On a lot of TG speaker designs there are stepped baffles with the HF unit set back 20mm.
I spoke to another speaker designer recently and he said that from 2 /3 metres distance he would doubt that you could actually hear a difference from using a stepped or flat baffle with the same crossover.
My question of course is what do you think.
I spoke to another speaker designer recently and he said that from 2 /3 metres distance he would doubt that you could actually hear a difference from using a stepped or flat baffle with the same crossover.
My question of course is what do you think.
Hi, yes, to my current listening skills it doesn't make a difference when room early reflections have big impact on perceived sound. Tried this by sitting otherside of room adjusting delay of tweeter with DSP, and all there was was frequency response change, until perhaps at 10ms delay, about 3meters, mid and tweeter started to feel separate. Before that, quite benign. This was very surprising, but also kind of non surprising, really demonstrate how big of an effect room has on sound. Listen too far and early reflections completely dominate perception and it's just a hazy blob of sound.
If it has impact on sound, expect it be audible listening close by, so that brain pays attention to the direct sound.
If it has impact on sound, expect it be audible listening close by, so that brain pays attention to the direct sound.
Depends on the acoustics and the speakers, you'd need to be as close as needed for perception to change from roomy sound to more direct sound, and now you have a chance to hear a difference.
You can find distance in your place with your gear by listening. This is a long story, but short version is you'd initially shrink your stereo listening triangle to quite small, say 2m equilateral triangle. Go standing otherside of the room, equidistant to both speakers. Put mono noise playing for strong phantom center image.
Now listen eyes closed, start moving closer toward speakers staying equidistant to both, and listen the phantom center. At start, it likely is big haxy blob of sound somewhere in portion of the room the speakers are at, but as you move closer you hopefully notice when the phantom center image perceptually shrinks and sharpens in a way. Try moving back and forth to confirm the distance where you think this happens. You need to be closer than that.
Difference between the big hazy image and small sharp one is your auditory system either not paying attention to the sound or finally paying attention sharply localizing it for your perception. If you want more please refer to David Griesinger studies on auditory proximity, which I have interpreted to this speaker context so that by definition, it's not possible to hear such detail, unless your auditory system is in state there is the sharp localization, which means, small enough listening triangle.
You can find distance in your place with your gear by listening. This is a long story, but short version is you'd initially shrink your stereo listening triangle to quite small, say 2m equilateral triangle. Go standing otherside of the room, equidistant to both speakers. Put mono noise playing for strong phantom center image.
Now listen eyes closed, start moving closer toward speakers staying equidistant to both, and listen the phantom center. At start, it likely is big haxy blob of sound somewhere in portion of the room the speakers are at, but as you move closer you hopefully notice when the phantom center image perceptually shrinks and sharpens in a way. Try moving back and forth to confirm the distance where you think this happens. You need to be closer than that.
Difference between the big hazy image and small sharp one is your auditory system either not paying attention to the sound or finally paying attention sharply localizing it for your perception. If you want more please refer to David Griesinger studies on auditory proximity, which I have interpreted to this speaker context so that by definition, it's not possible to hear such detail, unless your auditory system is in state there is the sharp localization, which means, small enough listening triangle.
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3 meters is the distance that sound travels in 10 msec. That is what he meant.
Thanks!
thinking bit further, perhaps the xo is such, that in addition to driver responses that the small offset makes bit better power response, in which case it might make it audible difference at any listening distance. This might be possible to test with VituixCAD. Perhaps it addresses listening height.
Also thinking that it's not very common design pattern, so.perhaps it isn't too important audibly. Simulation in head: if xo was around 3kHz, 2cm would be less than 1/4 wavelength/90deg, so not big of a difference but it would change angle of lobes a bit. My head is no computer so better check with one
thinking bit further, perhaps the xo is such, that in addition to driver responses that the small offset makes bit better power response, in which case it might make it audible difference at any listening distance. This might be possible to test with VituixCAD. Perhaps it addresses listening height.
Also thinking that it's not very common design pattern, so.perhaps it isn't too important audibly. Simulation in head: if xo was around 3kHz, 2cm would be less than 1/4 wavelength/90deg, so not big of a difference but it would change angle of lobes a bit. My head is no computer so better check with one
I find the difference in imaging to be between holographic with clear depth, and a pretty flat one. But I use very simple XOs (prefer series first order) if at all. Easy to try, remove tweeter and move it back and forth while (1) playing music; (2) test tone at the XO frequency. The optimum offset can be heard easily, and repeatedly nailed to within a millimeter.
For me no going back to unaligned acoustic centers.
For me no going back to unaligned acoustic centers.
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I doubt that. If power was a consideration, don't you think the baffle would have been made smooth instead of there being a step? Power, as far as lobing goes, can be controlled electrically.
Yeah, which makes think such stepped baffle is likely just to differentiate from competition, not necessarily anything important.
