Stepped Baffles

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#21
colmo said:
Reason I ask is that there is a TG design I like but would prefer a flat baffle rather than the designed stepped baffle. One other thing is that my HF hearing is poor as I am getting on a bit so would I notice anyway
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Most of it would be bragging rights in vertical measurement.

Otherwise there is plenty of systems where vertical is nothing special.
But drivers speak for themselves.

Sound quality real world is what it is
and good detail is found with many tweeters.
So anything noticed, not really.

Its still the basics with any tweeter.
Sound quality is the driver itself.
And at higher SPL
less distortion if not crossed to low.
And by far 3rd order is so simple and easy to achieve.
Which helps at higher volumes/ SPL
 
#23
tmuikku said:
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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I do all of the above (use my feet instead of friend) and the result/effect is consistent at any distance and (surprisingly) different frequency bands (doublebass/cello/violin for example -- suggesting what is relied on is "air"). Provided that adequate, common sense testing conditions and procedures are satisfied/followed as outlined below.

Ideally one should first align drivers' acoustic centers (via manufacturer info or eyeball-then-tweak). Then design XO (by tweaking values if necessary) such that at the XO frequency, phase is also aligned. This latter is verifiable by ear using a test tone, the combined loudness should be maximum over varying offsets (periodicity being XO wavelength). Then, when music is played (just one channel), a floating image or sense of air is present. (If the offset is now changed the effect vanishes.) Now play both channels, any distance, each tweeter axially aimed at one ear, but must be from L/R-front (not directly front nor directly from the side), where hearing is most sensitive, and a holographic soundstage should materialize. (This speaker placement and listening position combination can be assured by playing a test tone at the hearing upper limit frequency.) If the acoustic centers aren't aligned but phase is aligned at (ONLY) the XO frequency, the imaging will be far less holographic -- IN MY EXPERIENCE.

Whether or not one normally listened to music from the sweet spot, the above yields what is possible.
 
#27
colmo said:
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.
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I think audibility and measurability are 2 different things.

A quick survey of the vertical frequency plots at Stereophile will show a consistent pattern, which is that the worst off-axis dimension is above the tweeter axis. This is essentially the same as bringing the tweeter forward.

I'm pretty sure you could measure the problem at any distance, which is a drop in amplitude at the crossover point. I also think if you listened to a speaker with a tweeter too far forward and you could compare listening angles you'd now prefer to be significantly below the tweeter axis. In fact a lot of 2-way speakers already sound better at the mid-woofer axis, and this would just make things worse.

I do want to point out that the stepped baffle designs are a way of getting around the normal compromise crossovers have to make in flat baffle designs. We are usually forced to select the slopes/orders of the LP and HP filters because of phase alignment. The stepped baffle eliminates that problem.
 
#28
like this ?

I found a single capped tweeter (slightly horn loaded even) sounded better slid back about 2" behind the baffle of a woofer (run wide open with no inductor).

I think if you cover all of the flat areas with felt (or something) around the smaller driver below, it would sound better, or sharper.

similar to b102 and cat378 project.png
 
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#30
So compared to being at tweeter height, sitting at mid height pushes the tweeter back 7mm relative to the mid, leaving 12mm difference to Troels baffle config. That's 26 degrees at the crossover. It's not terribly significant, you may not notice. The phase itself is not a problem, after all Butterworth filters aren't in phase and they have a lot going for them. Besides, you can always tilt the box a few degrees.
 
#33
You can listen to the experts and be no further ahead.so try your speaker with flat baffle and then step baffle and listen do you hear a differance,do you like the differance if any.speakers are not all theory.speakers are listened to by people and they have differing preferances.go forth in the spirit of diy.
 
#34
My2c.
Precise physical alignment in the vertical plane is a property of an ideal speaker design.
It can be achieved by baffle steps, baffle slopes, or fixed time delays (DSP mainly).

It an be difficult to hear its advantages.
Because to hear its contribution to sound quality, truly complementary acoustic crossovers need to have also been achieved..

Using LR24's, the most common used electrically complementary crossover, snips two from this Rane note explain the xover / physical distance between drivers interdependence. https://www.ranecommercial.com/legacy/note160.html

1724601085823.png


1724601403997.png



And even if both of those are achieved like in 7b, a room hides both perfections and imperfections. Stereo doubles down the hiding. Can still be hard to hear.
That said, when magic is heard, ime it's always been from speakers that have not only great frequency magnitude response, but also great time domain response.
 
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#37
No offence, I'm not really sure what you are asking ?


Crossovers, phase, step response (beyond first order) is messy.

Honestly, It could be just how I "like" the sound to sound.

https://www.acculution.com/single-post/2017/08/23/009-time-alignment-in-loudspeaker

" the LR4 and higher cannot be considered transient-perfect. I do not particularly like this definition, as it does not consider the entire system, and also "perfect" should in my book mean perfect, not "somewhat perfect""

https://www.stereophile.com/content/kii-audio-three-loudspeaker-measurements

" time-coincident wavefront launch. Its step response is almost a perfect right-triangle shape,"

and on the Kii

https://www.erinsaudiocorner.com/loudspeakers/kii_three/

"And while I did do some A/B testing with the phase mode from “exact” to “minimal latency” and think this is the answer, it was a sighted test and who knows what my brain may have tricked me into believing."

lol
 
#38
All I'm saying is that you said you got an improvement when you align sources, and I said you got the improvement because of the response, and I could do the same by misaligning the drivers and fixing them electrically.
 
#40
Just want to add, tweaking the offset between LS50 Meta 1793 coax and up-firing Monitor Audio woofer in my latest LX, still made a surprisingly big difference in soundstage imaging (depth). 1st-order LPF ~450hz, down nearly 18dB plus off-axis attenuation by 2.7khz 12.5cm-wavelength the coax 3rd-order LPF frequency (tweeter passed much higher).

LX aligned-acoustic-centers near-point-source 2.5-way:
https://www.diyaudio.com/community/threads/full-range-speaker-photo-gallery.65061/post-7769008
 
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