff, like camplo has been doing Even needle point directivity stuff has some leeway on the vertical height, questimating polar maps in post #9292 it looks like there is roughly 6db change with 10 deg vertical movement at top octave. This corresponds roughly to the 6" vertical offset at 1 meter listening distance.
I suspect the "range of movement freedom" is about the same at that ~10deg vertical off-axis angle as it is with on-axis, which is very little, so just matter of adjusting the top octave with EQ to be good at the head in vice location. Or tilt the horn a bit to shoot the ears.
Note, if the polar maps are for horizontal directivity, one can see the head has to be in a vice quite literally to keep the sound constant. Move few inches to any direction and the response is down as many decibels on the top octave. Breath in and the sound goes "woosh", breath out and "woosh" back to the initial sound I suspect sound is more enjoyable anywhere else in the room than at the near field sweetspot, even though the top end was gone.
Main takeaway is to question stuff, like camplo has been doing Even needle point directivity stuff has some leeway on the vertical height, questimating polar maps in post #9292 it looks like there is roughly 6db change with 10 deg vertical movement at top octave. This corresponds roughly to the 6" vertical offset at 1 meter listening distance.I suspect the "range of movement freedom" is about the same at that ~10deg vertical off-axis angle as it is with on-axis, which is very little, so just matter of adjusting the top octave with EQ to be good at the head in vice location. Or tilt the horn a bit to shoot the ears.
Note, if the polar maps are for horizontal directivity, one can see the head has to be in a vice quite literally to keep the sound constant. Move few inches to any direction and the response is down as many decibels on the top octave. Breath in and the sound goes "woosh", breath out and "woosh" back to the initial sound
I suspect sound is more enjoyable anywhere else in the room than at the near field sweetspot, even though the top end was gone.
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