(30-minute limit... sigh) For example the LX configuration I'm listening to (working on), if the top driver was offset wrong the mono very near-field sound (to die for) became merely directional, losing well-focused depth well behind the "speaker". (I came back from dinner and doubly confirmed it.)
https://www.diyaudio.com/community/threads/full-range-speaker-photo-gallery.65061/post-7705368
Another test for coherence (in my experience) is up-firing: a phantom image would float midair beyond the speaker(s) if and only if the speaker is phase aligned (try placement say 1m from a corner). Can someone perhaps explain this phenomenon?
https://www.diyaudio.com/community/threads/full-range-speaker-photo-gallery.65061/post-7705368
Another test for coherence (in my experience) is up-firing: a phantom image would float midair beyond the speaker(s) if and only if the speaker is phase aligned (try placement say 1m from a corner). Can someone perhaps explain this phenomenon?
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Troels will tell you that any change to the baffle and positioning of the drivers on that baffle means you will need a different crossover.
As I understand it the stepped baffle means a simpler crossover.Indeed that tends to be the appeal of many of his designs.Other designers like SB Acoustic and PBN seem to use very complex crossovers with a high parts count and cost.Which is not DIY friendly.
I can't see anything wrong with the step.A bit more work to build I suppose but it makes sense from. a time alignment perspective.
As I understand it the stepped baffle means a simpler crossover.Indeed that tends to be the appeal of many of his designs.Other designers like SB Acoustic and PBN seem to use very complex crossovers with a high parts count and cost.Which is not DIY friendly.
I can't see anything wrong with the step.A bit more work to build I suppose but it makes sense from. a time alignment perspective.
Well I don't have pets or small children, so the tweeter simply sat on top of the cab, midwoofer positioned as high as possible on the baffle. (Can easily roundover or chamfer edge.) Usually a small box of paperclip/binderclip/staples served as seat sticking to the tweeter (or other nude driver) magnet. Voila! I have so many projects this is the most convenient way to set up and take down. (I guess one can encase the tweeter like B&W or JMR et al.)
Have done this for Satori TW29R-4/MW19TX-8 (series 1st-order 1.9khz offset 32mm); Wavecor TW045WA01/Molisio 8" widerange (just a cap 6khz offset 49mm); many tweeter/supertweeter/midtweeter/fullrange etc. In every case that I tried, the best offset was well-determined and easily found by ear using music or frequency tone. (My method couldn't be simpler, just physics first principles; described in various posts.)
Relevant thread:
https://www.diyaudio.com/community/...r-recessed-tweeter-design.410385/post-7629267
Have done this for Satori TW29R-4/MW19TX-8 (series 1st-order 1.9khz offset 32mm); Wavecor TW045WA01/Molisio 8" widerange (just a cap 6khz offset 49mm); many tweeter/supertweeter/midtweeter/fullrange etc. In every case that I tried, the best offset was well-determined and easily found by ear using music or frequency tone. (My method couldn't be simpler, just physics first principles; described in various posts.)
Relevant thread:
https://www.diyaudio.com/community/...r-recessed-tweeter-design.410385/post-7629267
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There would be two differences, the baffle shape related issues and the crossover positioning related issues. Neither of them will be especially large issues. It's hard to say but you could possibly ignore them and still be satisfied. Changes like this become more obvious the more you tune a system towards the ideal. Assuming you stick with the flat baffle, your main tool would be an equaliser which could deal with at least some of the difference, and compensate the rest.
Hi, how did you do the tuning!? sliding tweeter live from arms length distance? or did you have a friend/robot to move it while you listen bit further away? Or AB testing with different speakers? How is your xo?
I'm mostly interested audibility of it and I believe you there is a difference, at least close listening. I should do more listening tests on this.
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Setting the tweeter back will help overcome issues with the vertical response.
Mainly help overcome the dip off axis because of center to center mounting
restrictions of tweeters with large mounting rings.
If a design has a setback tweeter
It is admirable.
But if center to center spacing is a million miles apart
or too far apart.
Then its a udder waste of time.
To really really get magic in the vertical and overcome
all the issues.
Slight setback is needed, tight center to center.
And only 4th order to even get close to something magical
off axis
the difference between 18mm and 20mm is negligible
in some instances.
And in many instances only 3 to 5mm is all that is
needed to help On Axis response.
But nothing extremely magical in a sense of improving
vertical off axis. And the restraints your against with physical
center to center spacing.
Mainly help overcome the dip off axis because of center to center mounting
restrictions of tweeters with large mounting rings.
If a design has a setback tweeter
It is admirable.
But if center to center spacing is a million miles apart
or too far apart.
Then its a udder waste of time.
To really really get magic in the vertical and overcome
all the issues.
Slight setback is needed, tight center to center.
And only 4th order to even get close to something magical
off axis
the difference between 18mm and 20mm is negligible
in some instances.
And in many instances only 3 to 5mm is all that is
needed to help On Axis response.
But nothing extremely magical in a sense of improving
vertical off axis. And the restraints your against with physical
center to center spacing.
@tmuikku
I agree from listening experience.
Worst case was time coherent fullrange speaker back to the wall with the angle from the ceiling of a roof right starting above the speaker.
Due to early reflections the dsp corrected time coherent fullrange system sounded alike a bad designed Multi way at the same position.
After putting the speakers away from all room boundaries on correct stands you could hear the absolute quality.
I agree from listening experience.
Worst case was time coherent fullrange speaker back to the wall with the angle from the ceiling of a roof right starting above the speaker.
Due to early reflections the dsp corrected time coherent fullrange system sounded alike a bad designed Multi way at the same position.
After putting the speakers away from all room boundaries on correct stands you could hear the absolute quality.